------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Programmer Reference Manual Order Number EK-VT420-RM.002 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ First Edition, November 1989 Second Edition, February 1992 The information in this document is subject to change without notice and should not be construed as a commitment by Digital Equipment Corporation. Digital Equipment Corporation assumes no responsibility for any errors that may appear in this document. The software described in this document is furnished under a license and may be used or copied only in accordance with the terms of such license. No responsibility is assumed for the use or reliability of software on equipment that is not supplied by Digital Equipment Corporation or its affiliated companies. Restricted Rights: Use, duplication, or disclosure by the U. S. Government is subject to restrictions as set forth in subparagraph ( c ) ( 1 ) ( ii ) of the Rights in Technical Data and Computer Software clause at DFARS 252.227-7013. Copyright © Digital Equipment Corporation 1989, 1992 All Rights Reserved. Printed in U.S.A. The following are trademarks of Digital Equipment Corporation: DEC, DEClaser, DECnet, DECserver, LA, LA50, LA75 Companion, LA324, LN01, LN03, LQP02, Scholar, SSU, VMS, VT, VT52, VT100, VT220, VT320, and VT420. AT&T is a registered trademark of American Telephone and Telegraph Company. IBM is a registered trademark of International Business Machines Corporation. This document was prepared and published by Educational Services Development and Publishing, Digital Equipment Corporation. ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents ------------------------------------------------------------ About This Manual xvii Part 1 Introduction to Your VT420 Terminal 1 VT420 Features VT420 Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Keyboards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 New Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 PC TERM Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Two Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 User Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Page Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 Macro Feature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Rectangular Area Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 Local Copy and Paste Feature (VT Mode) . . . . . . . . . . . . . . . . . . 8 Number of Lines/Screen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 General Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Set-Up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Display Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Text Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Communication Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 Operating Modes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 iii ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ iv Contents 2 Character Encoding Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Coding Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 Characters and Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Code Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 7-Bit ASCII Code Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 8-Bit Code Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 VT420 Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 DEC Supplemental Graphic Character Set . . . . . . . . . . . . . . . . . 24 ISO Latin Alphabet Nr 1 Supplemental Character Set . . . . . . . . 26 National Replacement Character Sets (NRC Sets) (Worldwide Models Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 DEC Special Graphic Character Set . . . . . . . . . . . . . . . . . . . . . . . 29 DEC Technical Character Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Downloaded (Soft) Character Set . . . . . . . . . . . . . . . . . . . . . . . . . 31 Control Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 Sequence Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Escape Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Control Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 Numeric Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 Selective Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Device Control Strings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 Using Control Characters in Sequences . . . . . . . . . . . . . . . . . . . . 41 7-Bit Code Extension Technique . . . . . . . . . . . . . . . . . . . . . . . . . . 42 Working with 7-Bit and 8-Bit Environments . . . . . . . . . . . . . . . . . . 43 Conventions for Codes Received by the Terminal . . . . . . . . . . . . . 43 Conventions for Codes Sent by the Terminal . . . . . . . . . . . . . . . . 43 Using Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Define Macro (DECDMAC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Invoke Macro (DECINVM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 Display Controls Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents v Part 2 Control Functions Sent to the Host 3 ANSI, Short ANSI, and PC Keyboard Codes Keyboard Layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 Main Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Standard Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60 Special-Function Keys (ANSI Keyboard) . . . . . . . . . . . . . . . . . . . 62 Special-Function Keys (Short ANSI Keyboard) . . . . . . . . . . . . . . 63 Special-Function Keys (PC Keyboard) . . . . . . . . . . . . . . . . . . . . . 63 Editing Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64 Numeric Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 Top-Row Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73 7-Bit Control Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 Special Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Turning Autorepeat On and Off . . . . . . . . . . . . . . . . . . . . . . . . . . 79 Unlocking the Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 Part 3 Control Functions Received from the Host 4 Emulating VT Series Terminals Level 1 (VT100 Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Level 4 (VT400 Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 All Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84 Selecting an Operating Level (DECSCL) . . . . . . . . . . . . . . . . . . 87 Sending C1 Controls to the Host . . . . . . . . . . . . . . . . . . . . . . . . . 88 National Replacement Character Set Mode (DECNRCM) . . . . . . 89 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ vi Contents 5 Using Character Sets Selecting Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91 Designating Character Sets (SCS Sequences) . . . . . . . . . . . . . . . 93 Mapping Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 Locking Shifts (LS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98 Single Shifts (SS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 National Replacement Character Sets (Worldwide Model Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 Assigning User-Preferred Supplemental Sets (DECAUPSS) . . 100 ANSI Conformance Levels . . . . . . . . . . . . . . . . . . . . . . . . . . . 101 Soft Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 Designing a Soft Character Set . . . . . . . . . . . . . . . . . . . . . . . . . . 103 Coding the Soft Character Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 107 Downloading Soft Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113 Downline Load (DECDLD) . . . . . . . . . . . . . . . . . . . . . . . . . . . 114 Designating the Soft Character Set . . . . . . . . . . . . . . . . . . . . . . . 122 Soft Character Set Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 Clearing a Soft Character Set . . . . . . . . . . . . . . . . . . . . . . . . . . . 125 6 Page Memory What is Page Memory? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126 Page Memory for One Session . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 Page Memory for Two Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . 129 Controlling the Page Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 Selecting 80 or 132 Columns per Page . . . . . . . . . . . . . . . . . . . . 130 Set Lines per Page (DECSLPP) . . . . . . . . . . . . . . . . . . . . . . . . . 132 Set Left and Right Margins (DECSLRM) . . . . . . . . . . . . . . . . . . 133 Set Top and Bottom Margins (DECSTBM) . . . . . . . . . . . . . . . . . 134 Origin Mode (DECOM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 135 Vertical Split Screen Mode (DECVSSM) . . . . . . . . . . . . . . . . . . . 135 Moving to Another Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Next Page (NP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 Preceding Page (PP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 Page Position Absolute (PPA) . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Page Position Backward (PPB) . . . . . . . . . . . . . . . . . . . . . . . . . . 138 Page Position Relative (PPR) . . . . . . . . . . . . . . . . . . . . . . . . . . . 139 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents vii Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 7 Setting Visual Character and Line Attributes Setting Visual Character Attributes . . . . . . . . . . . . . . . . . . . . . . . . . 142 Select Graphic Rendition (SGR) . . . . . . . . . . . . . . . . . . . . . . . . . 143 Setting Line Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 Single-Width, Single-Height Line (DECSWL) . . . . . . . . . . . . . . . 144 Double-Width, Single-Height Line (DECDWL) . . . . . . . . . . . . . . 145 Double-Width, Double-Height Line (DECDHL) . . . . . . . . . . . . . . 145 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 8 Editing Inserting and Deleting Columns, Lines, and Characters . . . . . . . . . 148 Insert/Replace Mode (IRM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Delete Column (DECDC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 Insert Column (DECIC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Delete Line (DL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150 Insert Line (IL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 151 Delete Character (DCH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Insert Character (ICH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 Erasing Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Erase in Display (ED) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153 Erase in Line (EL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Erase Character (ECH) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 154 Selectively Erasing Text . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 155 Select Character Protection Attribute (DECSCA) . . . . . . . . . . . . 155 Selective Erase in Display (DECSED) . . . . . . . . . . . . . . . . . . . . . 156 Selective Erase in Line (DECSEL) . . . . . . . . . . . . . . . . . . . . . . . 157 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ viii Contents 9 Rectangular Area Operations Copying, Filling, and Erasing Rectangular Areas . . . . . . . . . . . . . . 160 Copy Rectangular Area (DECCRA) . . . . . . . . . . . . . . . . . . . . . . . 161 Fill Rectangular Area (DECFRA) . . . . . . . . . . . . . . . . . . . . . . . . 162 Erase Rectangular Area (DECERA) . . . . . . . . . . . . . . . . . . . . . . 164 Selective Erase Rectangular Area (DECSERA) . . . . . . . . . . . . . . 165 Changing Attributes of Rectangles . . . . . . . . . . . . . . . . . . . . . . . . . . 166 Select Attribute Change Extent (DECSACE) . . . . . . . . . . . . . . . 166 Change Attributes in Rectangular Area (DECCARA) . . . . . . . . . 167 Reverse Attributes in Rectangular Area (DECRARA) . . . . . . . . . 169 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172 10 Cursor Movement and Panning The Cursor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 Text Cursor Enable Mode (DECTCEM) . . . . . . . . . . . . . . . . . . . . 176 Moving the Cursor on the Current Page . . . . . . . . . . . . . . . . . . . . . 176 Back Index (DECBI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Forward Index (DECFI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 177 Cursor Position (CUP) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 Horizontal and Vertical Position (HVP) . . . . . . . . . . . . . . . . . . . . 178 Cursor Forward (CUF) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Cursor Backward (CUB) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179 Cursor Up (CUU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Cursor Down (CUD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 Panning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Pan Down (SU) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 181 Pan Up (SD) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 Cursor Coupling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 Vertical Cursor-Coupling Mode (DECVCCM) . . . . . . . . . . . . . . . 183 Page Cursor-Coupling Mode (DECPCCM) . . . . . . . . . . . . . . . . . . 184 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents ix 11 Keyboard, Printing, and Display Commands Keyboard Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187 Keyboard Action Mode (KAM) . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 Backarrow Key Mode (DECBKM) . . . . . . . . . . . . . . . . . . . . . . . . 188 Line Feed/New Line Mode (LNM) . . . . . . . . . . . . . . . . . . . . . . . . 189 Autorepeat Mode (DECARM) . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 Autowrap Mode (DECAWM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 Cursor Keys Mode (DECCKM) . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Numeric Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Keypad Application and Numeric Modes (DECKPAM and DECKPNM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 Numeric Keypad Mode (DECNKM) . . . . . . . . . . . . . . . . . . 193 Typewriter or Data Processing Keys . . . . . . . . . . . . . . . . . . . . 194 Key Position Mode (DECKPM) . . . . . . . . . . . . . . . . . . . . . . . . 195 Enable Local Functions (DECELF) . . . . . . . . . . . . . . . . . . . . . 195 Local Function Key Control (DECLFKC) . . . . . . . . . . . . . . . . 197 Select Modifier Key Reporting (DECSMKR) . . . . . . . . . . . . . . 198 Extended Keyboard Report (DECEKBD) . . . . . . . . . . . . . . . . 200 User-Defined Keys (DECUDK) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 Using UDKs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 202 UDK Memory Space . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Programming UDKs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 203 Printer Port Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210 Printer Extent Mode (DECPEX) . . . . . . . . . . . . . . . . . . . . . . . . . 210 Print Form Feed Mode (DECPFF) . . . . . . . . . . . . . . . . . . . . . . . 211 Printing Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 Printing a Display Line: Autoprint Mode . . . . . . . . . . . . . . . . . . 212 Sending Characters Directly to the Printer: Printer Controller Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Print Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 Print Composed Main Display . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Print All Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Print Cursor Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Start Printer-to-Host Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 Stop Printer-to-Host Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Assign Printer to Active Host Session . . . . . . . . . . . . . . . . . . . . . 214 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ x Contents Release Printer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Printing Visual Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 Sending Line Attributes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Sending Visual Character Attributes . . . . . . . . . . . . . . . . . . . . . . 215 Screen Display Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . 215 Local Echo: Send/Receive Mode (SRM) . . . . . . . . . . . . . . . . . . . . 216 Light or Dark Screen: Screen Mode (DECSCNM) . . . . . . . . . . . . 216 Scrolling Mode (DECSCLM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 Select Number of Lines/Screen (DECSNLS) . . . . . . . . . . . . . . . . 218 Selecting the Indicator or Host-Writable Status Line . . . . . . . . . . 219 Select Active Status Display (DECSASD) . . . . . . . . . . . . . . . . 219 Select Status Line Type (DECSSDT) . . . . . . . . . . . . . . . . . . . . 220 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222 12 VT420 Reports Device Attributes (DA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 Primary DA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 229 Secondary DA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 Tertiary DA (VT400 Mode Only) . . . . . . . . . . . . . . . . . . . . . . . . . 233 Terminal Identification (DECID) . . . . . . . . . . . . . . . . . . . . . . . . . 234 Device Status Report (DSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 235 DSR--VT420 Operating Status . . . . . . . . . . . . . . . . . . . . . . . . . . 235 DSR--Cursor Position Report (CPR) . . . . . . . . . . . . . . . . . . . . . . 236 DSR--Extended Cursor Position Report (DECXCPR) . . . . . . . . . 236 DSR--Printer Port . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237 DSR--User-Defined Keys (VT400 Mode Only) . . . . . . . . . . . . . . 238 DSR--Keyboard Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 DSR--Macro Space Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 240 DSR--Memory Checksum (DECCKSR) . . . . . . . . . . . . . . . . . . . . 240 DSR--Data Integrity Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 DSR--Multiple-Session Configuration Status Report . . . . . . . . . 242 Requesting a Checksum of a Rectangular Area . . . . . . . . . . . . . . . . 242 Request Checksum of Rectangular Area (DECRQCRA) (VT400 Mode Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 243 Checksum Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 Terminal State Reports (VT400 Mode Only) . . . . . . . . . . . . . . . . . . 244 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents xi Request Terminal State Report (DECRQTSR)--Host To VT420 . 245 Terminal State Report (DECTSR)--VT420 to Host . . . . . . . . . . . 245 Restore Terminal State (DECRSTS)--VT400 Mode Only . . . . . . 246 Presentation State Reports (VT400 Mode Only) . . . . . . . . . . . . . . . . 247 Request Presentation State Report (DECRQPSR) --Host to VT420 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 248 Cursor Information Report (DECCIR)--VT420 to Host . . . . . . . . 248 Tab Stop Report (DECTABSR)--VT420 To Host . . . . . . . . . . . . . 254 Restore Presentation State (DECRSPS)--VT400 Mode Only . . . 255 Mode Settings (VT400 Mode Only) . . . . . . . . . . . . . . . . . . . . . . . . . . 257 Request Mode (DECRQM)--Host To VT420 . . . . . . . . . . . . . . . . 257 Report Mode (DECRPM)--VT420 To Host . . . . . . . . . . . . . . . . . 261 Setting or Resetting Modes (SM and RM) . . . . . . . . . . . . . . . . . . 263 Set Mode (SM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 263 Reset Mode (RM) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 264 Control Function Settings (VT400 Mode Only) . . . . . . . . . . . . . . . . 266 Request Selection or Setting (DECRQSS)--Host To VT420 . . . . . 267 Report Selection or Setting (DECRPSS)--VT420 To Host . . . . . . 268 Saving and Restoring the Cursor State . . . . . . . . . . . . . . . . . . . . . . 269 Save Cursor (DECSC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 Restore Cursor (DECRC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270 Window Reports (VT400 Mode Only) . . . . . . . . . . . . . . . . . . . . . . . . 271 Request Displayed Extent (DECRQDE) . . . . . . . . . . . . . . . . . . . 271 Report Displayed Extent (DECRPDE) . . . . . . . . . . . . . . . . . . . . . 272 User-Preferred Supplemental Set (DECRQUPSS)--(VT400 Mode Only) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 274 13 Resetting and Testing the Terminal Resetting the Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 Soft Terminal Reset (DECSTR) . . . . . . . . . . . . . . . . . . . . . . . . . . 285 Reset to Initial State (RIS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 Secure Reset (DECSR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 288 Secure Reset Confirmation (DECSRC) . . . . . . . . . . . . . . . . . . . . 289 Tab Clear (TBC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 Testing the Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 291 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ xii Contents Screen Alignment Pattern (DECALN) . . . . . . . . . . . . . . . . . . . . . 291 Invoke Confidence Test (DECTST)--Power-Up Self-Test . . . . . . . 291 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 Part 4 Session Management 14 Session Management Two Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Two Ways to Manage Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 297 Session Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Independent Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 300 Shared Resources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 301 Multiple System Communications (MSC) . . . . . . . . . . . . . . . . . . . . . 301 SSU Software (VT Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 SSU Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 ANSI/VT52 Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 SSU Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302 XON/XOFF Data Flow Control . . . . . . . . . . . . . . . . . . . . . . . . 302 Using SSU Software . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Selecting Sessions (MSC or SSU Software) . . . . . . . . . . . . . . . . . . . 303 Enable Session Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 303 Part 5 Emulating a Personal Computer 15 Operating in PC TERM Mode How the VT420 Operates in PC TERM Mode . . . . . . . . . . . . . . . . . 307 Sequence of Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308 Control Codes Sent in PC TERM Mode . . . . . . . . . . . . . . . . . . . . 309 Enabling or Disabling PC TERM Mode . . . . . . . . . . . . . . . . . . . . . . 310 Change Emulation Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 Enabling PC Keyboard Commands . . . . . . . . . . . . . . . . . . . . . . . . . 312 Data and Commands Sent from the Host to the Terminal . . . . . . 313 Secondary DA--PC Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 DSR--PC Keyboard Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents xiii Using PC Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 Selecting PC Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 PC Keyboard Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Scan Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 318 Main Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Key Assignments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 319 Standard Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322 Editing Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324 Numeric Keypad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 Top-Row Function Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 326 A VT52 Mode Control Codes VT52 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 Exiting VT52 Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 B Communication Standards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330 Host System and Printer Port Interfaces . . . . . . . . . . . . . . . . . . . . . 330 Modems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Printers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 Character Format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 Terminal-to-Host Data Flow Control . . . . . . . . . . . . . . . . . . . . . . . . 332 Using Fill Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 Transmit Rate Limiting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 Transmit Rate Limiting (DECXRLM) . . . . . . . . . . . . . . . . . . . 334 Modem Connections and Disconnections . . . . . . . . . . . . . . . . . . . 335 Terminal-to-Printer Data Flow Control . . . . . . . . . . . . . . . . . . . . . . 335 Using C1 Control Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ xiv Contents C Related Documentation D Compatibility with Other Digital Terminals Glossary Figures 1-1 VT420 Video Display Terminal with Keyboards . . . . . . . . . . . 5 2-1 VT Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2-2 7-Bit ASCII Code Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2-3 7-Bit Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2-4 8-Bit Code Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2-5 8-Bit Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2-6 DEC Multinational Character Set (Left Half--C0 and GL Codes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 2-7 DEC Multinational Character Set (Right Half--C1 and GR Codes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2-8 ISO Latin Nr 1 Supplemental Character Set . . . . . . . . . . . . . 26 2-9 DEC Special Graphic Character Set . . . . . . . . . . . . . . . . . . . . 29 2-10 DEC Technical Character Set . . . . . . . . . . . . . . . . . . . . . . . . . 30 2-11 Display Controls Font (Left Half) . . . . . . . . . . . . . . . . . . . . . . 52 2-12 Display Controls Font (Right Half) . . . . . . . . . . . . . . . . . . . . 53 3-1 ANSI Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58 3-2 Short ANSI Keyboard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 3-3 PC Keyboard (North American/United Kingdom Keyboard) . . 60 3-4 Standard Key with a Data Processing Character (French/Belgian ANSI Keyboard) . . . . . . . . . . . . . . . . . . . . . . 62 5-1 Character Set Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 5-2 Designating and Mapping Character Sets in VT400 Mode . . . 96 5-3 Designating and Mapping Character Sets in VT100 Mode . . . 97 5-4 Character Cell Sizes for 24-Line by 80- and 132-Column Fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 5-5 Character Body Sizes for 24-Line by 80- and 132-Column Fonts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105 5-6 Example of an Uppercase D (24-Line by 80-Column Font) . . . 108 5-7 Sixel-to-ASCII Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Contents xv 6-1 A Page in Page Memory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 6-2 Page Sizes for One Session . . . . . . . . . . . . . . . . . . . . . . . . . . 128 6-3 Page Sizes for Two Sessions . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10-1 The Difference Between Scrolling and Panning . . . . . . . . . . . 175 14-1 Typical MSC Environments . . . . . . . . . . . . . . . . . . . . . . . . . . 298 14-2 Typical SSU Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . 299 15-1 PC TERM Mode Operation . . . . . . . . . . . . . . . . . . . . . . . . . . 308 15-2 PC International and PC Multilingual Character Sets (CO and GL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314 15-3 PC International Character Set (C1 and GR) . . . . . . . . . . . . . 315 15-4 PC Multilingual Character Set (C1 and GR) . . . . . . . . . . . . . 316 15-5 North American PC Keyboard (101 Keys) . . . . . . . . . . . . . . . 320 15-6 Worldwide PC Keyboard (102 Keys) . . . . . . . . . . . . . . . . . . . . 321 Tables 2-1 National Replacement Character Sets . . . . . . . . . . . . . . . . . . 28 2-2 C0 (7-Bit) Control Characters Recognized . . . . . . . . . . . . . . . 31 2-3 C1 (8-Bit) Control Characters Recognized . . . . . . . . . . . . . . . 33 2-4 8-Bit Control Characters and Their 7-Bit Equivalents . . . . . . 35 2-5 Displaying Controls in 36 or 48 Lines . . . . . . . . . . . . . . . . . . 49 3-1 Codes Sent by Editing Keys (ANSI/Short ANSI Keyboards) . 65 3-2 Codes Sent by Editing Keys (PC Keyboard) . . . . . . . . . . . . . . 65 3-3 Codes Sent by Arrow Keys . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 3-4 Codes Sent by Numeric Keypad Keys (ANSI, Short ANSI, and PC Keyboards) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 3-5 Codes Sent by Numeric Keypad Keys (PC Keyboard, PC Key Layout) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 3-6 Codes Sent by the Top-Row Function Keys . . . . . . . . . . . . . . 73 3-7 Keys Used to Send 7-Bit Control Characters . . . . . . . . . . . . . 78 4-1 Control Functions Ignored in Level 1 (VT100 mode) . . . . . . . 84 5-1 Character Sets Available . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 5-2 Designating a Character Set . . . . . . . . . . . . . . . . . . . . . . . . . 93 5-3 Character Set Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94 5-4 Mapping Character Sets with Locking Shifts . . . . . . . . . . . . . 98 5-5 Character Cell Sizes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104 5-6 Guidelines for Designing Soft Characters . . . . . . . . . . . . . . . 106 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ xvi Contents 5-7 Converting Binary Code to an ASCII Character . . . . . . . . . . 109 5-8 DECDLD Parameter Characters . . . . . . . . . . . . . . . . . . . . . . 116 5-9 Valid DECDLD Parameter Combinations . . . . . . . . . . . . . . . 121 6-1 Page Format Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 6-2 Sequences for Moving Through Page Memory . . . . . . . . . . . . 141 7-1 Visual Character Attribute Values . . . . . . . . . . . . . . . . . . . . . 143 7-2 Visual Character and Line Attribute Sequences . . . . . . . . . . 147 8-1 Editing Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 9-1 Rectangular Area Control Functions . . . . . . . . . . . . . . . . . . . 172 10-1 Cursor Movement and Panning Sequences . . . . . . . . . . . . . . 185 11-1 ANSI and Short ANSI Keyboards . . . . . . . . . . . . . . . . . . . . . 207 11-2 PC Keyboards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208 11-3 Keyboard Control Sequences . . . . . . . . . . . . . . . . . . . . . . . . . 222 11-4 Programming UDKs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 11-5 Printing Control Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . 226 11-6 Screen Display Control Sequences . . . . . . . . . . . . . . . . . . . . . 227 12-1 Alias Primary DA Responses From the VT420 . . . . . . . . . . . . 231 12-2 ANSI Modes for DECRQM, DECRPM, SM, and RM . . . . . . . 259 12-3 DEC Private Modes for DECRQM, DECRPM, SM, and RM . . 260 12-4 Control Functions for DECRQSS Requests . . . . . . . . . . . . . . 266 12-5 Sequences for VT420 Reports . . . . . . . . . . . . . . . . . . . . . . . . . 274 13-1 Soft Terminal Reset (DECSTR) States . . . . . . . . . . . . . . . . . . 285 13-2 VT420 Reset Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 293 15-1 Control Codes for PC Character Sets . . . . . . . . . . . . . . . . . . . 310 15-2 PC Keyboard Commands in PC TERM Mode . . . . . . . . . . . . . 312 15-3 National PC Character Sets . . . . . . . . . . . . . . . . . . . . . . . . . . 317 15-4 Scan Codes Sent by Standard Keys . . . . . . . . . . . . . . . . . . . . 322 15-5 Scan Codes Sent by Editing and Arrow Keys . . . . . . . . . . . . . 324 15-6 Scan Codes Sent by Numeric Keypad Keys . . . . . . . . . . . . . . 325 15-7 Scan Codes Sent by Programmable Function Keys . . . . . . . . 326 A-1 VT52 Escape Sequences . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ About This Manual ------------------------------------------------------------ This reference manual is for people with a general knowledge of computer programming. The manual provides programmers with information needed in writing applications for the VT420 text terminal. For general user information, see Installing and Using the VT420 Video Terminal. New Features in This Revision This revised manual provides new information on operating a VT420 text terminal in PC TERM mode. There are several versions of the VT420 text terminal: · North American model--Operates in VT mode. · Worldwide model--Operates in VT mode. · Worldwide model with PC TERM mode--Operates in VT mode or PC TERM mode. xvii ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ xviii About This Manual Organization The manual is divided into five parts. Part 1: Introduction to Your VT420 Terminal Part 1 covers information you need to know before you begin programming the terminal. · Chapter 1, ``VT420 Features,'' provides an overview of the terminal. The chapter briefly describes the terminal's major features and operating modes. · Chapter 2, ``Character Encoding,'' describes the character-encoding concepts used by the VT420. The chapter also describes the terminal's character sets, the format for control functions, and commands for using macros. Part 2: Control Functions Sent to the Host Part 2 covers the codes sent from the keyboard. · Chapter 3, ``ANSI, Short ANSI, and PC Keyboard Codes,'' describes the characters and control functions that the terminal sends to the host. Part 3: Control Functions Received from the Host Part 3 covers the control functions you can use to program the terminal in VT mode or PC TERM mode. Part 5 describes features unique to PC TERM mode. · Chapter 4, ``Emulating VT Series Terminals,'' describes the control functions used to emulate Digital's other VT series terminals. · Chapter 5, ``Using Character Sets,'' describes the control functions used to select the terminal's built-in character sets and your own soft character sets. · Chapter 6, ``Page Memory,'' describes the control functions used to format and move through the terminal's page memory. · Chapter 7, ``Setting Visual Character and Line Attributes,'' describes the control functions used to highlight text, such as bolding and underlining. · Chapter 8, ``Editing,'' describes the control functions used to edit characters in the terminal's page memory. ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ About This Manual xix · Chapter 9, ``Rectangular Area Operations,'' describes the control functions used to manipulate rectangular areas of text. · Chapter 10, ``Cursor Movement and Panning,'' describes the control functions used to move the cursor and pan through data in page memory. · Chapter 11, ``Keyboard, Printing, and Display Commands,'' describes the control functions used to program the terminal's keyboard, printer port, and display screen. · Chapter 12, ``VT420 Reports,'' describes the control functions used to request reports on the operating state of the terminal. The chapter also describes the format of the reports sent by the terminal, and the control functions use to restore the terminal to a previous state. · Chapter 13, ``Resetting and Testing the Terminal,'' describes the control functions used to reset and test the terminal's operating features. Part 4: Dual Sessions Part 4 describes two methods for managing sessions on the VT420-- multiple system communications (MSC) and SSU software. · Chapter 14, ``Session Management,'' describes MSC and SSU. The chapter also lists shared and independent resources available to each session when you use two sessions. Part 5: Emulating a Personal Computer Part 5 describes how the VT420 model with PC TERM mode can emulate a personal computer (PC). · Chapter 15, ``Operating in PC TERM Mode,'' describes how the terminal operates in PC TERM mode. The chapter describes control characters, PC character sets, and codes the PC keyboard sends to the host. Appendices · Appendix A, ``VT52 Mode Control Codes,'' describes control functions used when the terminal is in VT52 mode. · Appendix B, ``Communication,'' describes how the terminal communicates with the host system and local devices, such as modems and printers. The appendix also provides cabling information and describes how to connect to non-Digital systems. ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ xx About This Manual · Appendix C, ``Related Documentation,'' lists other VT420 documentation you can order from Digital. · Appendix D, ``Compatibility with Other Digital Terminals,'' compares the VT420 video terminal to Digital's VT320 and VT220 video terminals. Conventions The following conventions are used in this manual: Notes Provide general operating information. Programming tips Provide helpful suggestions to consider when writing applications. Set-up features The names of features appear in bold type. Example: Use the save feature in the Set-Up Directory screen. Set-up feature settings and fields appear in this type. Example: The cursor is on the Global field in the Set-Up Directory. ANSI keyboard keys Appear as normal text in a ------------------------------------------------------------ ------------------------------------------------------------ box ------------------------------------------------------------ ------------------------------------------------------------ . Example: Press the ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ key. PC keyboard keys Appear as bold text in a ------------------------------------------------------------ ------------------------------------------------------------ box ------------------------------------------------------------ ------------------------------------------------------------ . Example: Press the ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ key. ANSI keys (with PC keys) When a PC command sequence differs from an ANSI command sequence, the PC key sequence appears in parentheses after the ANSI sequence. Example: Press the ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ key ( ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ ). ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ key ------------------------------------------------------------ ------------------------------------------------------------ For ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key sequences, hold down ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ and press the other key. Characters in control functions Appear in bold type. Variables appear in italics. Below each character is a column/row number that indicates the character 's position in a standard code table. Example: ESC 1/11 # 2/3 6 3/6 ( = (= Control function Column/row numbers ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ About This Manual xxi Glossary entries Appear in italics when first used in text. Example: The VT420 stores information in its page memory. ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Part 1 Introduction to Your VT420 Terminal ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 1 VT420 Features ------------------------------------------------------------ This chapter provides an overview of the VT420 video terminal. The chapter briefly describes the major features and operating modes of the terminal. VT420 Models The VT420 is a monochrome text terminal. The terminal has two major components, a monitor/terminal unit and a keyboard. The monitor has a tilt-swivel base. The VT420 is available in three models: worldwide, worldwide with PC TERM mode, and North American. · The worldwide model supports 8-bit multinational character sets and several 7-bit national replacement character sets (NRCs) for western Europe. This model has two system communication ports (6-pin, DEC-423 port and 25-pin, RS-232 port) and a detachable power cord. · The worldwide model with PC TERM mode provides all the features of the worldwide model, plus an operating mode that supports personal computer (PC) character sets and PC application software. · The North American model is similiar to the worldwide model, but does not support the NRC sets or PC TERM mode. This model has one system communication port (6-pin, DEC-423 port) and an attached power cord. Chapter 1 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 4 VT420 Features VT420 Models All models have a 6-pin, DEC-423 printer port. The printer port can also serve as an extra communication port for connection to a host computer. Users can select whether this port acts as a local printer port or an extra communication port, by setting a feature in the Global Set-Up screen. This manual covers the programming information you need to use the features for the terminal. The terminal uses control functions specified by the American National Standards Institute (ANSI) and the International Organization for Standardization (ISO). Keyboards The terminal uses one of three Digital keyboards (Figure 1-1): · ANSI keyboard · Short ANSI keyboard · PC keyboard (with 101 or 102 keys) The ANSI and PC keyboards are available in various models for different languages. The PC keyboard is for the VT worldwide model with PC TERM mode; the North American model has 101 keys, and other models have 102 keys. You can use the ANSI and short ANSI keyboards with any VT420 model. See Installing and Using the VT420 Video Terminal with PC Terminal Mode for a comparison of the three keyboards. The next section describes some of the important new features of the terminal. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Features VT420 Models 5 Figure 1-1 VT420 Video Display Terminal with Keyboards ! ANSI keyboard " Short ANSI keyboard # PC keyboard (102-key model shown) Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 6 VT420 Features New Features New Features The VT420 is compatible with Digital's VT320 terminal and offers major new features, such as the ability to use PC applications, two sessions, and two windows. You can also create macros and perform rectangular area editing. Local page memory provides faster on-line transaction processing. PC TERM Mode The VT420 worldwide model with PC TERM mode supports PC character sets and PC application software. Chapter 15 describes PC TERM mode and PC character sets. Two Sessions When you electronically connect to a host system from your terminal, you start an interactive session. The VT420 lets you run two sessions at the same time. That is, you can connect to two different jobs on your system. If you connect your VT420 to two systems, you can log in to both systems and run those sessions at the same time. If you are using a PC keyboard, you can select a different operating mode for each session -- VT mode or PC TERM mode. If you connect your VT420 to a terminal server that supports several systems, you can run two VT mode sessions, each on a different system. The two-sessions feature gives you two terminals in one. The VT420 maintains the two sessions separately. You can easily switch back and forth between the two sessions from the keyboard. The VT420 has two different methods for managing dual sessions, multiple system communications (MSC) and Digital's SSU protocol. · MSC Uses two separate communication lines to maintain two sessions at the same time. · SSU (VT mode only) Uses one communication line and Digital's proprietary SSU software protocol to maintain two sessions at the same time. The SSU protocol is available as a separate VMS layered software product or as part of a DECServer 200, DECserver 300, or DECserver 500 system. You can select different operating features for each session. For example, you can use different set-up selections, page memory format, and user- defined keys. For more information on session management, see Chapter 14. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Features New Features 7 User Windows The VT420 lets you view data from two sessions at the same time. To view data from two sessions, you divide the screen into two windows. By default, each session you open with a VT420 terminal uses the complete screen. This means the terminal can only display data from one session at a time. To divide the screen into two windows, you press a sequence of keys. Each window is assigned to a session. Information from one session appears in one half of the screen, information from the second session appears in the other half. You can divide the screen horizontally. When you divide the screen, a border appears across the middle of the screen from column 1 to the last column. For more information on user windows, see Installing and Using the VT420 Video Terminal. Page Memory In VT mode, the VT420 has a multiple-page display memory. The multiple-page feature lets the terminal store more text than appears on the screen. For example, when you use two sessions the terminal can store up to three screen areas of text (three 24-line pages) for each session. In PC TERM mode, the host system stores data. Page memory provides a storage space for pop-up menus and a means for instant screen updates. You can select different page sizes. The page sizes available depend on whether you are running one or two sessions. Two Sessions · 3 pages of 24 lines  80 or 132 columns · 2 page of 25 lines  80 or 132 columns · 2 pages of 36 lines  80 or 132 columns · 1 page of 48 lines  80 or 132 columns · 1 page of 72 lines  80 or 132 columns One Session · 6 pages of 24 lines  80 or 132 columns · 5 pages of 25 lines  80 or 132 columns · 4 pages of 36 lines  80 or 132 columns Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 8 VT420 Features New Features · 3 pages of 48 lines  80 or 132 columns · 2 pages of 72 lines  80 or 132 columns · 1 page of 144 lines  80 or 132 columns A page is a section of the terminal's page memory. Each page has left, right, top and bottom margins. You can define the size and layout of a page by using set-up features or control functions. For more information on page memory, see Chapter 6. Macro Feature This feature lets you download ANSI text and commands into the terminal. The terminal stores the text and commands until you invoke them with a control function. The macro feature provides you with more convenience and flexibility. It lets you execute a group of ANSI control functions as a set. For more information, see Chapter 2. Rectangular Area Operations This feature lets you manipulate rectangular areas of text within page memory. You can · Copy them from one area in page memory to another. · Erase them. · Fill them with a character of your choice. · Change or reverse their visual character attributes. For more information, see Chapter 9. Local Copy and Paste Feature (VT Mode) This feature lets you copy text from the screen to an internal buffer. You can later send the text to the host. This feature is useful for copying text from the terminal screen to the host application. Number of Lines/Screen The VT420 has three different character font heights, so users can display 24, 36, or 48 lines of text on the screen. For more information, see Chapter 11. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Features General Features 9 General Features This section describes the general operating and communication features of the terminal. You can set many of these features from the keyboard, using set-up. Set-Up Set-up is a series of display screens. Each screen lists a group of features, such as communications or printing. You can use set-up screens to examine and change the current settings for features. For example, you can select the keyclick feature, transmit and receive speeds, page size, and type of session management. The VT420 set-up feature is similar to the VT320 set-up feature. Installing and Using the VT420 Video Terminal describes the set-up screens in detail. Display Features The VT420 screen has the following basic features: · 359 mm (14-inch), flat-screen monitor · 24, 36, or 48 display lines at a time 800 (horizontal)  400 (vertical) pixels · A separate status line for each session, at the bottom of the screen (You can disable the status line to have an additional line for data display.) · Horizontal split-screen scrolling on any line boundary (same as the VT100) Text Features The VT420 provides a variety of text and editing features. · Character sets - 5 sets of 94 characters each - 1 set of 96 characters - National replacement character sets (worldwide model) - 3 PC sets of 128 characters each (worldwide model with PC TERM mode) - Downloadable character set (94 or 96 characters) Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 10 VT420 Features General Features · ANSI keyboard function keys - 5 local function keys - 15 user-definable keys · PC keyboard function keys - 3 local function keys - 30 user-definable keys (VT mode) 51 user-definable keys (PC TERM mode) · PC keyboard scan codes sent to the host · All VT320 editing functions · Normal, bold, underline, blinking, and reverse video characters · Single-width/single-height lines Double-width/single-height lines Double-width/double-height lines · Control characters and functions - 7-bit and 8-bit control characters - ANSI control functions - DEC private control functions - Ability to display control functions Character Sets The VT420 has the following built-in character sets: · ASCII · DEC Supplemental Graphic · ISO Latin Alphabet Nr 1 supplemental graphic · National replacement character sets (NRCs) (worldwide model) · DEC Technical · DEC Special Graphic (VT100 line drawing) · PC character sets (worldwide model with PC TERM mode) -- PC International -- PC Multilingual -- PC Danish/Norwegian -- PC Portuguese -- PC Spanish You can also design a soft character set, then load it from the host system into the terminal. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Features General Features 11 Together, the ASCII and DEC Supplemental Graphic sets make up the DEC Multinational character set. When you turn on or reset the terminal, the VT420 automatically uses the DEC Multinational set. The ASCII and ISO Latin-1 supplemental sets make up the ISO Latin-1 character set. Chapter 2 describes the VT420 character sets. Chapter 5 describes how to select and use different character sets. Communication Features The VT420 provides the following features for communicating with the host system: · 7-bit or 8-bit environments · XPC communication protocol, which defines the XON and XOFF points · Asynchronous communication speeds up to 38,400 bits/second · One DEC-423 host port · One RS-232 host port, with a 25-pin D-subminiature connector for a host or external modem (worldwide model only) · One bidirectional DEC-423 printer port, which also serves as a communication port with a host system The VT420 has two major communication states, on-line and local. You select the communication state in set-up. · The on-line state lets the terminal communicate with a host system. The terminal sends data entered at the keyboard to the host. The terminal displays data received from the host on the screen. · The local state lets you place the host system on hold. Data entered at the keyboard is sent to the screen, but not to the host. The terminal stores data received from the host, until you put the terminal back on-line. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 12 VT420 Features Operating Modes Operating Modes The VT420 has four major operating modes for text operations. The VT420 with PC TERM mode has five major operating modes. You can select each mode from the keyboard (using set-up screens), or from the host (using control codes). The VT420 uses standard ANSI functions in all operating modes, except VT52 mode and PC TERM mode.  VT400 mode, 7-bit controls  VT400 mode, 8-bit controls  PC TERM mode  VT100 mode  VT52 mode VT400 mode, 7-bit controls is the default operating mode. This mode provides the full range of VT420 capabilities, using 8-bit characters and 7-bit control characters. All character sets are available. This mode provides full compatibility with Digital's VT300 series terminals. Digital recommends this mode for most applications. VT400 mode, 8-bit controls provides the full range of VT420 capabilities, using 8-bit characters and 8-bit control characters. All VT mode character sets are available, and the terminal recognizes both 7-bit and 8-bit controls. In this mode, the terminal can run VT300 applications that use 8-bit control characters. The worldwide model with PC TERM mode can use a PC keyboard. The terminal operates most efficiently in this mode, but some systems and applications do not yet support 8-bit operation. PC TERM mode enables the terminal to support PC application software and character sets. The terminal sends scan codes to the host, which PC applications recognize. The terminal sends scan codes when you press a key and when you release a key. This mode requires a PC keyboard. VT100 mode provides full compatibility with Digital's VT102 terminal. This mode restricts the terminal to a 7-bit environment. The keyboard is restricted to VT100 keys, and the only available character sets are ASCII, national replacement characters, and DEC Special Graphic. You can use this mode with applications that require strict VT100 compatibility. VT52 mode provides full compatibility with Digital's VT52 terminal. This mode only uses Digital's private control functions, not standard ANSI functions. You use this mode with applications written for the VT52. Chapter 2 describes the format for 7-bit and 8-bit character codes. Chapter 4 describes how the VT420 can emulate other VT series terminals. Chapter 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 2 Character Encoding ------------------------------------------------------------ This chapter describes the character-encoding system that the terminal uses in VT mode to communicate with a host system. See Chapter 15 for a description of PC TERM mode. You must have a basic understanding of the character-encoding system described in this chapter before you use the control functions in the rest of this manual. The chapter also describes the character sets available in VT mode and the format for sending control functions to the terminal. You can select character sets for different countries or for special uses, such as technical characters. You use control functions to make the terminal perform special functions, such as editing or printing. Overview The VT420 uses a communication line to exchange information with a host system. The terminal and the host send data in an encoded form that is different from what you see on the screen. In VT mode, the keys you type on your keyboard send scan codes to the terminal. The terminal converts the scan codes to character codes or ANSI control functions, then sends the information to the host. The host stores the information and passes it to application software programs. For example, your host may have applications that let you do word processing, data entry, or programming. The host processes the output from the application software and displays it on the terminal's screen. You can print the data by sending it to a printer connected to the terminal. Chapter 2 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 14 Character Encoding Overview Figure 2-1 VT Mode Operation Coding Standards All terminals and computers encode information as binary digits, or bits. Older systems use 7 bits to encode each character. Newer systems such as the VT420 use 8 bits, which provide more codes. The newer systems can also use the 7-bit codes. The VT420 uses an 8-bit character-encoding system and a 7-bit code extension technique. The ``7-Bit Code Extension Technique'' section in this chapter explains what 7-bit code extensions are. The American National Standards Institute (ANSI) and International Organization for Standardization (ISO) specify standards for character encoding in the information-processing industry. The VT420 terminal is compatible with the following ANSI and ISO standards. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Coding Standards 15 ------------------------------------------------------------ Standard Description ------------------------------------------------------------ dpANS X3.134.1 8-Bit ASCII structure and rules dpANS X3.134.2 Code for information interchange of 7-bit and 8-bit ASCII supplemental multilingual graphic character set ANSI X3.4--1977 American Standard Code for Information Interchange (ASCII) ANSI X3.41--1974 Code Extension Techniques for Use with the 7-Bit Coded Character Set of American National Code Information Interchange ANSI X3.32--1973 Graphic Representation of the Control Characters of American National Code for Information Interchange ANSI X3.64--1979 Additional Controls for Use with American National Standard for Information Interchange ISO 646--1977 7-Bit Coded Character Set for Information Processing Interchange ISO 2022 7-Bit and 8-Bit Coded Character Sets--Code Extension Techniques ISO 6429 Additional Control Functions for Character Imaging Devices ISO 8859-1 8-Bit single byte code graphic character sets-Part 1: Latin Alphabet Nr 1 ISBN 2-12-953907-0 ISO international register of character sets used with escape sequences ------------------------------------------------------------ You can order ANSI and ISO standards from the following sources: ANSI Standards Sales Department American National Standards Institute 1430 Broadway New York, NY 10018 ISO Standards CCITT UN Book Store United Nations Building New York, NY 10017 Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 16 Character Encoding Characters and Character Sets Characters and Character Sets In Digital's computing environment, a character is a symbol represented by an 8-bit binary code. These symbols include letters, digits, and punctuation marks, as well as other symbols used to organize, control, or represent data. Here are a few examples of characters and their corresponding 8-bit codes. Character Code A 01000001 } 01111101 CSI 10011011 There are two types of computing environments, 7-bit and 8-bit. In a 7-bit environment, only the last 7 bits of the character code define the character. In an 8-bit environment, all 8 bits define the character. The A character above is defined in a 7-bit or 8-bit environment, because the eighth bit of the code is 0. The 8-bit form of the CSI character is defined only in a 8-bit environment, because its eighth bit is 1. A coded character set is a group of characters that conform to certain rules and standards. These standards are set by organizations such ANSI and ISO. Each character in a character set is represented by a different combination of 8 bits. Code Table A code table is a convenient way to show all the characters in a character set with their codes. Most standard character sets put similar characters into groups, so they have similar codes. A code table lets you see groups of characters and their relative codes clearly. There are two basic types of characters, graphic characters and control characters. These two character types are defined by ANSI and ISO standards. The VT420 processes received characters based on these two character types. Graphic characters are characters you can display. Graphic characters include letters, numbers, punctuation marks, and any other characters you can display. Control characters are characters you do not usually display. They make the terminal or host system perform specific functions in data communications and text processing. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Code Table 17 NOTE You can display control characters on the screen, to help you debug your applications. To display control characters, you set the control representation mode feature in the Display Set-Up screen to Display Controls. See the ``Display Controls Mode'' section at the end of this chapter. This section describes the format for 7-bit and 8-bit code tables. 7-Bit ASCII Code Table Figure 2-2 is the 7-bit ASCII code table. The table has 128 character codes, arranged in 8 columns and 16 rows. Every character in a row uses the same binary code for its four least significant bits (Figure 2-3). This value appears at the left of each row. For example, every character in row 0 uses the binary code 0000 for its four least significant bits. Every character in a column uses the same binary code for its three most significant bits. This value appears at the top of each column. For example, every character in column 0 uses the binary code 000 for its three most significant bits. The ASCII table also shows the octal, decimal, and hexadecimal code for each character. Different programmers may prefer using octal, decimal, or hexadecimal codes for different purposes. This manual refers to characters by their position in the table. For example, the character H is at 4/8 (column 4, row 8). You can use the column/row number to find a character and its codes in the table. For example ESC 1/11 # 2/3 6 3/6 means The ESC character is at column 1, row 11. The # character is at column 2, row 3. The 6 character is at column 3, row 6. The ASCII graphic characters are in positions 2/1 through 7/14 of the ASCII table. ASCII graphic characters include all American and English alphanumeric characters, plus punctuation marks and various text symbols. Examples are C, n, ", !, +, and $. (The British pound sign is not an ASCII graphic character.) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 18 Character Encoding Code Table Figure 2-2 7-Bit ASCII Code Table Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Code Table 19 Figure 2-3 7-Bit Code The ASCII control characters are in positions 0/0 through 1/15 (columns 0 and 1) of the ASCII table. The SP character (2/0) may act as a graphic space character or a control character, depending on the context. DEL (7/15) is always a control character. ANSI and ISO standards define control character codes and their functions. These standards also define the mnemonic used to represent each control character in a code table. Here are some examples of ASCII control characters with their mnemonics. ASCII Control Character Mnemonic (Appears in Code Table) Carriage return CR Form feed FF Cancel CAN Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 20 Character Encoding Code Table 8-Bit Code Table Figure 2-4 shows the format for an 8-bit code table. It has the same number of rows as the 7-bit table, but twice as many columns and character code positions. Each character in a row of the 8-bit table uses the same binary code for its four least significant bits (Figure 2-5). Each character in a column uses the same binary code for its four most significant bits. The codes on the left half of the 8-bit table (columns 0 through 7) work like the codes in the 7-bit table. You can use these codes in a 7-bit or 8-bit environment. The eighth bit of these codes is 0. The codes on the right half of the table (columns 8 through 15) have an eighth bit of 1. You can only use these codes in an 8-bit environment. The 8-bit code table has two sets of control characters, C0 (control zero) and C1 (control one). The VT420 uses the ANSI definitions for the functions of C0 and C1 controls. The C0 controls are in columns 0 and 1. The C0 controls are the same as the ASCII control characters in the 7-bit table. You can use C0 controls in a 7-bit environment. The C1 controls are in columns 8 and 9. They perform different functions than the C0 controls. You can only use C1 controls directly in an 8-bit environment. You can select C1 codes indirectly in a 7-bit environment. The ``7-Bit Code Extension Technique'' section in this chapter explains how to select C1 controls indirectly. Some C1 code positions are blank, because their functions are not yet standardized. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Code Table 21 Figure 2-4 8-Bit Code Table Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 22 Character Encoding Code Table Figure 2-5 8-Bit Code NOTE The VT420 does not recognize all C0 and C1 codes. Tables 2-2 and 2-3 list the codes the terminal recognizes. The terminal generally ignores all other control codes. The table also has two sets of graphic characters, GL (graphic left) and GR (graphic right). There are 94 GL codes in positions 2/1 through 7/14. You can use GL codes in 7-bit or 8-bit environments. There are 96 GR codes in positions 10/0 through 15/15. Some 8-bit character sets only use 94 of these GR codes. You can use GR codes only in an 8-bit environment. Together, the GL and GR sets make up the terminal's in-use table. The in-use table contains the graphic characters the terminal can currently use. Before the terminal can display and send characters from a character set, the set must be mapped into the in-use table. Chapter 5 describes the in-use table in detail. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding VT420 Character Sets 23 VT420 Character Sets The VT420 provides the following built-in graphic character sets: ASCII DEC Supplemental Graphic ISO Latin Alphabet Nr 1 supplemental graphic National replacement character sets (NRCs) DEC Special Graphic DEC Technical See Chapter 15 for additional sets available in PC TERM mode. You can also design and load a soft character set into the terminal. Downloadable (soft) set All VT420 character sets contain graphic and control characters. The function of control characters never change, no matter what character set you use. The terminal always interprets C0 and C1 control codes as defined by ANSI. The terminal stores the codes for graphic characters in GL and GR tables. Selecting a new character set changes the characters associated with the GL or GR codes. When you turn on or reset the terminal, you automatically select the following character sets: ASCII in GL DEC Supplemental (or ISO Latin-1 supplemental) graphic in GR Together, the ASCII set and one of the supplemental sets make up a multinational character set. · The ASCII set and DEC Supplemental Graphic sets are known as the DEC Multinational character set. · The ASCII set and the ISO Latin-1 supplemental set are known as the ISO Latin Alphabet Nr 1 set. You select the supplemental set with (1) the UPSS (user-preferred supplemental set) feature in the General Set-Up screen, or (2) the assign user-preferred supplemental set (DECAUPSS) control function (Chapter 5). Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 24 Character Encoding VT420 Character Sets DEC Supplemental Graphic Character Set This 8-bit character set has 94 graphic characters. The graphic characters include accented letters and diacritical marks, used in many European languages. There are also special symbols, such as currency signs. When you first turn on your terminal, you automatically select the ASCII character set and the DEC Supplemental Graphic set. The terminal maps the ASCII set into its GL table, and the DEC Supplemental Graphic set into its GR table. Together, these two character sets are known as the DEC Multinational character set (Figures 2-6 and 2-7). Figure 2-6 DEC Multinational Character Set (Left Half--C0 and GL Codes) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding VT420 Character Sets 25 NOTE All control function descriptions in this manual assume that the terminal is using the DEC Multinational set. The DEC Supplemental Graphic set is the right half of the DEC Multinational set (Figure 2-7). The C1 controls are in columns 8 and 9. The graphic characters are in columns 10 through 15. You can select the DEC Supplemental Graphic set as the default by using control functions (Chapter 5) or the UPSS feature in the General Set-Up screen. You can use the DEC Supplemental Graphic set in VT400 mode and PC TERM mode. Figure 2-7 DEC Multinational Character Set (Right Half--C1 and GR Codes) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 26 Character Encoding VT420 Character Sets ISO Latin Alphabet Nr 1 Supplemental Character Set This 8-bit character set has 96 graphic characters. The graphic characters are similar to those in the DEC Supplemental Graphic set. The ISO Latin-1 supplemental set includes accented letters and diacritical marks, used in many European languages. It also has other special symbols and letters, not included in the DEC Supplemental Graphic set. Figure 2-8 shows the ISO Latin-1 supplemental set. The C1 controls are in columns 8 and 9. The graphic characters are in columns 10 through 15. Figure 2-8 ISO Latin Nr 1 Supplemental Character Set You can select the ISO Latin-1 supplemental set as the default by using control functions (Chapter 5) or the UPSS feature in the General Set-Up Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding VT420 Character Sets 27 screen. The combination of the ASCII character set in GL and the ISO Latin-1 supplemental set in GR is called the ISO Latin Alphabet Nr 1 character set. You can use the ISO Latin-1 set in VT400 mode and PC TERM mode. National Replacement Character Sets (NRC Sets) (Worldwide Models Only) The NRC sets provide character sets for many European languages. There are several NRC sets. Each is a 7-bit character set with 94 graphic characters. The NRC sets are similar to the ASCII set, except for a few characters. See Chapter 15 for additional 8-bit sets available in PC TERM mode. NOTE Digital recommends that you operate the terminal in an 8-bit environment. The NRC sets are only provided for compatibility with 7-bit environments. Table 2-1 lists the characters in each NRC set that are different from the ASCII set. To use an NRC set, you must select national replacement character set mode. You can select this mode by using a control function (Chapter 4) or the character set mode feature in the General Set-Up screen. You can only use one NRC set at a time. The NRC set used depends on the keyboard selected in set-up, as follows: Keyboard NRC Set United Kingdom United Kingdom Danish Norwegian/Danish Finnish Finnish Flemish French French/Belgian French French Canadian French Canadian Canadian English French Canadian German German Italian Italian Norwegian Norwegian/Danish Portuguese Portuguese Spanish Spanish Swedish Swedish Swiss (French) Swiss Swiss (German) Swiss Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 28 Character Encoding VT420 Character Sets Table 2-1 National Replacement Character Sets ------------------------------------------------------------ Character Set 2/3 4/0 5/11 5/12 5/13 5/14 ------------------------------------------------------------ ASCII # @ [ \ ] ^ United Kingdom £ @ [ \ ] ^ Finnish # @ Ä Ö Å Ü French £ à ° ç § ^ French Canadian # à â ç ê î German # § Ä Ö Ü ^ Italian £ § ° ç é ^ Norwegian/Danish # @ Æ Ø Å ^ Portuguese # @ Ã Ç Õ ^ Spanish £ § ¡ Ñ ¿ ^ Swedish # É Ä Ö Å Ü Swiss ù à é ç ê î ------------------------------------------------------------ Character Set 5/15 6/0 7/11 7/12 7/13 7/14 ------------------------------------------------------------ ASCII _ ‘ { | } ~ United Kingdom _ ‘ { | } ~ Finnish _ é ä ö å ü French _ ‘ é ù è :: French Canadian _ ô é ù è û German _ ‘ ä ö ü ß Italian _ ù à ò è ì Norwegian/Danish _ ‘ æ ø å ~ Portuguese _ ‘ ã ç õ ~ Spanish _ ‘ ° ñ ç ~ Swedish _ é ä ö å ü Swiss è ô ä ö ü û ------------------------------------------------------------ Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding VT420 Character Sets 29 DEC Special Graphic Character Set This 7-bit character set has 94 graphic characters. Most of the graphic characters are also in the ASCII character set. The other graphic characters include special symbols and line-drawing characters. Figure 2-9 shows the DEC Special Graphic set. The C0 controls are in columns 0 and 1. The graphic characters are in columns 2 through 7. Another name for this character set is the VT100 line-drawing character set. The line-drawing characters let you create a limited range of pictures when you use the VT420 as a text terminal. You can use the DEC Special Graphic set to replace the ASCII set in GL or the DEC Supplemental Graphic set in GR. Chapter 5 describes how to select character sets. Figure 2-9 DEC Special Graphic Character Set Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 30 Character Encoding VT420 Character Sets DEC Technical Character Set This 7-bit character set has 94 graphic characters. The DEC Technical set has characters and symbols often used in technical applications, such as schematic and logic diagrams. Figure 2-10 shows the DEC Technical character set. The C0 controls are in columns 0 and 1. The graphic characters and symbols are in columns 2 through 7. You can use the characters in positions 2/1 through 3/7 to form large composite characters. You can use the DEC Technical set to replace the ASCII set in GL or the DEC Supplemental Graphic set in GR. You can only use the DEC Technical set in VT400 mode. Figure 2-10 DEC Technical Character Set Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding VT420 Character Sets 31 Downloaded (Soft) Character Set The VT420 lets you download a character set from the host system. The character set can have up to 96 graphic characters. You can design your own character set, then load the set into the terminal. You can use the set in GL or GR. Chapter 5 describes how to load and use a soft character set. You can only use this character set in VT400 mode. Control Characters The purpose of a control character is to control an action such as line spacing, paging, or data flow. The terminal does not display control characters unless you select display controls mode (described later in this chapter). There are two groups of control characters. C0 C1 7-bit control characters, in columns 0 and 1 of the 8-bit code table 8-bit control characters, in columns 8 and 9 of the 8-bit code table Table 2-2 lists the C0 control characters the VT420 recognizes. Table 2-3 lists the C1 control characters the VT420 recognizes. You can also code C1 control characters as 7-bit escape sequences. Table 2-4 lists the equivalent 7-bit sequences for 8-bit control characters. All three tables give column/row locations to help you find the characters in the character sets. Table 2-2 C0 (7-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Null NUL 0/0 NUL has no function (ignored by the terminal). Enquiry ENQ 0/5 Sends the answerback message. (Communications Set-Up) Bell BEL 0/7 Sounds the bell tone if the bell is enabled in Keyboard Set-Up. BS BS 0/8 Moves the cursor one character position to the left. If the cursor is at the left margin, no action occurs. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 32 Character Encoding Control Characters Table 2-2 (Cont.) C0 (7-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Horizontal tab HT 0/9 Moves the cursor to the next tab stop. If there are no more tab stops, the cursor moves to the right margin. HT does not cause text to auto wrap. Line feed LF 0/10 Causes a line feed or a new line operation, depending on the setting of line feed/new line mode. Vertical tab VT 0/11 Treated as LF. Form feed FF 0/12 Treated as LF. Carriage return CR 0/13 Moves the cursor to the left margin on the current line. Shift out (locking shift 1) SO (LS1) 0/14 Maps the G1 character set into GL. You designate G1 by using a select character set (SCS) sequence (Chapter 5). Shift in (locking shift 0) SI (LS0) 0/15 Maps the G0 character set into GL. You designate G0 by using a select character set (SCS) sequence (Chapter 5). Device control 1 (XON) DC1 1/1 Also known as XON. If XON/XOFF flow control is enabled in Communications Set-Up, DC1 clears DC3 (XOFF). This action causes the VT420 to continue sending characters. Device control 3 (XOFF) DC3 1/3 Also known as XOFF. If XON /XOFF flow control is enabled in Communications Set-Up, DC3 causes the VT420 to stop sending characters. The terminal cannot resume sending characters until it receives a DC1 control character. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Control Characters 33 Table 2-2 (Cont.) C0 (7-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Device control 4 DC4 1/4 Introduces an SSU session management command. The VT420 and host use this control to separate SSU commands from ANSI text and control functions. See Chapter 14. Cancel CAN 1/8 Immediately cancels an escape sequence, control sequence, or device control string in progress. The VT420 does not display any error characters. Substitute SUB 1/10 Immediately cancels an escape sequence, control sequence, or device control string in progress. The VT420 displays a reverse question mark for an error character. Escape ESC 1/11 Introduces an escape sequence. ESC also cancels any escape sequence, control sequence, or device control string in progress. Delete DEL 7/15 Ignored when received, unless a 96- character set is mapped into GL. DEL is not used as a fill character. Digital does not recommend using DEL as a fill character. Use NUL instead. ------------------------------------------------------------ Table 2-3 C1 (8-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Index IND 8/4 Moves the cursor down one line in the same column. If the cursor is at the bottom margin, the page scrolls up. Next line NEL 8/5 Moves the cursor to the first position on the next line. If the cursor is at the bottom margin, the page scrolls up. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 34 Character Encoding Control Characters Table 2-3 (Cont.) C1 (8-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Horizontal tab set HTS 8/8 Sets a horizontal tab stop at the column where the cursor is. Reverse index RI 8/13 Moves the cursor up one line in the same column. If the cursor is at the top margin, the page scrolls down. Single shift 2 SS2 8/14 Temporarily maps the G2 character set into GL, for the next graphic character. You designate the G2 set by using a select character set (SCS) sequence (Chapter 5). Single shift 3 SS3 8/15 Temporarily maps the G3 character set into GL, for the next graphic character. You designate the G3 set by using a select character set (SCS) sequence (Chapter 5). Device control string DCS 9/0 Introduces a device control string. Used for loading function keys or a soft character set. Start of string SOS 9/8 Ignored. DEC private identification DECID 9/10 Makes the terminal send its device attributes response to the host (same as an ANSI device attributes (DA) sequence). Programs should use the ANSI DA sequence instead. NOTE If the printer is in controller mode, the terminal sends the sequence to the printer. Control sequence introducer CSI 9/11 Introduces a control sequence. String terminator ST 9/12 Ends a device control string. You use ST in combination with DCS. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Control Characters 35 Table 2-3 (Cont.) C1 (8-Bit) Control Characters Recognized ------------------------------------------------------------ Name Mnemonic Column/Row Function ------------------------------------------------------------ Operating system command OSC 9/13 Introduces an operating system command.  Privacy message PM 9/14 Introduces a privacy message string.  Application program command APC 9/15 Introduces an application program command.  ------------------------------------------------------------  The VT420 ignores all following characters until it receives a SUB, ST, or any other C1 control character. ------------------------------------------------------------ Table 2-4 8-Bit Control Characters and Their 7-Bit Equivalents ------------------------------------------------------------ Name 8-Bit Character 7-Bit Sequence ------------------------------------------------------------ Index IND 8/4 ESC 1/11 D 4/4 Next line NEL 8/5 ESC 1/11 E 4/5 Horizontal tab set HTS 8/8 ESC 1/11 H 4/8 Reverse index RI 8/13 ESC 1/11 M 4/13 Single shift 2 SS2 8/14 ESC 1/11 N 4/14 Single shift 3 SS3 8/15 ESC 1/11 O 4/15 Device control string DCS 9/0 ESC 1/11 P 5/0 Start of string SOS 9/8 ESC 1/11 X 5/8 Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 36 Character Encoding Control Characters Table 2-4 (Cont.) 8-Bit Control Characters and Their 7-Bit Equivalents ------------------------------------------------------------ Name 8-Bit Character 7-Bit Sequence ------------------------------------------------------------ DEC private identification DECID 9/10 ESC 1/11 Z 5/10 Control sequence introducer CSI 9/11 ESC 1/11 [ 5/11 String terminator ST 9/12 ESC 1/11 \ 5/12 Operating system command OSC 9/13 ESC 1/11 ] 5/13 Privacy message PM 9/14 ESC 1/11 ^ 5/14 Application program APC 9/15 ESC 1/11 _ 5/15 ------------------------------------------------------------ Control Functions You use control functions to make the terminal perform special actions in your applications. These functions range from the simple--editing data-- to the complex--reporting on the terminal's operating state. The rest of this manual covers the many uses for control functions. Here are some examples. Move the cursor. Delete a line of text. Select bold or underlined text. Change character sets. Make the terminal emulate a VT52 or VT100 terminal. There are single-character and multiple-character control functions. The single-character functions are the C0 and C1 control characters. You can use C0 characters in a 7-bit or 8-bit environment. C1 characters provide a few more functions than C0 characters, but you can only use C1 characters directly in an 8-bit environment. Multiple-character functions provide many more functions than the C0 and C1 characters. Multiple-character functions can use control characters and graphic characters. There are three basic types of multiple-character functions. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Control Functions 37 Escape sequences Control sequences Device control strings Many sequences are based on ANSI and ISO standards, and are used throughout the industry. Others are private sequences created by manufacturers like Digital for specific families of products. ANSI sequences and private sequences follow ANSI and ISO standards for control functions. In this manual, private control functions created by Digital have the prefix DEC in their mnemonic name. For example, column mode has the mnemonic DECCOLM. All other control functions are standardized. The following sections describe the format for escape sequences, control sequences, and device control strings. Programming Tip When you use control functions, remember that the binary codes define a function--not the graphic characters. This manual uses graphic characters from the DEC Multinational character set to show control functions. If you use another character set, the graphic characters for control functions may change, but the code is always the same. Sequence Format This manual shows escape and control sequences in their 8-bit format. You can also use equivalent 7-bit sequences (Table 2-4). The 8-bit format uses the C0 and C1 control characters and ASCII characters from the DEC Multinational character set. The sequences also show each character 's column/row position in the character set table, below the character. The column/row code eliminates confusion over similar-looking characters such as 0 (3/0) and O (4/15). NOTE Spaces appear between characters in a sequence for clarity. These spaces are not part of the sequence. If a space is part of the sequence, the SP (2/0) character appears. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 38 Character Encoding Control Functions Escape Sequences An escape sequence uses two or more bytes to define a specific control function. Escape sequences do not include variable parameters, but may include intermediate characters. Here is the format for an escape sequence. ESC 1/11 I 2/0 to 2/15 F 3/0 to 7/14 Escape character Intermediate characters (zero or more characters) Final character (one character) ESC introduces escape sequences. After receiving the ESC control character, the terminal interprets the next received characters as part of the sequence. I represents zero or more intermediate characters that can follow the ESC character. Intermediate characters come from the 2/0 through 2/15 range of the code table. F is the final character. This character indicates the end of the sequence. The final character comes from the 3/0 through 7/14 range of the code table. The intermediate and final characters together define a single control function. For example, the following escape sequence changes the current line of text to double-width, single-height characters: ESC 1/11 # 2/3 6 3/6 Control Sequences A control sequence uses two or more bytes to define a specific control function. Control sequences usually include variable parameters. Here is the format for a control sequence. CSI 9/11 P...P 3/0 to 3/15 I...I 2/0 to 2/25 F 4/0 to 7/14 Control sequence introducer Parameter (zero or more characters) Intermediate (zero or more characters) Final (one character) CSI is the control sequence introducer. You can also use the equivalent 7-bit sequence, ESC (1/11) [ (5/11), as a substitute for CSI. After receiving CSI, the terminal interprets the next received characters as part of the sequence. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Control Functions 39 P...P are parameter characters received after CSI. These characters are in the 3/0 to 3/15 range in the code table. Parameter characters modify the action or interpretation of the sequence. You can use up to 16 parameters per sequence. You must use the ; (3/11) character to separate parameters. All parameters are unsigned, positive decimal integers, with the most significant digit sent first. Any parameter greater than 9999 (decimal) is set to 9999 (decimal). If you do not specify a value, a 0 value is assumed. A 0 value or omitted parameter indicates a default value for the sequence. For most sequences, the default value is 1. NOTE All parameters must be positive decimal integers. Do not use a decimal point in a parameter--the terminal will ignore the command. If the first character in a parameter string is the ? (3/15) character, it indicates that DEC private parameters follow. The terminal interprets private parameters according to ANSI X3.64 and ISO 6429. The VT420 processes two types to parameters, numeric and selective. Numeric Parameters A numeric parameter indicates a number value such as a margin location. In this manual, numeric parameters appear as actual values or as Pn, Pn1, Pn2, and so on. The following is an example of a control sequence with numeric parameters: CSI 9/11 5 3/5 ; 3/11 2 0 3/2 3/0 r 7/2 Control sequence introducer First numeric parameter Delimiter Second numeric parameter Final character This sequence sets the top and bottom margins of the current page. The top margin is at line 5, the bottom is at line 20. The ; (3/11) separates the two parameters. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 40 Character Encoding Control Functions Selective Parameters A selective parameter selects an action associated with the specific parameter. In this manual, selective parameters usually appear as Ps, Ps1, Ps2, and so on. The following is an example of a control sequence using selective parameters: CSI 9/11 1 3/1 ; 3/11 4 3/4 m 6/13 Control sequence introducer First selective parameter Delimiter Second selective parameter Final character This control sequence turns on the bold and underline attribute at the cursor position. The parameters are 1 (indicating the bold attribute) and 4 (indicating the underline attribute). The ; (3/11) delimiter separates the two parameters. I...I are zero or more intermediate characters received after CSI. These characters are in the 2/0 to 2/15 range. F is the final character from the 4/0 to 7/14 range. The final character indicates the end of the sequence. The intermediate and final characters together define a control function. If there are no intermediate characters, the final character defines the function. Device Control Strings Device control strings (DCS), like control sequences, use two or more bytes to define specific control functions. However, a DCS also includes a data string. Here is the format for a device control string. DCS 9/0 P...P 3/0 to 3/15 I...I 2/0 to 3/15 F 4/0 to 3/15 Data string ************ ST 9/12 Device control string introducer Zero or more para- meters Zero or more inter- mediates Final String String terminator DCS is the device control string introducer. DCS is the C1 control character at position 9/0. You can also use the equivalent 7-bit sequence, ESC (1/11) P (5/0). After receiving DCS, the terminal processes the next received characters as part of the string function. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Control Functions 41 P..P are parameter characters received after DCS. The use of parameter characters in a device control string is a Digital extension to the ANSI syntax. According to ANSI standards, any elements included after DCS are part of the data string. Parameter characters are in the 3/0 to 3/15 range. They modify the action or interpretation of the device control string. You can use up to 16 parameters per string. Each parameter is separated with a ; (3 /11) character. These characters follow the same rules as in a control sequence. See the ``Control Sequences'' section in this chapter. I...I are zero or more intermediate characters received after CSI. These characters are in the 2/0 to 2/15 range. F is the final character in the 4/0 to 7/14 range. The final character indicates the end of the string. The intermediate and final characters define the string. If there are no intermediates, the final character defines the string. Data string follows the final character and usually includes several definition strings. Each definition string can be several characters in length. Individual strings are separated by the ; (3/11) delimiter. ST is the string terminator. ST (9/12) indicates the end of a string. You can also use the equivalent 7-bit sequence, ESC (1/11) \ (5/12). The following is an example of a device control string: DCS 9/0 0 3/0 ! 2/1 u 7/5 % 2/5 5 3/5 ST 9/12 Device control string introducer Para- meter Inter- mediate Final Data string String terminator This device control string assigns the DEC Supplemental Graphic set as the user-preferred supplemental set. Using Control Characters in Sequences You can use control characters--ESC, CAN, and SUB--to interrupt or recover from errors in escape sequences, control sequences, and device control strings. · You can send ESC (1/11) to cancel a sequence in progress and begin a new sequence. · You can send CAN (1/8) to indicate the present data is in error or to cancel a sequence in progress. The VT420 interprets the characters following CAN as usual. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 42 Character Encoding Control Functions · You can send SUB (1/10) to cancel a sequence in progress. The VT420 interprets the characters following SUB as usual. The VT420 does not lose data when errors occur in escape or control sequences and device control strings. The terminal ignores unrecognized sequences and strings, unless they end a current escape sequence. 7-Bit Code Extension Technique You can represent all C1 control characters as 7-bit escape sequences. You can use the C1 characters indirectly, by representing them as 2-character escape sequences. ANSI calls this technique a 7-bit code extension. The 7-bit code extension provides a way of using C1 characters in applications written for a 7-bit environment. Here are some examples. 8-Bit C1 Character 7-Bit Code Extension Escape Sequence CSI 9/11 ESC 1/11 [ 5/11 SS3 8/15 ESC 1/11 O 4/15 IND 8/4 ESC 1/11 D 4/4 DCS 9/0 ESC 1/11 P 5/0 In general, you can use the 7-bit code extension technique in two ways. · You can represent any C1 control character as a 2-character escape sequence. The second character of the sequence has a code that is 40 16 or 64 10 less than the code of the C1 character. · You can make any escape sequence whose second character is in the range of 4/0 through 5/15 one byte shorter by removing the ESC character and adding 40 16 to the code of the second character. This generates an 8-bit control character. For example, you can change ESC [ to CSI with this method. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Working with 7-Bit and 8-Bit Environments 43 Working with 7-Bit and 8-Bit Environments There are three requirements for using one of the terminal's 8-bit character sets. · Your program and communication environment must be 8-bit compatible. · The terminal cannot be in national replacement character set mode (DECNRCM). · The terminal must operate in VT400 mode or PC TERM mode. When the terminal operates in VT100 mode or VT52 mode, you are limited to working in a 7-bit environment (Chapter 4). The following sections describe conventions that apply in VT400 mode. Conventions for Codes Received by the Terminal The terminal expects to receive character codes in a form compatible with 8-bit coding. Your application can use the C0 and C1 control characters, as well as the 7-bit C1 code extensions, if necessary. The terminal always interprets these codes correctly. When your program sends GL or GR codes, the terminal interprets the character codes according to the graphic character sets in use. When you turn on or reset the terminal, you automatically select the ASCII character set in GL and the current user-preferred character set (DEC Supplemental Graphic or ISO Latin-1 supplemental) in GR. You select the user-preferred set in the General Set-Up screen. This mapping assumes the current terminal mode is VT400 mode. Conventions for Codes Sent by the Terminal The terminal can send data to an application in two ways. · Directly from the keyboard · In response to commands from the host (application or operating system) Most function keys on the keyboard send multiple-character control functions. Many of these functions start with CSI (9/11) or SS3 8/15,) which are C1 characters. If your application cannot handle 8-bit characters, you can make the terminal automatically convert all C1 characters to their equivalent 7-bit code extensions before sending them to the application. To convert C1 characters, you use the DECSCL commands described in Chapter 4. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 44 Character Encoding Define Macro (DECDMAC) By default, the terminal is set to automatically convert all C1 characters sent to the application to 7-bit code extensions. However, to ensure the correct mode of operation, always use the appropriate DECSCL commands. NOTE In VT400 mode, the terminal can send GR graphic characters to an application, even if the application cannot handle 8-bit codes. However, in a 7-bit environment, the terminal sends C1 controls as 7-bit escape sequences and does not send 8-bit graphic characters. New programs should accept both 7-bit and 8-bit forms of the C1 control characters. Using Macros The VT420 lets you define and invoke macros to suit the needs of your application. A macro is a string of ANSI text and commands downloaded into the terminal. By invoking the macro, you can execute a group of control functions with one operation. ------------------------------------------------------------ Define Macro (DECDMAC) This device control string lets you define a macro consisting of a string of ANSI text and control functions. After you define the macro, you can execute it by using the invoke macro control function (DECINVM). The terminal processes the macro as normal input. Available in: VT400 mode only Programming Tip You can find how much memory space you have available for macros by using a device status report sequence. See Chapter 12. Format DCS 9/0 Pid 3/? ; 3/11 Pdt 3/? ; 3/11 Pen 3/? ! 2/1 z 7/10 D...D ... ST 9/12 Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Define Macro (DECDMAC) 45 Parameters Pid is the macro ID number. Pid can be any number between 0 and 63, otherwise the terminal ignores the command. If you give a macro an ID that already exists, DECDMAC deletes the old macro definition before using the new one. Pdt defines how the terminal treats new macro definitions. Pdt Meaning 0 or omitted DECDMAC deletes the old macro with the same ID number before defining this new macro. 1 DECDMAC deletes all current macro definitions before defining this macro. Other The terminal ignores the macro. Pen selects the encoding format for the text of the macro definition. Pen Meaning 0 or omitted Use standard ASCII characters in the macro. 1 Use hex pairs in the macro. Each pair of characters in the macro is the hex value for a single ASCII character. Other The terminal ignores the macro. D...D is the data of the control string. This data is the string of text and control functions performed when an application invokes the macro. The data can consist of ASCII text or hex pairs. When you use ASCII text (Pen = 0 or omitted), the macro consists of the graphic characters that appear in the device control string. Only characters from positions 2/0 through 7/14 and 10/00 through 15/15 in the code table are valid. When you use hex pairs (Pen = 1), the macro consists of pairs of hex numbers, each of which represents an ASCII character. When using hex pairs, you can also use a repeat introducer in the data string. The repeat introducer is the ! (2/1) character. The repeat introducer lets you repeat any hex pair within the definition string Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 46 Character Encoding Define Macro (DECDMAC) any number of times. You embed repeat sequences within the data string of the macro definition. NOTE If ASCII text is specified as the encoding format, you cannot use the repeat sequence. ! is the repeat sequence introducer. The format of the hex string with the repeat introducer is as follows: ! Pn; D...D ; Pn is a numeric parameter that specifies the number of times to repeat the sequence. If Pn is omitted, the macro repeats the sequence once. D...D is the sequence of hex pairs to repeat Pn times. A semicolon ; (3/11) separates the repeat count from the sequence of hex pairs. Another semicolon ends the sequence. If any characters are included before the first semicolon, the terminal ignores the macro. If a string terminator is placed before the final semicolon, the repeat string ends normally. Notes on DECDMAC · The VT420 has 6 Kbytes of memory available for the storage of macros. The terminal ignores any macro definitions that cannot fit into this space. · A reset to initial state (RIS) or secure reset (DECSR) operation clears all macro definitions. A soft terminal reset (DECSTR) has no effect on stored macro definitions. · You can include characters from positions 0/8 through 0/13 to format the device control string, but these characters cannot be part of the macro definition. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Invoke Macro (DECINVM) 47 ------------------------------------------------------------ Invoke Macro (DECINVM) This control function let you execute a stored macro. You store macros with the define macro (DECDMAC) control string. The terminal substitutes the DECINVM sequence with the contents of the macro definition and executes the macro. Available in: VT400 mode only Format CSI 9/11 Pid 3/n * 2/10 z 7/10 Parameters Pid is the macro ID number. If the Pid number is not associated with a particular macro, the terminal ignores the command. Notes on DECINVM · Any functions executed with a macro invocation remain in effect after the macro is executed. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 48 Character Encoding Invoke Macro (DECINVM) Macro Examples Suppose you want to create a macro that clears all pages in page memory, writes the word ``top'' at the top of each page, and leaves the cursor on page 1. First, you would write the string with ASCII characters as follows: DCS 1 ; 0 ; 1 ! z CSI 6 sp P ! 6 ; CSI 1 ; 1 H CSI 2 J TOP CSI 1 V ; ST Now, you must convert the string into hexadecimal code because the string uses the repeat (!) character. Remember that you can only use the repeat character with hexadecimal sequences. Here is the same string in hex: DCS 1 ; 0 ; 1 ! z 9B 36 20 50 ! 6 ; 9B 31 3B 48 9B 32 49 54 4F 50 9B 31 56 ; ST To invoke the macro, use the following sequence: CSI 1 * z Display Controls Mode The VT420 lets you display control characters as graphic characters, when you want to debug your applications. In this mode, the terminal does not perform all control functions. To select this mode, you must set the control representation mode feature in the Display Set-Up screen to Display Controls. You cannot select this mode with an escape sequence. The effect of the Display Controls setting depends on the operating mode you use. See Chapter 15 for information on PC TERM mode. In VT400 mode When you select Display Controls, the terminal temporarily loads a special graphic character set into C0, GL, C1, and GR. Figures 2-11 and 2-12 shows this special set, called the display controls font. The terminal uses this font to display control characters on the screen. Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Display Controls Mode 49 In VT52 or VT100 mode When you select Display Controls, the terminal temporarily loads the left half of the display controls font into C0 and GL. The terminal uses this half of the font to display all C0 and GL characters. (C1 and GR are meaningless in VT52 or VT100 mode.) When Displaying 36 or 48 Lines on the Screen When you display 36 or 48 lines on the screen (DECSNLS, Chapter 11), the terminal uses a smaller font to display control characters. The smaller font represents each control character as a two-character symbol instead of a three-character symbol. Figures 2-11 and 2-12 show what the control characters look like when displaying 24 lines on the screen. Table 2-5 shows the abbreviation for the control characters in the smaller font. Table 2-5 Displaying Controls in 36 or 48 Lines ------------------------------------------------------------ Control Character in 24 Lines Control Character in 36 or 48 Lines Name ------------------------------------------------------------ NUL NL Null SOH SH Start of heading STX SX Start of text ETX EX End of text EOT ET End of transmission ENQ EN Enquire ACK AK Acknowledge BEL BL Bell BS BS Backspace HT HT Horizontal tab LF LF Line feed VT VT Vertical tab FF FF Form feed CR CR Carriage return SO SO Shift out SI SI Shift in DLE DE Data link escape DC1 D1 Device control 1 (XON) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 50 Character Encoding Display Controls Mode Table 2-5 (Cont.) Displaying Controls in 36 or 48 Lines ------------------------------------------------------------ Control Character in 24 Lines Control Character in 36 or 48 Lines Name ------------------------------------------------------------ DC2 D2 Device control 2 DC3 D3 Device control 3 (XOFF) DC4 D4 Device control 4 NAK NK Negative acknowledge SYN SY Synchronous idle ETB EB End of transmission block CAN CA Cancel EM EM End of medium SUB SB Substitute ESC EC Escape FS FS Field separator GS GS Group separator RS RS Record separator US US Unit separator IND IN Index NEL NE Next line SSA SA Start selected area ESA EA End selected area HTS HS Horizontal tab set HTJ HJ Horizontal tab with justify VTS VS Vertical tab set PLD PD Partial line down PLU PU Partial line up RI RI Reverse index SS2 S2 Single shift 2 SS3 S3 Single shift 3 DCS DC Device control string PU1 P1 Private use 1 PU2 P2 Private use 2 Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Display Controls Mode 51 Table 2-5 (Cont.) Displaying Controls in 36 or 48 Lines ------------------------------------------------------------ Control Character in 24 Lines Control Character in 36 or 48 Lines Name ------------------------------------------------------------ STS SS Set transmit state CCH CC Cancel character MW MW Message waiting SPA SP Start protected area EPA EP End protected area CSI CS Control sequence introducer ST ST String terminator OSC OS Operating system command PM PM Private message APC AP Application program command NS NS No-break space ------------------------------------------------------------ Exceptions Some control functions still work in this mode. · LF, FF, and VT cause a carriage return and line feed (CR LF) that move the cursor to a new line. The terminal displays the LF, FF, or VT character before performing the new line function. · XOFF (DC3) and XON (DC1) maintain flow control, if enabled in set- up. The terminal displays the DC1 or DC3 character after performing the control function. · The terminal does not display SSU session management commands (Chapter 14). Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 52 Character Encoding Display Controls Mode Figure 2-11 Display Controls Font (Left Half) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Character Encoding Display Controls Mode 53 Figure 2-12 Display Controls Font (Right Half) Chapter 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Part 2 Control Functions Sent to the Host ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 3 ANSI, Short ANSI, and PC Keyboard Codes ------------------------------------------------------------ This chapter describes the codes the terminal can send to an application program in VT mode. See Chapter 15 for a description of the codes the terminal sends in PC TERM mode. This chapter assumes that you are familiar with the character-encoding concepts described in Chapter 2. In VT400 or VT100 mode, the keyboard keys send codes that are compatible with ANSI standards. In VT52 mode, some keys send codes that differ from those sent in the ANSI-compatible modes. This chapter lists the ANSI codes and the VT52 codes that differ from the ANSI-compatible codes. The VT420 worldwide model can use several different national keyboard dialects. Each keyboard dialect pertains to a different country or region of western Europe. You can select the appropriate dialect by setting the keyboard language feature in the Set-Up Directory. This chapter describes significant differences among the national keyboards. Chapter 3 57 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 58 ANSI, Short ANSI, and PC Keyboard Codes Keyboard Layouts Keyboard Layouts The terminal uses one of three Digital keyboards: · The ANSI keyboard (Figure 3-1) has four groups of keys: a main keypad, an editing keypad, a numeric keypad, and the top-row function keys. · The short ANSI keyboard (Figure 3-2) has an ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key and three groups of keys: a main keypad, arrow keys, top-row function keys. · The PC keyboard (Figure 3-3) for the VT420 with PC TERM mode has four groups of keys: a main keypad, an editing keypad, a numeric keypad, and the top-row function keys. In VT mode, you can switch the PC keyboard to the ANSI keyboard layout if desired. This section shows the North American/United Kingdom version of each keyboard. Figure 3-1 ANSI Keyboard Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Keyboard Layouts 59 Figure 3-2 Short ANSI Keyboard ! Main keypad " Arrow keys # Top-row function keys $ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 60 ANSI, Short ANSI, and PC Keyboard Codes Keyboard Layouts Figure 3-3 PC Keyboard (North American/United Kingdom Keyboard) ! Main keypad " Editing keypad # Numeric keypad $ Top-row function keys % ------------------------------------------------------------ ------------------------------------------------------------ Esc ------------------------------------------------------------ ------------------------------------------------------------ key & Visual indicators Main Keypad The main keypad has standard keys and function keys. You use the standard keys to send letters, numbers, and other symbols. You use the function keys to send special function codes. Standard Keys The standard keys send alphanumeric characters. Some standard keys vary on the different ANSI, short ANSI, and PC keyboard models. On the North American/United Kingdom keyboard, all standard keys are ASCII characters and send only ASCII codes. The North American/United Kingdom keyboard does not have any standard keys that send DEC Supplemental Graphic or ISO Latin-1 supplemental characters alone. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Main Keypad 61 The North American/United Kingdom keyboard is a special case. Most other keyboards have some standard keys that send DEC Supplemental Graphic or ISO Latin-1 supplemental characters, as well as ASCII characters. For example, many of the European keyboards have standard keys that send characters with accent marks or diacritical marks. The PC keyboard can send PC characters. Even if a character is not available on a standard key, you can create any DEC Supplemental Graphic, ISO Latin-1 supplemental character, or PC character by typing a sequence of keys. On the ANSI or short ANSI keyboards, each sequence begins with the ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ key (or ------------------------------------------------------------ ------------------------------------------------------------ Group Shift ------------------------------------------------------------ ------------------------------------------------------------ key on the German keyboard). On the PC keyboards, each sequence begins with the ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ key. Installing and Using the VT420 Video Terminal explains how to type additional characters. In a character set, each graphic character has a unique code. This code is always the same, no matter which keyboard you use or how many keys you press to create that character. The code is based on the character 's position in the 8-bit code table (Chapter 2). You can use GL characters in a 7-bit or 8-bit environment. You can use GR characters only in an 8-bit environment. VT400 mode is intended for use in 7-bit and 8-bit environments, as well as data exchange over 7-bit or 8-bit host lines. PC TERM mode always operates in an 8-bit environment. VT52 and VT100 modes are intended for use in 7-bit environments only, as well as data exchange over a 7-bit host line. Data Processing Characters (Worldwide Model Only) On VT420 worldwide models, some standard keys can send data processing characters. The data processing characters are on the right half of the keycap. Data processing characters allow European model keyboards to use characters that appear as standard typewriter characters on the North American/United Kingdom keyboard. The data processing characters are commonly used in data processing applications. For example, Figure 3-4 shows the backslash character on the French /Belgian ANSI keyboard. You can select Typewriter Keys or Data Processing Keys in the Keyboard Set-Up screen. When you select Data Processing Keys, the data processing keys send the character on the right half of their keycap. When you select Typewriter Keys, they send the character on the left half of their keycap. You can select the shifted (upper) character codes for these keys by holding the ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key down. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 62 ANSI, Short ANSI, and PC Keyboard Codes Main Keypad Figure 3-4 Standard Key with a Data Processing Character (French /Belgian ANSI Keyboard) Special-Function Keys (ANSI Keyboard) This section describes the function keys on the main keypad of the ANSI keyboard. The column/row numbers that appear after a character indicate the position of the character in the code table (Chapter 2). For example, the DEL character is at column 7 / row 15. < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ The < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ key sends a delete character (DEL, 7/15) or a backspace character (BS, 0/8), depending on the setting of the < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ key feature in the Keyboard Set-Up screen. ------------------------------------------------------------ ------------------------------------------------------------ Tab ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Tab ------------------------------------------------------------ ------------------------------------------------------------ sends a horizontal tab character (HT, 0/9). ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ sends either a carriage return (CR, 0/13), or a carriage return (CR, 0/13) and line feed (LF, 0/10), depending on the state of line feed/new line mode (LNM). ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ The ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key alone does not send a code. You use ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ with another key to send a control code. The lock key alone does not send a code. You use the lock key to set or clear the Caps Lock or Shift Lock state. You select Caps Lock or Shift Lock in the Keyboard Set-Up screen. ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ (left and right) The ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ keys alone do not send a code. You use ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ with another standard key to send an uppercase character or the top character shown on the key. Space bar The space bar sends a space character (SP, 2/0). Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Main Keypad 63 ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ does not send a code. Pressing ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ starts a compose sequence. You can use compose sequences to create characters that do not appear on any single key (such as characters from the DEC Supplemental Graphic set). You can disable the ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ key in set-up. See Installing and Using the VT420 Video Terminal with PC Terminal Mode. ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ (left and right) ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ is a modifier key, pressed in combination with other keys to send a special function code to host applications. See the ``Select Modifier Key Reporting (DECSMKR)'' and ``Extended Keyboard Report (DECEKBD)'' sections in Chapter 11. Special-Function Keys (Short ANSI Keyboard) The short ANSI keyboard has the same special-function keys as the ANSI keyboard, with one exception. The short ANSI keyboard has an ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key rather than a lock key. ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ front ------------------------------------------------------------ ------------------------------------------------------------ The ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key alone does not send a code. You use two- stroke ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ sequences to perform the same functions as the following keys on the ANSI keyboard: ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ , editing keypad, and numeric keypad. Functions are printed on the front of short ANSI keys. ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ Pressing the ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ and right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ keys does not send a code. This sequence sets or clears caps lock mode or shift lock mode. You select the mode in the Keyboard Set-Up screen. The default setting is Caps Lock mode. See Installing and Using the VT420 Video Terminal with PC Terminal Mode for more operating information. Special-Function Keys (PC Keyboard) This section describes the function keys on the main keypad of the PC keyboard. The column/row numbers that appear after a character indicate the position of the character in the code table (Chapter 2). For example, the DEL character is at column 7 / row 15. The ------------------------------------------------------------ ------------------------------------------------------------ Tab ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ , and space bar keys work the same as on the ANSI keyboard. ------------------------------------------------------------ ------------------------------------------------------------ Esc ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Esc ------------------------------------------------------------ ------------------------------------------------------------ sends an escape character (ESC, 1/11). Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 64 ANSI, Short ANSI, and PC Keyboard Codes Main Keypad ------------------------------------------------------------ ------------------------------------------------------------ Caps Lock ------------------------------------------------------------ ------------------------------------------------------------ The ------------------------------------------------------------ ------------------------------------------------------------ Caps Lock ------------------------------------------------------------ ------------------------------------------------------------ key alone does not send a code. You use ------------------------------------------------------------ ------------------------------------------------------------ Caps Lock ------------------------------------------------------------ ------------------------------------------------------------ to set or clear caps lock or shift lock mode. You select the mode in the Keyboard Set-Up screen. ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ The ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ key alone does not send a code. You use ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ with another key to generate characters or alternate functions that do not appear as standard keys on the PC keyboard, such as characters from the PC International character set. NOTE The North American version of the keyboard has a left and right ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ key. They perform the same function. ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ (right) The ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ key does not send a code alone. You use ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ with Janus-faced or front-faced keys to generate the third character on a keycap. The North American version of the keyboard does not have an ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ key. ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ sends either a carriage return (CR, 0/13), or a carriage return (CR, 0/13) and line feed (LF, 0/10), depending on the state of line feed/new line mode (LNM). ------------------------------------------------------------ ------------------------------------------------------------ Backspace ------------------------------------------------------------ ------------------------------------------------------------ The ------------------------------------------------------------ ------------------------------------------------------------ Backspace ------------------------------------------------------------ ------------------------------------------------------------ key sends a delete character (DEL, 7/15) or a backspace character (BS, 0/8), depending on the setting of the ------------------------------------------------------------ ------------------------------------------------------------ Backspace ------------------------------------------------------------ ------------------------------------------------------------ key feature in the Keyboard Set-Up screen. Editing Keypad The ANSI and PC keyboards have an editing keypad with editing keys and arrow keys. The short ANSI keyboard has arrow keys; you use ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key sequences to perform editing functions. · Table 3-1 lists the codes sent by the editing keys on the ANSI and short ANSI keyboards. Chapter 4 describes how to select VT400 or VT100 mode. · Table 3-2 lists the codes sent by the editing keys on the PC keyboard, when it is in ANSI key layout or PC key layout. · Table 3-3 lists the codes sent by the arrow keys on all keyboards. Normally, you use the arrow keys to move the cursor on the screen. See ``Cursor Keys Mode (DECCKM)'' in Chapter 11. Appendix A describes how to select VT52 mode. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Editing Keypad 65 Table 3-1 Codes Sent by Editing Keys (ANSI/Short ANSI Keyboards) ------------------------------------------------------------ Key ------------------------------------------------------------ Code Sent ------------------------------------------------------------ ANSI S. ANSI VT400 mode VT100, VT52 Modes ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Find ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 0 ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 1 3/1 ~ 7/14 The editing keys do not send codes in these two modes. ------------------------------------------------------------ ------------------------------------------------------------ Insert Here ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ - ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 2 3/2 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Remove ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ = ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 3 3/3 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Select ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ P ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 4 3/4 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Prev ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ { ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 5 3/5 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Next ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ } ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 6 3/6 ~ 7/14 ------------------------------------------------------------ Table 3-2 Codes Sent by Editing Keys (PC Keyboard) ------------------------------------------------------------ Codes Sent in VT400 Mode ------------------------------------------------------------ Key ANSI Key Layout PC Key Layout ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Insert ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 2 3/2 ~ 7/14 CSI 9/11 2 3/2 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Home ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 1 3/1 ~ 7/14 CSI 9/11 1 4/8 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Page Up ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 5 3/5 ~ 7/14 CSI 9/11 5 3/5 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ Delete ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 3 3/3 ~ 7/14 CSI 9/11 DEL 7/15 ~ 7/14 ------------------------------------------------------------ ------------------------------------------------------------ End ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 4 3/4 ~ 7/14 CSI 9/11 4 3/4 ~ 7/14 Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 66 ANSI, Short ANSI, and PC Keyboard Codes Editing Keypad Table 3-2 (Cont.) Codes Sent by Editing Keys (PC Keyboard) ------------------------------------------------------------ Codes Sent in VT400 Mode ------------------------------------------------------------ Key ANSI Key Layout PC Key Layout ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Page Down ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 6 3/6 ~ 7/14 CSI 9/11 6 3/6 ~ 7/14 ------------------------------------------------------------ Table 3-3 Codes Sent by Arrow Keys ------------------------------------------------------------ Cursor Key Mode Setting (DECCKM) ANSI Mode  ------------------------------------------------------------ VT52 Mode  ------------------------------------------------------------ Key Cursor Application Cursor or Application ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ " ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 A 4/1 SS3 8/15 A 4/1 ESC 1/11 A 4/1 ------------------------------------------------------------ ------------------------------------------------------------ # ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 B 4/2 SS3 8/15 B 4/2 ESC 1/11 B 4/2 ------------------------------------------------------------ ------------------------------------------------------------ ! ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 C 4/3 SS3 8/15 C 4/3 ESC 1/11 C 4/3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ CSI 9/11 D 4/4 SS3 8/15 D 4/4 ESC 1/11 D 4/4 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. VT52 mode is not compatible with ANSI mode. ------------------------------------------------------------ Numeric Keypad The characters sent by the numeric keypad depend on the setting of numeric keypad mode and VT52 mode. The application usually selects the application keypad codes. However, you can select the application keypad codes in the Keyboard Set-Up screen. For more information, see ``Numeric Keypad Mode (DECNKM)'' in Chapter 11. Chapter 4 describes how to select VT400 or VT100 mode. Appendix A describes how to select VT52 mode. · Table 3-4 lists the character codes sent by the numeric keypad on the ANSI and short ANSI keyboards, and the PC keyboard in ANSI key layout. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad 67 · Table 3-5 lists the character codes sent by the numeric keypad on the PC keyboard in PC key layout. Table 3-4 Codes Sent by Numeric Keypad Keys (ANSI, Short ANSI, and PC Keyboards) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ VT52 Mode  ------------------------------------------------------------ Key Numeric Application Numeric Application ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ SS3 P 8/15 5/0 SS3 P 8/15 5/0 ESC P 1/11 5/0 ESC P 1/11 5/0 ------------------------------------------------------------ ------------------------------------------------------------ PF2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ / ------------------------------------------------------------ ------------------------------------------------------------ SS3 Q 8/15 5/1 SS3 Q 8/15 5/1 ESC Q 1/11 5/1 ESC Q 1/11 5/1 ------------------------------------------------------------ ------------------------------------------------------------ PF3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ * ------------------------------------------------------------ ------------------------------------------------------------ SS3 R 8/15 5/2 SS3 R 8/15 5/2 ESC R 1/11 5/2 ESC R 1/11 5/2 ------------------------------------------------------------ ------------------------------------------------------------ PF4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ - ------------------------------------------------------------ ------------------------------------------------------------ SS3 S 8/15 5/3 SS3 S 8/15 5/3 ESC S 1/11 5/3 ESC S 1/11 5/3 ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ CR 0/13 or SS3 M 8/15 4/13 CR 0/13 or ESC ? M 1/11 3/15 4/13 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. VT52 mode is not compatible with ANSI standards. Keys in column 1 are shown in the following order. For the short ANSI keyboard, press the ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key before the key listed. ANSI: ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI: ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ PC: ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 68 ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad Table 3-4 (Cont.) Codes Sent by Numeric Keypad Keys (ANSI, Short ANSI, and PC Keyboards) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ VT52 Mode  ------------------------------------------------------------ Key Numeric Application Numeric Application ------------------------------------------------------------ CR LF+ 0/13 0/10 CR LF+ 0/13 0/10 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ L ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ comma 2/12 SS3 l 8/15 6/12 - 2/12 ESC ? l 1/11 3/15 6/13+ ------------------------------------------------------------ ------------------------------------------------------------ + ------------------------------------------------------------ ------------------------------------------------------------ plus 2/11 SS3 l 8/15 6/12 ------------------------------------------------------------ ------------------------------------------------------------ -- ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ O ------------------------------------------------------------ ------------------------------------------------------------ minus 2/13 SS3 m 8/15 6/13 - 2/13 ESC ? m 1/11 3/15 6/13+ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ - ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ . ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ . ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ . ------------------------------------------------------------ ------------------------------------------------------------ period 2/14 SS3 n 8/15 6/14 . 2/14 ESC ? n 1/11 3/15 6/14 ------------------------------------------------------------ ------------------------------------------------------------ 0 ------------------------------------------------------------ ------------------------------------------------------------ space bar ------------------------------------------------------------ ------------------------------------------------------------ 0 ------------------------------------------------------------ ------------------------------------------------------------ 0 3/0 SS3 p 8/15 7/0 0 3/0 ESC ? p 1/11 3/15 7/0 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. VT52 mode is not compatible with ANSI standards. +You cannot use this sequence on a VT52 terminal. +Keypad numeric mode. ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ sends the same codes as ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ . You can use line feed/new line mode (LNM) to change the code sent by ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ . When LNM is reset, pressing ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ sends one control character (CR). When LNM is set, pressing ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ sends two control characters (CR, LF). Keys in column 1 are shown in the following order. For the short ANSI keyboard, press the ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key before the key listed. ANSI: ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI: ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ PC: ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad 69 Table 3-4 (Cont.) Codes Sent by Numeric Keypad Keys (ANSI, Short ANSI, and PC Keyboards) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ VT52 Mode  ------------------------------------------------------------ Key Numeric Application Numeric Application ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ N ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 1 ------------------------------------------------------------ ------------------------------------------------------------ 1 3/1 SS3 q 8/15 7/1 1 3/1 ESC ? q 1/11 3/15 7/1 ------------------------------------------------------------ ------------------------------------------------------------ 2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ M ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 2 ------------------------------------------------------------ ------------------------------------------------------------ 2 3/2 SS3 r 8/15 7/2 2 3/2 ESC ? r 1/11 3/15 7/2 ------------------------------------------------------------ ------------------------------------------------------------ 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 3 ------------------------------------------------------------ ------------------------------------------------------------ 3 3/3 SS3 s 8/15 7/3 3 3/3 ESC ? s 1/11 3/15 7/3 ------------------------------------------------------------ ------------------------------------------------------------ 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ H ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 4 ------------------------------------------------------------ ------------------------------------------------------------ 4 3/4 SS3 t 8/15 7/4 4 3/4 ESC ? t 1/11 3/15 7/4 ------------------------------------------------------------ ------------------------------------------------------------ 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ J ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 5 ------------------------------------------------------------ ------------------------------------------------------------ 5 3/5 SS3 u 8/15 7/5 5 3/5 ESC ? u 1/11 3/15 7/5 ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ K ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ 6 3/6 SS3 v 8/15 7/6 6 3/6 ESC ? v 1/11 3/15 7/6 ------------------------------------------------------------ ------------------------------------------------------------ 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Y ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 7 ------------------------------------------------------------ ------------------------------------------------------------ 7 3/7 SS3 w 8/15 7/7 7 3/7 ESC ? w 1/11 3/15 7/7 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. VT52 mode is not compatible with ANSI standards. Keys in column 1 are shown in the following order. For the short ANSI keyboard, press the ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key before the key listed. ANSI: ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI: ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ PC: ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 70 ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad Table 3-4 (Cont.) Codes Sent by Numeric Keypad Keys (ANSI, Short ANSI, and PC Keyboards) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ VT52 Mode  ------------------------------------------------------------ Key Numeric Application Numeric Application ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ U ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 8 ------------------------------------------------------------ ------------------------------------------------------------ 8 3/8 SS3 x 8/15 7/8 8 3/8 ESC ? x 1/11 3/15 7/8 ------------------------------------------------------------ ------------------------------------------------------------ 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ I ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 9 ------------------------------------------------------------ ------------------------------------------------------------ 9 3/9 SS3 y 8/15 7/9 9 3/9 ESC ? x 1/11 3/15 7/9 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. VT52 mode is not compatible with ANSI standards. Keys in column 1 are shown in the following order. For the short ANSI keyboard, press the ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key before the key listed. ANSI: ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI: ------------------------------------------------------------ ------------------------------------------------------------ 6 ------------------------------------------------------------ ------------------------------------------------------------ PC: ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad 71 Table 3-5 Codes Sent by Numeric Keypad Keys (PC Keyboard, PC Key Layout) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ ANSI Mode  ------------------------------------------------------------ Key Numeric Application ------------------------------------------------------------ Num Lock On ------------------------------------------------------------ Num Lock Off ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ (PF1) SS3 P 8/15 5/0 ------------------------------------------------------------ ------------------------------------------------------------ / ------------------------------------------------------------ ------------------------------------------------------------ (PF2) slash 2/15 slash 2/15 SS3 Q 8/15 5/1 ------------------------------------------------------------ ------------------------------------------------------------ * ------------------------------------------------------------ ------------------------------------------------------------ (PF3) asterisk 2/10 asterisk 2/10 SS3 R 8/15 5/2 ------------------------------------------------------------ ------------------------------------------------------------ - ------------------------------------------------------------ ------------------------------------------------------------ (PF4) minus 2/13 minus 2/13 SS3 S 8/15 5/3 ------------------------------------------------------------ ------------------------------------------------------------ + ------------------------------------------------------------ ------------------------------------------------------------ plus 2/11 plus 2/11 SS3 l 8/15 6/12 ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ CR 0/13 or CR 0/13 or SS3 M 8/15 4/13 CR LF+ CR LF+ ------------------------------------------------------------ ------------------------------------------------------------ . Del ------------------------------------------------------------ ------------------------------------------------------------ period 2/14 DEL 7/15 SS3 n 8/15 6/14 ------------------------------------------------------------ ------------------------------------------------------------ 0 Ins ------------------------------------------------------------ ------------------------------------------------------------ 0 3/0 CSI 2 9/11 3/2 SS3 p 8/15 7/0 ------------------------------------------------------------ ------------------------------------------------------------ 1 End ------------------------------------------------------------ ------------------------------------------------------------ 1 3/1 CSI 4 9/11 3/4 SS3 q 8/15 7/1 ------------------------------------------------------------ ------------------------------------------------------------ 2 # ------------------------------------------------------------ ------------------------------------------------------------ 2 3/2 CSI B 9/11 4/2 SS3 r 8/15 7/2 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. +Keypad numeric mode. ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ sends the same codes as ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ . You can use line feed/new line mode (LNM) to change the code sent by ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ . When LNM is reset, pressing ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ sends one control character (CR). When LNM is set, pressing ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ sends two control characters (CR, LF). Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 72 ANSI, Short ANSI, and PC Keyboard Codes Numeric Keypad Table 3-5 (Cont.) Codes Sent by Numeric Keypad Keys (PC Keyboard, PC Key Layout) ------------------------------------------------------------ Numeric Keypad Mode Setting (DECNKM) ANSI Mode  ------------------------------------------------------------ ANSI Mode  ------------------------------------------------------------ Key Numeric Application ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 3 PgDn ------------------------------------------------------------ ------------------------------------------------------------ 3 3/3 CSI 6 9/11 3/6 SS3 s 8/15 7/3 ------------------------------------------------------------ ------------------------------------------------------------ 4 ------------------------------------------------------------ ------------------------------------------------------------ 4 3/4 CSI D 9/11 4/4 SS3 t 8/15 7/4 ------------------------------------------------------------ ------------------------------------------------------------ 5 ------------------------------------------------------------ ------------------------------------------------------------ 5 3/5 ------------------------------------------------------------ ------------------------------------------------------------ 6 ! ------------------------------------------------------------ ------------------------------------------------------------ 6 3/6 CSI C 9/11 4/3 SS3 v 8/15 7/6 ------------------------------------------------------------ ------------------------------------------------------------ 7 Home ------------------------------------------------------------ ------------------------------------------------------------ 7 3/7 CSI H 9/11 4/8 SS3 w 8/15 7/7 ------------------------------------------------------------ ------------------------------------------------------------ 8 " ------------------------------------------------------------ ------------------------------------------------------------ 8 3/8 CSI A 9/11 4/1 SS3 x 8/15 7/8 ------------------------------------------------------------ ------------------------------------------------------------ 9 PgUp ------------------------------------------------------------ ------------------------------------------------------------ 9 3/9 CSI 5 9/11 3/5 SS3 y 8/15 7/9 ------------------------------------------------------------  ANSI mode applies to VT400 and VT100 modes. ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Top-Row Function Keys 73 Top-Row Function Keys The keyboards have the following top-row function keys and key sequences: ANSI 40 keys: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI 40 keys: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ PC 48 keys: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ The first five keys on the ANSI and short ANSI keyboard perform predefined local functions: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold), ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print), ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up), ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session), and ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break). In VT mode, the PC keyboard also has predefined keys to perform the same functions: ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ (for hold), ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ SetUp ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ (for session), and ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Break ------------------------------------------------------------ ------------------------------------------------------------ . In PC TERM mode, three of these functions are predefined: ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ SetUp ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ (for session), and ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ . Table 3-6 lists the codes sent by the top-row keys. See Installing and Using the VT420 Video Terminal with PC Terminal Mode for more information. Table 3-6 Codes Sent by the Top-Row Function Keys ------------------------------------------------------------ Keyboard Key ------------------------------------------------------------ Mode with Code Sent ------------------------------------------------------------ ANSI Short ANSI PC VT400 VT100 VT52 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold)  ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 1 3/1 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print)  ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (SetUp)  ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 3 3/3 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session)  ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 4 3/4 ~ 7/14 -- ------------------------------------------------------------  By default, ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ on the ANSI and Short ANSI keyboards perform predefined local functions; however, you can disable the keys in the Keyboard Set-Up screen. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 74 ANSI, Short ANSI, and PC Keyboard Codes Top-Row Function Keys Table 3-6 (Cont.) Codes Sent by the Top-Row Function Keys ------------------------------------------------------------ Keyboard Key ------------------------------------------------------------ Mode with Code Sent ------------------------------------------------------------ ANSI Short ANSI PC VT400 VT100 VT52 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break)  ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 5 3/5 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 7 3/7 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 8 3/8 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 9 3/9 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 0 3/0 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 1 3/1 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ (ESC) ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 3 3/3 ~ 7/14 ESC 1/11 ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ (BS) ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 4 3/4 ~ 7/14 BS 0/8 ------------------------------------------------------------ ------------------------------------------------------------ F13 ------------------------------------------------------------ ------------------------------------------------------------ (LF) ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 5 3/5 ~ 7/14 LF 0/10 ------------------------------------------------------------ ------------------------------------------------------------ F14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 6 3/6 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Help ------------------------------------------------------------ ------------------------------------------------------------ (F15) ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 8 3/8 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Do ------------------------------------------------------------ ------------------------------------------------------------ (F16) ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 9 3/9 ~ 7/14 -- ------------------------------------------------------------  By default, ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ on the ANSI and Short ANSI keyboards perform predefined local functions; however, you can disable the keys in the Keyboard Set-Up screen. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Top-Row Function Keys 75 Table 3-6 (Cont.) Codes Sent by the Top-Row Function Keys ------------------------------------------------------------ Keyboard Key ------------------------------------------------------------ Mode with Code Sent ------------------------------------------------------------ ANSI Short ANSI PC VT400 VT100 VT52 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F17 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 1 3/1 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F18 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F19 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 3 3/3 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 4 3/4 ~ 7/14 -- -- -- ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 5 3/5 ~ 7/14 -- -- -- ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 6 3/6 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold)  ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 1 3/1 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print)  ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 2 3/2 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (SetUp)  ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 3 3/3 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session)  ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 4 3/4 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break)  ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 5 3/5 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------  By default, ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ on the ANSI and Short ANSI keyboards perform predefined local functions; however, you can disable the keys in the Keyboard Set-Up screen. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 76 ANSI, Short ANSI, and PC Keyboard Codes Top-Row Function Keys Table 3-6 (Cont.) Codes Sent by the Top-Row Function Keys ------------------------------------------------------------ Keyboard Key ------------------------------------------------------------ Mode with Code Sent ------------------------------------------------------------ ANSI Short ANSI PC VT400 VT100 VT52 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 7 3/7 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 8 3/8 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ CSI 1 9/11 3/1 9 3/9 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 0 3/0 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 1 3/1 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ (ESC) ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 3 3/3 ; 3/11 2 3/2 ~ 7/14 ESC 1/11 ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ (BS) ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 4 3/4 ; 3/11 2 3/2 ~ 7/14 BS 0/8 ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F13 ------------------------------------------------------------ ------------------------------------------------------------ (LF) ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 5 3/5 ; 3/11 2 3/2 ~ 7/14 LF 0/10 ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 6 3/6 ; 3/11 2 3/2 ~ 7/14 -- Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes Top-Row Function Keys 77 Table 3-6 (Cont.) Codes Sent by the Top-Row Function Keys ------------------------------------------------------------ Keyboard Key ------------------------------------------------------------ Mode with Code Sent ------------------------------------------------------------ ANSI Short ANSI PC VT400 VT100 VT52 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Help ------------------------------------------------------------ ------------------------------------------------------------ (F15) ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 8 3/8 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Do ------------------------------------------------------------ ------------------------------------------------------------ (F16) ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ CSI 2 9/11 3/2 9 3/9 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F17 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 1 3/1 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F18 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 2 3/2 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F19 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F9 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 3 3/3 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 4 3/4 ; 3/11 2 3/2 ~ 7/14 -- -- -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 5 3/5 ; 3/11 2 3/2 ~ 7/14 -- -- -- ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ CSI 3 9/11 3/3 6 3/6 ; 3/11 2 3/2 ~ 7/14 -- ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 78 ANSI, Short ANSI, and PC Keyboard Codes 7-Bit Control Characters 7-Bit Control Characters Table 3-7 lists the key or keys you use to send each 7-bit control character. This table applies to all keyboards. The 7-bit control characters are the C0 characters. You cannot send 8-bit C1 control characters from the keyboard, except when using hexadecimal compose sequences. Table 3-7 Keys Used to Send 7-Bit Control Characters ------------------------------------------------------------ Control Character Mnemonic Code Table Position Key Pressed With ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ (All Modes) Dedicated Function Key ------------------------------------------------------------ NUL 0/00 2 or space bar -- SOH 0/01 A -- STX 0/02 B -- ETX 0/03 C -- EOT 0/04 D -- ENQ 0/05 E -- ACK 0/06 F -- BEL 0/07 G -- BS 0/08 H ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ (BS)  HT 0/09 I ------------------------------------------------------------ ------------------------------------------------------------ Tab ------------------------------------------------------------ ------------------------------------------------------------ LF 0/10 J ------------------------------------------------------------ ------------------------------------------------------------ F13 ------------------------------------------------------------ ------------------------------------------------------------ (LF)  VT 0/11 K -- FF 0/12 L -- CR 0/13 M ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ SO 0/14 N -- SI 0/15 O -- DLE 1/00 P -- DC1 1/01 Q+ -- DC2 1/02 R -- DC3 1/03 S+ -- DC4 1/04 T -- NAK 1/05 U -- SYN 1/06 V -- ------------------------------------------------------------  7-bit control characters sent in VT100 or VT52 modes only. +7-bit control codes sent only when XON/XOFF support is off. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ANSI, Short ANSI, and PC Keyboard Codes 7-Bit Control Characters 79 Table 3-7 (Cont.) Keys Used to Send 7-Bit Control Characters ------------------------------------------------------------ Control Character Mnemonic Code Table Position Key Pressed With ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ (All Modes) Dedicated Function Key ------------------------------------------------------------ ETB 1/07 W -- CAN 1/08 X -- EM 1/09 Y -- SUB 1/10 Z -- ESC 1/11 3 or [ ------------------------------------------------------------ ------------------------------------------------------------ F11 ------------------------------------------------------------ ------------------------------------------------------------ (ESC)  FS 1/12 4 or / -- GS 1/13 5 or ] -- RS 1/14 6 or ~ -- US 1/15 7 or ? -- DEL 7/15 8 < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------  7-bit control characters sent in VT100 or VT52 modes only. ------------------------------------------------------------ Special Cases This section describes special functions and modes that affect the keyboard. Turning Autorepeat On and Off The autorepeat feature makes most keys send their character repeatedly when you hold the key down. You can turn the autorepeat feature on and off by using the Keyboard Set-Up screen or the autorepeat mode (DECARM) control function (Chapter 11). The following keys on the ANSI and short ANSI keyboards do not repeat: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold) ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print) ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up) ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session) ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ Lock key ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ The following keys on the PC keyboard do not repeat: ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Caps Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Pause ------------------------------------------------------------ ------------------------------------------------------------ Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 80 ANSI, Short ANSI, and PC Keyboard Codes Special Cases ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ Shifted keys and keys pressed with ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ can repeat. Keys that can auto repeat usually start repeating after a delay of 0.5 seconds. The autorepeat speed depends on the baud rate of the host system and the type of key. At speeds of 2400 baud or above, all keys repeat 30 times/second. In general, the transmit rate limit feature in the Communications Set-Up screen does not affect repeat rates. The terminal can send codes at the speed of 150 characters/second at most baud rates. In local mode, keys repeat at 30 keystrokes/second. Unlocking the Keyboard Two conditions can cause the keyboard to lock: · An application sends a control function to set the keyboard action mode (KAM), as described in Chapter 11. · The keyboard input buffer is full. When the keyboard is locked, all keys except ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold), ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print), ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set- Up), ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session), and ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) are disabled. Also, the Wait indicator appears on the keyboard indicator line at the bottom of the screen. Any of the following events can unlock the keyboard: · The output buffer becomes less than full (assuming KAM is not set). · The terminal receives KAM when the output buffer is not full (Chapter 11). · You select the Clear Comm, Reset Session, or Recall fields from the Set-Up Directory screen. (Entering set-up unlocks the keyboard. If you do not select one of these functions in set-up, the keyboard locks again when you leave set-up.) · The terminal performs the power-up self-test (DECTST) or a hard reset (RIS). See Chapter 13. Chapter 3 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Part 3 Control Functions Received from the Host ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 4 Emulating VT Series Terminals ------------------------------------------------------------ The VT420 terminal can operate like Digital's VT300, VT200, and VT100 series text terminals. This feature lets you use the VT420 with applications designed for these terminals. You can select from three possible levels of operation. (See Chapter 15 for PC TERM mode.) Level 1 for VT100 operation Level 4 for VT200, VT300, and VT400 operation (default) VT52 mode When you operate the terminal at level 1, you cannot use some VT420 control functions. Table 4-1 lists the functions you cannot use. Level 4 includes all the characteristics of levels 2 and 3. This means that applications designed for level 2 terminals (such as the VT200 series) and level 3 terminals (VT300 series) run in level 4. The following paragraphs describe other limits that apply to each operating level. The chapter also describes how to select an operating level and how to send 7-bit or 8-bit C1 controls to the host. The VT420 also has an operating mode that lets you use the terminal with applications designed for Digital's VT52 terminal. Appendix A describes how to use VT52 mode. Level 1 (VT100 Mode) The following limits apply to operating level 1: · The keyboard only sends 7-bit ASCII characters. · The terminal interprets keystrokes that send DEC Supplemental Graphic or ISO Latin-1 supplemental characters as errors. · The following keys do not operate: -- special-function keys, except F11 (ESC), F12 (BS), and F13 (LF) Chapter 4 83 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 84 Emulating VT Series Terminals Level 1 (VT100 Mode) -- six editing keys -- user-defined keys · Only the ASCII, national replacement (NRC), and DEC Special Graphic character sets are available. · Soft character sets are not available. · The terminal sets the eighth bit of all received characters to 0. · The terminal sends all C1 control characters as 7-bit escape sequences (ESC Fe). Level 4 (VT400 Mode) In VT400 mode, you can use all VT400 features. This mode is fully compatible with Digital's VT200 and VT300 series terminals. All keyboard functions are available. You can use all control functions and device control strings described in this manual, except VT52 control functions. All Levels You can use the following features at any operating level: · Printer port · Status line (You can enable or change the status line at any level.) · Session management · User windows Table 4-1 Control Functions Ignored in Level 1 (VT100 mode) ------------------------------------------------------------ Name Mnemonic ------------------------------------------------------------ Assign user-preferred supplemental set DECAUPSS Back index DECBI Change attributes in rectangular area DECCARA Checksum report DECCKSR Delete column DECDC Copy rectangular area DECCRA Cursor information report DECCIR Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Emulating VT Series Terminals All Levels 85 Table 4-1 (Cont.) Control Functions Ignored in Level 1 (VT100 mode) ------------------------------------------------------------ Name Mnemonic ------------------------------------------------------------ Define macro DECDMAC Downline-loadable set DECDLD Enable local functions DECELF Erase character ECH Erase rectangular area DECERA Fill rectangular area DECFRA Forward index DECFI Insert character ICH Insert column DECIC Invoke stored macro DECINVM Keyboard usage mode DECKBUM Key position mode DECKPM Local function key control DECLFKC Locking shift 2 LS2 Locking shift 3 LS3 Locking shift 1 right LS1R Locking shift 2 right LS2R Locking shift 3 right LS3R Numeric keypad mode DECNKM Presentation state report DECPSR Report displayed extent DECRPDE Report mode DECRPM Report selection or setting DECRPSS Report terminal unit ID DECRPTUI Request checksum of rectangular area DECRQCRA Request displayed extent DECRQDE Request mode DECRQM Request presentation state DECRQPSR Request selection or setting DECRQSS Request terminal state DECRQTSR Restore presentation state DECRSPS Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 86 Emulating VT Series Terminals All Levels Table 4-1 (Cont.) Control Functions Ignored in Level 1 (VT100 mode) ------------------------------------------------------------ Name Mnemonic ------------------------------------------------------------ Restore terminal state DECRSTS Reverse attributes in rectangular area DECRARA Secure reset DECSR Select active status display DECSASD Select attribute change extent DECSACE Select character attribute DECSCA Select font DECSF Select modifier key reporting DECSMKR Selective erase in display DECSED Selective erase in line DECSEL Selective erase rectangular area DECSERA Select status display type DECSSDT Send 7-bit C1 controls S7C1T Send 8-bit C1 controls S8C1T Set columns per page DECSCPP Set left and right margins DECSLRM Set terminal unit ID DECSTUI Soft terminal reset DECSTR Tabulation stop report DECTABSR Terminal state report DECTSR UDK and keyboard language DSR User-defined keys DECUDK Vertical split-screen mode DECVSSM ------------------------------------------------------------ Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Emulating VT Series Terminals Selecting an Operating Level (DECSCL) 87 ------------------------------------------------------------ Selecting an Operating Level (DECSCL) You select the terminal's operating level by using the following select compatibility level (DECSCL) control sequences. The factory default is level 4 (VT400 mode, 7-bit controls). NOTE When you change the operating level, the terminal performs a hard reset (RIS). See Chapter 13 for details. Format ------------------------------------------------------------ Sequence Level Selected ------------------------------------------------------------ Level 1 CSI 9/11 6 3/6 1 3/1 " 2/2 p 7/0 VT100 mode Level 4  CSI 9/11 6 3/6 n 3/n " 2/2 p 7/0 VT400 mode, 8-bit controls CSI 9/11 6 3/6 n 3/n ; 3/11 0 3/0 " 2/2 p 7/0 VT400 mode, 8-bit controls CSI 9/11 6 3/6 n 3/n ; 3/11 1 3/2 " 2/2 p 7/0 VT400 mode, 7-bit controls CSI 9/11 6 3/6 n 3/n ; 3/11 2 3/2 " 2/2 p 7/0 VT400 mode, 8-bit controls ------------------------------------------------------------  Level 4 includes levels 2 and 3. In these sequences, n can be 2, 3, or 4 ------------------------------------------------------------ Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 88 Emulating VT Series Terminals Sending C1 Controls to the Host ------------------------------------------------------------ Sending C1 Controls to the Host The VT420 can send C1 control characters to the host as single 8-bit characters or as 7-bit escape sequences. You should select the format that matches the operating level you are using. You can use the following sequences to select the format for C1 control characters. See Chapter 2 for information on working with 7-bit and 8-bit environments. The following sequence causes the terminal to send all C1 control characters as 7-bit escape sequences or single 8-bit characters: Select 7-Bit C1 Control Characters (S7C1T) ESC 1/11 sp 2/0 F 4/7 This sequence changes the terminal mode as follows: ------------------------------------------------------------ Mode Before Mode After ------------------------------------------------------------ VT400 mode, 8-bit controls VT400 mode, 7-bit controls. VT400 mode, 7-bit controls Same. Terminal ignores sequence. VT100 or VT52 mode, 7-bit controls Same. Terminal ignores sequence. ------------------------------------------------------------ The following sequence causes the terminal to send C1 control characters to the host as single 8-bit characters: Select 8-Bit C1 Control Characters (S8C1T) ESC 1/11 sp 2/0 G 4/6 This sequence changes the terminal mode as follows: ------------------------------------------------------------ Mode Before Mode After ------------------------------------------------------------ VT400 mode, 8-bit controls Same. Terminal ignores sequence. VT400 mode, 7-bit controls VT400 mode, 8-bit controls. VT100 or VT52 mode Same. Terminal ignores sequence. ------------------------------------------------------------ Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Emulating VT Series Terminals National Replacement Character Set Mode (DECNRCM) 89 ------------------------------------------------------------ National Replacement Character Set Mode (DECNRCM) (Worldwide Model Only) The terminal has several 7-bit character sets for different national languages. Only one national replacement character set is available at a time. To use a 7-bit NRC set, you must select national replacement character set mode. When you reset this mode, the terminal uses the 7-bit and 8-bit characters from the DEC Multinational or ISO Latin-1 character set. Default: Multinational Format CSI 9/11 ? 3/15 4 3/4 2 3/2 h 6/8 Set: national. CSI 9/11 ? 3/15 4 3/4 2 3/2 l 6/12 Reset: multinational. Notes on DECNRCM · When DECNRCM is reset, the VT420 operates as a level 4 terminal. The terminal can send and receive 8-bit characters from the DEC Multinational or ISO Latin-1 character set. When DECNRCM is set (national), the VT420 operates as a level 4 terminal. However, the terminal can only send and receive 7-bit characters. Also, the terminal uses one of the national replacement character sets. · Setting DECNRCM causes the terminal to change character sets to their default state (at power-up or reset). · If the North American/United Kingdom keyboard is currently selected in set-up, the terminal ignores DECNRCM. Chapter 4 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 5 Using Character Sets ------------------------------------------------------------ This chapter describes how you can select character sets to use with your terminal in VT mode. See Chapter 15 for information on character sets in PC TERM mode. The chapter assumes you are familiar with the character-encoding concepts described in Chapter 2. You can use hard character sets or soft character sets. Hard character sets are sets built into the terminal, such as the ASCII and DEC Supplemental Graphic sets. Soft character sets are sets that you download into the terminal from a host system. You can design your own soft character sets. Table 5-1 lists the hard character sets available in VT400 and VT100 modes. See Chapter 4 to select a mode. VT400 mode supports VT200 and VT300 operation. Table 5-1 Character Sets Available ------------------------------------------------------------ Level 1 (VT100 mode) Level 4 (VT400 mode) ------------------------------------------------------------ ASCII Yes All character sets are available. DEC Supplemental Graphic No ISO Latin-1 supplemental No User-preferred supplemental No National replacement (NRCs)  Yes DEC Special Graphic Yes DEC Technical No Soft character sets (DRCS) No ------------------------------------------------------------  Worldwide model only ------------------------------------------------------------ 90 Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Selecting Character Sets 91 Selecting Character Sets To understand how to select character sets, you must first understand the function of the terminal's in-use table. The in-use table contains the character sets the terminal can currently access. You can place any two character sets in the terminal's in-use table. The in-use table consists of the graphic left (GL) and graphic right (GR) logical tables. Each time you turn on the terminal, the terminal places the following default character sets in the in-use table: ASCII in GL DEC Supplemental Graphic (or ISO Latin-1 supplemental) in GR Together, the ASCII and DEC Supplemental Graphic sets make up the DEC Multinational set. The ASCII and ISO Latin-1 supplemental sets make up the ISO Latin-1 set, which is the worldwide standard. You can select a different character set by following these two steps: 1. Designate the set as G0, G1, G2, or G3. G0 through G3 are logical sets that the terminal uses to access character sets. You can designate up to four character sets and have them ready for use in the in-use table. 2. Map the designated set into the in-use table. After you map the set into the in-use table, you can display or send any character from that set by using 8-bit codes. Figure 5-1 shows how you select character sets. The following sections describe the control functions you use to designate and map character sets. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 92 Using Character Sets Selecting Character Sets Figure 5-1 Character Set Selection Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selecting Graphic Character Sets Designating Character Sets (SCS Sequences) 93 ------------------------------------------------------------ Designating Character Sets (SCS Sequences) You designate a hard character set as G0 through G3 by using a select character set (SCS) escape sequence. You cannot designate a 96-character set as G0. SCS sequences use the following format. Table 5-3 lists the code used to select each available character set. NOTE The ISO Latin-1 supplemental character set is the only 96- character hard set available in the terminal. All other hard sets have 94 characters. Format ESC 1/11 I 1 *** I 2 *** ... ... I n *** F *** Parameters I 1 , intermediate character Designates the character set as G0, G1, G2, or G3. Table 5-2 Designating a Character Set ------------------------------------------------------------ I 1 Character Code Set Selection ------------------------------------------------------------ 94-Character Sets ( left parenthesis 2/8 G0 (initial setting for GL) ) right parenthesis 2/9 G1 * asterisk 2/10 G2 (initial setting for GR) + plus sign 2/11 G3 96-Character Sets  - hyphen 2/13 G1 . period 2/14 G2 / slash 2/15 G3 ------------------------------------------------------------  You cannot designate a 96-character set into G0. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 94 Selecting Graphic Character Sets Designating Character Sets (SCS Sequences) ------------------------------------------------------------ I 2 ...I n F, intermediate and final characters Selects one of the standard character sets. The following table lists the characters used to select standard sets. Table 5-3 Character Set Codes ------------------------------------------------------------ Character Set I 2 ...I n F Characters Code ------------------------------------------------------------ 94-Character Sets ------------------------------------------------------------ ASCII (initial setting for G1 and G0) B 4/2 DEC Supplemental Graphic (initial setting for G2 and G3) %5 2/5, 3/5 DEC Special Graphics 0 3/0 DEC Technical > 3/14 User-preferred supplemental < 3/12 NRC Sets  ------------------------------------------------------------ ISO United Kingdom A 4/1 DEC Finnish+ 5 or C 3/5 4/3 ISO French R 5/2 DEC French Canadian+ 9 or Q 3/9 5/1 ISO German K 4/11 ISO Italian Y 5/9 ISO Norwegian/Danish+ ` 6/0 DEC Norwegian/Danish 6 or E 3/6 4/5 ------------------------------------------------------------  Only one national character set is available at a time. You must select national mode to use national character sets. See ``National Replacement Character Sets (Worldwide Model Only)'' in this section. +Digital recommends using the first code shown. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selecting Graphic Character Sets Designating Character Sets (SCS Sequences) 95 Table 5-3 (Cont.) Character Set Codes ------------------------------------------------------------ Character Set I 2 ...I n F Characters Code ------------------------------------------------------------ DEC Portuguese %6 2/5, 3/6 ISO Spanish Z 5/10 DEC Swedish+ 7 or H 3/7 4/8 DEC Swiss = 3/13 96-Character Sets ------------------------------------------------------------ ISO Latin-1 Supplemental A 4/1 ------------------------------------------------------------ +Digital recommends using the first code shown. ------------------------------------------------------------ Examples The following sequence designates the DEC Special Graphic character set as the G1 logical set: ESC ) 0 The following sequence designates the ISO Latin-1 supplemental character set as the G3 logical set: ESC / A Mapping Character Sets After you designate a character set as G0, G1, G2, or G3, you must map the set into the in-use table as GL or GR. To map a set, you use locking-shift or single-shift control functions. Figure 5-2 shows how you use locking shifts and single shifts in VT400 mode. Figure 5-3 shows how you use locking shifts and single shifts in VT100 mode. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 96 Selecting Graphic Character Sets Designating Character Sets (SCS Sequences) Figure 5-2 Designating and Mapping Character Sets in VT400 Mode Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selecting Graphic Character Sets Designating Character Sets (SCS Sequences) 97 Figure 5-3 Designating and Mapping Character Sets in VT100 Mode Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 98 Selecting Graphic Character Sets Locking Shifts (LS) ------------------------------------------------------------ Locking Shifts (LS) When you use a locking shift, the character set remains in GL or GR until you use another locking shift. Table 5-4 lists all locking shifts available. Format Table 5-4 Mapping Character Sets with Locking Shifts ------------------------------------------------------------ Locking Shift Code Function ------------------------------------------------------------ LS0 (locking shift 0) SI 0/15 Map G0 into GL.(default) LS1 (locking shift 1) SO 0/14 Map G1 into GL. The following locking shift functions are available only in VT400 mode. LS1R (locking shift 1, right) ESC 1/11 ~ 7/14 Map G1 into GR. LS2 (locking shift 2) ESC 1/11 n 6/14 Map G2 into GL. LS2R (locking shift 2, right) ESC 1/11 } 7/13 Map G2 into GR. LS3 (locking shift 3) ESC 1/11 o 6/15 Map G3 into GL. LS3R (locking shift 3, right) ESC 1/11 | 7/12 Map G3 into GR. ------------------------------------------------------------ Examples The following sequence designates the DEC Technical character set as G1, then maps G1 into GL: ESC ) > Designate as G1. SO Map G1 into GL. The following sequences designate the ISO Latin-1 supplemental character set as G2, then map G2 into GR: ESC . A Designate as G2. ESC } Map G2 into GR. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selecting Graphic Character Sets Single Shifts (SS) 99 ------------------------------------------------------------ Single Shifts (SS) You use a single shift when you want to display the next character from a different character set. A single shift maps the G2 or G3 set into GL. The character set is active for only one character. Then the terminal returns to the previous character set in GL. The terminal has two single-shift control functions available. Format ------------------------------------------------------------ Single-Shift Control 8-Bit Character 7-Bit Equivalent Sequence Function ------------------------------------------------------------ Single shift 2 SS2 8/14 ESC 1/11 N 4/14 Maps G2 into GL for the next character. Single shift 3 SS3 8/15 ESC 1/11 O 4/15 Maps G3 into GL for the next character. ------------------------------------------------------------ Example Suppose the ASCII character set is in GL. You want to display the alpha character from the DEC Technical character set, already designated as G3. You do not want to replace the ASCII set just to display one character. Instead, you can use single shift 3 to temporarily map the DEC Technical set (G3) into GL. SS3 single shift 3 a alpha character After displaying the alpha character, the terminal maps the ASCII set (G1) back into GL, replacing the DEC Technical set (G3). Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 100 Selecting Graphic Character Sets Assigning User-Preferred Supplemental Sets (DECAUPSS) National Replacement Character Sets (Worldwide Model Only) The terminal has several 7-bit character sets for different national languages (Chapter 2). Only one national replacement character set is available at a time. To use a national replacement character set, you must select national replacement character set mode. When you reset this mode, the terminal uses 7-bit and 8-bit characters from one of the multinational character sets (DEC Multinational or ISO Latin-1). When you set this mode, the terminal uses 7-bit characters from an NRC set. See ``National Replacement Character Set Mode'' at the end of Chapter 4. ------------------------------------------------------------ Assigning User-Preferred Supplemental Sets (DECAUPSS) You can assign the supplemental character set you use most often as a special standby set. This standby set is called the user-preferred supplemental set. This feature provides applications with an easy way to access the user 's preferred supplemental set. Default: DEC Supplemental Graphic Format DCS 9/0 0 3/0 ! 2/1 u 7/5 % 2/5 5 3/5 ST 9/12 DEC Supplemental Graphic set. DCS 9/0 0 3/0 ! 2/1 u 7/5 A 4/1 ST 9/12 ISO Latin-1 set. Description You can assign the DEC Supplemental Graphic or ISO Latin-1 supplemental set as the standby set. After you assign a set, you must designate and map the set before using it. 1. Designate the set as G1, G2, or G3. 2. Map the set into GR. For more information on designating and mapping sets, see ``Selecting Character Sets'' in this chapter. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selecting Graphic Character Sets ANSI Conformance Levels 101 ------------------------------------------------------------ ANSI Conformance Levels This control function lets an application map certain character sets into the terminal's in-use table as default sets. The character sets are based on ANSI conformance levels, listed in this section. These conformance levels are from the dpANS X3.134.1 standard. ANSI conformance levels represent an agreement between the sender and receiver for compatible data exchange. The control function acts as an announcer for the data exchange that follows between the terminal and application software. The control function selects which character sets the terminal uses by default in the data exchange. The VT420 supports three ANSI conformance levels. ANSI Levels 1 and 2 · ASCII designated as G0. · ISO Latin-1 supplemental designated as G1. · G0 mapped into GL. · G1 mapped into GR. ANSI Level 3 · ASCII designated as G0. · G0 mapped into GL. Format ESC 1/11 sp 2/0 Final 4/** Parameters Final indicates the ANSI conformance level for the subsequent data exchange. Final ANSI Conformance Level L Level 1 M Level 2 N Level 3 Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 102 Using Character Sets ANSI Conformance Levels Notes on ANSI Conformance Levels · If the terminal is reset, turned off, or changed with a set conformance level (DECSCL) sequence, software must send another announcer sequence to the terminal. Otherwise, the terminal uses the default character sets (ASCII in GL, DEC Supplemental or ISO Latin-1 supplemental in GR). · The announcer sequence is available in VT400 mode only. · Do not confuse ANSI conformance levels with Digital conformance levels (Chapter 2). Soft Character Sets You can download soft character set from the host system into the terminal. This feature lets you design your own soft character sets for use with the terminal. You can only load soft character sets in VT400 mode. NOTE VT220 or VT320 fonts may appear different on a VT420 terminal, because VT420 character cell sizes are different from those terminals. See the Pcmw parameter in Table 5-8. The soft character set is also known as a dynamically redefinable character set (DRCS). The terminal stores the soft characters in its DRCS buffer. NOTE The terminal does not store the soft character set in nonvolatile RAM. When you turn off the terminal, the soft characters are lost. The next section describes the guidelines for designing a soft set. The sections that follow describe how to code, load, designate, and clear a soft set. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 103 Designing a Soft Character Set Your terminal displays each character by turning on a series of pixels. A pixel (picture element) is the smallest displayable unit on the screen. Each character must fit in a limited area, called the character cell. The size of the character cell depends on the number of lines and columns on the screen. The screen can display 24, 36, or 48 lines in 80 or 132 columns. With 24 lines on the screen, the VT420 uses a default character cell size of 10 by 16 pixels for 80 columns and 6 by 16 pixels for 132 columns (Figure 5-4). Figure 5-4 Character Cell Sizes for 24-Line by 80- and 132-Column Fonts Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 104 Using Character Sets Soft Character Sets Table 5-5 shows the default character cell widths and heights based on the number of lines and columns on the screen. Table 5-5 Character Cell Sizes ------------------------------------------------------------ Cell Size 80 Columns 132 Columns ------------------------------------------------------------ 24 Lines/Screen Width 10 pixels 6 pixels Height 16 16 36 Lines/Screen Width 10 6 Height 10 10 48 Lines/Screen Width 10 6 Height 8 8 ------------------------------------------------------------ When you design a character, you should lay out a character cell on grid paper. The little boxes on the grid paper represent pixels. You fill in the pixels that make up the character. The next section shows an example of a character design. You should design six versions of your character set to fit six different character cell sizes. This means that there will be a version of your soft character set to fit any combination of lines and columns available on the terminal: · 24 lines  80 columns · 24 lines  132 columns · 36 lines  80 columns · 36 lines  132 columns · 48 lines  80 columns · 48 lines  132 columns Design your character set, then load six versions of the set, one for each possible line/column combination. The terminal automatically selects which version of the set to use, based on the current number of lines and columns on the screen. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 105 The built-in fonts supplied by Digital follow the guidelines in Table 5-6. The table lists the different guidelines for characters displayed with 24 lines, 36 lines, or 48 lines on the screen. In all cases, the screen resolution is 800 by 400 pixels for 80 columns, 792 by 400 pixels for 132 columns. The pixel aspect ratio is 1:1.4. You must design your characters to fit the cell. The terminal ignores any pixels that are defined outside the cell. Also, you should include empty pixels on the left or right side of the character cell to allow for space between characters. Figure 5-5 shows an example of spacing for an uppercase D character with 24 lines on the screen. In this example, the character for the 80-column font has two pixel columns reserved for spacing. Figure 5-5 Character Body Sizes for 24-Line by 80- and 132-Column Fonts Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 106 Using Character Sets Soft Character Sets Table 5-6 Guidelines for Designing Soft Characters ------------------------------------------------------------ Character Dimension 80-Column Font 132-Column Font ------------------------------------------------------------ 24 Lines/Screen ------------------------------------------------------------ Cell width 10 pixels 6 pixels Cell height 16 16 Body width 8 4 Body height 10 9 Ascender height 3 3 Descender height 3 3 Spacing before character 1 1 Spacing after character 1 1 ------------------------------------------------------------ 36 Lines/Screen ------------------------------------------------------------ Cell width 10 pixels 6 pixels Cell height 10 10 Body width 7 5 Body height 7 7 Ascender height 2 1 Descender height 1 2 Spacing before character 2 1 Spacing after character 1 0 Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 107 Table 5-6 (Cont.) Guidelines for Designing Soft Characters ------------------------------------------------------------ Character Dimension 80-Column Font 132-Column Font ------------------------------------------------------------ ------------------------------------------------------------ 48 Lines/Screen ------------------------------------------------------------ Cell width 10 pixels 6 pixels Cell height 8 8 Body width 7 4 Body height 6 7 Ascender height 1 1 Descender height 1 1 Spacing before character 2 1 Spacing after character 1 1 ------------------------------------------------------------ Coding the Soft Character Set After you design your characters, you must code them for the terminal. This section describes how to code soft characters. The next section describes how to load the character codes into the terminal. Each pixel of a soft character cell receives a binary value of 0 or 1. A 1 bit indicates the pixel is on, and a 0 bit indicates the pixel is off. The terminal receives the code for a soft character in sections, called sixels. A sixel is a 6-bit binary code that represents a vertical column of 6 pixels on the screen. Each bit in a sixel corresponds to a pixel on the screen. The following example describes how to design and code a soft character. Example Suppose you want to design an uppercase D for a 24-line by 80-column font. 1. Draw your design on a grid. Use the grid for an 80-column character cell to draw your design. Mark which pixels will be on and which pixels will be off. Your design may look like Figure 5-5. 2. Divide the character cell into columns of 6 bits each. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 108 Using Character Sets Soft Character Sets Use the format shown in Figure 5-6. Each 6-bit pattern represents 6 pixels, or a sixel. The least significant bit is at the top, and the most significant bit is at the bottom. The terminal would receive the sixel columns in order (1 to 10), starting with Group A. Figure 5-6 Example of an Uppercase D (24-Line by 80-Column Font) Because the character cell height (16 pixels) is not a multiple of 6, the columns on the bottom of the character cell (Group D) have only 4 bits each, b0 through b3. Bits b4 and b5 in the bottom cell do not affect the character 's appearance, so they have been excluded from Figure 5-6. 3. Convert the binary value of each sixel to its hexadecimal value. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 109 Sixels codes are restricted to characters in the range of ? (3F 16 ) to ~ (7E 16 ), so you must add an offset of 3F 16 to the hexadecimal value of each column. For example: 000000 2 = 00 16 110101 2 = 35 16 111111 2 = 3F 16 + 3F 16 + 3F 16 + 3F 16 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 3F 16 74 16 7E 16 4. Use Table 5-7 to convert each binary number to the equivalent ASCII character. Table 5-7 lists the results of steps 3 and 4 for each possible binary value. All you have to do is find the 6-digit binary number for each sixel bit pattern in your character design. Figure 5-7 shows this conversion for the uppercase D in this example. You use this procedure to convert each character of your soft character set into a string of sixel bit patterns. Then you can download your DRCS characters into the terminal, using the DECDLD device control string described in the next section. Table 5-7 Converting Binary Code to an ASCII Character ------------------------------------------------------------ Binary Value Hex. Value Hex. Value + 3F Offset Character Equivalent ------------------------------------------------------------ 000000 00 3F ? 000001 01 40 @ 000010 02 41 A 000011 03 42 B 000100 04 43 C 000101 05 44 D 000110 06 45 E 000111 07 46 F 001000 08 47 G 001001 09 48 H 001010 A 49 I 001011 B 4A J 001100 C 4B K Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 110 Using Character Sets Soft Character Sets Table 5-7 (Cont.) Converting Binary Code to an ASCII Character ------------------------------------------------------------ Binary Value Hex. Value Hex. Value + 3F Offset Character Equivalent ------------------------------------------------------------ 001101 D 4C L 001110 E 4D M 001111 F 4E N 010000 10 4F O 010001 11 50 P 010010 12 51 Q 010011 13 52 R 010100 14 53 S 010101 15 54 T 010110 16 55 U 010111 17 56 V 011000 18 57 W 011001 19 58 X 011010 1A 59 Y 011011 1B 5A Z 011100 1C 5B [ 011101 1D 5C \ 011110 1E 5D ] 011111 1F 5E ^ 100000 20 5F _ 100001 21 60 ` 100010 22 61 a 100011 23 62 b 100100 24 63 c 100101 25 64 d 100110 26 65 e 100111 27 66 f 101000 28 67 g 101001 29 68 h 101010 2A 69 i Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 111 Table 5-7 (Cont.) Converting Binary Code to an ASCII Character ------------------------------------------------------------ Binary Value Hex. Value Hex. Value + 3F Offset Character Equivalent ------------------------------------------------------------ 101011 2B 6A j 101100 2C 6B k 101101 2D 6C l 101110 2E 6D m 101111 2F 6E n 110000 30 6F o 110001 31 70 p 110010 32 71 q 110011 33 72 r 100100 34 73 s 110101 35 74 t 110110 36 75 u 110111 37 76 v 111000 38 77 w 111001 39 78 x 111010 3A 79 y 111011 3B 7A z 111100 3C 7B { 111101 3D 7C | 111110 3E 7D } 111111 3F 7E ~ ------------------------------------------------------------ Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 112 Using Character Sets Soft Character Sets Figure 5-7 Sixel-to-ASCII Conversion Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Soft Character Sets 113 Downloading Soft Characters The VT420 lets you load up to six variations of the same soft character set for each session. These six variations correspond to the six different combinations of character width and character height the VT420 supports. Character Width For 80 columns: 10 pixels For 132 columns: 6 pixels Character Height For 24 lines/screen: 16 pixels For 36 lines/screen: 10 pixels For 48 lines/screen: 8 pixels You can adjust the screen size by using the select number of lines/screen (DECSNLS) control function (Chapter 11). The terminal automatically selects the appropriate soft set for the screen size. When loading a soft set, you specify which of the six width/height variations the set is intended for. Your set replaces any soft set already loaded for that width/height variation. You should load six variations of your set to correspond to the six variations of character width and height available in the terminal (80 or 132 columns by 24, 36, or 48 lines). Do not confuse the font rendition with the actual character set. You cannot load six different soft sets. However, you can load six different renditions of the same soft set. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 114 Soft Character Sets Downline Load (DECDLD) ------------------------------------------------------------ Downline Load (DECDLD) You load your soft character set with a DECDLD device control string. See Chapter 2 for general information about device control strings. After you load your soft character set, you must designate the set as G0, G1, G2, or G3. Format DCS Pfn ; Pcn; Pe; Pcmw; Pss; Pt; Pcmh; Pcss { Dscs Sxbp1 ; Sxbp2 ;...; Sxbpn ST Parameters DCS (9/0) is the device control string introducer. DCS is an 8-bit C1 character. You can use the equivalent 7-bit sequence ESC P (1/11, 5/0) when coding for a 7-bit environment. Pfn; Pcn; Pe; Pcmw; Pss; Pt; Pcmh; Pcss are parameter characters, separated by semicolons (3/11). Table 5-8 describes these parameters and lists their possible values. Table 5-9 describes the combinations of Pcmw, Pt, and Pcmh you can use for 80- and 132-column fonts. If you use any other combinations, the terminal ignores the DECDLD string. { is the final character. It marks the end of the parameter characters and indicates that this string is a DECDLD function. Dscs defines the name for the soft character set. You use this name in the select character set (SCS) escape sequence. You use the following format for the Dscs name: I F I is 0, 1 or 2 intermediate characters from the range 2/0 to 2/15 in the ASCII character set. F is a final character in the range 3/0 to 7/14. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Soft Character Sets Downline Load (DECDLD) 115 Examples of Dscs Names Name Function sp 2/0 @ 4/0 Defines the character set as an unregistered soft set. This value is the recommended default for user-defined sets. The value of Pcss defines whether this set has 94 or 96 characters. A 4/2 If Pcss is 0, A defines the soft character set as the U.K. national replacement character set. If Pcss is 1, A defines the soft character set as the ISO Latin-1 supplemental set. & 2/6 % 2/5 C 4/3 Defines the soft character set as % C, which is currently an unregistered set. The value of Pcss defines whether this set has 94 or 96 characters. Sxbp1 ; Sxbp2 ; . . . ; Sxbpn are the sixel bit patterns for individual characters, separated by semicolons (3/11). Your character set can have 1 to 94 patterns or 1 to 96 patterns, depending on the setting of the character set size parameter (Pcss). Each sixel bit pattern is in the following format: S...S/S...S the first S...S represents the sixels in Group A of the soft character (Figure 5-6). the second S...S advances the sixel pattern to Group B of the soft character. / (2/5) represents the sixels in Group B of the soft character. ST is the string terminator. ST is an 8-bit C1 character. You can use the equivalent 7-bit sequence ESC \ (1/11, 5/12) when coding for a 7-bit environment. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 116 Soft Character Sets Downline Load (DECDLD) Table 5-8 DECDLD Parameter Characters ------------------------------------------------------------ Parameter Name Description ------------------------------------------------------------ Pfn Font number Selects the DRCS font buffer to load. The VT420 has two DRCS font buffers. One font buffer is dedicated to session 1, the other to session 2. Each font buffer is called DRCS buffer 1. Pfn has two valid values, 0 and 1. Both values refer to DRCS buffer 1 for each session. Pcn Starting character Selects where to load the first character in the DRCS font buffer. The location corresponds to a location in the ASCII code table (Figure 2-2). For example, a Pcn value of 0 means that the first soft character is loaded into position 2/0 of the character table. A Pcn value of 1 means position 2/1 in the table, and so on, up to Pcn = 95 (position 7/15). Pcn is affected by the character set size. See Pcss below. Pe Erase control Selects which characters to erase from the DRCS buffer before loading the new font. 0 = erase all characters in the DRCS buffer with this number, width, and rendition. 1 = erase only characters in locations being reloaded. 2 = erase all renditions of the soft character set (normal, bold, 80-column, 132-column). NOTE Erased characters are undefined (not blank). The terminal displays these characters as the error character (reverse question mark). Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Soft Character Sets Downline Load (DECDLD) 117 Table 5-8 (Cont.) DECDLD Parameter Characters ------------------------------------------------------------ Parameter Name Description ------------------------------------------------------------ Pcmw Character matrix width Selects the maximum character cell width. VT400 mode 0 = 10 pixels wide for 80 columns, 6 pixels wide for 132 columns. (default) 1 = illegal. 2 = 5  10 pixel cell (VT220 compatible). 3 = 6  10 pixel cell (VT220 compatible). 4 = 7  10 pixel cell (VT220 compatible). 5 = 5 pixels wide. 6 = 6 pixels wide. . . . 10 = 10 pixels wide. If you omit a Pcmw value, the terminal uses the default character width. If the Pe parameter is 0, Pcmw must be less than 10. Any Pcmw value over 10 is illegal. For illegal values of Pcmw, the terminal ignores the rest of the load sequence. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 118 Soft Character Sets Downline Load (DECDLD) Table 5-8 (Cont.) DECDLD Parameter Characters ------------------------------------------------------------ Parameter Name Description ------------------------------------------------------------ For VT200 compatible software: Use a Pcmw value of 2, 3, or 4. When you use these values, the VT420 doubles the height of the font definitions in memory. This makes the soft set the same height as the hard sets. If you use a Pcmw value of 0, the VT420 does not double the height and the soft set appears smaller than the hard sets. Remember that the VT200 fonts may appear different on the VT420. For fonts designed for the VT420: Use values 5 through 10. For compatibility between VT200 and VT420 terminals: Use a Pcmw value of 5, 6, or 7. Pss Font set size Defines the screen width and screen height for this font. 0,1 = 80 columns, 24 lines. (default) 2 = 132 columns, 24 lines 11 = 80 columns, 36 lines 12 = 132 columns, 36 lines 21 = 80 columns, 48 lines 22 = 132 columns, 48 lines For illegal values of Pss, the terminal ignores the rest of the load sequence. If the number of columns or lines/screen changes, the terminal uses the appropriate variation of the soft set. If you try to display a DRCS character when there is no soft set defined for the current number of lines and columns, the terminal displays the error character (reverse question mark). Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Soft Character Sets Downline Load (DECDLD) 119 Table 5-8 (Cont.) DECDLD Parameter Characters ------------------------------------------------------------ Parameter Name Description ------------------------------------------------------------ NOTE For VT220 compatibility, you must use a soft font of 80 or 132 columns (not both). The VT220 allows a single font to be used for 80 and 132 columns. You can load a font for any of the six sizes at any time. When a new soft set is loaded, any characters from the previous soft set are lost. Characters currently displayed from the old set become reverse question marks. Pt Text or full cell Defines the font as a text font or full-cell font. 0 = text. (default) 1 = text. 2 = full cell. Full-cell fonts can individually address all pixels in a cell. Text fonts cannot individually address all pixels. If you specify a text cell, the terminal automatically performs spacing and centering of the characters. Pcmh Character matrix height Selects the maximum character cell height. 0 or omitted = 16 pixels high. (default) 1 = 1 pixel high. 2 = 2 pixels high. 3 = 3 pixels high. . . . 16 = 16 pixels high. Pcmh values over 16 are illegal. If the value of Pcmw is 2, 3, or 4, Pcmh is ignored. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 120 Soft Character Sets Downline Load (DECDLD) Table 5-8 (Cont.) DECDLD Parameter Characters ------------------------------------------------------------ Parameter Name Description ------------------------------------------------------------ Pcss Character set size Defines the character set as a 94- or 96- character graphic set. 0 = 94-character set. (default) 1 = 96-character set. The value of Pcss changes the meaning of the Pcn (starting character) parameter above. ------------------------------------------------------------ Examples ------------------------------------------------------------  If Pcss = 0 (94-character set) The terminal ignores any attempt to load characters into the 2/0 or 7/15 table positions. Pcn Specifies 1 column 2/row 1 . . . 94 column 7/row 14  If Pcss = 1 (96-character set) Pcn Specifies 0 column 2/row 0 . . . 95 column 7/row 15 ------------------------------------------------------------ Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Soft Character Sets Downline Load (DECDLD) 121 Table 5-9 Valid DECDLD Parameter Combinations ------------------------------------------------------------ Pt Pcmw Pcmh Pss  ------------------------------------------------------------ 80-column, 24 lines 0 or 1 0 to 8 0 to 16 0 or 1 2 0 to 10 0 to 16 0, 1 132-column, 24 lines 0 or 1 0 to 5 0 to 16 2 2 0 to 6 1 to 16 2 80-column, 36 lines 0 or 1 0 to 8 0 to 10 11 2 0 to 10 0 to 10 11 132-column, 36 lines 0 or 1 0 to 5 0 to 10 12 2 0 to 6 0 to 10 12 80-column, 48 lines 0 or 1 0 to 8 0 to 8 21 2 0 to 10 0 to 8 21 132-column, 48 lines 0 or 1 0 to 5 0 to 8 22 2 0 to 6 0 to 8 22 ------------------------------------------------------------  The default values are the maximum legal values in each case. ------------------------------------------------------------ NOTE For illegal combinations of the Pss, Pt, Pcmw, and Pcmh parameters, the terminal ignores the rest of the sequence. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 122 Soft Character Sets Downline Load (DECDLD) Designating the Soft Character Set You designate your soft character set the same way you designate the hard character sets--using a select character set (SCS) sequence. You also use the same format for the SCS sequence. ESC 1/11 Intermediate(s) ********* Final ***** Intermediate(s) are one or more characters that designate the soft character set as one of the logical sets, G0 through G3. You use the same intermediate characters that you use for hard character sets (Table 5-2). The intermediate character(s) also indicates whether the soft character set is a 94- or 96-character set. Make sure you use an intermediate character that matches the setting of the character set size parameter (Pcss) in the DECDLD string (Table 5-8). Final is the Dscs name you used for the soft character set in the DECDLD string. Notes on Designating Soft Character Sets · Replacing a soft set with a new soft set If you use a new Dscs name when you replace the current soft set with another soft set, then the following occurs: - Characters from the old soft set are undefined. If you redefine the soft set, characters currently on the screen may change. - Any logical sets (G0, G1, G2, G3) used to designate the old soft set are undefined. The in-use table is also undefined. After you load a new soft set, use a select character set (SCS) sequence to designate the soft set. Using SCS eliminates the confusion involved with undefined characters. · Replacing a hard set with a soft set You can define a soft set that replaces one of the hard sets (such as ASCII or DEC Special Graphic). Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Soft Character Sets Downline Load (DECDLD) 123 A soft set that replaces a hard set remains in effect until you perform one of the following actions: - Clear the soft set by: · Recalling saved settings or factory-default settings with the Save or Default fields in the Set-Up Directory. · Running the power-up self-test. - Redefine the soft set (using another DECDLD string). Soft Character Set Example Suppose you want to create a soft character set containing a solid rectangle, a blank, a rectangular box, and a striped rectangle. You decide to use a font that is 24 lines by 80 columns with a character cell size of 8 by 16 pixels. This example shows how you would 1. Download the set. 2. Designate the set as G1. 3. Map the G1 set into GL. NOTE Make sure the terminal is in VT400 mode before you try to load a soft character set. You cannot load soft sets in VT100 mode. 1. You could use the following DECDLD string to load your character set. The string is shown divided into sections for clarity. DCS 1 ; 1 ; 0 ; 12 ; 1 ; 1 ; 12; 0 { sp @ --------/--------/--------; ????????/????????/????????; ~@@@@@@~/~??????~/~GGGGGG~; TTTTTTTT/TTTTTTTT/TTTTTTTT; ST DCS (9/0) introduces the device control string. 1 ; 1 ; 0 ; 12 ; 1 ; 1 ; 12 ; 0 is the parameter string specifying the following functions. See Table 5-8 for parameter definitions. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 124 Soft Character Sets Downline Load (DECDLD) Parameter Function Pfn = 1 Loads this soft set into the DRCS font buffer. Pcn = 1 Selects the character at row 2/ column 1 in the ASCII table (Chapter 2) as the first character to load. Pe = 0 Erases all characters in the font buffer for that rendition. Pcmw = 12 Selects a maximum character width of 12 pixels. Pss = 1 Selects a font set size of 80 columns, 24 lines. Pt = 1 Defines the set as a text font. Pcmh = 12 Selects a maximum character height of 12 pixels. Pcss = 0 Defines the set as a 94-character set. { (7/11) indicates the end of the parameter characters and specifies that this sequence is a DECDLD string. sp @ defines the character set as an unregistered soft set. This value is the recommended default value for user-defined sets. The sp represents one space. You can use other values to define other specific character sets. -----/-----/----- represents the first character (a solid rectangle). ; separates the soft characters.) ????????/????????/???????? represents the second character (a blank). ~@@@@@@~/~??????~/~GGGGGG~ represents the third character (a hollow rectangle). TTTTTTTT/TTTTTTTT/TTTTTTTT represents the fourth character (a set of horizontal stripes). ST (9/12) indicates the end of the DECDLD string. 2. Now you are ready to designate the character set as G1. You can use the following SCS escape sequence: ESC ) sp @ Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Using Character Sets Downline Load (DECDLD) 125 ESC (1/11) introduces the SCS sequence. ) (2/9) designates the character set as G1. sp @ (2/0, 4/0) selects the soft set as the set to designate as G1. Remember, sp @ was the name used for the soft set in the DECDLD string. 3. Finally, you want to map the G1 set into the in-use table as GL. You can map the set by sending a shift out (SO) control character. To send the SO character, you hold down the ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key and press the ------------------------------------------------------------ ------------------------------------------------------------ N ------------------------------------------------------------ ------------------------------------------------------------ key. NOTE For information on using shift characters, see Chapter 3. For information on mapping sets, see ``Mapping Character Sets'' in this chapter. The soft character set should now be loaded and ready for use. Clearing a Soft Character Set You can clear a soft character set that you loaded into the terminal by using the following DECDLD control string: DCS 1;1;2 { sp @ ST Any of the following actions also clear the soft character set: · Performing the power-up self-test. · Selecting the Recall or Default set-up fields from the Set-Up Directory. · Using a reset to initial state (RIS) sequence. Chapter 5 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 6 Page Memory ------------------------------------------------------------ This chapter describes the control functions that affect the terminal's page memory. The chapter covers the following topics: · What is page memory? · Controlling the page format · Moving through pages This chapter assumes you are familiar with the character-encoding concepts described in Chapter 2. What is Page Memory? Many terminals only have enough memory to store the data that appears on their screen. The VT420 has memory to store more data than you can display on the screen. The size of this memory is equal to 144 lines by 80 or 132 columns. You can divide this memory into one or more pages. Page memory lets you store more text locally in the terminal. The screen can display 24, 36, or 48 lines from page memory at a time. You can select how many lines to display by using the select number of lines /screen (DECSNLS) control function (Chapter 11). You can use control functions (such as scrolling and panning functions) to display the other lines from page memory that are not on the screen. Page memory can provide a means for faster screen updates. While the terminal displays one page, the host can write to another (Chapter 10). You divide page memory into a number of equally sized pages, by selecting one of several standard page sizes. A page in page memory is similar to a page in a book. Each page has left, right, top, and bottom margins. You can define the position of the top and bottom, left and right margins on a page. You select the page format by using control functions or set-up. This chapter describes the control functions. 126 Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Page Memory What is Page Memory? 127 Applications can write to page memory by first addressing a page, then writing data to the page. If the application wants to write to another page, the application must address that page. Figure 6-1 shows the basic parts of a page. The figure shows the default page size of 24 lines by 80 columns. Your terminal screen can display up to 48 lines at a time. However, you can make the length of a page larger than the screen. Figure 6-1 A Page in Page Memory Page Memory for One Session When you use one session, the full 144 lines of page memory are available. See Chapter 14 for details on session management. You can select one of the following page sizes for one session. Figure 6-2 shows these page sizes. · 6 pages of 24 lines  80 or 132 columns · 5 pages of 25 lines  80 or 132 columns · 4 pages of 36 lines  80 or 132 columns · 3 pages of 48 lines  80 or 132 columns · 2 pages of 72 lines  80 or 132 columns · 1 page of 144 lines  80 or 132 columns Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 128 Page Memory What is Page Memory? Figure 6-2 Page Sizes for One Session Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Page Memory What is Page Memory? 129 Page Memory for Two Sessions When you use two sessions, each session has 72 lines of page memory available. See Chapter 14 for details on session management. Figure 6-3 Page Sizes for Two Sessions You can select one of the following page sizes for two sessions. Figure 6-3 shows these page sizes. · 3 pages of 24 lines  80 or 132 columns Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 130 Controlling the Page Format Selecting 80 or 132 Columns per Page · 2 pages of 25 lines  80 or 132 columns · 2 pages of 36 lines  80 or 132 columns · 1 page of 48 lines  80 or 132 columns · 1 page of 72 lines  80 or 132 columns Controlling the Page Format This section describes how to select the page size and set margins for pages in page memory. You use the same basic control functions for one or two sessions. ------------------------------------------------------------ Selecting 80 or 132 Columns per Page There are two control functions that can set the page width to 80 or 132 columns, DECSCPP and DECCOLM. Programming Tip Digital recommends that new applications use DECSCPP rather than DECCOLM. DECSCPP does not clear page memory or reset the scrolling regions, as does DECCOLM. DECCOLM is provided mainly for compatibility with previous products. Default: 80 columns Set Columns per Page (DECSCPP) ------------------------------------------------------------ Sequence Sets Each Page to . . . ------------------------------------------------------------ CSI 9/11 $ 2/4 | 7/12 80 columns. CSI 9/11 0 3/0 $ 2/4 | 7/12 80 columns. CSI 9/11 8 3/8 0 3/0 $ 2/4 | 7/12 80 columns. CSI 9/11 1 3/1 3 3/3 2 3/2 $ 2/4 | 7/12 132 columns. ------------------------------------------------------------ Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Controlling the Page Format Selecting 80 or 132 Columns per Page 131 Notes on DECSCPP · DECSCPP changes the font to match the current number of columns on the page. · DECSCPP does not move the cursor. If, however, the cursor is beyond the width of the new page when DECSCPP executes, the cursor moves to the right column of the new page. · If you switch from 132-column to 80-column pages, you can lose data from page memory. Columns no longer present in page memory are lost. Make sure you set page columns before you enter data into page memory. Column Mode (DECCOLM) CSI 9/11 ? 3/15 3 3/3 h 6/8 Set: 132-column font. CSI 9/11 ? 3/15 3 3/3 l 6/12 Reset: 80-column font. Notes on DECCOLM · DECCOLM sets the number of columns on the page to 80 or 132 and selects the corresponding 80- or 132-column font. · If you change the DECCOLM setting, the terminal: -- Sets the left, right, top and bottom scrolling margins to their default positions. -- Erases all data in page memory. · DECCOLM resets vertical split screen mode (DECVSSM) to unavailable. · DECCOLM clears data from the status line if the status line is set to host-writable. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 132 Controlling the Page Format Set Lines per Page (DECSLPP) ------------------------------------------------------------ Set Lines per Page (DECSLPP) This control function sets the number of lines for each page in page memory. The number of lines you can select depends on whether you use one session or two sessions. Default: Two sessions--3 pages of 24 lines One session--6 pages of 24 lines Format ------------------------------------------------------------ Page Length ------------------------------------------------------------ Sequence Two Sessions One Session ------------------------------------------------------------ CSI 9/11 2 3/2 4 3/4 t 7/4 3 pages of 24 lines 6 pages of 24 lines CSI 9/11 2 3/2 5 3/5 t 7/4 2 pages of 25 lines 5 pages of 25 lines CSI 9/11 3 3/3 6 3/6 t 7/4 2 pages of 36 lines 4 pages of 36 lines CSI 9/11 4 3/4 8 3/8 t 7/4 1 page of 48 lines 3 pages of 48 lines CSI 9/11 7 3/7 2 3/2 t 7/4 1 page of 72 lines 2 pages of 72 lines CSI 9/11 1 3/1 4 3/4 4 3/4 t 7/4 Not available 1 page of 144 lines ------------------------------------------------------------ Notes on DECSLPP · If you switch to a smaller page size, data that was on the larger page may be split across the smaller pages. To avoid confusion, make sure you set the lines/page before you enter data into page memory. · DECSLPP usually does not change the top and bottom scrolling margins. If, however, you change the page size so that the current scrolling margins exceed the new page size, the terminal resets the margins to the page limits. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Controlling the Page Format Set Left and Right Margins (DECSLRM) 133 ------------------------------------------------------------ Set Left and Right Margins (DECSLRM) This control function sets the left and right margins to define the scrolling region. DECSLRM only works when vertical split screen mode (DECVSSM) is set. Available in: VT400 mode only Default: Margins are at the left and right page borders. Format CSI 9/11 Pl 3/n ; 3/11 Pr 3/n s 7/3 Parameters Pl is the column number for the left margin. Default: Pl = 1. Pr is the column number for the right margin. Default: Pr = 80 or 132 (depending on the page width). Notes on DECSLRM · The value of the left margin (Pl) must be less than the right margin (Pr). · The maximum size of the scrolling region is the page size, based on the setting of set columns per page (DECSCPP). · The minimum size of the scrolling region is two columns. · The terminal only recognizes this control function if vertical split screen mode (DECVSSM) is set. · DECSLRM moves the cursor to column 1, line 1 of the page. · If the left and right margins are set to columns other than 1 and 80 (or 132), the terminal cannot scroll smoothly. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 134 Controlling the Page Format Set Top and Bottom Margins (DECSTBM) ------------------------------------------------------------ Set Top and Bottom Margins (DECSTBM) This control function sets the top and bottom margins for the current page. You cannot perform scrolling outside the margins. Default: Margins are at the page limits. Format CSI 9/11 Pt 3/n ; 3/11 Pb 3/n r 7/2 Parameters Pt is the line number for the top margin. Default: Pt = 1. Pb is the line number for the bottom margin. Default: Pb = current number of lines per screen. Notes on DECSTBM · The value of the top margin (Pt) must be less than the bottom margin (Pb). · The maximum size of the scrolling region is the page size. · DECSTBM moves the cursor to column 1, line 1 of the page. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Controlling the Page Format Vertical Split Screen Mode (DECVSSM) 135 ------------------------------------------------------------ Origin Mode (DECOM) This control function allows cursor addressing relative to the top and bottom margins or the complete page. DECOM determines if the cursor position is restricted to inside the page margins. When you power up or reset the terminal, you reset origin mode. Default: Origin is at the upper-left of the screen, independent of margins. Format CSI 9/11 ? 3/15 6 3/6 h 6/8 Set: within margins. CSI 9/11 ? 3/15 6 3/3 l 6/12 Reset: Upper-left corner. Description When DECOM is set, the home cursor position is at the upper-left corner of the screen, within the margins. The starting point for line numbers depends on the current top margin setting. The cursor cannot move outside of the margins. When DECOM is reset, the home cursor position at the upper-left corner of the screen. The starting point for line numbers is independent of the margins. The cursor can move outside of the margins. ------------------------------------------------------------ Vertical Split Screen Mode (DECVSSM) This control function defines whether or not the set left and right margins (DECSLRM) control function can set margins. Available in: VT400 mode only Default: DECSLRM cannot set margins. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 136 Moving to Another Page Next Page (NP) Format CSI 9/11 ? 3/15 6 3/6 9 3/9 h 6/8 Set: DECSLRM can set margins. CSI 9/11 ? 3/15 6 3/3 9 3/9 l 6/12 Reset: DECSLRM cannot set margins. Description When DECVSSM is set, DECSLRM can set the left and right margins. All line attributes currently in page memory for the session are set to single width, single height. The terminal ignores any sequences to change the line attributes to double width or double height (DECDWL or DECDHL). When DECVSSM is reset, DECSLRM cannot set the left and right margins. The margins are set to the page borders for every page. The terminal can process sequences to change the line attributes to double width or double height (DECDWL or DECDHL). Moving to Another Page The following control functions let you move the cursor forward or backward to another page in page memory. You can move in sequence or randomly. Applications can use these control functions to select the page to write to. ------------------------------------------------------------ Next Page (NP) This control function moves the cursor forward to the home position on one of the following pages in page memory. If there is only one page, the terminal ignores NP. Default: Move to the next page. Format CSI 9/11 Pn 3/n U 5/5 Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Moving to Another Page Preceding Page (PP) 137 Parameters Pn indicates how many pages to move the cursor forward. Default: Pn = 0. If Pn is 0 or 1, then the cursor moves to the next page in page memory. If Pn tries to move the cursor past the last page in memory, then the cursor stops at the last page. ------------------------------------------------------------ Preceding Page (PP) This control function moves the cursor backward to the home position on one of the preceding pages in page memory. If there is only one page, the terminal ignores PP. Default: Move to the preceding page. Format CSI 9/11 Pn 3/n V 5/6 Parameters Pn indicates how many pages to move the cursor backward. Default: Pn = 0. If Pn is 0 or 1, the cursor moves to the preceding page. If Pn tries to move the cursor back farther than the first page in memory, the cursor stops at the first page. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 138 Moving to Another Page Page Position Backward (PPB) ------------------------------------------------------------ Page Position Absolute (PPA) This control function can move the cursor to the corresponding row and column on any page in page memory. You select the page by its number. If there is only one page, the terminal ignores PPA. Default: Move to page 1. Format CSI 9/11 Pn 3/n sp 2/0 P 5/0 Parameters Pn is the number of the page to move the cursor to. If Pn is greater than the number of the last page in memory, the cursor stops at the last page. If Pn is less than the number of the first page, the cursor stops at the first page. ------------------------------------------------------------ Page Position Backward (PPB) This control function moves the cursor backward to the corresponding row and column on one of the preceding pages in page memory. If there is only one page, the terminal ignores PPB. Default: Move backward one page. Format CSI 9/11 Pn 3/n sp 2/0 R 5/2 Parameters Pn indicates the number of pages to move the cursor backward. If Pn tries to move the cursor back farther than the first page in memory, the cursor stops at the first page. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Moving to Another Page Page Position Relative (PPR) 139 ------------------------------------------------------------ Page Position Relative (PPR) This control function moves the cursor forward to the corresponding row and column on one of the following pages in page memory. If there is only one page, the terminal ignores PPR. Default: Move to the next page. Format CSI 9/11 Pn 3/n sp 2/0 Q 5/1 Parameters Pn indicates how many pages to move the cursor forward. If Pn tries to move the cursor beyond the last page in memory, the cursor stops at the last page. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 140 Page Memory Summary Summary Tables 6-1 and 6-2 list the control functions described in this chapter. Table 6-1 Page Format Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Set columns per page DECSCPP CSI Pn $ | Pn columns (80 or 132). Column mode DECCOLM Set: CSI ? 3 h 132 columns. Reset: CSI ? 3 l 80 columns. (D) Set lines per page DECSLPP CSI Pn t Pn lines per page. The number of pages depend on how many sessions you use. ------------------------------------------------------------ Pn Two Sessions One Session ------------------------------------------------------------ 24 3 pages 6 pages 25 2 5 36 2 4 48 1 3 72 1 2 144 -- 1 ------------------------------------------------------------ Set left and right margins DECSLRM CSI Pl ; Pr s Pl = column number of left margin. Pr = column number of right margin. Set top and bottom margins DECSTBM CSI Pt ; Pb r Pt = line number of top margin. Pb = line number of bottom margin. ------------------------------------------------------------ (D) = default. Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Page Memory Summary 141 Table 6-1 (Cont.) Page Format Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Origin mode DECOM Set: CSI ? 6 h Move within margins. Reset: CSI ? 6 l Move outside margins. (D) Vertical split screen mode DECVSSM Set: CSI ? 6 9 h Left and right margins can be changed. Reset: CSI ? 6 9 l Left and right margins cannot be changed. (D) ------------------------------------------------------------ (D) = default. ------------------------------------------------------------ Table 6-2 Sequences for Moving Through Page Memory ------------------------------------------------------------ Name Mnemonic Sequence  New Cursor Position ------------------------------------------------------------ Next page NP CSI Pn U Home. Preceding page PP CSI Pn V Home. Page position absolute PPA CSI Pn P Same as on the old page. Page position backward PPB CSI Pn R Same as on the old page. Page position relative PPR CSI Pn Q Same as on the old page. ------------------------------------------------------------  Pn = the number of pages to move, except for PPA. For PPA, Pn = the actual page number. ------------------------------------------------------------ Chapter 6 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 7 Setting Visual Character and Line Attributes ------------------------------------------------------------ This chapter describes how to select visual attributes for display characters. Visual character attributes change the way characters appear on the screen, without changing the actual characters. For example, the bold character attribute makes a character appear bolder on the screen. You can also select the visual attributes for a complete display line on the screen. Setting Visual Character Attributes This section describes how to select, change, and reverse visual character attributes. You can set the following attributes: · Bold · Underline · Blinking · Negative image (dark character on a light background) · Invisible 142 Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Setting Visual Character Attributes Select Graphic Rendition (SGR) 143 ------------------------------------------------------------ Select Graphic Rendition (SGR) This control function selects one or more character attributes at the same time. Default: Clear all attributes. Format CSI 9/11 Ps 3/n ; 3/11 Ps 3/n . . . . . . m 6/13 Parameters Ps is a number representing a certain visual attribute. You can use more than one Ps value to select different character attributes. Table 7-1 lists Ps values and the attributes they select. Default: Ps = 0 (clears all attributes). Table 7-1 Visual Character Attribute Values ------------------------------------------------------------ Ps Attribute ------------------------------------------------------------ 0 All attributes off 1 Bold 4 Underline 5 Blinking 7 Negative image 8 Invisible image 22 Bold off 24 Underline off 25 Blinking off 27 Negative image off 28 Invisible image off ------------------------------------------------------------ Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 144 Setting Line Attributes Single-Width, Single-Height Line (DECSWL) Examples When you select more than one attribute in an SGR sequence, they are pexecuted in order. For example, you can use the following sequence to display text that is bold, blinking, and underlined: CSI 0 ; 1 ; 5 ; 4 m The following sequence displays the negative image of text: CSI 7 m Notes on SGR · After you select an attribute, the terminal applies that attribute to all new characters received. If you move characters by scrolling, the attributes move with the characters. · If you display control characters, the terminal ignores the bold attribute for displayed control characters. See ``Display Controls Mode'' in Chapter 2. Setting Line Attributes Line attributes are display features that affect the way a line of characters appears on the screen. For example, the double-width, single- height line (DECDWL) attribute makes a line of characters appear twice as wide as a normal line of characters. This section describes how to select line attributes. ------------------------------------------------------------ Single-Width, Single-Height Line (DECSWL) This control function makes the line with the cursor a single-width, single-height line. This line attribute is the standard for all new lines on the screen. Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Setting Line Attributes Double-Width, Double-Height Line (DECDHL) 145 Format ESC 1/11 # 2/3 5 3/5 ------------------------------------------------------------ Double-Width, Single-Height Line (DECDWL) This control function makes the line with the cursor a double-width, single-height line. If the line was single width and single height, all characters to the right of the screen's center are lost. Format ESC 1/11 # 2/3 6 3/6 ------------------------------------------------------------ Double-Width, Double-Height Line (DECDHL) These two control functions make the line with the cursor the top or bottom half of a double-height, double-width line. You must use these sequences in pairs on adjacent lines. In other words, the same display characters must appear in the same positions on both lines to form double-height characters. If the line was single width and single height, all characters to the right of the screen center are lost. Format ESC 1/11 # 2/3 3 3/3 Top Half ESC 1/11 # 2/3 4 3/4 Bottom Half Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 146 Setting Line Attributes Double-Width, Double-Height Line (DECDHL) Example The following sequences make the phrase ``VT420 Video Terminal'' a double-height, double-width line. ESC#3 VT420 Video Terminal ESC#4 VT420 Video Terminal Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Setting Visual Character and Line Attributes Summary 147 Summary Table 7-2 lists the control functions described in this chapter. Table 7-2 Visual Character and Line Attribute Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Select graphic rendition SGR CSI Ps...Ps m Ps = character attribute value(s). (Table 7-1) Single-width, single-height line DECSWL ESC # 5 Double-width, single-height line DECDWL ESC # 6 Double-width, double-height line DECDHL ESC # 3 (top half) ESC # 4 (bottom half) ------------------------------------------------------------ Chapter 7 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 8 Editing ------------------------------------------------------------ This chapter describes how to edit characters in page memory. You use editing control functions to insert, delete, and erase characters. The cursor does not move when you use these functions. You can · Insert or delete columns, lines, or characters · Erase all or part of the display, all or part of a line, or a selected number of characters · Define characters as erasable or not, so you can selectively erase text Inserting and Deleting Columns, Lines, and Characters This section describes control functions that let you insert or delete data in the scrolling region. The scrolling region is the area of the screen inside the top and bottom margins (Chapter 11). 148 Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Inserting and Deleting Columns, Lines, and Characters Delete Column (DECDC) 149 ------------------------------------------------------------ Insert/Replace Mode (IRM) This control function selects how the terminal adds characters to page memory. The terminal always adds new characters at the cursor position. Default: Replace. Format CSI 9/11 4 3/4 h 6/8 Set: insert mode. CSI 9/11 4 3/4 l 6/12 Reset: replace mode. Description If IRM mode is set, new characters move characters in page memory to the right. Characters moved past the page's right border are lost. If IRM mode is reset, new characters replace the character at the cursor position. ------------------------------------------------------------ Delete Column (DECDC) This control function deletes one or more columns in the scrolling region, starting with the column that has the cursor. Available in: VT400 mode only Format CSI 9/11 Pn 3/? ' 2/7 ~ 7/14 Parameters Pn is the number of columns to delete. Default: Pn = 1. Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 150 Inserting and Deleting Columns, Lines, and Characters Delete Line (DL) Description As columns are deleted, the remaining columns between the cursor and the right margin move to the left. The terminal adds blank columns with no visual character attributes at the right margin. DECDC has no effect outside the scrolling margins. ------------------------------------------------------------ Insert Column (DECIC) This control function inserts one or more columns into the scrolling region, starting with the column that has the cursor. Available in: VT400 mode only Format CSI 9/11 Pn 3/? ' 2/7 } 7/13 Parameters Pn is the number of columns to insert. Default: Pn = 1. Description As columns are inserted, the columns between the cursor and the right margin move to the right. DECIC inserts blank columns with no visual character attributes. DECIC has no effect outside the scrolling margins. ------------------------------------------------------------ Delete Line (DL) This control function deletes one or more lines in the scrolling region, starting with the line that has the cursor. Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Inserting and Deleting Columns, Lines, and Characters Insert Line (IL) 151 Format CSI 9/11 Pn 3/n M 4/13 Parameters Pn is the number of lines to delete. Default: Pn = 1. Description As lines are deleted, lines below the cursor and in the scrolling region move up. The terminal adds blank lines with no visual character attributes at the bottom of the scrolling region. If Pn is greater than the number of lines remaining on the page, DL deletes only the remaining lines. DL has no effect outside the scrolling margins. ------------------------------------------------------------ Insert Line (IL) This control function inserts one or more blank lines, starting at the cursor. Format CSI 9/11 Pn 3/n L 4/12 Parameters Pn is the number of lines to insert. Default: Pn = 1. Description As lines are inserted, lines below the cursor and in the scrolling region move down. Lines scrolled off the page are lost. IL has no effect outside the page margins. Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 152 Inserting and Deleting Columns, Lines, and Characters Insert Character (ICH) ------------------------------------------------------------ Delete Character (DCH) This control function deletes one or more characters, from the cursor position to the right. Format CSI 9/11 Pn 3/n P 5/0 Parameters Pn is the number of characters to delete. If Pn is greater than the number of characters between the cursor and the right margin, DCH only deletes the remaining characters. Default: Pn = 1. Description As characters are deleted, the remaining characters between the cursor and right margin move to the left. Character attributes move with the characters. The terminal adds blank spaces with no visual character attributes at the right margin. DCH has no effect outside the scrolling margins. ------------------------------------------------------------ Insert Character (ICH) This control function inserts one or more space (SP) characters, starting at the cursor position. Available in: VT400 mode only Format CSI 9/11 Pn 3/n @ 4/0 Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Erasing Text Erase in Display (ED) 153 Parameters Pn is the number of characters to insert. Default: Pn = 1. Description The ICH sequence inserts Pn blank characters with the normal character attribute. The cursor remains at the beginning of the blank characters. Text between the cursor and right margin moves to the right. Characters scrolled past the right margin are lost. ICH has no effect outside the scrolling margins. Erasing Text This section describes control functions that let you erase data from the display. These control functions can affect data inside or outside the scrolling region. They are not restricted by margins. ------------------------------------------------------------ Erase in Display (ED) This control function erases characters from part or all of the display. When you erase complete lines, they become single-height, single-width lines, with all visual character attributes cleared. ED works inside or outside the scroling margins. Format CSI 9/11 Ps 3/n J 4/10 Parameters Ps represents the amount of the display to erase, as follows: Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 154 Erasing Text Erase Character (ECH) Ps Area Erased 0 (default) From the cursor through the end of the display 1 From the beginning of the display through the cursor 2 The complete display Programming Tip Use a Ps value of 2 to erase the complete display in a fast, efficient manner. ------------------------------------------------------------ Erase in Line (EL) This control function erases characters on the line that has the cursor. EL clears all character attributes from erased character positions. EL works inside or outside the scrolling margins. Format CSI 9/11 Ps 3/n K 4/11 Parameters Ps represents the section of the line to erase, as follows: Ps Section Erased 0 (default) From the cursor through the end of the line 1 From the beginning of the line through the cursor 2 The complete line ------------------------------------------------------------ Erase Character (ECH) This control function erases one or more characters, from the cursor position to the right. ECH clears character attributes from erased character positions. ECH works inside or outside the scrolling margins. Available in: VT400 mode only Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selectively Erasing Text Select Character Protection Attribute (DECSCA) 155 Format CSI 9/11 Pn 3/n X 5/8 Parameters Pn is the number of characters to erase. A Pn value of 0 or 1 erases one character. Default: Pn = 1. Selectively Erasing Text This section describes control functions that let you selectively erase data on the screen. You can only erase characters that you define as erasable. ------------------------------------------------------------ Select Character Protection Attribute (DECSCA) This control function defines the characters that come after it as erasable or not erasable from the screen. The selective erase control functions (DECSED and DECSEL) can only erase characters defined as erasable. Available in: VT400 mode only Format CSI 9/11 Ps 3/n " 2/2 q 7/1 Parameters Ps defines all characters that follow the DECSCA function as erasable or not erasable. Ps Meaning 0 (default) DECSED and DECSEL can erase characters. 1 DECSED and DECSEL cannot erase characters. 2 Same as 0. Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 156 Selectively Erasing Text Selective Erase in Display (DECSED) Notes on DECSCA · DECSCA does not affect visual character attributes set by the select graphic rendition (SGR) function. ------------------------------------------------------------ Selective Erase in Display (DECSED) This control function erases some or all of the erasable characters in the display. DECSED can only erase characters defined as erasable by the DECSCA control function. DECSED works inside or outside the scrolling margins. Available in: VT400 mode only Format CSI 9/11 ? 3/15 Ps 3/n J 4/10 Parameters Ps represents the area of the display to erase, as follows: Ps Area Erased 0 (default) From the cursor through the end of the display 1 From the beginning of the display through the cursor 2 The complete display Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Selectively Erasing Text Selective Erase in Line (DECSEL) 157 ------------------------------------------------------------ Selective Erase in Line (DECSEL) This control function erases some or all of the erasable characters in a single line of text. DECSEL erases only those characters defined as erasable by the DECSCA control function. DECSEL works inside or outside the scrolling margins. Available in: VT400 mode only Format CSI 9/11 ? 3/15 Ps 3/n K 4/11 Parameters Ps represents the section of the line to erase, as follows: Ps Section Erased 0 (default) From the cursor through the end of the line 1 From the beginning of the line through the cursor 2 The complete line Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 158 Editing Summary Summary Table 8-1 lists the control functions described in this chapter. Table 8-1 Editing Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Insert/replace mode IRM Set: CSI 4 h Insert characters. Reset: CSI 4 l Replace characters. Delete column  DECDC CSI Pn ' ~ Pn columns. Insert column  DECIC CSI Pn ' } Pn columns. Delete line DL CSI Pn M Pn lines. Insert line IL CSI Pn L Pn lines. Delete character DCH CSI Pn P Pn characters. Insert character ICH CSI Pn @ Pn characters. Erase in display ED CSI Ps J Ps = 0, cursor to end. (D) Ps = 1, beginning to cursor. Ps = 2, complete display. Erase in line EL CSI Ps K Ps = 0, cursor to end. (D) Ps = 1, beginning to cursor. Ps = 2, complete line. Erase character  ECH CSI Pn X Pn characters. ------------------------------------------------------------  Available in VT400 mode only. (D) = default. Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Editing Summary 159 Table 8-1 (Cont.) Editing Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Select character protection attribute  DECSCA CSI Ps " q Ps = 0, DECSED and DECSEL can erase. (D) Ps = 1, DECSED and DECSEL cannot erase. Ps = 2, DECSED and DECSEL can erase. Selective erase in display  DECSED CSI ? Ps J Ps = 0, cursor to end. (D) Ps = 1, beginning to cursor. Ps = 2, complete display. Selective erase in line  DECSEL CSI ? Ps K Ps = 0, cursor to end. (D) Ps = 1, beginning to cursor. Ps = 2, complete line. ------------------------------------------------------------  Available in VT400 mode only. (D) = default. ------------------------------------------------------------ Chapter 8 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 9 Rectangular Area Operations ------------------------------------------------------------ This chapter describes control functions you can use to manipulate rectangular areas of text in page memory. You can · Copy, fill, or erase rectangular areas · Selectively erase parts of a rectangular area · Change or reverse visual character attributes in rectangular areas Copying, Filling, and Erasing Rectangular Areas This section describes the control functions for copying, filling, or erasing a rectangular area from page memory. 160 Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Copying, Filling, and Erasing Rectangular Areas Copy Rectangular Area (DECCRA) 161 ------------------------------------------------------------ Copy Rectangular Area (DECCRA) This control function copies a rectangular area of characters from one section to another in page memory. The copied text retains its character values and attributes. Available in: VT400 mode only Format CSI 9/11 Pts; Pls; Pbs; Prs; Pps; area to be copied Ptd; Pld; Ppd destination $ 2/4 v 7/6 Parameters Pts; Pls; Pbs; Prs; Pps; define the rectangular area to be copied (the source). A semicolon (3/11) separates parameters. Pts is the top-line border. Pts must be less than or equal to Pbs. Default: Pts = 1. Pls is the left-column border. Pls must be less than or equal to Prs. Default: Pls = 1. Pbs is the bottom-line border. Default: Pbs = the last line of the page. Prs is the right-column border. Default: Prs = the last column of the page. Pps is the number of the page where the rectangular area is located. Default: Pps = 1. Ptd; Pld; Ppd; define the destination of the copied rectangular area. Ptd is the top-line border. Default: Ptd = 1. Pld is the left-column border. Default: Pld = 1. Ppd is the number of the page. Default: Ppd = 1. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 162 Copying, Filling, and Erasing Rectangular Areas Fill Rectangular Area (DECFRA) Notes on DECCRA · If Pbs is greater than Pts, or Pls is greater than Prs, the terminal ignores DECCRA. · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECCRA is not affected by the page margins. · The copied text takes on the line attributes of the destination area. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · If a page value exceeds the number of pages available in the current page arrangement, the value is treated as the last available page number. · If the destination area is partially off the page, DECCRA clips the off-page data. · DECCRA does not change the active cursor position. ------------------------------------------------------------ Fill Rectangular Area (DECFRA) This control function fills a rectangular area in page memory with a specified character. DECFRA replaces the rectangular area's character positions and attributes with the specified fill character. The fill character assumes the visual character attributes set by the last select graphic rendition (SGR) command. DECFRA does not change the current line attributes. Available in: VT400 mode only Format CSI 9/11 Pch 3/n ; 3/11 Pt; Pl; Pb; Pr 3/n $ 2/4 x 7/8 Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Copying, Filling, and Erasing Rectangular Areas Fill Rectangular Area (DECFRA) 163 Parameters Pch is the decimal value of the fill character. Pch can be any value from 32 to 126, or from 160 to 255. If Pch is not in this range, the terminal ignores the DECFRA command. The decimal value refers to the character in the current GL or GR in-use table (Chapter 5). See the character tables in Chapter 2 for the decimal values of characters. Pt; Pl; Pb; Pr define the rectangular area to be filled: Pt is the top-line border. Pt must be less than or equal to Pbs. Default: Pt = 1. Pl is the left-column border. Pl must be less than or equal to Pr. Default: Pl = 1. Pb is the bottom-line border. Default: Pb = the last line of the active page. Pr is the right-column border. Default: Pr = the last column of the active page. Notes on DECFRA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECFRA is not affected by the page margins. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · DECFRA does not change the active cursor position. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 164 Copying, Filling, and Erasing Rectangular Areas Erase Rectangular Area (DECERA) ------------------------------------------------------------ Erase Rectangular Area (DECERA) This control function erases characters from the specified rectangular area in page memory. When an area is erased, DECERA replaces all character positions with the space character (2/0). DECERA erases character values and visual attributes from the specified area. DECERA does not erase line attributes. Available in: VT400 mode only Format CSI 9/11 Pt 3/n ; 3/11 Pl; Pb; Pr ******** $ 2/4 z 7/10 Parameters Pt, Pl, Pb, and Pr define the rectangular area to be erased: Pt is the top-line border. Pt must be less than or equal to Pb. Default: Pt = 1. Pl is the left-column border. Pl must be less than or equal to Pr. Default: Pl = 1. Pb is the bottom-line border. Default: Pb = the last line of the active page. Pr is the right-column border. Default: Pr = the last column of the active page. Notes on DECERA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECERA is not affected by the page margins. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · DECERA does not change the active cursor position. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Copying, Filling, and Erasing Rectangular Areas Selective Erase Rectangular Area (DECSERA) 165 ------------------------------------------------------------ Selective Erase Rectangular Area (DECSERA) This control function erases all erasable characters from a specified rectangular area in page memory. The select character protection attribute (DECSCA) control function defines whether or not DECSERA can erase characters (Chapter 8). When an area is erased, DECSERA replaces character positions with the space character (2/0). DECSERA does not change · Visual attributes set by the select graphic rendition (SGR) function · Protection attributes set by DECSCA · Line attributes (Chapter 7) Available in: VT400 mode only Format CSI 9/11 Pt 3/n ; 3/11 Pl; Pb; Pr ********* $ 2/4 { 7/11 Parameters Pt, Pl, Pb, and Pr define the rectangular area to be selectively erased: Pt is the top-line border. Pt must be less than or equal to Pb. Default: Pt = 1. Pl is the left-column border. Pl must be less than or equal to Pr. Default: Pl = 1. Pb is the bottom-line border. Default: Pb = the last line of the active page. Pr is the right-column border. Default: Pr = the last column of the active page. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 166 Changing Attributes of Rectangles Select Attribute Change Extent (DECSACE) Notes on DECSERA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECSERA is not affected by the page margins. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · DECSERA does not change the active cursor position. Changing Attributes of Rectangles This section describes the control functions that let you change or reverse the visual character attributes in a rectangular area. ------------------------------------------------------------ Select Attribute Change Extent (DECSACE) This control function lets you select which character positions in a rectangle can have their attributes changed or reversed. DECSACE controls the effect of two other functions--change attributes in rectangular area (DECCARA) and reverse attributes in rectangular area (DECRARA). Available in: VT400 mode only Format CSI 9/11 Ps 3/n * 2/10 x 7/8 Parameters Ps selects the area of character positions affected. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Changing Attributes of Rectangles Change Attributes in Rectangular Area (DECCARA) 167 Ps Area Affected 0 (default) DECCARA or DECRARA affect the stream of character positions that begins with the first position specified in the DECCARA or DECRARA command, and ends with the second character position specified. 1 Same as 0. 2 DECCARA and DECRARA affect all character positions in the rectangular area. The DECCARA or DECRARA command specifies the top-left and bottom-right corners. ------------------------------------------------------------ Change Attributes in Rectangular Area (DECCARA) This control function lets you change the visual character attributes (bold, blink, reverse video, and underline) of a specified rectangular area in page memory. The select attribute change extent (DECSACE) control function determines whether all or some of the character positions in the rectangle are affected. DECCARA does not change the values of characters, just the visual attributes of those characters. Available in: VT400 mode only Format CSI 9/11 Pt; Pl; Pb; Pr; area to be changed Ps1; . . . Psn attributes to change $ 2/4 r 7/2 Parameters Pt; Pl; Pb; Pr; define the rectangular area to be changed. A semicolon (3/11) separates parameters. Pt is the top-line border. Pt must be less than or equal to Pb. Default: Pt = 1. Pl is the left-column border. Pl must be less than or equal to Pr. Default: Pl = 1. Pb is the bottom-line border. Default: Pb = last line of the active page. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 168 Changing Attributes of Rectangles Change Attributes in Rectangular Area (DECCARA) Pr is the right-column border. Default: Pr = last column of the active page. Ps1; . . . Psn select the visual character attributes to change. These values correspond to the values used in the select graphic rendition (SGR) function (Chapter 7). Psn Meaning 0 (default) Attributes off (no bold, no underline, no blink, positive image) 1 Bold 4 Underline 5 Blink 7 Negative image 22 No bold 24 No underline 25 No blink 27 Positive image DECCARA ignores all other parameter values. When you use more than one parameter in a command, DECCARA executes them cumulatively in sequence. Examples The following sequence changes the video attributes of the complete screen to blink and underscore: CSI ; ; ; ; 0; 4; 5; $ r The following sequence turns off the blinking character attribute from position line 10, column 2 to position line 14, column 45 on the current page: CSI 10; 2; 14; 45; 25 $ r Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Changing Attributes of Rectangles Reverse Attributes in Rectangular Area (DECRARA) 169 Notes on DECCARA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECCARA is not affected by the page margins. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · DECCARA does not change the active cursor position. · DECCARA does not change the current rendition set by the select graphic rendition (SGR) function (Chapter 7). · The exact character positions affected by DECCARA depend on the current setting of the select attribute change extent (DECSACE) function. ------------------------------------------------------------ Reverse Attributes in Rectangular Area (DECRARA) This control function lets you reverse the visual character attributes (bold, blink, reverse video, and underline) of a specified rectangular area in page memory. The select attribute change extent (DECSACE) control function determines whether all or some of the character positions in the rectangle are affected. Reversing a visual attribute means to change the attribute to its opposite setting, on or off. For example, DECRARA can change character positions that are bold and not underlined to positions that are underlined and not bold. DECRARA does not change the values of characters, just the visual attributes of those characters. Available in: VT400 mode only Format CSI 9/11 Pt; Pl; Pb; Pr; area to be reversed Ps1; . . . Psn attributes to reverse $ 2/4 t 7/4 Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 170 Changing Attributes of Rectangles Reverse Attributes in Rectangular Area (DECRARA) Parameters Pt, Pl, Pb, and Pr define the rectangular area to be reversed. Pt is the top-line border. Pt must be less than or equal to Pb. Default: Pt = 1. Pl is the left-column border. Pl must be less than or equal to Pr. Default: Pr = 1. Pb is the bottom-line border. Default: Pb = last line of the active page. Pr is the right-column border. Default: Pr = last column of the active page. Ps1; . . . Psn select the visual character attributes to reverse. These values correspond to the values used in the select graphic rendition (SGR) function (Chapter 7). Ps Meaning 0 Reverse all attributes (default). 1 Reverse the bold attribute. 4 Reverse the underline attribute. 5 Reverse the blink attribute. 7 Reverse the negative-image attribute. DECRARA ignores all other parameter values. When you use more than one parameter in a command, DECRARA executes them cumulatively in sequence. Examples The following sequence reverses the blink and underscore attributes of the complete screen: CSI ; ; ; ; 0; 4; 5; $ t Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Changing Attributes of Rectangles Reverse Attributes in Rectangular Area (DECRARA) 171 The following sequence reverses all attributes except the blink attribute, from position line 10, column 2 to position line 14, column 45 on the current page: CSI 10; 2; 14; 45; 1; 4; 7 $ t Notes on DECRARA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). · DECRARA is not affected by the page margins. · If the value of Pt, Pl, Pb, or Pr exceeds the width or height of the active page, the value is treated as the width or height of that page. · DECRARA does not change the active cursor position. · DECRARA does not change the current rendition set by the select graphic rendition (SGR) function (Chapter 7). · The exact character positions affected by DECRARA depend on the current setting of the select attribute change extent (DECSACE) function. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 172 Rectangular Area Operations Summary Summary Table 9-1 is a summary of the control functions in this chapter. Table 9-1 Rectangular Area Control Functions ------------------------------------------------------------ Name Mnemonic Sequence  ------------------------------------------------------------ Copy rectangular area DECCRA CSI Pts; Pls; Pbs; Prs; Pps; Ptd; Pld; Ppd $ v Source Pts = top-line border. Pls = left-column border. Pbs = bottom-line border. Prs = right-column border. Pps = page number. Destination Ptd = top-line border. Pld = left-column border. Ppd = page number. Erase rectangular area DECERA CSI Pt; Pl; Pb; Pr $ z Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. Fill rectangular area DECFRA CSI Pch; Pt; Pl; Pb; Pr $ x Pch = decimal code of fill character. Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. Selective erase rectangular area DECSERA CSI Pt; Pl; Pb; Pr $ { Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. ------------------------------------------------------------  All sequences in this chapter work in VT400 mode only. Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Rectangular Area Operations Summary 173 Table 9-1 (Cont.) Rectangular Area Control Functions ------------------------------------------------------------ Name Mnemonic Sequence  ------------------------------------------------------------ Select attribute change extent DECSACE CSI Ps * x Ps = character positions affected. 0 or 1 = stream of character positions. 2 = rectangular area of character positions. Change attributes in rectangular area DECCARA CSI Pt; Pl; Pb; Pr; Ps1..Psn $ r Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. Psn = visual character attributes. Reverse attributes in rectangular area DECRARA CSI Pt; Pl; Pb; Pr; Ps1..Psn $ t Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. Psn = visual character attributes. ------------------------------------------------------------  All sequences in this chapter work in VT400 mode only. ------------------------------------------------------------ Chapter 9 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 10 Cursor Movement and Panning ------------------------------------------------------------ This chapter describes the control functions you use to move the cursor and view different areas in the terminal's page memory. You can · Move the cursor on a page · Pan the user window across a page or to another page Chapter 6 describes page memory. Scrolling and Panning Before you read this chapter, you should understand the difference between scrolling and panning. Scrolling is the movement of data between the margins of a page. Data scrolled beyond the margins is lost from the terminal's page memory. Panning is the movement of the user window in page memory, to view different parts of a page. The user window is the area in page memory currently visible on the screen. You do not lose data in page memory, because the window moves rather than the data. You only use panning functions when the page you are viewing is larger than the user window. For example, suppose the current page is 72 lines by 80 columns and the screen is 24 lines. Initially, only the first 24 lines are visible. To view other parts of the page, you can pan the user window up or down. 174 Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Cursor Movement and Panning 175 Figure 10-1 shows the difference between scrolling and panning. Figure 10-1 The Difference Between Scrolling and Panning The default user window for the VT420 is 24 lines by 80 columns. You can also divide the screen into two user windows, to view data from two sessions at the same time. Installing and Using the VT420 Video Terminal describes how to use windows. Also see Chapter 14 of this manual for more details on using two sessions. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 176 Cursor Movement and Panning The Cursor The Cursor The cursor is a marker that indicates the active position in page memory. The active position is the point on the current page where the next character is written. The default text cursor style is a blinking block. The cursor can also be a steady block, a blinking underscore, or a steady underscore. The user can select one of these cursor styles in the Display Set-Up screen. See Installing and Using the VT420 Video Terminal for details. Usually, the cursor appears on the screen. However, you can use control functions to move the cursor anywhere on the current page, or to any other page in page memory. ------------------------------------------------------------ Text Cursor Enable Mode (DECTCEM) This control function makes the cursor visible or invisible. Default: Visible Format CSI 9/11 ? 3/15 2 3/2 5 3/5 h 6/8 Set: makes the cursor visible. CSI 9/11 ? 3/15 2 3/2 5 3/5 l 6/12 Reset: makes the cursor invisible. Moving the Cursor on the Current Page This section describes the control functions you can use to move the cursor on the current page. Remember, page and display are two different concepts. The area of the main display is restricted to the screen - 24, 36, or 48 lines by 80 or 132 columns, depending on the number of lines/screen you select (Chapter 11). The area of the current page can be 24, 25, 36, 48, 72, or 144 lines by 80 or 132 columns, depending on the page format you select (Chapter 6). NOTE Some C0 and C1 control characters not covered in this chapter also move the cursor. See Chapter 2 for detailed descriptions of these control characters. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Moving the Cursor on the Current Page Forward Index (DECFI) 177 In the following sequences, the parameters Pn, Pl, and Pc indicate cursor position. If you omit a parameter or use a value of 0, the terminal uses a default value of 1. ------------------------------------------------------------ Back Index (DECBI) This control function moves the cursor backward one column. If the cursor is at the left margin, all screen data within the margins moves one column to the right. The column shifted past the right margin is lost. Available in: VT400 mode only Format ESC 1/11 6 3/6 Description DECBI adds a new column at the left margin, with no visual attributes. DECBI is not affected by the margins. If the cursor is at the left border of the page when the terminal receives DECBI, the terminal ignores DECBI. ------------------------------------------------------------ Forward Index (DECFI) This control function moves the cursor forward one column. If the cursor is at the right margin, all screen data within the margins moves one column to the left. The column shifted past the left margin is lost. Available in: VT400 mode only Format ESC 1/11 9 3/6 Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 178 Moving the Cursor on the Current Page Horizontal and Vertical Position (HVP) Description DECFI adds a new column at the right margin, with no visual attributes. DECFI is not affected by the margins. If the cursor is at the right border of the page when the terminal receives DECFI, the terminal ignores DECFI. ------------------------------------------------------------ Cursor Position (CUP) This control function moves the cursor to the specified line and column. The starting point for lines and columns depends on the setting of origin mode (DECOM). CUP applies only to the current page. Format CSI 9/11 Pl 3/n ; 3/11 Pc 3/n H 4/8 Parameters Pl is the number of the line to move to. If Pl is 0 or 1, the cursor moves to line 1. Pc is the number of the column to move to. If Pc is 0 or 1, the cursor moves to column 1. ------------------------------------------------------------ Horizontal and Vertical Position (HVP) This control function works the same as the cursor position (CUP) function. New applications should use CUP instead of HVP. HVP is provided for compatibility with earlier Digital products. Format CSI 9/11 Pl 3/n ; 3/11 Pc 3/n f 6/6 Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Moving the Cursor on the Current Page Cursor Backward (CUB) 179 ------------------------------------------------------------ Cursor Forward (CUF) This control function moves the cursor to the right by a specified number of columns. The cursor stops at the right border of the page. Format CSI 9/11 Pn 3/n C 4/3 Parameters Pn is the number of columns to move the cursor to the right. ------------------------------------------------------------ Cursor Backward (CUB) This control function moves the cursor to the left by a specified number of columns. The cursor stops at the left border of the page. Format CSI 9/11 Pn 3/n D 4/4 Parameters Pn is the number of columns to move the cursor to the left. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 180 Moving the Cursor on the Current Page Cursor Down (CUD) ------------------------------------------------------------ Cursor Up (CUU) Moves the cursor up a specified number of lines, in the same column. The cursor stops at the top margin. If the cursor is already above the top margin, the cursor stops at the top line. Format CSI 9/11 Pn 3/n A 4/1 Parameters Pn is the number of lines to move the cursor up. ------------------------------------------------------------ Cursor Down (CUD) This control function moves the cursor down a specified number of lines, in the same column. The cursor stops at the bottom margin. If the cursor is already below the bottom margin, the cursor stops at the bottom line. Format CSI 9/11 Pn 3/n B 4/2 Parameters Pn is the number of lines to move the cursor down. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Panning Pan Down (SU) 181 Panning You can display any part of the current page by moving the user window across the page. The following control functions let you pan the user window up or down. To a user viewing the screen, data appears to scroll in the opposite direction. For example, if you pan up, the data appears to scroll down. In the following sequences, Pn indicates the cursor position. If you omit Pn or use a value of 0, the terminal uses a default value of 1. The term current page refers to the page with the cursor. NOTE The ANSI mnemonics in parentheses are provided only for reference. These mnemonics do not indicate how the VT420 uses the panning functions. For example, the ANSI mnemonic for pan down is SU (scroll up). ------------------------------------------------------------ Pan Down (SU) This control function moves the user window down a specified number of lines in page memory. Format CSI 9/11 Pn 3/n S 5/3 Parameters Pn is the number of lines to move the user window down in page memory. Pn new lines appear at the bottom of the display. Pn old lines disappear at the top of the display. You cannot pan past the bottom margin of the current page. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 182 Panning Pan Up (SD) ------------------------------------------------------------ Pan Up (SD) This control function moves the user window up a specified number of lines in page memory. Format CSI 9/11 Pn 3/n T 5/4 Parameters Pn is the number of lines to move the user window up in page memory. Pn new lines appear at the top of the display. Pn old lines disappear at the bottom of the display. You cannot pan past the top margin of the current page. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Cursor Coupling Vertical Cursor-Coupling Mode (DECVCCM) 183 Cursor Coupling This section describes control functions that make the user window pan with the cursor when the cursor moves past the window's boundaries. These functions are called cursor-coupling modes. A coupled cursor is a cursor that appears to pull the user window through the page. When an application tries to write data beyond the borders of the user window, the window pans in that direction to keep the cursor visible in the display. The cursor looks like it is connected, or coupled, to the display. You can have applications set the coupling modes to cause automatic panning. You can also reset the coupling modes to write data into off- screen page memory. ------------------------------------------------------------ Vertical Cursor-Coupling Mode (DECVCCM) This control function determines whether the user window pans with the cursor when the cursor moves past the top or bottom border of the user window. DECVCCM is only useful when the height of the current user window is smaller than the page. The cursor must stay on the current page. Default: Coupled Format CSI 9/11 ? 3/15 6 3/6 1 3/1 h 6/8 Set: couples the cursor to the display. CSI 9/11 ? 3/15 6 3/6 1 3/1 l 6/12 Reset: uncouples the cursor. Description When DECVCCM is set, the cursor is coupled to the display for vertical movement. When the cursor moves past the top or bottom border of the user window, the window pans to keep the cursor in view. If the cursor moves past the top of the display, the user window pans up. New lines appear at the top of the screen, while lines at the bottom move out of view. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 184 Cursor Coupling Page Cursor-Coupling Mode (DECPCCM) When DECVCCM is reset, the cursor is uncoupled from the display. If the cursor moves past the top or bottom border of the user window, the cursor disappears. ------------------------------------------------------------ Page Cursor-Coupling Mode (DECPCCM) This control function determines if a new page appears in the display when the cursor moves to a new page. DECPCCM is only useful with a multiple-page format (Chapter 6). Default: Coupled Format CSI 9/11 ? 3/15 6 3/6 4 3/4 h 6/8 Set: couples the cursor to the display. CSI 9/11 ? 3/15 6 3/6 1 3/1 l 6/12 Reset: uncouples the cursor. Description When DECPCCM is set, the cursor is coupled to the display when the cursor moves to a new page. The new page appears in the display to keep the cursor in view. When DECPCCM is reset, the cursor is uncoupled from the display. If the cursor moves to a new page, the cursor disappears. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Cursor Movement and Panning Summary 185 Summary Table 10-1 lists the control functions described in this chapter. Table 10-1 Cursor Movement and Panning Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Enabling the Cursor ------------------------------------------------------------ Text cursor enable mode DECTCEM Set: CSI ? 25 h Visible cursor. (D) Reset: CSI ? 25 l Invisible cursor. ------------------------------------------------------------ Moving the Cursor  ------------------------------------------------------------ Back index+ DECBI ESC 6 Forward index+ DECFI ESC 9 Cursor position CUP CSI Pl ; Pc H Line Pl, column Pc. Horizontal and vertical position HVP CSI Pl ; Pc f Line Pl, column Pc. (Digital recommends using CUP instead.) Cursor forward CUF CSI Pn C Pn columns to the right. Cursor backward CUB CSI Pn D Pn columns to the left. Cursor up CUU CSI Pn A Pn lines up. Cursor down CUD CSI Pn B Pn lines down. ------------------------------------------------------------ Panning  ------------------------------------------------------------ Pan down SU CSI Pn S Pn lines down. Pan up SD CSI Pn T Pn lines up. ------------------------------------------------------------  In these sequences, the default value for Pn, Pl, and Pc is 1. +Available in VT400 mode only. (D) = default. Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 186 Cursor Movement and Panning Summary Table 10-1 (Cont.) Cursor Movement and Panning Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Panning  ------------------------------------------------------------ Vertical cursor-coupling mode DECVCCM Set: CSI ? 61 h Coupled. (D) Reset: CSI ? 61 l Uncoupled. Page cursor-coupling mode DECPCCM Set: CSI ? 64 h Coupled. (D) Reset: CSI ? 64 l Uncoupled. ------------------------------------------------------------  In these sequences, the default value for Pn, Pl, and Pc is 1. (D) = default. ------------------------------------------------------------ Chapter 10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 11 Keyboard, Printing, and Display Commands ------------------------------------------------------------ This chapter describes the control functions for the following areas: · Keyboard keys, including user-defined keys · Printing, including printer port controls · Screen displays, including the status line and scrolling In general, the control functions apply to all VT420 keyboards--ANSI, short ANSI, and PC keyboards. Keyboard Control Functions This section describes control functions that affect keyboard operation. · Keyboard action mode (locking or unlocking the keyboard) · Backarrow key mode · Line feed/new line mode · Autorepeat mode · Autowrap mode · Cursor keys mode · Numeric keypad controls · Typewriter or data processing keys · User-defined keys Chapter 11 187 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 188 Keyboard Control Functions Backarrow Key Mode (DECBKM) ------------------------------------------------------------ Keyboard Action Mode (KAM) This control function locks or unlocks the keyboard. Default: Unlocked Format CSI 9/11 2 3/2 h 6/8 Set: locks the keyboard. CSI 9/11 2 3/2 l 6/12 Reset: unlocks the keyboard. Description If KAM is set, the keyboard cannot send characters to the host. The Wait indicator appears on the keyboard indicator line at the bottom of the screen. The terminal ignores all keystrokes that send characters to the host. KAM does not affect the ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up) or ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session) keys. If KAM is reset, the terminal unlocks the keyboard. The keyboard can send characters to the host. ------------------------------------------------------------ Backarrow Key Mode (DECBKM) This control function determines whether the < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ key works as a backspace key or delete key. NOTE For compatibility with Digital's software, you should keep DECBKM reset (delete key setting). Default: Delete key Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard Control Functions Line Feed/New Line Mode (LNM) 189 Format CSI 9/11 ? 3/15 6 3/6 7 3/7 h 6/8 Set: backspace key. CSI 9/11 ? 3/15 6 3/6 7 3/7 l 6/12 Reset: delete key. Description If DECBKM is set, < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ works as a backspace key. When you press < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ , the terminal sends a BS character to the host. If DECKBKM is reset, < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ works as a delete key. When you press < ------------------------------------------------------------ x ------------------------------------------------------------ ------------------------------------------------------------ , the terminal sends a DEL character to the host. ------------------------------------------------------------ Line Feed/New Line Mode (LNM) This control function selects the characters sent to the host when you press the ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ key. LNM also controls how the terminal interprets line feed (LF), form feed (FF), and vertical tab (VT) characters. NOTE For compatibility with Digital's software, you should keep LNM reset (line feed). Default: Line feed Format CSI 9/11 2 3/2 0 3/0 h 6/8 Set: new line. CSI 9/11 2 3/2 0 3/0 l 6/12 Reset: line feed Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 190 Keyboard Control Functions Autorepeat Mode (DECARM) Description If LNM is set, the cursor moves to the first column on the next line when the terminal receives an LF, FF, or VT character. When you press ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ , the terminal sends both a carriage return (CR) and line feed (LF). If LNM is reset, the cursor moves to the current column on the next line when the terminal receives an LF, FF, or VT character. When you press ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ , the terminal sends only a carriage return (CR) character. Notes on LNM · When the auxiliary keypad is in keypad numeric mode (DECKPNM), the ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ key sends the same character(s) as the ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ key. ------------------------------------------------------------ Autorepeat Mode (DECARM) This control function determines whether or not keys automatically repeat their character when held down. If DECARM is set, most keys you press for more than 0.5 seconds send a character repeatedly until you release the key. Default: Repeat Format CSI 9/11 ? 3/15 8 3/8 h 6/8 Set: keys autorepeat when pressed for more than 0.5 seconds. CSI 9/11 ? 3/15 8 3/8 l 6/12 Reset: keys do not autorepeat. Notes on DECARM · The following keys on the ANSI and short ANSI keyboards do not repeat: ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold) ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print) ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up) ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session) ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ Lock key ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard Control Functions Autowrap Mode (DECAWM) 191 · The following keys on the PC keyboard do not repeat: ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ AltGr ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Caps Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Pause ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Enter ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Num Lock ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Autowrap Mode (DECAWM) This control function determines whether or not received characters automatically wrap to the next line when the cursor reaches the right border of a page in page memory. Default: No autowrap Format CSI 9/11 ? 3/15 7 3/7 h 6/8 Set: autowrap. CSI 9/11 ? 3/15 7 3/7 l 6/12 Reset: no autowrap. Description If the DECAWM function is set, graphic characters received when the cursor is at the right border of the page appear at the beginning of the next line. Any text on the page scrolls up if the cursor is at the end of the scrolling region. If the DECAWM function is reset, graphic characters received when the cursor is at the right border of the page replace characters already on the page. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 192 Numeric Keypad Cursor Keys Mode (DECCKM) ------------------------------------------------------------ Cursor Keys Mode (DECCKM) This control function selects the sequences the arrow keys send. You can use the four arrow keys to move the cursor through the current page or to send special application commands. See Chapter 3 for the sequences the keys send. Default: Cursor Format CSI 9/11 ? 3/15 1 3/1 h 6/8 Set: application sequences. CSI 9/11 ? 3/15 1 3/1 l 6/12 Reset: cursor sequences. Description If the DECCKM function is set, the arrow keys send application sequences to the host. If the DECCKM function is reset, the arrow keys send ANSI cursor sequences to the host. Numeric Keypad The following control functions are for the numeric keypad. The keypad application and numeric modes (DECKPAM and DECKPNM) work the same as numeric keypad mode (DECNKM). See Chapter 3 for the sequences the keys send. ------------------------------------------------------------ Keypad Application and Numeric Modes (DECKPAM and DECKPNM) These control functions select whether the numeric keypad sends numeric characters or application sequences to the host. Default: Numeric characters Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Numeric Keypad Keypad Application and Numeric Modes (DECKPAM and DECKPNM) 193 Format ESC 1/11 = 3/13 DECKPAM: application sequences. ESC 1/11 > 3/14 DECKPNM: keypad characters Description If DECKPAM is selected, the numeric keypad sends application sequences. If DECKPNM is selected, the numeric keypad sends the characters shown on each key--number, comma, period, or minus sign. Keys ------------------------------------------------------------ ------------------------------------------------------------ PF1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ PF4 ------------------------------------------------------------ ------------------------------------------------------------ send application sequences. Notes on DECKPAM and DECKPNM · When you turn on or reset the terminal, the terminal automatically selects numeric keypad mode. ------------------------------------------------------------ Numeric Keypad Mode (DECNKM) This control function works like the DECKPAM and DECKPNM functions above. DECNKM is provided mainly for use with the request and report mode (DECRQM/DECRPM) control functions (Chapter 12). Available in: VT400 mode only Default: Numeric Format CSI 9/11 ? 3/15 6 3/6 6 3/6 h 6/8 Set: application sequences. CSI 9/11 ? 3/15 6 3/6 6 3/6 l 6/12 Reset: keypad characters. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 194 Keyboard Control Functions Typewriter or Data Processing Keys ------------------------------------------------------------ Typewriter or Data Processing Keys You can select whether the main keyboard keys act as data processing keys or typewriter keys, by using the keyboard usage mode (DECKBUM) function. See Chapter 3 for a description of data processing keys. Default: Typewriter keys Keyboard Usage Mode (DECKBUM) CSI 9/11 ? 3/15 6 3/6 8 3/8 h 6/8 Set: data processing keys. CSI 9/11 ? 3/15 6 3/6 8 3/8 l 6/12 Reset: typewriter keys. Description If DECKBUM is set, data processing keys send the characters on the right half of their keycaps. If DECKBUM is reset, data processing keys send the characters on the left half of their keycaps. Notes on DECKBUM · DECKBUM changes the characters that the main keyboard keys send. Make sure you are aware of this change if you use DECKBUM in an application. · If you use the North American dialect, DECKBUM should always be reset (typewriter). For all other languages, you can use either mode. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard Control Functions Enable Local Functions (DECELF) 195 ------------------------------------------------------------ Key Position Mode (DECKPM) This control function selects whether the keyboard sends character codes or key position reports to the host. DECKPM lets new applications take full control of the keyboard including single shifts, locking shifts, and compose character processing. Default: Send character codes Format CSI 9/11 8 3/8 1 3/1 h 6/8 Set: Send key position reports. CSI 9/11 8 3/8 1 3/1 l 6/12 Reset: Send character codes. Description If the DECKPM function is set, all keyboard keys send extended reports that include the key position and the state of modifier keys when pressed. A modifier key is pressed in combination with another key to modify the code sent by that key. The ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key is a modifier key. If the DECKPM function is reset, the keyboard keys send character codes. NOTE DECKPM only affects keyboard input. It does not affect how the terminal interprets data from the host. ------------------------------------------------------------ Enable Local Functions (DECELF) This control function lets you enable or disable the keys used to perform several local terminal functions: cutting and pasting tex between sessions, panning, and resizing windows. DECELF is useful for · Simplifying the keyboard for novice users · Letting the corresponding keys send position codes to the host when key position mode (DECKPM) is set · Disabling features that are not compatible with the application Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 196 Keyboard Control Functions Enable Local Functions (DECELF) Format CSI 9/11 Pf1 3/n ; 3/11 Pc1 3/n ; 3/11 . . . . . . Pfn; Pcn 3/n 3/n + 2/11 q 7/1 Parameters Pfn is a number that specifies the local function affected. Pfn Local Functions Affected Default Setting 0 (default) All local functions listed for 1, 2, and 3. 1 Copy and paste keys, including ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold), ------------------------------------------------------------ ------------------------------------------------------------ Select ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ Remove ------------------------------------------------------------ ------------------------------------------------------------ , and ------------------------------------------------------------ ------------------------------------------------------------ Insert Here ------------------------------------------------------------ ------------------------------------------------------------ . The keys are enabled. 2 Panning keys, including ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ with ------------------------------------------------------------ ------------------------------------------------------------ " ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ # ------------------------------------------------------------ ------------------------------------------------------------ , ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ , or ------------------------------------------------------------ ------------------------------------------------------------ ! ------------------------------------------------------------ ------------------------------------------------------------ . The keys are enabled. 3 Window resizing keys, including: ------------------------------------------------------------ ------------------------------------------------------------ Control ------------------------------------------------------------ ------------------------------------------------------------ and ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ with ------------------------------------------------------------ ------------------------------------------------------------ " ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ # ------------------------------------------------------------ ------------------------------------------------------------ keys. The keys are enabled. Pcn controls the action of the local function specified by the correspondng Pfn value. Pcn Meaning 0 Selects the default setting of the local function. In VT mode, the default setting is enabled. In PC TERM mode, the default setting is disabled. 1 Enables the local function. The associated keys perform the local function and cannot send position codes to the host. 2 Disables the local function. The associated keys do not perform the local function and may send position codes to the host. Description DECELF can accept any number of parameter pairs. The terminal executes the parameters in the order it receives them. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard Control Functions Local Function Key Control (DECLFKC) 197 ------------------------------------------------------------ Local Function Key Control (DECLFKC) This control function lets you select the action performed by some of local-function keys on the top row of the keyboard: ------------------------------------------------------------ ANSI Keyboards ------------------------------------------------------------ PC Keyboards ------------------------------------------------------------ Key Action Key Action ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ Hold ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ Hold ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ Print ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ Print ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ Set-Up ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ SetUp ------------------------------------------------------------ ------------------------------------------------------------ Set-Up ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ Session ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ Session ------------------------------------------------------------ You can have the key perform its local function, send a function key sequence to the host, or do nothing. This control function is useful for · Simplifying the keyboard for novice users · Disabling features that are not compatible with the application, such as local printing Format CSI 9/11 Pk1 3/n ; 3/11 Pf1 3/n . . . . . . Pkn; Pfn 3/n 3/n * 2/10 } 7/13 Parameters Pkn is a number from 0 to 4 that corresponds to the local-function key affected (F1 to F4). A Pkn value of 0 means that all four keys (F1 through F4) are affected. Pfn controls the action of the local-function key specified by the corresponding Pkn value. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 198 Keyboard Control Functions Select Modifier Key Reporting (DECSMKR) Pfn Meaning 0 Selects the default function of the key. VT mode Local print PC TERM mode Scan code 1 The key performs its local function either shifted, unshifted, or with the ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key. VT mode Print PC TERM mode Local print 2 The unshifted key sends its function key sequence to the host. The key sends nothing when pressed with ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ . VT mode Function key PC TERM mode Scan code 3 The key is disabled. VT mode Disabled PC TERM mode Does not exist Description DECLFKC can accept any number of parameter pairs. The terminal executes the parameters in the order it receives them. NOTE Applications cannot disable the ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) key. This restriction is required for secure systems, to ensure that the operator has control of the communication line. ------------------------------------------------------------ Select Modifier Key Reporting (DECSMKR) This control function lets you program the modifier keys to send extended keyboard reports when pressed or released. Modifier keys are keys such as ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ or ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ whose current state (pressed or released) affects the interpretation of other keys. DECSMKR only works when key position mode (DECKPM) is set. Applications can use DECSMKR to gain more control over the keyboard, by monitoring the action of each modifier key. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard Control Functions Select Modifier Key Reporting (DECSMKR) 199 Format CSI 9/11 Pm1 3/n ; 3/11 Pf1 3/n ... ... Pmn; Pfn ******** + 2/11 r 7/2 Parameters Pmn is the key number that corresponds to the modifier key affected. A Pmn value of 0 selects all modifier keys. Pmn Key Default Function 1 left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ Local shift. 2 right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ Local shift. 3 Lock Local lock. 4 ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ Local control. 5 left ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ Report up or down transitions. 6 right ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ Report up or down transitions. 7 left ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ Local compose. 8 right ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ Local compose. Pfn controls the action of the modifier key specified by the corresponding Pmn value. Pfn Meaning 0 Selects the default function of the key. 1 The key performs its default modifier function. 2 The key sends an extended keyboard report when pressed or released. The key does not modify other keystrokes or perform its default function. 3 The key is disabled. Description DECSMKR can accept any number of parameter pairs. The terminal executes the parameters in the order it receives them. NOTE Applications cannot change the function of the ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) key. This restriction is required for secure systems to ensure that the operator has control of the communication line. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 200 Keyboard Control Functions Extended Keyboard Report (DECEKBD) ------------------------------------------------------------ Extended Keyboard Report (DECEKBD) This control function is a report that provides applications with more complete keystroke information. Each report consists of an ISO key position code and the current state of the eight modifier keys--pressed or released. Format APC 9/15 : 3/10 ppp *** mm ** ST 9/12 Parameters ppp is a three-character ISO key position name, for example C01. For keys that occupy more than one position in the ISO key position map, the VT420 uses the largest lower-left position. The position for the space bar is A02; ------------------------------------------------------------ ------------------------------------------------------------ Return ------------------------------------------------------------ ------------------------------------------------------------ is C13. mm are two ASCII hexadecimal digits that represent the state of the modifier keys. The terminal represents the state of each modifier key as a bit in an 8-bit binary number. A bit value of 1 means the key is pressed, and a bit value of 0 means the key is not pressed. mm is the hexadecimal equivalent of the resulting 8-bit binary number. The following table shows the order in which keys are represented in the binary number, and their corresponding hexadecimal values when pressed. The least significant bit represents the left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key. The most significant bit represents the right ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ key. For example, 00000010 2 means that the right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key is pressed. The hexadecimal value for 00000010 2 is 02 16 . Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Extended Keyboard Report (DECEKBD) 201 mm Key 01 left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ Least significant bit 02 right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ 04 Lock 08 ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ 10 left ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ 20 right ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ 40 left ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ 80 right ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ Most significant bit Description The terminal only sends extended key position reports when key position mode (DECKPM) is set. The terminal uses the following rules when sending extended key reports: · A single report may contain more than one keystroke. In this case, each keystroke is separated by a slash (/, 2/15) character. The terminal sends the control string envelope (APC ... ST) when a modifier key changes, or to separate keystroke data from other terminal reports. · The terminal only sends the modifier key state when it changes in the first keystroke after an APC character. · The terminal sends repeated key position reports as a single repeat character, period (.). Examples The following sequence reports an ------------------------------------------------------------ ------------------------------------------------------------ a ------------------------------------------------------------ ------------------------------------------------------------ key with no modifier keys, four ------------------------------------------------------------ ------------------------------------------------------------ ! ------------------------------------------------------------ ------------------------------------------------------------ keys, one ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ key, and a ------------------------------------------------------------ ------------------------------------------------------------ b ------------------------------------------------------------ ------------------------------------------------------------ key: APC : C01 00 / B18.../ B16 / B05 ST The following sequence reports a left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key and an ------------------------------------------------------------ ------------------------------------------------------------ A ------------------------------------------------------------ ------------------------------------------------------------ key: APC : B99 01 / C01 ST Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 202 Keyboard, Printing, and Display Commands User-Defined Keys (DECUDK) User-Defined Keys (DECUDK) The following keyboards have the following user-defined keys (UDKs): ANSI Keyboard ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ Short ANSI Keyboard ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F10 ------------------------------------------------------------ ------------------------------------------------------------ PC Keyboard ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F12 ------------------------------------------------------------ ------------------------------------------------------------ The following five keys on the ANSI keyboards-- ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold), ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print), ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up), ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session), and ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break)--have dedicated local functions. You can change the function of keys ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ to ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ on the ANSI keyboards by using the local function key control (DECLFKC) function. Applications cannot disable the ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break) key. Using UDKs User-defined keys (UDKs) are only available in VT400 mode and PC TERM mode. UDKs do not work in VT100 and VT52 modes. You define the function of keys by using a DECUDK device control string, as described in the ``Programming UDKs'' section that follows. After you define a key, you can use the new function by pressing ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ key ------------------------------------------------------------ ------------------------------------------------------------ where ------------------------------------------------------------ ------------------------------------------------------------ key ------------------------------------------------------------ ------------------------------------------------------------ is the key you defined. This chapter describes how to program the keys by using a DECUDK device control string. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ User-Defined Keys (DECUDK) Programming UDKs 203 UDK Memory Space There are 768 bytes of memory available for the 48 user-defined keys. Space is supplied on a first-come/first-serve basis. When the 768 bytes are full, you cannot define any more keys until you clear some of the memory space. There are three ways you can clear space. · Redefine one or more UDKs, with a DECUDK control string. · Clear one or more UDKs, with a DECUDK control string. · Clear all UDKs, with a terminal power-up or reset (RIS) operation. ------------------------------------------------------------ Programming UDKs You use the following device control string format to download definitions for user-defined keys. See Chapter 2 for general information about device control strings. Available in: VT400 mode and PC TERM mode only. Format DCS Device Control String Introducer Pc ; Pl ; Pm Clear, Lock, and Modifier Parameters | Final Character Ky1/St1;...Kyn/Stn Key Definition String ST String Terminator Parameters DCS (9/0) indicates the beginning of a device control string. DCS is an 8-bit C1 character. You can use ESC P (1/11 5/0) for a 7-bit environment. Pc is the clear parameter. Pc selects how to clear key definitions. Pc Action 0 (default) or none Clear all keys before loading new values. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 204 User-Defined Keys (DECUDK) Programming UDKs 1 Clear one key at a time, before loading a new value. When Pc is 1, the terminal only clears the keys you are loading. By using a Pc value of 1, you can redefine some keys without redefining them all. NOTE There are 768 bytes of memory for all user-defined keys. A key definition can only use the number of bytes available when that key is loaded. Programming Tip If Pc is 1, a key load may fail because no memory space is available. The reason for this is as follows. With Pc set to 1, keys are cleared and loaded sequentially. If the new definition for a key is larger than the old one, you may exceed the 768 byte limit. For example, suppose ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ contains 412 bytes, ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ contains 330 bytes, and ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ contains 20 bytes. You try to load ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ with 40 bytes, ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ with 1 byte, and ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ with 1 byte, in that order. This works if all keys are cleared first (Pc is 0), but not if keys are cleared one at a time (Pc is 1). When you try to load ------------------------------------------------------------ ------------------------------------------------------------ F8 ------------------------------------------------------------ ------------------------------------------------------------ with 40 bytes, the load fails because only 26 bytes are free at that time. 768 (maximum) 412 ( ------------------------------------------------------------ ------------------------------------------------------------ F6 ------------------------------------------------------------ ------------------------------------------------------------ ) 330 ( ------------------------------------------------------------ ------------------------------------------------------------ F7 ------------------------------------------------------------ ------------------------------------------------------------ ) = 26 Pl is the lock parameter. Pl determines whether the key definitions are locked or unlocked after you load them. Pl Action 0 or none Lock the keys. If you want to load new values into the keys, you must unlock the keys by using set-up. 1 Do not lock the keys. The keys are unlocked and can be redefined with another DECUDK string. If Pl is 1 and the keys are already locked, nothing happens. The terminal uses a special lock to prevent or allow the programming of user-defined keys. You can turn on this lock from set-up or from the host (with a DECUDK device control string). The lock affects all programmable keys. When you use the lock, you should follow these guidelines: · Unlock the keys to define them. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ User-Defined Keys (DECUDK) Programming UDKs 205 The keys must be unlocked before you can define them. You can only unlock the keys from set-up. If a key is locked and an application tries to redefine the key with a DECUDK sequence, the terminal ignores the sequence. · Lock the keys to prevent redefinition. You can lock the keys from set-up or from the host (by sending a DECUDK sequence). New key definitions are locked by default. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 206 User-Defined Keys (DECUDK) Programming UDKs Pm is the modifier parameter. Pm designates whether the key is shifted or unshifted. Pm Action 0, 2, or none Define the shifted function key. 1 Defines the unshifted function key. 3 Defines the alternate unshifted function key. 4 Defines the alternate shifted function key. | is the final character. The vertical bar (7/12) identifies this control string as a DECUDK. Ky1/St1;...Kyn/Stn are the key definition strings. You include these strings between the final character ( | ) and the string terminator (ST). Each string consists of a key selector number (Kyn) and a string parameter (Stn), separated by a slash (/, 2/15). A semicolon (3/11) separates different strings. · The key selector number (Kyn) indicates which key you are defining. Tables 11-1 and 11-2 list the definable keys and their identifying values. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ User-Defined Keys (DECUDK) Programming UDKs 207 Table 11-1 ANSI and Short ANSI Keyboards ------------------------------------------------------------ Pm = 1 ------------------------------------------------------------ Pm = none, 0, or 2 ------------------------------------------------------------ Kyn ANSI Short ANSI ANSI Short ANSI ------------------------------------------------------------ 11 F1 F1 Shift F1 Shift F1 12 F2 F2 Shift F2 Shift F2 13 F3 F3 Shift F3 Shift F3 14 F4 F4 Shift F4 Shift F4 15 F5 F5 Shift F5 Shift F5 17 F6 F6 Shift F6 Shift F6 18 F7 F7 Shift F7 Shift F7 19 F8 F8 Shift F8 Shift F8 20 F9 F9 Shift F9 Shift F9 21 F10 F10 Shift F10 Shift Extend F10 23 F11 Extend F1 Shift F11 Shift Extend F1 24 F12 Extend F2 Shift F12 Shift Extend F2 25 F13 Extend F3 Shift F13 Shift Extend F3 26 F14 Extend F4 Shift F14 Shift Extend F4 28 F15 Extend F5 Shift F15 Shift Extend F5 29 F16 Extend F6 Shift F16 Shift Extend F6 31 F17 Extend F7 Shift F17 Shift Extend F7 32 F18 Extend F8 Shift F18 Shift Extend F8 33 F19 Extend F9 Shift F19 Shift Extend F9 34 F20 Extend F10 Shift F20 Shift Extend F10 NOTE Pm values of 3 and 4 are specific to the PC keyboard. They are ignored when you use an ANSI or short ANSI keyboard. ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 208 User-Defined Keys (DECUDK) Programming UDKs Table 11-2 PC Keyboards ------------------------------------------------------------ Pm Value ------------------------------------------------------------ Kyn 1 None, 0, or 2 3 4 ------------------------------------------------------------ 11 F1 Shift F1 Alt F1 Alt Shift F1 12 F2 Shift F2 Alt F2 Alt Shift F2 13 F3 Shift F3 Alt F3 Alt Shift F3 14 F4 Shift F4 Alt F4 Alt Shift F4 15 F5 Shift F5 Alt F5 Alt Shift F5 17 F6 Shift F6 Alt F6 Alt Shift F6 18 F7 Shift F7 Alt F7 Alt Shift F7 19 F8 Shift F8 Alt F8 Alt Shift F8 20 F9 Shift F9 Alt F9 Alt Shift F9 21 F10 Shift F10 Alt F10 Alt Shift F10 23 F11 Shift F11 Alt F11 Alt Shift F11 24 F12 Shift F12 Alt F12 Alt Shift F12 25 Alt F3 Alt Shift F3 - - 26 Alt F4 Alt Shift F4 - - 28 Alt F5 Alt Shift F5 - - 29 Alt F6 Alt Shift F6 - - 31 Alt F7 Alt Shift F7 - - 32 Alt F8 Alt Shift F8 - - 33 Alt F9 Alt Shift F9 - - 34 Alt F10 Alt Shift F10 - - 35 Alt F11 Alt Shift F11 - - 36 Alt F12 Alt Shift F12 - - ------------------------------------------------------------ · The string parameters (Stn) are the encoded definition of the keys. String parameters consist of hex pairs in the following ranges: 3/0 through 3/9 (0 through 9) 4/1 through 4/6 (A through F) 6/1 through 6/6 (a through f) When you combine these hex values, they represent an 8-bit quantity. The ASCII table in Chapter 2 lists the hex values of characters. This method lets you use any of the 256 character codes in the key string. You can enter key definition strings in any order. Default: Empty. The key is undefined. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ User-Defined Keys (DECUDK) Programming UDKs 209 ST is the string terminator. ST (9/12) is a C1 8-bit character. You can use ESC \ (1/11, 5/12) for a 7-bit environment. Notes On Loading UDKs Here are some general guidelines you should keep in mind when loading UDKs. · Clear UDK memory space before loading new definitions. Use a DECUDK string to clear keys without locking them. Then you can use another DECUDK string to redefine the keys and lock them. · If you redefine a key, the old definition is lost. This may clear some space if the new definition uses less bytes than the old one. · There is only one way to unlock UDKs. To unlock UDKs, you must use the General Set-Up screen. · The value for each key definition is empty. When you clear UDKs, they are empty. · An invalid hex pair in a DECUDK string stops a UDK load sequence. When a load sequence stops (due to error or other cause), the terminal saves any keys already loaded and sends the rest of the DECUDK sequence to the screen. Examples of DECUDK Device Control Strings The following sequence clears unshifted UDKs: DCS 0 ; 1 ; 1 | ST The following sequence locks unshifted UDKs: DCS 1 ; 0 ; 1 | ST Suppose you want to define the unshifted ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ key to be ``PRINT'', without clearing or locking any other keys. The first part of your sequence would look like this: Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 210 Printer Port Control Functions Printer Extent Mode (DECPEX) DCS 1 ; 1 ; 1 | 3 4 / 34 is the code for the ------------------------------------------------------------ ------------------------------------------------------------ F20 ------------------------------------------------------------ ------------------------------------------------------------ key. After the slash character (/, 2/15), you include the definition. The rest of the sequence after the slash character would look like this: 5 0 5 2 4 9 4 E 5 4 ST The hex encoding for ``PRINT'' is as follows: 50 = P 52 = R 49 = I 4E = N 54 = T The ST character (9/12) marks the end of the control string. The complete string is as follows: DCS 1 ; 1 ; 1 | 34 / 50 52 49 4E 54 ST Printer Port Control Functions This section describes control functions you use to control a local printer. ------------------------------------------------------------ Printer Extent Mode (DECPEX) This control function selects how much data you can print when you use the print page function described in the ``Printing Functions'' section that follows. Default: Scrolling region Format CSI 9/11 ? 3/15 1 3/1 9 3/9 h 6/8 The print function prints the complete page. CSI 9/11 ? 3/15 1 3/1 9 3/9 l 6/12 The print function prints the scrolling region only (data inside the margins). Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Print Form Feed Mode (DECPFF) 211 ------------------------------------------------------------ Print Form Feed Mode (DECPFF) This control function selects whether or not the terminal sends a form feed (FF) character to the printer at the end of a printing function. DECPFF does not affect the print cursor line function described in the next section. Default: No form feed Format CSI 9/11 ? 3/15 1 3/1 8 3/8 h 6/8 The terminal sends a form feed (FF) to the printer at the end of a printing function. CSI 9/11 ? 3/15 1 3/1 8 3/8 l 6/12 The terminal sends nothing to the printer at the end of a printing function. Printing Functions This section describes control functions you use to print text from the terminal. If you do not have a printer connected to the terminal, the terminal ignores these functions. When you print characters from the screen or current page, the printer converts all tabs to spaces. Printed characters are spaced with the space (SP) character. The terminal sends a carriage return (CR), line feed (LF), vertical tab (VT), or form feed (FF) character to the printer after the last printed character on a line. All the printing functions described in this section are variations of the media copy (MC) command. There are two versions of the MC command, standard and DEC private. The format of each version is as follows: MC ANSI standard CSI 9/11 Ps 3/n i 6/9 MC DEC private CSI 9/11 ? 3/n Ps 3/n i 6/9 where Ps indicates the function of the command. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 212 Keyboard, Printing, and Display Commands Printing Functions Printing a Display Line: Autoprint Mode In this mode, the printer prints a line from the screen when you move the cursor off that line with an LF, FF, or VT character, or an autowrap occurs. The printed line ends with a CR and the character (LF, FF, or VT) that moved the cursor off the previous line. ------------------------------------------------------------ Sequence Action ------------------------------------------------------------ CSI ? 5 i Turns on autoprint mode. CSI ? 4 i Turns off autoprint mode. ------------------------------------------------------------ Sending Characters Directly to the Printer: Printer Controller Mode This mode lets the host control the operation of the printer. The terminal sends characters and control sequences directly to the printer, without displaying them on the screen. The terminal sends all characters and control sequences except NUL, XON, XOFF, and the printer controller mode sequences. ------------------------------------------------------------ Sequence Action ------------------------------------------------------------ CSI 5 i Turns on printer controller mode. CSI 4 i Turns off printer controller mode. ------------------------------------------------------------ Notes on Printer Controller Mode · Printer controller mode cancels autoprint mode. When the terminal leaves printer controller mode, the terminal returns to the normal method for printing operations. · The printer 's active column position should always be on the left margin before the terminal leaves printer controller mode. Print Page This control function prints the page that has the cursor. The terminal stores data from the keyboard until printing is complete. You can use either of the following sequences to print the page: CSI i or CSI 0 i Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Printing Functions 213 Notes on Print Page · If printer extent mode (DECPEX) is currently reset, the print page function only prints the scrolling region. Print Composed Main Display This control function prints the data on the screen. This data may include information from two sessions, if the screen is displaying data from both sessions. See Chapter 14 for information on using two sessions. CSI ? 10 i Notes on Print Composed Main Display · Printer extent mode (DECPEX) does not affect this function. Print All Pages This control function prints all pages in page memory for the current session. For example, if the current page format is 3 pages of 24 lines each, the printer prints 3 pages of 24 lines. The terminal stores new data from the keyboard until printing is complete. CSI ? 11 i Notes on Print All Pages · If print form feed mode (DECPFF) is set, the terminal sends a form feed (FF) to the printer after each page. Print Cursor Line This control function prints the line that has the cursor. The cursor does not move. CSI ? 1 i Start Printer-to-Host Session NOTE The following control functions are related to the use of two sessions. See Chapter 14 for details on session management. This control function enables communication from the printer port to the active host session. CSI ? 9 i Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 214 Keyboard, Printing, and Display Commands Printing Functions Stop Printer-to-Host Session This control function disables communication from the printer port to the active host session. CSI ? 8 i Assign Printer to Active Host Session This control function lets the terminal accept printer commands from the current session only. Software should use a device status report (DSR) to ask if the printer is not assigned to the other session. If the inactive session sends a DSR while the printer is assigned to the active session, the inactive session receives a printer assigned message. See Chapter 12 for details on for details on DSR reports. CSI ? 18 i Release Printer This control function lets the terminal accept printer commands from both sessions. See Chapter 14 for details on session management. CSI ? 19 i Printing Visual Attributes This section describes how the terminal sends visual attributes to a local printer, such as bold or underlining. To send visual attributes, the printed data type feature in the Printer Set-Up screen must be set to one of the following three modes: National and line drawing Multinational Print all characters See Installing and Using the VT420 Video Terminal for details. The VT420 can send two types of visual attributes, line attributes and visual character attributes. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Printing Visual Attributes 215 Sending Line Attributes The terminal sends line attributes to a printer by (1) sending the appropriate line attribute control function, followed by (2) the characters in the current line. There are four line attribute control functions. Single-width line ESC # 5 Double-width line ESC # 6 Double-width/double-height line Top half ESC # 3 Bottom half ESC # 4 Sending Visual Character Attributes The terminal initializes character attributes at the beginning of each print line or print page operation by sending the following select graphic rendition (SGR) sequence to the printer (Chapter 7): ESC [ 0 m This sequence sets all character attributes to the normal rendition. To send a visual character attribute to a printer, the VT420 (1) sends the appropriate SGR sequence for that attribute, followed by (2) the current character. The SGR sequence is as follows: ESC [ 0; Ps; Ps; ... Ps m Ps indicates a character attribute sent. Ps Attribute 0 Normal (all attributes off) 1 Bold 2 Underline 5 Blinking After each print line or print page operation, the terminal clears all attributes by sending the following sequence: ESC [ 0 m Screen Display Control Functions This section describes control functions that affect how the terminal displays data. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 216 Screen Display Control Functions Light or Dark Screen: Screen Mode (DECSCNM) ------------------------------------------------------------ Local Echo: Send/Receive Mode (SRM) This control function turns local echo on or off. When local echo is on, the terminal sends keyboard characters to the screen. The host does not have to send (echo) the characters back to the terminal display. When local echo is off, the terminal only sends characters to the host. It is up to the host to echo characters back to the screen. Default: No local echo Format CSI 9/11 1 3/1 2 3/2 h 6/8 Set: local echo off. CSI 9/11 1 3/1 2 3/2 l 6/12 Reset: local echo on. Description When the SRM function is set, the terminal sends keyboard characters to the host only. The host can echo the characters back to the screen. When the SRM function is reset, the terminal sends keyboard characters to the host and to the screen. The host does have to echo characters back to the terminal. ------------------------------------------------------------ Light or Dark Screen: Screen Mode (DECSCNM) This control function selects a dark or light background on the screen. Default: Dark background Format CSI 9/11 ? 3/15 5 3/5 h 6/8 Set: reverse video. CSI 9/11 ? 3/15 5 3/5 l 6/12 Reset: normal display. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Screen Display Control Functions Scrolling Mode (DECSCLM) 217 Description When DECSCNM is set, the screen displays dark characters on a light background. When DECSCNM is reset, the screen displays light characters on a dark background. Notes on DECSCNM · Screen mode only affects how the data appears on the screen. DECSCNM does not change the data in page memory. ------------------------------------------------------------ Scrolling Mode (DECSCLM) This control function selects the way the terminal scrolls lines. You can select one of two scroll settings, smooth or jump. Default: Smooth scroll Format CSI 9/11 ? 3/15 4 3/4 h 6/8 Set: smooth scroll. CSI 9/11 ? 3/15 4 3/4 l 6/12 Reset: jump scroll. Description When DECSLM is set, the terminal adds lines to the screen at a moderate, smooth rate. You can select a slow rate or fast rate in Display Set-Up. See Installing and Using the VT420 Video Terminal. When DECSLM is reset, the terminal can add lines to the screen as fast as it receives them. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 218 Screen Display Control Functions Select Number of Lines/Screen (DECSNLS) ------------------------------------------------------------ Select Number of Lines/Screen (DECSNLS) This control function selects the maximum number of lines that the screen can display. The terminal supports three different font heights that let it display 24, 39, or 49 lines on the screen, and a status line. When you change the number of lines on the screen, the terminal automatically selects an appropriate font size. Format CSI 9/11 Pn 3/n * 2/10 | 7/12 Parameters Pn is the number of lines the terminal displays on the screen. Pn can be any number from 1 to 255. If you use a value that the terminal does not support, the terminal uses the next highest supported value. If you use a value that is higher than the highest supported value, the terminal uses the highest supported value. NOTE You should specify Pn to match the page size (either 24, 36, or 48). This lets the terminal display a complete page with the minimum number of blank lines on the bottom. Specifying Pn to match the page size also provides the best compatibility between implementations. Notes on DECSNLS · If the screen is split horizontally for two sessions, the number of display lines is limited by the amount of screen space allocated to that session. For example, if DECSNLS selects 24 lines but only half the screen is allocated to that session, the terminal can only display 12 lines. · The number of displayable lines is also limited by the current page size. For example, if DECSNLS selects 39 lines but the page size is 36 lines, the bottom 3 lines are blank. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Screen Display Control Functions Select Active Status Display (DECSASD) 219 Selecting the Indicator or Host-Writable Status Line The line below the last line of the user window is reserved for the status line. The terminal lets you use the status line in two ways--as an indicator of the terminal's current state, or as a window the host can use to display application-specific messages. The indicator status display provides information about the current state of the terminal. · Page number · Text cursor position (line, column) · Printer status · Modem status The indicator status display is enabled by default. It appears in reverse video (negative image) on the line below the last line of the user window. This status line always appears in set-up. The host-writable status display can provide specific information from the host. That is, you can program this status line to display any information you want. For two sessions, each session has its own host-writable status line. See Chapter 14 for more information on two sessions. You can send data to the status line and select the type of status line with the following control sequences. ------------------------------------------------------------ Select Active Status Display (DECSASD) This control function selects whether the terminal sends data to the main display or the status line. Available in: VT400 mode only Default: Main display Format CSI 9/11 Ps 3/n $ 2/4 } 7/13 Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 220 Screen Display Control Functions Select Status Line Type (DECSSDT) Parameters Ps represents the display the terminal sends data to, as follows: Ps Action 0 (default) Selects the main display. The terminal sends data to the main display only. 1 Selects the status line. The terminal sends data to the status line only. ------------------------------------------------------------ Select Status Line Type (DECSSDT) This control function lets the host select the type of status line displayed. Available in: VT400 mode only Default: Indicator status display Format CSI 9/11 Ps 3/n $ 2/4 ~ 7/14 Parameters Ps indicates which status line the host selects, as follows: Ps Status Line Selected 0 (default) No status line 1 Indicator status line 2 Host-writable status line Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Screen Display Control Functions Select Status Line Type (DECSSDT) 221 Notes on DECSSDT · If you select no status line (Ps = 0), the terminal uses the line as an additional user window line to display data. · If you change from an indicator to a host-writable status line, the new host-writable status line is empty. · When you select the host-writable status line, most of the control functions that affect the main display also affect the status line. The following list describes the exceptions to the above rule: Control Function Action Select character set (SCS) Both the main display and status line use the same character set. Cursor position controls Only the column parameters in cursor- positioning commands operate in the status line. ANSI mode (DECANM) Ignored if received in the status line. Set conformance level (DECSCL) Exits the status line. Scrolling mode (DECSCLM) Affects the main display and the status line. Soft terminal reset (DECSTR) Exits the status line. Insert/replace mode (IRM) Affects the main display and the status line. Hard terminal reset (RIS) Erases and exits the status line. Tab stops Affect the main display and status line. Autowrap mode (DECAWM) Affects the main display and status line. · DECSSDT does not affect the status line type displayed in set-up. In set-up, the terminal always uses the indicator status line. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 222 Keyboard, Printing, and Display Commands Summary Summary Tables 11-3 through 11-6 list the control sequences described in this chapter. Table 11-3 Keyboard Control Sequences ------------------------------------------------------------ Sequence ------------------------------------------------------------ Mode Mnemonic Set Reset ------------------------------------------------------------ Keyboard action KAM CSI 2 h Locked. CSI 2 l Unlocked. (D) Backarrow key DECBKM CSI ? 67 h Backspace. CSI ? 67 l Delete. (D) Line feed/ new line LNM CSI 20 h New line. CSI 20 l Line feed. (D) Autorepeat DECARM CSI ? 8 h Repeat. (D) CSI ? 8 l No repeat. Autowrap DECAWM CSI ? 7 h Autowrap. CSI ? 7 l No autowrap. (D) Cursor keys DECCKM CSI ? 1 h Application. CSI ? 1 l Cursor. (D) Keypad application/ numeric modes DECKPAM ESC = Application. ESC > Numeric. (D) Numeric keypad DECNKM CSI ? 66 h Application. CSI ? 66 l Numeric. (D) Keyboard usage DECKBUM CSI ? 68 h Data processing. CSI ? 68 l Typewriter. (D) Key position DECKPM CSI 81 h Position reports. CSI 81 l Character codes. (D) ------------------------------------------------------------ (D) = default. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Summary 223 Table 11-3 (Cont.) Keyboard Control Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Enable local functions DECELF CSI Pf1; Pc1; ... Pfn; Pcn + q Pfn = function number. 0 = all local functions. 1 = local copy and paste. 2 = local panning. 3 = local window resize. Pcn = control performed. 0 = factory default. 1 = enable local function. 2 = disable local function. Local function key control DECLFKC CSI Pk1; Pf1; ... Pkn; Pfn = } Pkn = function key number. 0 = all local function keys. 1 = ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold). 2 = ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print). 3 = ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up). 4 = ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session). Pfn = function performed. 0 = factory default. 1 = local function. 2 = send key sequence. 3 = disable key. Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 224 Keyboard, Printing, and Display Commands Summary Table 11-3 (Cont.) Keyboard Control Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Select modifier key reporting DECSMKR CSI Pm1; Pf1; ... Pmn; Pfn + r Pmn = key number. 0 = all keys. 1 = left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ . 2 = right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ . 3 = Lock. 4 = ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ . 5 = left ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ . 6 = right ------------------------------------------------------------ ------------------------------------------------------------ Alt Function ------------------------------------------------------------ ------------------------------------------------------------ . 7 = left ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ . 8 = right ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ . Pcn = control performed. 0 = factory default. 1 = modifier function. 2 = extended keyboard report. 3 = key disabled. Extended keyboard report DECEKBD APC : ppp mm ST ppp = key position number. mm = modifier key state. 0 = not pressed. 1 = pressed. ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Summary 225 Table 11-4 Programming UDKs ------------------------------------------------------------ DECUDK Device Control String Format DCS Pc ; Pl ; Pm ; | Ky1/St1;...Kyn/Stn ST Pc is the clear parameter. 0 or none = Clear all keys before loading new value. 1 = Clear one key at a time, before loading a new value. Pl is the lock parameter. 0 or none = Lock the keys. 1 = Do not lock the keys. Pm is the modifier parameter. 0, 2, or none = Define the shifted function key. 1 = Define the unshifted function key. 3 = Define the alternate unshifted function key. 4 = Define the alternate shifted function key. Ky1/St1;...Kyn/Stn are the key definition strings. The key selector number (Kyn) indicates which key you are defining. See Tables 11-1 and 11-2. The string parameters (Stn) are the key definitions, encoded as pairs of hex codes. 3/0 through 3/9 (0 through 9) 4/1 through 4/6 (A through F) 6/1 through 6/6 (a through f) ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 226 Keyboard, Printing, and Display Commands Summary Table 11-5 Printing Control Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Printer extent mode DECPEX Set: CSI ? 19 h Page. (D) Reset: CSI ? 19 l Scrolling region. Print form feed mode DECPFF Set: CSI ? 18 h Form feed. Reset: CSI ? 18 l No form feed. (D) Auto print mode MC On: CSI ? 5 i Off: CSI ? 4 i Printer controller mode MC On: CSI 5 i Off: CSI 4 i Print page MC CSI I or CSI 0 i Print composed main display MC CSI ? 10 i Print all pages MC CSI ? 11 i Print cursor line MC CSI ? 1 i Start printer-to-host session MC CSI ? 9 i Stop printer-to-host session MC CSI ? 8 i Assign printer to active session MC CSI ? 18 i Release printer MC CSI ? 19 i ------------------------------------------------------------ (D) = default. ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Keyboard, Printing, and Display Commands Summary 227 Table 11-6 Screen Display Control Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Send/receive mode SRM Set: CSI 12 h Local echo off. (D) Reset: CSI 12 l Local echo on. Screen mode DECSCNM Set: CSI ? 5 h Light background. Reset: CSI ? 5 l Dark background. (D) Scrolling mode DECSCLM Set: CSI ? 4 h Smooth scroll. (D) Reset: CSI ? 4 l Jump scroll. Select number of lines per screen DECSNLS CSI Pn * | Pn = number of lines. Select active status display  DECSASD CSI Ps $ } Ps = 0, main display. Ps = 1, status line. Select status line type  DECSSDT CSI Ps $ - Ps = 0, none. Ps = 1, indicator. (D) Ps = 2, host-writable. ------------------------------------------------------------  Available in VT400 mode only. (D) = default. ------------------------------------------------------------ Chapter 11 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 12 VT420 Reports ------------------------------------------------------------ The VT420 sends reports in response to requests from the host system. These reports provide the host with information about the terminal such as: Identification (type of terminal) Cursor state Operating status Operating level (VT100 or VT400) Almost all terminal states that software can set The host can use the reports to adjust the computing environment to match the terminal. Device Attributes (DA) The terminal and host computer exchange DA sequences to provide the host with the following information: Conformance level (1, 2, or 3) and extensions Basic features Identification code Firmware version level Hardware options Manufacturing site code Terminal ID number Based on this information, the host can · Use the information it receives to make the best use of the terminal's features. · Select the correct application software for the terminal. · Determine the cause of certain communication errors. 228 Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Attributes (DA) Primary DA 229 There are three types of DA exchanges between the host and the terminal, primary DA, secondary DA, and tertiary DA. The host can request any type of DA report, depending on the information the host needs. ------------------------------------------------------------ Primary DA In this DA exchange, the host asks for the terminal's architectural class and basic attributes. Host Request The host uses the following sequence to send this request: CSI 9/11 c 6/3 or CSI 9/11 0 3/0 c 6/3 Terminal Response The terminal responds by sending its architectural class and basic attributes to the host. This response depends on the terminal's current operating level (VT100 or VT400). CSI 9/11 ? 3/15 Psc 3/n ; 3/11 Ps1 3/n ; 3/11 . . . . . . Psn 3/n c 6/3 Parameters Psc indicates the terminal's architectural class code. The value of Psc depends on the terminal's current operating level, as follows: Psc Operating Level 61 Level 1 (VT100 family) 62, 63, 64 Level 4 (VT400 family) Ps1; . . . Psn indicate which of the following extensions the terminal supports: Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 230 Device Attributes (DA) Primary DA Ps Meaning 1 132 columns 2 Printer port 6 Selective erase 7 Soft character set (DRCS) 8 User-defined keys 9 National replacement character sets (worldwide model only) 15 DEC technical character set 18 Windowing capability 19 Dual sessions 21 Horizontal scrolling Primary DA Example Here is a typical primary DA exchange. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI c or CSI 0 c The host asks for the terminal's architectural class code and supported extensions. Response (VT420 to host) CSI ? 64; 1; 2; 6; 7; 8; 9; 15; 18; 19; 21 c The terminal is a class 4 device (64) and supports the following extensions: · 132 columns (1) · Printer port (2) · Selective erase (6) Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Attributes (DA) Primary DA 231 ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ · Soft character set (DRCS) (7) · User-defined keys (8) · NRC sets (9) (worldwide model only) · DEC Technical character set (15) · Windowing (18) · Dual sessions (19) · Horizontal scrolling (21) ------------------------------------------------------------ Table 12-1 lists all the primary DA alias responses that the VT420 can send to the host. The terminal uses an alias response to identify itself to the host as some other type of terminal. You can select these responses in set-up. Each response corresponds to a certain operating level. Table 12-1 Alias Primary DA Responses From the VT420 ------------------------------------------------------------ Terminal Identification Sequence Meaning ------------------------------------------------------------ VT100 DA ESC [ ? 1; 2 c VT100 terminal VT101 DA ESC [ ? 1; 0 c VT101 terminal VT102 DA ESC [ ? 6 c VT102 terminal VT220 DA  CSI ? 62; 1; 2; 6; 7; 8; 9 c VT220 terminal VT320 DA  CSI ? 63; 1; 2; 6; 7; 8; 9 c VT320 terminal VT420 DA  CSI ? 64; 1; 2; 6; 7; 8; 9; 15; 18; 19; 21 c VT420 terminal NOTE To change an alias response, you must use the General Set-Up screen. See Installing and Using the VT420 Terminal. ------------------------------------------------------------  These responses correspond to the worldwide model of the terminal. The North American model does not support NRC sets (9). ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 232 Device Attributes (DA) Secondary DA ------------------------------------------------------------ Secondary DA In this DA exchange, the host requests the terminal's identification code, firmware version level, and hardware options. Host Request The host uses the following sequence to send this request: CSI 9/11 > 3/14 c 6/3 or CSI 9/11 > 3/14 0 3/0 c 6/3 Terminal Response The terminal uses the following sequence to respond: CSI 9/11 > 3/14 4 3/4 1 3/1 ; 3/11 Pv 3/n ; 3/11 Po 3/n c 6/3 Parameters 41 indicates the identification code for the terminal. The VT420 has an identification code of 41. Pv indicates the firmware version level of the terminal. Firmware is the software implementation of all the terminal's functions (for example, the editing functions). Examples Pv Version 10 V1.0 (released version 1.0) 20 V2.0 (released version 2.0) Po indicates the hardware options installed in the terminal. The VT420 does not have any hardware options, so Po is 0. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Attributes (DA) Tertiary DA (VT400 Mode Only) 233 Po Options 0 No options. 1 LK443 (101 keys) or LK444 (102 keys) PC keyboard with LK401 interface. Secondary DA Example Here is a typical secondary DA exchange. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI > c or CSI > 0 c The host asks for the terminal's identification, firmware version, current hardware options. Response (VT420 to host) CSI > 41; 20; 1 c The terminal identifies itself as a VT420 that uses version 2.0 firmware and has a PC keyboard option. ------------------------------------------------------------ ------------------------------------------------------------ Tertiary DA (VT400 Mode Only) In this DA exchange, the host asks for the terminal unit identification code. This ID code serves as a way to identify each terminal in a system. The unit ID code is preset at the factory. Host Request The host uses the following sequence to send this request: CSI 9/11 = 3/13 c 6/3 or CSI 9/11 = 3/13 0 3/0 c 6/3 Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 234 Device Attributes (DA) Terminal Identification (DECID) Terminal Response The terminal responds by sending a report terminal unit ID (DECRPTUI) control string to the host. DECRPTUI is available in VT400 mode only. DCS 9/0 ! 2/1 | 7/12 D...D ... ST 9/12 Parameters D..D is the unit ID of the terminal, consisting of four hex pairs. The first hex pair represents the manufacturing site code. This code can be any hex value from 00 through FF. The last three hex pairs are the terminal ID number. This number is unique for each terminal manufactured at that site. Tertiary DA Example Here is a typical tertiary DA exchange. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI = c or CSI = 0 c The host asks for the terminal unit ID. DECRPTUI Response (VT420 to host) DCS ! | 00 01 02 05 ST The terminal was manufactured at site 00 and has a unique ID number of 125. ------------------------------------------------------------ ------------------------------------------------------------ Terminal Identification (DECID) This control function is similar to a primary device attributes (DA) request from the host. See the previous ``Device Attributes (DA)'' section. NOTE Digital does not recommend using DECID. DECID may not be supported in Digital terminals. You should use the primary device attributes request for this purpose. In VT400 mode, the terminal ignores DECID. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Status Reports (DSR) DSR--VT420 Operating Status 235 Host DECID Request ESC 1/11 Z 5/10 Terminal Response The terminal uses the same response as for a primary DA request. The terminal uses this response for all operating levels (1 or 4). Device Status Report (DSR) The host computer and terminal exchange DSR sequences to provide the host with the operating status of the following features: VT420 operating status Cursor position Cursor position with page Printer port User-defined keys Keyboard dialect Macro space Memory checksum Data integrity Multiple-session status DSR requests and reports follow one of two formats, ANSI standard or DEC private. The format for each is as follows: ANSI standard CSI 9/11 Ps 3/? n 6/14 DEC private CSI 9/11 ? 3/15 Ps 3/? n 6/14 Ps indicates the type of DSR requested. There is a different DSR request for each feature. The following sections describe the possible DSR reports. If the terminal is in printer controller mode (Chapter 11), the printer receives the DSR request. The printer can respond through the bidirectional printer port. ------------------------------------------------------------ DSR--VT420 Operating Status The host requests the terminal's operating status. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 236 Device Status Reports (DSR) DSR--Extended Cursor Position Report (DECXCPR) ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI 5 n The host requests the terminal's operating status. The host asks if the terminal is in good operating condition. Responses (VT420 to host) CSI 0 n The terminal indicates that it is in good operating condition. or CSI 3 n The terminal indicates that it has a malfunction. ------------------------------------------------------------ ------------------------------------------------------------ DSR--Cursor Position Report (CPR) The host asks the terminal for a cursor position report. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI 6 n The host asks for a cursor position report (CPR). CPR response (VT420 to host) CSI Pl; Pc R The terminal indicates that the cursor is currently at line Pl, column Pc. ------------------------------------------------------------ ------------------------------------------------------------ DSR--Extended Cursor Position Report (DECXCPR) The host asks the terminal for the current cursor position, including the current page number. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 6 n The host asks for an extended cursor position report (DECXCPR). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Status Reports (DSR) DSR--Printer Port 237 ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ DECXCPR response (VT420 to host) CSI Pl; Pc; Pp R The terminal indicates that the cursor is currently at line Pl, column Pc, on page Pp. ------------------------------------------------------------ ------------------------------------------------------------ DSR--Printer Port The host asks for the status of the terminal's printer. NOTE Host software should check the printer status before entering any print mode or starting any printing function. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 15 n The host asks for the current printer status. Possible responses (VT420 to host) CSI ? 13 n No printer. The data terminal ready (DTR) signal has not been asserted on the printer port since the last power-up or reset. CSI ? 10 n Printer ready. DTR is asserted on the printer port. CSI ? 11 n Printer not ready. DTR is not currently asserted on the printer port. CSI ? 18 n Printer busy. DTR is asserted on the printer port, but the other session is using the printer (Chapter 14). In VT100 mode, the terminal sends the printer not ready sequence above. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 238 Device Status Reports (DSR) DSR--Keyboard Status ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ CSI ? 19 n Printer assigned to other session. DTR is asserted on the printer port, but the printer is assigned to the other session. The printer is not available to this session (Chapter 14). In VT100 mode, the terminal sends the no printer sequence above. ------------------------------------------------------------ ------------------------------------------------------------ DSR--User-Defined Keys (VT400 Mode Only) The host asks if the user-defined keys (UDKs) are locked or unlocked. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 25 n The host asks if UDKs are locked or unlocked. Possible responses (VT420 to host) CSI ? 20 n CSI ? 21 n UDKs are unlocked. UDKs are locked. ------------------------------------------------------------ ------------------------------------------------------------ DSR--Keyboard Status The host asks for the current keyboard dialect, operating status, and type. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 26 n The host asks for the keyboard status. Response (VT420 to host) CSI ? 27; Pn; Pst; Ptyp n The keyboard dialect is Pn, the keyboard status is Pst, and the keyboard type is Ptyp. ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Status Reports (DSR) DSR--Keyboard Status 239 ------------------------------------------------------------ Dialect ------------------------------------------------------------ Pn ANSI PC Pst Keyboard Status  ------------------------------------------------------------ 0 Unknown Unknown 0 Keyboard ready. 1 North American+ North American+ The terminal 2 British British sends typed 3 Flemish Belgian characters to the 4 Canadian (French) -- current session 5 Danish Danish (Chapter 14). 6 Finnish Finnish 7 German German 3 No keyboard. 8 Dutch -- The terminal 9 Italian Italian does not detect 10 Swiss (French) Swiss (French) the keyboard. 11 Swiss (German) Swiss (German) 12 Swedish Swedish 8 Keyboard busy. 13 Norwegian Norwegian The other 14 French/Belgian French session is 15 Spanish Int. Spanish Int. currently using 16 Portuguese Portuguese the keyboard 28 Canadian (English) -- (Chapter 14). 32 -- Spanish National Ptyp ------------------------------------------------------------ Keyboard Type ------------------------------------------------------------ 0 LK201 /LK301 1 LK401 2 LK443 /LK444 3 LK421 ------------------------------------------------------------  The terminal only sends Pst in VT400 mode. +The terminal does not transmit Unknown. Unknown is for devices that cannot determine the keyboard type. ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 240 Device Status Reports (DSR) DSR--Memory Checksum (DECCKSR) ------------------------------------------------------------ DSR--Macro Space Report The host asks for the available macro space in the form of a macro space report (DECMSR). ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 62 n The host asks for a macro space report (DECMSR). DECMSR response (VT420 to host) CSI Pn * { The terminal indicates the number of bytes available for macro definitions: P n = n u m b e r o f b y te s ------------------------------------------------------------ 16 r o u n d ed do wn : ------------------------------------------------------------ ------------------------------------------------------------ DSR--Memory Checksum (DECCKSR) The host asks for a memory checksum report of current text macro definitions. Programming Tip Enter your macro definitions, then request and save a memory checksum. Later, you can request another checksum and see if it has changed. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 63; Pid n The host asks for a memory checkum report of current text macro definitions (DECCKSR). Pid is an optional numeric parameter that provides a label to identify the particular checksum request. The checksum report returns the label. This label lets you differentiate between multiple checksum reports. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Device Status Reports (DSR) DSR--Data Integrity Report 241 ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ DECCKSR response (VT420 to host) DCS Pid ! ~ D..D ST Pid is a label indicating which DSR request the report is for. D..D is the data string consisting of four hexadecimal digits indicating the checksum. The digits can be in the range of 3/0 through 3/9 and 4/0 through 4/6. ------------------------------------------------------------ ------------------------------------------------------------ DSR--Data Integrity Report The host asks for the status of the data integrity flag. The data integrity flag indicates the integrity of the data flow between the terminal and host. This flag is reset each time the terminal sends a data integrity report. Programming Tip Applications using the flag should always reset the flag before sending data to the terminal. You can reset the flag with a DSR request (CSI ? 75 n) sequence. After the application sends data, the application should send another request to find out if a parity error has occurred. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 75 n The host asks for the status of the data integrity flag. Possible responses (VT420 to host) CSI ? 70 n Ready, no communication errors or power-ups have occurred since last report. CSI ? 71 n Malfunction, a communication error has occurred since the last report. CSI ? 73 n The terminal has not reported data integrity since the last power-up or hard reset (RIS). ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 242 VT420 Reports DSR--Multiple-Session Configuration Status Report ------------------------------------------------------------ DSR--Multiple-Session Configuration Status Report The host asks for the status of the terminal's multiple-session configuration. See Chapter 14 for details on dual sessions. ------------------------------------------------------------ Exchange Sequence Meaning ------------------------------------------------------------ Request (Host to VT420) CSI ? 85 n The host asks for the status of the multiple-session configuration. Possible responses (VT420 to host) CSI ? 80 ; Ps2 n Multiple sessions are operating using the session support utility (SSU) and the current SSU state is enabled. Ps2 indicates the maximum number of sessions available. Default: Ps2 = 2. CSI ? 81 ; Ps2 n The terminal is currently configured for multiple sessions using SSU but the current SSU state is pending. Ps2 indicates the maximum number of sessions available. Default: Ps2 = 2. CSI ? 83 n The terminal is not configured for multiple-session operation. CSI ? 87 n Multiple sessions are operating using a separate physical line for each session, not SSU. ------------------------------------------------------------ Requesting a Checksum of a Rectangular Area You can request a checksum of a rectangular area in page memory. To request a checksum of a rectangular area, you use the DECRQCRA control function. In response to this request, the terminal returns a checksum report in the form of a DECCKSR control string. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Requesting a Checksum of a Rectangular Area Request Checksum of Rectangular Area (DECRQCRA) (VT400 Mode Only) 243 ------------------------------------------------------------ Request Checksum of Rectangular Area (DECRQCRA) (VT400 Mode Only) This control function requests a checksum of the specified rectangular area in the specified page. The terminal returns a checksum report (DECCKSR) in response to this request. Format CSI 9/11 Pid 3/n ; 3/11 Pp; 3/n Pt; Pl; Pb; Pr 3/n . . . 3/n * 2/10 y 7/9 Parameters Pid is a numeric label you can provide to identify the checksum request. The checksum report returns this number. The number serves to differentiate between multiple checksum reports. Pp is the page number of the page that has the rectangular area. If Pp is 0 or omitted, the terminal ignores the following parameters and reports a checksum for all pages in page memory. If Pp is a higher number than the number of pages available, the terminal reports on the last page. Pt; Pl; Pb; Pr are the top, left, bottom, and right borders of the rectangular area. Pt and Pb are line numbers. Pt must be less than or equal to Pb. Pl and Pr are column numbers. Pl must be less that or equal to Pr. Defaults are Pt = 1, Pb = current page length, Pr = current page width. If these parameters are omitted, the terminal returns a checksum of page Pp. Notes on DECRQCRA · The coordinates of the rectangular area are affected by the setting of origin mode (DECOM). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 244 VT420 Reports Checksum Report ------------------------------------------------------------ Checksum Report The terminal returns a checksum report in response to one of the following requests: Request checksum of rectangular area (DECRQCRA) Device status report (DSR) request for a macro definition checksum Format DCS 9/0 Pn 3/n ! 2/1 ~ 7/14 D...D ... ST 9/12 Parameters Pn is a numeric label for the checksum report requested in the DECRQCRA or DSR control function. Pn serves to differentiate between multiple checksum reports if needed. D..D is the data string. The string consists of four hexadecimal digits that indicate the checksum. The digits are in the range of 3/0 through 3/9 and 4/1 through 4/6. Terminal State Reports (VT400 Mode Only) The host can request the terminal's current operating state. In response to this request, the terminal returns a terminal state report. The host can use the information in the report to save the current terminal state. Later, the host can restore the terminal to the saved state. This operation is useful for applications that need to temporarily change the terminal's operating state. When the application is finished, it can restore the terminal to the previous operating state. A terminal state report is a device control string. The report indicates the settings of most of the terminal's features. The terminal sends the report in response to a request terminal state report (DECRQTSR) sequence from the host. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Terminal State Reports (VT400 Mode Only) Terminal State Report (DECTSR)--VT420 to Host 245 ------------------------------------------------------------ Request Terminal State Report (DECRQTSR)--Host To VT420 The host sends this control function to request a terminal state report (DECTSR). The terminal responds by sending a report indicating the settings of many device attributes. Format CSI 9/11 Ps 3/n $ 2/4 u 7/5 Parameters Ps indicates the type of report the host requests from the terminal. Ps Report Requested 0 or none Ignored. No report sent. 1 Terminal state report (DECTSR) ------------------------------------------------------------ Terminal State Report (DECTSR)--VT420 to Host The terminal sends this sequence in response to a request terminal state report (DECRQTSR) sequence. DECTSR informs the host of the entire state of the terminal, except for user-defined key definitions and the current soft character set. Programming Tip Applications can use the information in the terminal state report to save the current terminal state. Later, the application can restore the terminal to the saved state. This operation is useful for applications that need to temporarily change the terminal's operating state. When the application is finished, it can restore the terminal to the previous operating state. You use the restore terminal state (DECRSTS) function to restore the terminal state. DECRSTS is described later in this chapter. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 246 Terminal State Reports (VT400 Mode Only) Restore Terminal State (DECRSTS)--VT400 Mode Only Format DCS 9/0 1 3/1 $ 2/4 s 7/3 D . . . D . . . ST 9/12 Parameters D...D is a data string indicating the status of most of the terminal's features. Notes on DECTSR · Software should not expect the format of DECTSR to be the same for all members of the VT400 family, or for different revisions within each member of the family. ------------------------------------------------------------ Restore Terminal State (DECRSTS)--VT400 Mode Only This sequence restores the terminal to a previous state specified in a terminal state report (DECTSR). Programming Tip Applications can use DECRSTS to restore the terminal to a previous operating state specified in a terminal state report. See the previous ``Terminal State Report (DECTSR)'' section in this chapter. Available in: VT400 mode Format DCS 9/0 Ps 3/n $ 2/4 p 7/0 D . . . D . . . ST 9/12 Parameters Ps indicates the format of the data string (D...D). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Restore Terminal State (DECRSTS)--VT400 Mode Only 247 Ps Data String Format 0 Error, restore ignored 1 Selects the format of the terminal state report (DECTSR). D...D is a data string that contains the restored information. This string is identical to the data string used by the report you are restoring. Notes on DECRSTS · If there is an invalid value in the DECRSTS sequence, the terminal ignores the rest of the sequence. This action may leave the terminal in a partially restored state. · Software should not expect the format of the terminal state report (DECTSR) to be the same for all VT400 family members. Presentation State Reports (VT400 Mode Only) The terminal can send two presentation state reports. Cursor information report (DECCIR) Reports on the cursor position, including its visual attributes. Also reports on origin mode (DECOM), and the current active character sets. Tab stop report (DECTABSR) Reports the current tab stop settings. The host can request the terminal's current presentation state. In response to this request, the terminal returns a presentation state report. The host can use the information in the report to save the current presentation state. Later, the host can restore the terminal to the saved state. This operation is useful for applications that need to temporarily change the terminal's presentation state. When the application is finished, it can restore the terminal to the previous presentation state. A presentation state report is a device control string. The terminal sends the report in response to a request presentation state report (DECRQPSR) sequence from the host. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 248 Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host ------------------------------------------------------------ Request Presentation State Report (DECRQPSR) --Host to VT420 The host sends this sequence to request a cursor information report (DECCIR) or a tabulation stop report (DECTABSR). Format CSI 9/11 Ps 3/n $ 2/4 w 7/7 Parameters Ps indicates which report the host requests. Ps Report Requested 0 Error, request ignored. 1 Cursor information report (DECCIR). 2 Tab stop report (DECTABSR). ------------------------------------------------------------ Cursor Information Report (DECCIR)--VT420 to Host The terminal sends this sequence in response to a request presentation state report (DECRQPSR) sequence. DECCIR reports the status of the cursor position, including visual attributes and character protection attributes. DECCIR also reports the status of of origin mode (DECOM) and the current active character sets. Programming Tip Applications can use the information in the cursor information report to save the current presentation state. Later, the application can restore the terminal to the saved state. This operation is useful for applications that need to temporarily change the terminal's presentation state. When the application is finished, it can restore the terminal to the previous presentation state. You use the restore presentation state (DECRSPS) function to restore the presentation state. DECRSPS is described later in this chapter. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host 249 Format DCS 9/0 1 3/1 $ 2/4 u 7/5 D . . . D . . . ST 9/12 Parameters D...D is the data string containing the cursor information. The format for this data string is as follows: Pr; Pc; Pp; Srend; Satt; Sflag; Pgl; Pgr; Scss; Sdesig Pr is the number of the line the cursor is on. Pc is number of the column the cursor is at. Pp is the number of the current page. Srend is one or more characters indicating the visual attributes (such as bold and blinking) currently in use for writing (Chapter 7). To find out what attributes are set, you must convert the character to an 8-bit binary number. You can use the code table in Chapter 2 to convert characters. After you convert a character, you can find the meaning of its 8-digit binary number in the following table. The table lists the most significant bit (8) to the least significant bit (1). ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 8 - Always 0 (off). 7 - Always 1 (on). 6 Extension indicator 1 = another character (byte) of visual attribute data follows this one. 0 = no more attribute data. 5 - Always 0 (off). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 250 Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 4 Reverse video 0 = off. 1 = on. 3 Blinking 0 = off. 1 = on. 2 Underline 0 = off. 1 = on. 1 Bold 0 = off. 1 = on. Example If the bold and underline attributes are currently set for writing, Srend is the ASCII uppercase C character (01000011 2 ). ------------------------------------------------------------ Satt is one or more characters indicating any selective erase attributes (Chapter 8) currently set for writing. To find what attributes are set, you must convert each character to an 8-bit binary number. Use the same method you used to convert the Srend parameter above. Then use the following table to find the meaning of the 8-bit binary number: ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 8 - Always 0 (off). 7 - Always 1 (on). 6 Extension indicator 1 = another character (byte) of selective erase data follows this one. 0 = no more protection data. 5 - 0 Reserved for future use. 4 - 0 Reserved for future use. 3 - 0 Reserved for future use. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host 251 ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 2 - 0 Reserved for future use. 1 Selective erase (DECSCA) 0 = off. 1 = on. Example If the selective erase protection attribute is currently set for writing, then Satt is the ASCII uppercase A character (01000001 2 ). ------------------------------------------------------------ Sflag is one or more characters that indicate several flags and modes the terminal must save. To see the current state of the flags and modes, you must convert each character to an 8-bit binary number. Use the same method you used to convert the Srend and Satt parameters above. Then use the following table to find the meaning of the 8-bit binary number: ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 8 - Always 0 (off). 7 - Always 1 (on). 6 Extension indicator 1 = another character (byte) of flag data follows this one. 0 = no more flag data. 5 - 0 Reserved for future use. 4 Autowrap 1 = autowrap pending. 0 = autowrap not pending. 3 Single shift 3 (SS3) setting 1 = G3 is mapped into GL for the next typed character only. 0 = single shift 3 is off. 2 Single shift 2 (SS2) setting 1 = G2 is mapped into GL for the next typed character only. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 252 Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 0 = single shift 2 is off. 1 Origin mode 1 = origin mode set. 0 = origin mode reset. Example If origin mode is set, autowrap is pending, and a single shift 3 has been received, then Sflag is the ASCII uppercase M character (01001101 2 ). ------------------------------------------------------------ Pgl indicates the number of the logical character set (G0 through G3) mapped into GL. 0 = G0 is in GL. 2 = G2 is in GL. 1 = G1 is in GL. 3 = G3 is in GL. Pgr indicates the number of the logical character set (G0 through G3) mapped into GR. 0 = G0 is in GR. 2 = G2 is in GR. 1 = G1 is in GR. 3 = G3 is in GR. Scss is a character indicating the size of the character sets in G0 through G3. To find out what the character means, you must convert it to an 8-bit binary number. Use the same method you used to convert the Srend, Satt, and Sflag parameters. Then use the following table to find the meaning of the 8-bit binary number: ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 8 - Always 0 (off) 7 - Always 1 (on) 6 Extension indicator 1 = another character (byte) of character size data follows this one. 0 = no more size data. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Presentation State Reports (VT400 Mode Only) Cursor Information Report (DECCIR)--VT420 to Host 253 ------------------------------------------------------------ Bit Attribute Bit Value ------------------------------------------------------------ 5 - 0 Reserved for future use. 4 G3 set size 0 = 94 characters. 1 = 96 characters. 3 G2 set size 0 = 94 characters. 1 = 96 characters. 2 G1 set size 0 = 94 characters. 1 = 96 characters. 1 G0 set size 0 = 94 characters. 1 = 96 characters. Example Suppose the following conditions exist: · The ISO Latin-1 supplemental set is designated as G2 and G3. · The ASCII set is designated as G0 and G1. · Single shift 2 (SS2) is set. Then Scss is the ASCII backslash \ character (01011100 2 ). ------------------------------------------------------------ Sdesig is a string of intermediate and final characters indicating the character sets designated as G0 through G3. These final characters are the same as those used in select character set (SCS) sequences (Chapter 5). Example Suppose the ASCII character set is designated as G0, DEC Special Graphic as G1, and DEC Supplemental Graphic as G2 and G3. The Sdesig string would be B0%5%5. Each character corresponds to a final character in an SCS sequence, as follows: G0 B ASCII set G1 0 DEC Special Graphic G2 %5 DEC Supplemental Graphic G3 %5 DEC Supplemental Graphic Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 254 Presentation State Reports (VT400 Mode Only) Tab Stop Report (DECTABSR)--VT420 To Host Example The following is an example of a cursor information report: DCS 1 $ u 1; 1; 1; @; @; @; 0; 2; @; BB%5%5 ST 1; 1; 1; indicates that the cursor is at row 1, column 1, on the first page. @; @; @; indicates that (1) no visual character attributes or selective erase attributes are set for writing, (2) DECOM is reset, and (3) there is no SS2, SS3, or autowrap pending. 0; 2; indicates that G0 is mapped into GL, and G2 is in GR. @; indicates that all character sets have 94 characters. BB%5%5 indicates that ASCII is in G0 and G1, and DEC Supplemental Graphic is in G2 and G3. Notes on DECCIR · The cursor information in a DECCIR sequence is the same information saved through a save cursor (DECSC) command. ------------------------------------------------------------ Tab Stop Report (DECTABSR)--VT420 To Host The terminal sends this sequence to the host in response to a request presentation state report (DECRQPSR) sequence. DECTABSR informs the host of the terminal's current tab settings. Programming Tip Applications can use information in the tab stop report to save the current tab stops. Later, the application can restore the saved tab stops. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Presentation State Reports (VT400 Mode Only) Restore Presentation State (DECRSPS)--VT400 Mode Only 255 This operation is useful for applications that need to temporarily change the terminal's tab stops. When the application is finished, it can restore the tab stops that were in effect before the application changed them. You use the restore presentation state (DECRSPS) function to restore tab stops. DECRSPS is described later in this chapter. Format DCS 9/0 2 3/2 $ 2/4 u 7/5 D . . . D . . . ST 9/12 Parameters D...D is a data string indicating the column number location of each tab stop. Example The following is an example of a DECTABSR sequence: DCS 2 $ u 9/ 17/ 25/ 33/ 41/ 49/ 57/ 65/ 73 ST 9, 17, 25, 33, 41, 49, 57, 65, and 73 are the column numbers for tab stops. ------------------------------------------------------------ Restore Presentation State (DECRSPS)--VT400 Mode Only This control function restores the terminal to a previous state based on one of the presentation state reports. There are two presentation state reports. Cursor information report (DECCIR) Tab stop report (DECTABSR) A DECRSPS sequence can only restore the information from one report at a time, cursor information or tab stop. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 256 Presentation State Reports (VT400 Mode Only) Restore Presentation State (DECRSPS)--VT400 Mode Only Programming Tip Applications can use DECRSPS to restore the terminal to a previous state specified in a presentation state report. See the previous ``Cursor Information Report (DECCIR)'' and ``Tab Stop Report (DECTABSR)'' sections in this chapter. Available in: VT400 mode Format DCS 9/0 Ps 3/n $ 2/4 t 7/4 D . . . D . . . ST 9/12 Parameters Ps indicates the format of the data string (D...D). You can use one of the two following formats for the data string. These formats correspond to the formats used in the two presentation state reports (DECPSR). Make sure you use the format of the report you are restoring. Ps Data String Format 0 Error, restore ignored. 1 Selects the format of the cursor information report (DECCIR). 2 Selects the format of the tab stop report (DECTABSR). D...D is a data string that contains the restored information. This string is identical to the data string used in the report you are restoring--the cursor information report (DECCIR) or tab stop report (DECTABSR). Example The following DECRSPS sequence restores tab stops according to the tab stop report (DECTABSR): DCS 2 $ t 9/ 17/ 25/ 33/ 41/ 49/ 57/ 65/ 73 ST Note that the data string format above is exactly the same as the format for the tab stop report (DECTABSR). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Mode Settings (VT400 Mode Only) Request Mode (DECRQM)--Host To VT420 257 Notes on DECRSPS · If there is an invalid value in the DECRSPS sequence, the terminal ignores the rest of the sequence. This action may leave the terminal in a partially restored state. Mode Settings (VT400 Mode Only) The host can request the current settings of any ANSI or DEC private modes. In response to this request, the terminal returns a report indicating which modes are set and which are reset. The host can use the information in the report to save the current mode settings. Later, the host can restore the mode settings to their saved state. This operation is useful for applications that need to temporarily change a number of modes. When the application is finished, it can restore the modes to their previous state. The host requests the setting of a mode with a DECRQM sequence. The terminal responds with a DECRPM sequence. The host can then restore a saved setting with an SM or RM sequence. The following sections describe these sequences. ------------------------------------------------------------ Request Mode (DECRQM)--Host To VT420 The host sends this control function to find out if a particular mode is set or reset. The terminal responds with a report mode function (DECRPM). There are two versions of the DECRQM function, for ANSI and DEC private modes. Requesting ANSI Modes CSI 9/11 Pa 3/n $ 2/4 p 7/0 Parameters Pa indicates the ANSI mode that the host is asking about. Table 12-2 lists the values for Pa. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 258 Mode Settings (VT400 Mode Only) Request Mode (DECRQM)--Host To VT420 Requesting DEC Private Modes CSI 9/11 ? 3/15 Pd 3/n $ 2/4 p 7/0 Parameters Pd indicates the DEC private mode the host is asking about. Table 12-3 lists the values for Pd. Examples The following sequences request the setting of some ANSI modes: Host Request Meaning CSI 2 $ p What is the current state of keyboard action mode (KAM)? (KAM = 2) CSI 4 $ p What is the current state of insert/replace mode (IRM)? (IRM = 4) The following sequences request the setting of some DEC private modes: Host Request Meaning CSI ? 61 $ p What is the current state of vertical cursor-coupling mode (DECVCCM)? (VCCM = 61) CSI ? 6 $ p What is the current state of origin mode (DECOM)? (DECOM = 6) Notes on DECRQM · A DECRQM sequence can only ask about one mode at a time. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Mode Settings (VT400 Mode Only) Request Mode (DECRQM)--Host To VT420 259 Table 12-2 ANSI Modes for DECRQM, DECRPM, SM, and RM ------------------------------------------------------------ Mode Mnemonic Sequence ------------------------------------------------------------ Guarded area transfer GATM  1 Keyboard action KAM 2 Control representation CRM+ 3 Insert/replace IRM 4 Status reporting transfer SRTM  5 Vertical editing VEM  7 Horizontal editing HEM  10 Positioning unit PUM  11 Send/receive SRM 12 Format effector action FEAM  13 Format effector transfer FETM  14 Multiple area transfer MATM  15 Transfer termination TTM  16 Selected area transfer SATM  17 Tabulation stop TSM  18 Editing boundary EBM  19 Line feed/new line LNM 20 ------------------------------------------------------------  This control function is permanently reset. +The host cannot change the setting of CRM. You can only change CRM from set-up. If CRM is set, the terminal ignores DECRQM and most other control functions. ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 260 Mode Settings (VT400 Mode Only) Request Mode (DECRQM)--Host To VT420 Table 12-3 DEC Private Modes for DECRQM, DECRPM, SM, and RM ------------------------------------------------------------ Mode Mnemonic Pd ------------------------------------------------------------ Cursor keys DECCKM 1 ANSI DECANM 2 Column DECCOLM 3 Scrolling DECSCLM 4 Screen DECSCNM 5 Origin DECOM 6 Autowrap DECAWM 7 Autorepeat DECARM 8 Print form feed DECPFF 18 Printer extent DECPEX 19 Text cursor enable DECTCEM 25 National replacement character set DECNRCM 42 Horizontal cursor coupling DECHCCM 60 Vertical cursor coupling DECVCCM 61 Page cursor coupling DECPCCM 64 Numeric keypad DECNKM 66 Backarrow key DECBKM 67 Keyboard usage DECKBUM 68 Vertical split screen DECVSSM 69 Transmit rate limiting DECXRLM 73 Key position mode DECKPM 81 ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Mode Settings (VT400 Mode Only) Report Mode (DECRPM)--VT420 To Host 261 ------------------------------------------------------------ Report Mode (DECRPM)--VT420 To Host The terminal sends this control function in response to a request mode (DECRQM) function. DECRPM informs the host whether a certain mode is set or reset. Programming Tip Applications can use the information in the DECRPM report to save the current mode settings. Later, the application can restore the saved mode settings. This operation is useful for applications that need to temporarily change some of the terminal's mode settings. When the application is finished, it can restore the mode settings that were in effect before the application changed them. You use the set mode (SM) and reset mode (RM) functions to restore mode settings. SM and RM are described later in this chapter. There are two versions of DECRPM, for ANSI and DEC private modes. Reporting ANSI Modes CSI 9/11 Pa 3/n ; 3/11 Ps 3/n $ 2/4 y 7/9 Parameters Pa indicates which ANSI mode the terminal is reporting on. Table 12-2 lists the values for Pa. Ps indicates the setting of the mode, as follows: Ps Mode Setting 0 Mode not recognized. 1 Set. 2 Reset. 3 Permanently set. 4 Permanently reset. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 262 Mode Settings (VT400 Mode Only) Report Mode (DECRPM)--VT420 To Host Reporting DEC Private Modes CSI 9/11 ? 3/15 Pd 3/n ; 3/11 Ps 3/n $ 2/4 y 7/9 Parameters Pd indicates which DEC private mode the terminal is reporting on. Table 12-3 lists the values for Pd. Ps indicates the setting of the mode. The Ps values are the same as for the ANSI version above. Examples The following sequences report the setting of some ANSI modes: VT420 Report Meaning CSI 2 ; 1 $ y Keyboard action mode (KAM) is currently set. (KAM = 2, set = 1) CSI 4 ; 2 $ y Insert/replace mode is currently reset (IRM). (IRM = 4, reset = 2) The following sequences report the setting of some DEC private modes: VT420 Report Meaning CSI ? 61; 1 $ y Vertical cursor coupling mode is currently set. (DECVCCM = 61, set = 1) CSI ? 6 ; 2 $ y Origin mode (DECOM) is currently reset. (DECOM = 6, reset = 2) Notes on DECRPM · The terminal can only report on one mode at a time. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Setting or Resetting Modes (SM and RM) 263 Setting or Resetting Modes (SM and RM) ANSI and DEC private modes are control functions that have only two settings, set or reset. Soft terminal reset and hard terminal reset affect many control functions, including some ANSI and DEC private modes. Programming Tip Applications can use the SM and RM functions to restore any number of VT420 modes to a desired state. See the previous ``Report Mode (DECRPM)'' section in this chapter for details. ------------------------------------------------------------ Set Mode (SM) This control function has two versions. You use the ANSI version to set one or more ANSI modes. You use the DEC private version to set one or more DEC private modes. You cannot set ANSI and DEC private modes with the same SM sequence. Setting ANSI Modes CSI 9/11 Pa 3/n ; 3/11 . . . . . . Pa 3/n h 6/8 Parameters Pa indicates the ANSI mode to set. Table 12-2 lists Pa values for ANSI modes. You can use more than one Pa value in a sequence. Setting DEC Private Modes CSI 9/11 ? 3/15 Pd 3/n ; 3/11 . . . . . . Pd 3/n h 6/8 Parameters Pd indicates a DEC private mode to set. Table 12-3 lists the Pd values for DEC private modes. You can use more than one Pd value in a sequence. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 264 Setting or Resetting Modes (SM and RM) Set Mode (SM) Examples ANSI Modes The following sequence sets keyboard action mode (KAM) and insert /replace mode (IRM): CSI 2 ; 4 h 2 indicates keyboard action mode. 4 indicates insert/replace mode. DEC Private Modes The following sequence sets scrolling mode (DECSCLM) and vertical cursor-coupling mode (DECVCCM): CSI ? 4; 61 h 4 indicates scrolling mode. 61 indicates vertical cursor-coupling mode. ------------------------------------------------------------ Reset Mode (RM) There are two versions of this control function. You use the ANSI version to reset one or more ANSI modes. You use the DEC private version to reset one or more DEC private modes. You cannot reset ANSI and DEC private modes with the same RM sequence. Resetting ANSI Modes CSI 9/11 Pa 3/n ; 3/11 . . . . . . Pa 3/n l 6/12 Parameters Pa indicates an ANSI mode to reset. Table 12-2 lists the Pa values for ANSI modes. You can use more than one Pa value in a sequence. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Setting or Resetting Modes (SM and RM) Reset Mode (RM) 265 Resetting DEC Private Modes CSI 9/11 ? 3/15 Pd 3/n ; 3/11 . . . . . . ; 3/11 Pd 3/n l 6/12 Parameters Pd indicates a DEC private mode to reset. Table 12-3 lists the Pd values for DEC private modes. You can use more than one Pd value in a sequence. Examples ANSI Modes The following sequence resets keyboard action mode (KAM) and insert /replace mode (IRM): CSI 2 ; 4 l 2 indicates keyboard action mode. 4 indicates insert/replace mode. DEC Private Modes The following sequence resets scrolling mode (DECSCLM) and vertical cursor-coupling mode (DECVCCM): CSI ? 4; 61 l 4 indicates scrolling mode. 61 indicates vertical cursor-coupling mode. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 266 VT420 Reports Control Function Settings (VT400 Mode Only) Control Function Settings (VT400 Mode Only) The host can request the current selection or setting of any control function listed in Table 12-4. In response to this request, the terminal returns a report indicating the current selection or setting of the selected control function. The host can use the information in the report to save the current setting. Later, the host can restore the control function to its saved state. This operation is useful for applications that need to temporarily change a number of control function settings. When the application is finished, it can restore the control functions to their previous state. The host requests the setting of a control function with a DECRQSS sequence. The terminal responds with a DECRPSS sequence. The host can then restore the control function, based on the DECRPSS report. The following sections describe DECRQSS and DECRPSS. Table 12-4 Control Functions for DECRQSS Requests ------------------------------------------------------------ Control Function Mnemonic Intermediate and Final Characters(s) ------------------------------------------------------------ Enable local functions DECELF + q Local function key control DECLFKC * } Select active status display DECSASD $ } Select attribute change extent DECSACE * x Select graphic rendition SGR m Select modifier key reporting DECSMKR + r Set character attribute DECSCA " q Set columns per page DECSCPP $ | Set conformance level DECSCL " p Set left and right margins DECSLRM s Set lines per page DECSLPP t Set number of lines per screen DECSNLS * | Set status line type DECSSDT $ ~ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Control Function Settings (VT400 Mode Only) Request Selection or Setting (DECRQSS)--Host To VT420 267 Table 12-4 (Cont.) Control Functions for DECRQSS Requests ------------------------------------------------------------ Control Function Mnemonic Intermediate and Final Characters(s) ------------------------------------------------------------ Set top and bottom margins DECSTBM r ------------------------------------------------------------ ------------------------------------------------------------ Request Selection or Setting (DECRQSS)--Host To VT420 The host sends this sequence to ask for the setting of a control function. The terminal responds with a report selection or setting (DECRPSS) sequence. Format DCS 9/0 $ 2/4 q 7/1 D . . . D . . . ST 9/12 Parameters D...D indicates the control function the host is asking about. D...D consists of the intermediate and/or final characters of the control function requested. Table 12-4 lists the control functions the host can ask about, with their final characters. Examples The following DECRQSS sequence asks about the select graphic rendition (SGR) function: DCS $ q m ST m is the final character of the SGR sequence. The following sequence asks about the set status line type (DECSSDT) function: DCS $ q $ ~ ST $ ~ are the intermediate and final characters of the DECSSDT sequence. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 268 Control Function Settings (VT400 Mode Only) Report Selection or Setting (DECRPSS)--VT420 To Host Notes on DECRQSS · A DECRQSS sequence can only ask about one control function at a time. · For control functions that have parameters (DECELF, DECLFKC), specify only the intermediate and final characters. The report will contain all parameters and show which are set and reset. ------------------------------------------------------------ Report Selection or Setting (DECRPSS)--VT420 To Host The terminal sends the host this sequence in response to a request selection or setting (DECRQSS) sequence. The terminal sends DECRPSS to report the setting of a particular control function. Programming Tip Applications can use the information in the DECRPSS report to save the current selections or settings of some control functions. Later, the application can restore the control functions to their saved state. This operation is useful for applications that need to temporarily change the settings of some of the terminal's control functions. When the application is finished, it can restore the control functions to their previous state. Format DCS 9/0 Ps 3/n $ 2/4 r 7/2 D . . . D . . . ST 9/12 Parameters Ps indicates whether or not the request from the host is valid. 0 Host's request is valid. 1 Host's request is invalid. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Report Selection or Setting (DECRPSS)--VT420 To Host 269 D . . . D indicates the current setting of a valid control function that the host asked about. D...D consists of all the characters in the control function, except the CSI (9/11) or ESC [ (1/11, 5/11) introducer characters. Examples ! The host requests the setting of the select graphic rendition (SGR) function. If the current graphic rendition is underline, blinking, and reverse, the terminal responds with the following DECRPSS sequence: DCS 0 $ r 0 ; 4 ; 5 ; 7 m ST 0; 4 ; 5 ; 7 m are all the characters in the SGR sequence, except CSI. " The host requests the setting of the set top and bottom margin function (DECSTBM). If the current top and bottom margins are set to include the complete screen area (24 lines/screen), the terminal responds with the following DECRPSS sequence: DCS 0 $ r 1 ; 24 r ST 1 ; 24 r are all the characters in the DECSTBM sequence, except CSI. # The host requests the setting of a function that the terminal does not recognize. The terminal responds with the following DECRPSS sequence: DCS 1 $ r ST The terminal does not send a data string (D...D) to the host when the terminal receives an invalid request. Saving and Restoring the Cursor State The save cursor function (DECSC) stores many of the terminal's selections and settings. The restore cursor function (DECRC) restores the terminal to the state saved by DECSC. Programming Tip Applications can use DECSC to save the current settings of many modes and control functions. Later, the application can use DECRC restore the control functions and modes to their saved state. This operation is useful for applications that need to temporarily change the settings of some of the terminal's modes and control functions. When the application is finished, it can restore the modes and control functions to their previous state. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 270 Saving and Restoring the Cursor State Restore Cursor (DECRC) ------------------------------------------------------------ Save Cursor (DECSC) Format ESC 1/11 7 3/7 Description Saves the following in the terminal's memory: · Cursor position · Character attributes set by the SGR command · Character sets (G0, G1, G2, or G3) currently in GL and GR · Wrap flag (autowrap or no autowrap) · State of origin mode (DECOM) · Selective erase attribute · Any single shift 2 (SS2) or single shift 3 (SS3) functions sent ------------------------------------------------------------ Restore Cursor (DECRC) Restores the terminal to the state saved by the save cursor (DECSC) function. Format ESC 1/11 8 3/8 Description If nothing was saved by DECSC, then DECRC performs the following actions: · Moves the cursor to the home position (upper left of screen). · Resets origin mode (DECOM). · Turns all character attributes off (normal setting). Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Window Reports (VT400 Mode Only) Request Displayed Extent (DECRQDE) 271 · Maps the ASCII character set into GL, and the DEC Supplemental Graphic set into GR. Notes on DECSC and DECRC · The terminal maintains a separate DECSC buffer for the main display and the status line. This feature lets you save a separate operating state for the main display and the status line. Window Reports (VT400 Mode Only) The host can ask the terminal how much of the current page is displayed on the screen at any time. The terminal responds by reporting how much of the page is on the screen, in terms of lines and columns. Programming Tip This operation is useful for applications that need to know the size of the current user window. ------------------------------------------------------------ Request Displayed Extent (DECRQDE) The host sends this control function to ask how much of the current page is displayed on the screen. The terminal responds with a report displayed extent (DECRPDE) sequence. Format CSI 9/11 " 2/2 v 7/6 Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 272 Window Reports (VT400 Mode Only) Report Displayed Extent (DECRPDE) ------------------------------------------------------------ Report Displayed Extent (DECRPDE) The terminal sends this control function in response to a request displayed extent (DECRQDE) sequence. DECRPDE indicates how much of the current page is displayed on the screen for the active session. Remember that the screen can be split into two user windows, one per session. DECRPDE indicates how much of the screen the active session has to display the current page. See Installing and Using the VT420 Video Terminal for details on user windows. Format CSI 9/11 Ph 3/n ; 3/11 Pw; 3/n Pml; 3/n Pmt; 3/n Pmp; 3/n " 2/2 w 7/7 Parameters Ph is the number of lines of the current page displayed in the active session's window, excluding the status line. Pw is the number of columns of the current page displayed in the active session's window. Pml is the column number displayed in the leftmost column of the active session's window. Pmt is the line number displayed in the top line of the active session's window. Pmp is the page number displayed in the active session's window. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports User-Preferred Supplemental Set (DECRQUPSS)--(VT400 Mode Only) 273 User-Preferred Supplemental Set (DECRQUPSS)--(VT400 Mode Only) Applications can ask for the current user-preferred supplemental set. The terminal responds with the assign user-preferred supplemental set (DECAUPSS) sequence (Chapter 5). Host Request (DECRQUPSS) The host requests the current user-preferred supplemental set by sending the following sequence: Format CSI 9/11 & 2/6 u 7/5 Terminal Response The terminal uses the DECAUPSS device control string to report the current user-preferred supplemental set (Chapter 5). The terminal sends DECAUPSS in response to a DECRQUPSS sequence. The terminal can send one of the following reports: DCS 0 ! u % 5 ST The user-preferred supplemental set is DEC Supplemental Graphic. DCS 1 ! u A ST The user-preferred supplemental set is ISO Latin-1 supplemental. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 274 VT420 Reports Summary Summary Table 12-5 lists all the sequences described in this chapter. Table 12-5 Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Primary Device Attributes ------------------------------------------------------------ Primary DA request (Host to VT420) DA CSI c or CSI 0 c Primary DA response (VT420 to host) DA CSI ? Psc; Ps1; ... Psn c Psc = architectural class. 61 = level 1 (VT100 mode). 62, 63, 64 = level 4 (VT400 mode). Ps1...Psn = extensions. 1 = 132 columns. 2 = printer port. 6 = selective erase. 7 = soft character set. 8 = user-defined keys. 9 = NRC sets. 15 = DEC Technical character set. 18 = user windows. 19 = dual sessions. 21 = horizontal scrolling. See Table 12-1 for alias responses. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Summary 275 Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ ------------------------------------------------------------ Secondary Device Attributes ------------------------------------------------------------ Secondary DA request (Host to VT420) DA CSI > c or CSI > 0 c Secondary DA response (VT420 to host) DA CSI > 41; Pv;Po c Pv = firmware version. Po = keyboard options. ------------------------------------------------------------ Tertiary Device Attributes (VT400 Mode Only) ------------------------------------------------------------ Tertiary DA request (Host to VT420) DA CSI = c or CSI = 0 c DECRPTUI response (VT420 to host) DA DCS ! | D..D ST D...D = unit ID. ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ VT420 Operating Status Request (Host to VT420) DSR CSI 5 n Report (VT420 to host) DSR CSI 0 n No malfunction. CSI 3 n Malfunction. Cursor Position Report Request (Host to VT420) DSR CSI 6 n Report (VT420 to host) CPR CSI Pl; Pc R Pl = line number. Pc = column number. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 276 VT420 Reports Summary Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ Extended Cursor Position Report Request (Host to VT420) DSR CSI ? 6 n Report (VT420 to host) DECXCPR CSI Pl; Pc; Pp R Pl = line number. Pc = column number. Pp = page number. Printer Status Request (Host to VT420) DSR CSI ? 15 n Report (VT420 to host) DSR CSI ? 13 n No printer. CSI ? 10 n Printer ready. CSI ? 11 n Printer not ready. CSI ? 18 n Printer busy. CSI ? 19 n Printer assigned to other session. UDK Status (VT400 Mode Only) Request (Host to VT420) DSR CSI ? 25 n Report (VT420 to host) DSR CSI ? 20 n UDKs unlocked. UDKs unlocked. CSI ? 21 n UDKs locked. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Summary 277 Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ Keyboard Status Request (Host to VT420) DSR CSI ? 26 n Report (VT420 to host) DSR CSI ? 27; Pn; Pst; Ptyp n Dialect ------------------------------------------------------------ Pn ------------------------------------------------------------ ANSI ------------------------------------------------------------ PC ------------------------------------------------------------ Pst ------------------------------------------------------------ Keyboard Status  ------------------------------------------------------------ 0 Unknown Unknown 0 Keyboard ready. 1 North American+ North American+ 3 No keyboard. 2 British British 8 Keyboard busy. 3 Flemish Belgian 4 Canadian (French) -- Ptyp ------------------------------------------------------------ Keyboard Type ------------------------------------------------------------ 5 Danish Danish 6 Finnish Finnish 0 LK201/LK301 7 German German 1 LK401 8 Dutch -- 2 LK443/LK444 9 Italian Italian 3 LK421 10 Swiss (French) Swiss (French) 11 Swiss (German) Swiss (German) 12 Swedish Swedish 13 Norwegian Norwegian 14 French/Belgian French 15 Spanish Int. Spanish Int. 16 Portuguese Portuguese 28 Canadian (English) -- 32 -- Spanish National ------------------------------------------------------------  The terminal only sends Pst in VT400 mode. +The terminal does not transmit Unknown. Unknown is for devices that cannot determine the keyboard type. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 278 VT420 Reports Summary Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ Macro Space Request (Host to VT420) DSR CSI ? 62 n Report (VT420 to host) DECMSR CSI Pn * { P n = n u m b e r o f b y te s ------------------------------------------------------------ 16 r o u n d ed do wn : Memory Checksum Request (Host to VT420) DSR CSI ? 63; Pid n Pid = request number. Report (VT420 to host) DECCKSR DCS Pid ! ~ D..D ST Pid = request number. D...D = checksum. Data Integrity Request (Host to VT420) DSR CSI ? 75 n Report (VT420 to host) DSR CSI ? 70 n No communication errors. CSI ? 71 n Communication errors. CSI ? 73 n Not reported since last power-up or RIS. ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ Multiple-Session Status Request (Host to VT420) DSR CSI ? 85 n Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Summary 279 Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Device Status Reports ------------------------------------------------------------ Report (VT420 to host) DSR CSI ? 80; Ps2 n SSU sessions enabled. Ps2 = Maximum number of sessions. CSI ? 81; Ps2 n SSU sessions available but pending. Ps2 = Maximum number of sessions. CSI ? 83 n SSU sessions not ready. CSI ? 87 n Sessions on separate lines. Requesting Checksum of Rectangular Area (VT400 Mode Only) Request (Host to VT420) DECRQCRA CSI Pid; Pp; Pt; Pl; Pb; Pr * y Pid = request label. Pp = page number. Pt = top-line border. Pl = left-column border. Pb = bottom-line border. Pr = right-column border. Checksum report (VT420 to host) DECCKSR DCS Pid ! ~ D..D ST Pid = request number. D..D = checksum. ------------------------------------------------------------ Terminal State Reports (VT400 Mode Only) ------------------------------------------------------------ Request (Host to VT420) DECRQTSR CSI Ps $ u Ps = report requested. 0 = ignored. 1 = terminal state report. Terminal state report (VT420 to host) DECTSR DCS 1 $ s D..D ST D...D = report data. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 280 VT420 Reports Summary Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Terminal State Reports (VT400 Mode Only) ------------------------------------------------------------ Restore terminal state DECRSTS DCS Ps $ p D...D ST Ps = data string format. 0 = error. 1 = terminal state report. D...D = restored data. ------------------------------------------------------------ Presentation State Reports (VT400 Mode Only) ------------------------------------------------------------ Request (Host to VT420) DECRQPSR CSI Ps $ w Ps = report requested. 0 = error. 1 = cursor information report. 2 = tab stop report. Cursor information report (VT420 to host) DECCIR DCS 1 $ u D...D ST D..D = data string. See text for description. Tab stop report (VT420 to host) DECTABSR DCS 2 $ u D...D ST D...D = tab stops. Restore DECRSPS DCS Ps $ t D...D ST Ps = data string format. 0 = error. 1 = cursor information report. 2 = tab stop report. D...D = data string. Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Summary 281 Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Mode Settings (VT400 Mode Only) ------------------------------------------------------------ Request mode (Host to VT420) DECRQM CSI Pa $ p Pa = ANSI mode. (Table 12-2) CSI ? Pd $ p Pd = DEC private mode. (Table 12-3) Report mode (VT420 to host) DECRPM CSI Pa; Ps $ y Pa = ANSI mode. (Table 12-2) Ps = mode state. 0 = unknown mode. 1 = set. 2 = reset. 3 = permanently set. 4 = permanently reset. Set mode SM CSI Pa; ... Pa h Pa = ANSI mode(s). (Table 12-2) CSI ? Pd; ... Pd h Pd = DEC private mode(s). (Table 12-3) Reset mode RM CSI Pa; ... Pa l Pa = ANSI mode(s). (Table 12-2) CSI ? Pd; ... Pd l Pd = DEC private mode(s). (Table 12-3) Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 282 VT420 Reports Summary Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Control Function Settings (VT400 Mode Only) ------------------------------------------------------------ Request (Host to VT420) DECRQSS DCS $ q D...D ST D...D = intermediate and/or final characters of function. (Table 12-4) Report (VT420 to host) DECRPSS DCS Ps $ r D...D ST Ps = 0, valid request. Ps = 1, invalid request. D...D = intermediate and/or final characters of function. (Table 12-4) ------------------------------------------------------------ Saving and Restoring the Cursor State ------------------------------------------------------------ Save cursor state DECSC ESC 7 Restore cursor state DECRC ESC 8 ------------------------------------------------------------ Window Report (VT400 Mode Only) ------------------------------------------------------------ Request (Host to VT420) DECRQDE CSI " v Report (VT420 to host) DECRPDE CSI Ph; Pw; Pml; Pmt; Pmp " w Ph = number of lines. Pw = number of columns. Pml = first column at left. Pmt = top line. Pmp = page number. ------------------------------------------------------------ User-Preferred Supplemental Set (VT400 Mode) ------------------------------------------------------------ Request (Host to VT420) DECRQUPSS CSI & u Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ VT420 Reports Summary 283 Table 12-5 (Cont.) Sequences for VT420 Reports ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ User-Preferred Supplemental Set (VT400 Mode) ------------------------------------------------------------ Report (VT420 to host) DECAUPSS DCS 0 ! u % 5 ST DEC Supplemental Graphic DCS 1 ! u A ST ISO Latin-1 supplemental ------------------------------------------------------------ Chapter 12 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 13 Resetting and Testing the Terminal ------------------------------------------------------------ This chapter describes how to reset the settings of many VT420 control functions at the same time. The chapter also describes how to run the power-up self-test and other tests on the terminal, using control functions. NOTE You can also reset your VT420 by using set-up. See Installing and Using the VT420 Video Terminal for information on using set-up. Resetting the Terminal This section describes the control functions you can use to reset the VT420 to a saved or factory-default state. There are four control functions you can use to reset the terminal. Soft terminal reset (DECSTR) Hard terminal reset (RIS) Secure reset (DECSR) Tab clear (TBC) Selects most of the power-up factory-default settings. Selects the saved settings stored in nonvolatile memory. Sets the terminal to its power-up state to guarantee the terminal state for secure connections Clears tab stops. Soft terminal reset, hard terminal reset, and secure reset affect many control functions, including some ANSI and DEC private modes. ANSI and DEC private modes are control functions that have only two settings, set or reset. 284 Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Resetting the Terminal Soft Terminal Reset (DECSTR) 285 ------------------------------------------------------------ Soft Terminal Reset (DECSTR) This control function changes most of the terminal's current settings to the power-up default settings listed in Table 13-1. Available in: VT400 mode only Format CSI 9/11 ! 2/1 p 7/0 You can also perform a soft terminal reset by selecting Reset Session in the Set-Up Directory screen. See Installing and Using the VT420 Video Terminal. Notes on DECSTR · DECSTR affects only those functions listed in Table 13-1. · National replacement character set mode (DECNRCM) is not reset when you select Reset in set-up. Table 13-1 Soft Terminal Reset (DECSTR) States ------------------------------------------------------------ Mode Mnemonic State After DECSTR ------------------------------------------------------------ Text cursor enable DECTCEM Cursor enabled. Insert/replace IRM Replace. Origin DECOM Absolute (cursor origin at upper-left of screen). Autowrap DECAWM No autowrap. National replacement character set DECNRCM Multinational set. Keyboard action KAM Unlocked. Numeric keypad DECNKM Numeric characters. Cursor keys DECCKM Normal (arrow keys). Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 286 Resetting the Terminal Reset to Initial State (RIS) Table 13-1 (Cont.) Soft Terminal Reset (DECSTR) States ------------------------------------------------------------ Mode Mnemonic State After DECSTR ------------------------------------------------------------ Other Control Functions Set top and bottom margins DECSTBM Top margin = 1. Bottom margin = page length. All character sets G0, G1, G2, G3, GL, GR VT420 default settings. (DECSTR works only in VT400 mode.) Select graphic rendition SGR Normal rendition. Select character attribute DECSCA Normal (erasable by DECSEL and DECSED). Save cursor state DECSC Home position with VT420 defaults. Assign user-preferred supplemental set DECAUPSS Set selected in set-up. Select active status display DECSASD Main display (first 24 lines). Key position DECKPM Send character codes. Select modifier key reporting DECSMKR Modifier keys perform default functions. ------------------------------------------------------------ ------------------------------------------------------------ Reset to Initial State (RIS) This control function causes a nonvolatile memory (NVR) recall to occur. RIS replaces all set-up features with their saved settings. See Installing and Using the VT420 Video Terminal. The terminal stores these saved settings in NVR memory. The saved setting for a feature is the same as the factory-default setting, unless you saved a new setting. NOTE Digital does not recommend using RIS to reset the terminal. You should use a soft terminal reset (DECSTR) instead. RIS usually causes a communication line disconnect and may change the current baud rate settings. When performing a RIS, the terminal Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Resetting the Terminal Reset to Initial State (RIS) 287 sends XOFF to the host to stop communication. When the RIS is complete, the terminal sends XON to resume communication. Format ESC 1/11 c 6/3 RIS Actions · Sets all features listed on set-up screens to their saved settings. · Causes a communication line disconnect. · Clears user-defined keys for both sessions. (See Chapter 14 for details on session management.) · Clears the screen and all off-screen page memory · Clears the soft character set. · Clears page memory. All data stored in page memory is lost. · Clears the screen. · Returns the cursor to the upper-left corner of the screen. · Sets the select graphic rendition (SGR) function to normal rendition. · Selects the default character sets (ASCII in GL, and DEC Supplemental Graphic in GR). · Clears all macro definitions. · Erases the paste buffer. Using RIS with SSU Sessions If you use Digital's SSU software (Chapter 14) to manage sessions, RIS does not disconnect communications. If SSU is enabled and at least one session is open, RIS does the following: · Erases the screen. · Moves the cursor to the home position. · Performs a soft terminal reset (DECSTR). Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 288 Resetting the Terminal Secure Reset (DECSR) · Resets the current session. ------------------------------------------------------------ Secure Reset (DECSR) This control function sets the terminal to its power-up state. DECSR lets applications know the exact state of the terminal before any attempted operations. You can use DECSR to guarantee the terminal state for secure connections. DECSR is similar to RIS, but does not perform a disconnect from the host. Format ESC 1/11 [ 5/11 Pr 3/n + 2/11 p 7/0 Parameters Pr is a optional random number from 0 to 16383. If Pr is included, the terminal sends a confirmation (DECSRC) with this number. DECSR Actions · Clears user-defined keys. · Clears soft character sets. · Clears the screen and all off-screen page memory. · Returns the cursor to the upper-left corner of the first page. · Resets the scrolling margins. · Resets origin mode (DECOM) to absolute. · Sets visual character attributes to normal. · Sets the selective erase (DECSCA) attribute to not selectively erasable. · Sets all character sets to the defaults (G0, G1, G2, G3, GL, GR). · Erases macro memory. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Resetting the Terminal Secure Reset Confirmation (DECSRC) 289 · Erases the paste buffer. · Reinitializes the keyboard state by - Clearing the keyboard input buffer - Canceling compose sequences - Resetting the keyboard to send its default codes (in NVR) - Unlocking the keyboard (resetting KAM) DECSR replaces all set-up parameters to their saved settings or power-up default values. If you include the optional Pr parameter, the terminal returns a secure reset report to the host. Notes on DECSR · When using two sessions, DECSR only affects the current session. The terminal only supports secure connections for a single session. Changing from one session to two sessions causes the terminal to send a break signal to alert the host. · DECSR works in all conformance levels (level 1 or higher). · DECSR works in display controls mode (CRM) and causes the terminal to exit this mode. · DECSR does not work in VT52 mode or printer controller mode. The host software must explicitly exit these modes. You can send DECSR to an attached printer if the terminal is in printer controller mode. · The terminal buffers DECSR like any other incoming data. ------------------------------------------------------------ Secure Reset Confirmation (DECSRC) The terminal returns this report to the host if the Pr parameter was included in the last secure reset (DECSR) control function. DECSRC report indicates that the secure reset operation was successful. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 290 Resetting the Terminal Tab Clear (TBC) Format ESC 1/11 [ 5/11 Pr 3/n * 2/10 q 7/1 Parameters Pr is the number from 0 to 16383 that was included in the corresponding secure reset sequence. ------------------------------------------------------------ Tab Clear (TBC) This control function clears tab stops. Format CSI 9/11 Ps 3/n g 6/7 Parameters Ps indicates the tab stops to clear. There are only two values for Ps, 0 and 3. 0 or none (default) The terminal only clears the tab stop at the cursor. 3 The terminal clears all tab stops. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Testing the Terminal Invoke Confidence Test (DECTST)--Power-Up Self-Test 291 Testing the Terminal This section describes control functions you can use to test the operating status of the terminal. There are two tests you can run: Screen alignment display (DECALN) Confidence test (DECTST) ------------------------------------------------------------ Screen Alignment Pattern (DECALN) This control functions fills the complete screen area with a test pattern used for adjusting screen alignment. Normally, only Digital's manufacturing and service personnel would use DECALN. Format ESC 1/11 # 2/3 8 3/8 NOTE DECALN sets the margins to the extremes of the page, and moves the cursor to the home position. ------------------------------------------------------------ Invoke Confidence Test (DECTST)--Power-Up Self-Test This control function runs one or more tests to check the terminal's operating status. If possible, the terminal displays an error message on the screen for each error it finds. The VT420 Service Guide explains the meaning of each message. Format CSI 9/11 4 3/4 ; 3/11 Ps1; ** . . . . . . Psn ** y 7/9 Parameters Ps1...Psn specifies one or more tests to run on the terminal. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 292 Testing the Terminal Invoke Confidence Test (DECTST)--Power-Up Self-Test Ps Test 0 All tests (1,2,3,6). 1 Power-up self test. 2 RS-232 port loopback test (worldwide model only). 3 Printer port loopback test. 6 RS-232 port modem control line loopback test (worldwide model only). 7 DEC-423 port loopback test. 9 Repeat the other tests in the control sequence. You can run several tests at once by including more than one Ps parameter in the sequence. The tests do not necessarily execute in the order they appear in the sequence. Notes on DECTST · After executing the power-up self test, the terminal displays either a diagnostic message in the upper-left corner of the screen, or a VT420 OK message in the center of the screen. · DECTST causes a disconnect to occur. You should not use DECTST if you have a modem. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Resetting and Testing the Terminal Summary 293 Summary Table 13-2 lists all the control functions described in this chapter. Table 13-2 VT420 Reset Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Resetting the Terminal Soft terminal reset  DECSTR CSI ! p Hard terminal reset RIS ESC c Not recommended. Secure reset DECSR ESC [ Pr + p Pr can be any number from 0 to 16383. Secure reset comfirmation DECSRC ESC [ Pr * q Pr can be any number from 0 to 16383. Tabulation clear TBC CSI 0 g Clear tab at cursor position. CSI 3 g Clear all tabs. Testing the Terminal Screen alignment display DECALN ESC 8 ------------------------------------------------------------  Available in VT400 mode only. Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 294 Resetting and Testing the Terminal Summary Table 13-2 (Cont.) VT420 Reset Sequences ------------------------------------------------------------ Name Mnemonic Sequence ------------------------------------------------------------ Invoke confidence test DECTST CSI 4; Ps1;...Psn y Ps = test to run. 0 = all tests. 1 = power-up self-test. 2 = RS-232 port data loopback. 3 = printer port loopback. 6 = RS-232 modem control line loopback. 7 = DEC-423 port loopback. 9 = repeat tests. ------------------------------------------------------------ Chapter 13 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Part 4 Session Management ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 14 Session Management ------------------------------------------------------------ Two Sessions A session is an electronic connection between the terminal and a host system. The VT420 lets you run two sessions at the same time. Each time you establish a connection with your host system from the terminal, you open a session on the terminal. You can use two sessions to process and view information from two sources at the same time. You can easily move back and forth between these sessions. You do not have to end one session before you begin another. You can run the two sessions on separate host systems or on the same system. The VT420 maintains a separate context for each session. What you do in one session does not affect the other session. Two Ways to Manage Sessions When you run two sessions at the same time, you need some way to manage the flow of data to and from each session. For example, suppose a user wants to switch from session 1 to session 2. The terminal must be able to inform the host system of the switch, without affecting the normal data flow. You can use one of two ways to manage sessions on a VT420. Multiple system communications (MSC) SSU software Chapter 14 297 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 298 Session Management Two Ways to Manage Sessions Multiple system communications uses two communication lines between the terminal and host to run two sessions. Each session uses a separate line. On the VT420, the second session uses the printer/comm port. You can connect the lines to the same host (or terminal server) or two separate hosts (or terminal servers). Figure 14-1 shows some typical MSC environments. MSC is basically a hardware solution for session management. MSC is the same type of system used by terminals that can run only one session. MSC does not require special programming commands. MSC session management is transparent to the host. The terminal manages each session locally. Figure 14-1 Typical MSC Environments Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Session Management Two Ways to Manage Sessions 299 SSU software uses only one communication line to run two sessions. Usually, you use SSU software to run two sessions on the same host computer or terminal server. Figure 14-2 shows a typical SSU environment. SSU software uses a protocol of system-level commands to maintain two sessions. You can use the commands that best suit your needs. SSU software differs from MSC in the following ways: SSU Software MSC Uses one communication line for two sessions. Requires two communication lines, one for each session. Uses a set of commands to control both sessions. Does not use commands. Requires that the host and terminal recognize SSU commands. Is transparent to the host, since there are no commands to recognize. NOTE Make sure your system supports SSU software before you use this protocol. Your host system must be able to interpret and send SSU commands. The next section describes how the VT420 divides its resources between two sessions. The rest of the chapter describes the two methods of session management, MSC and SSU. Figure 14-2 Typical SSU Environment Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 300 Session Management Session Resources Session Resources When you run two sessions on the terminal, you interact with one session at a time. This active session has primary access to the terminal's features and resources. The inactive session must wait to use some resources. This section describes which resources each session can use independently and which resources they must share. Independent Resources The terminal maintains two sets of some features, so each session can use those features independently. For example, the terminal has two sets of page memory, one for each session. The terminal has two sets of the following features: · Page memory When you run two sessions, each session has 72 lines by 80 or 132 columns of page memory. · ANSI text state Each session maintains a record of current character sets, text attributes, and pages. · Status lines Each session has a status line. · Set-Up Each session has its own set-up feature settings. · Macro space Each session has its own memory for macro definitions. · Downloadable character set You can design and load a soft character set for each session. · User-defined keys (UDKs) Each session can have a set of UDK definitions. · Communication lines In an MSC environment, each session has a communication line. Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Session Management Session Resources 301 Shared Resources Only one session can use the following features at a time. If session 1 is using the resource, session 2 must wait until session 1 is finished. · Screen You can divide the screen to display data from two sessions at the same time. However, both sessions must compete for time to update the screen. See Installing and Using the VT420 Video Terminal for details on dividing the screen into two windows. · Copy and paste buffer Only the active session can use the copy and paste buffer. This feature lets you copy text from one session, switch to the other session, then send the text to the other session's host. · Keyboard Only the active session can use the keyboard. · Printer port Only one session at a time can use the printer port. If session 1 is using the printer, session 2 must wait until session 1 is finished. You can assign the printer to a particular session by using set-up, or by using a print control function Chapter 11. When you assign the printer port to a session, you restrict the use of the printer to that session. Multiple System Communications (MSC) Multiple system communications lets you run two sessions without software support from the host. MSC uses the primary communication port and the printer port on the rear of the terminal, one port for each session. Each session has a dedicated physical link to the host. You can select MSC by using set-up. See Installing and Using the VT420 Video Terminal. You cannot use MSC and SSU software at the same time. Unlike SSU software, MSC does not use a system-level protocol to maintain two sessions. MSC uses two hardwire links to the host. Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 302 Session Management SSU Software (VT Mode) SSU Software (VT Mode) SSU software lets the terminal run two sessions over a single communication line. That is, each session shares the same communication line. SSU is a set of system-level commands that the terminal and host use to maintain sessions. NOTE Make sure your system supports SSU software before you use this protocol. Your host system must be able to interpret and send SSU commands. SSU Environment The VT420 and the host system exchange different types of data at different levels, called layers. When you use SSU software, there are three basic layers of data exchange between the terminal and host. These layers have an order of priority, as follows: ANSI/VT52 layer SSU layer XON/XOFF flow control ANSI/VT52 Layer This layer includes all alphanumeric characters as well as text functions the terminal uses. The alphanumeric characters include all characters in the character sets that the terminal supports. Text functions include such tasks as selecting page format, character sets, and character attributes (for example, bold, and underline). SSU Layer At this layer, the terminal and host exchange SSU commands to maintain the session environment. This layer connects the terminal to the host, and controls how the terminal and host switch from session to session. SSU software can also control the flow of data between the terminal and host at the session level. However, SSU data flow control is secondary to the XON/XOFF data flow control. XON/XOFF Data Flow Control This layer controls the flow of data between the terminal and the host. When the terminal's receive buffer is full, this layer tells the host to stop sending data to the terminal. When the terminal's receive buffer can accept more data, this layer tells the host to resume sending data to the terminal. Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Session Management Enable Session Command 303 This layer affects both sessions, because it controls the link between the terminal proper and the host. Appendix B describes XON/XOFF flow control in detail. Using SSU Software See Installing and Using The VT420 Video Terminal for details on using SSU session management. Selecting Sessions (MSC or SSU Software) You can select the active session by using the ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ key ( ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ) or the enable session control function. If session 1 is the active session and you press ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ ( ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ), session 2 becomes the active session. Session 1 becomes the inactive session. If your host system also requires you to log in, you can log in to the second session. The enable session command works like the ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ key ( ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ). If session 1 is the active session and the terminal receives the enable session command, session 2 becomes the active session. Session 1 becomes the inactive session. ------------------------------------------------------------ Enable Session Command This command works with MCS or SSU sessions. Format CSI 9/11 & 2/6 x 7/8 The session receiving the enable session command becomes the active session. The other session becomes the inactive session. Chapter 14 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Part 5 Emulating a Personal Computer ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 15 Operating in PC TERM Mode ------------------------------------------------------------ The VT420 worldwide model with PC TERM mode can emulate a personal computer. When the terminal is in PC TERM mode, you can use PC application software. You can still use most VT420 control functions described in Part 3. The primary difference between VT mode and PC TERM mode is how keyboard data is sent to the host. This chapter describes how to enable PC TERM mode, choose PC character sets, and perform other operations in PC TERM mode. The chapter covers the following topics: · How the VT420 operates in PC TERM mode · Selecting PC TERM mode and PC character sets · Scan codes sent to the host How the VT420 Operates in PC TERM Mode To have the VT420 emulate a personal computer, you select PC TERM mode and use a PC keyboard. In PC TERM mode, Digital's PC keyboard sends scan codes to the terminal each time you press a key or release a key. Figure 15-1 illustrates PC mode operation. The terminal remaps the keyboard scan codes into IBM PC scan codes before sending them to the host. The host passes the information to the PC application software. The software defines each key stroke, then the host processes the information and sends it to the terminal. Finally, the terminal displays the information on the screen. Chapter 15 307 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 308 Operating in PC TERM Mode How the VT420 Operates in PC TERM Mode Figure 15-1 PC TERM Mode Operation Sequence of Operations When you select PC TERM mode, the terminal performs the following functions: · Copies current set-up values into a work area in memory. This area is not in the terminal's nonvolatile RAM (NVR). · Resets the terminal. · Sets the screen display to 25 lines  1 page, without a status display line. · Resets the keyboard, which turns off the LEDs. · Switches the XON code to 65 16 characters and the XOFF code to 67 16 characters. These pseudo scan codes are created to prevent a conflict with any keyboard key when the terminal sends data to the host. When the host wants to hold up data from the terminal, the host uses the normal ASCII characters of 11 16 for XON and 13 16 for XOFF. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode How the VT420 Operates in PC TERM Mode 309 · Loads font tables to generate characters. · Disables the following local keyboard commands: -- Print screen (hard copy): ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ -- Change window configuration: ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ -- Switch session: ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ The host application may send the DECELF control command later to enable local keyboard commands. · Enables the local keyboard command for entering and leaving set-up:: ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ . · Sends XON (65 16 ) to host. · Turns off autowrap mode. · Sets the cursor to blinking. The shape of the cursor is defined in the host configuration file. · Passes keyboard scan codes directly to the host. · Interprets control codes based on type of character set (PC or ISO Latin-1 / DEC Multinational). See ``Control Codes Sent in PC TERM Mode'' in this chapter. · Ignores the select character set (SCS) sequences when you select a PC character set. The terminal uses the SCS sequences to designate ASCII character sets as a logical set (G0, G1, G2, G3) before they are mapped to the GL or GR in-use table with lock-shift sequences such as LS0 and LS1R. You can select a character set from the General Set-Up screen. Control Codes Sent in PC TERM Mode In PC TERM mode, the terminal interprets control codes based on the type of character set--PC or ISO Latin-1 / DEC Multinational. The ISO Latin-1 and DEC Multinational character sets have control codes in the C0 and C1 locations (Chapter 2). If you select the ISO Latin-1 or DEC Multinational set in PC TERM mode, the terminal treats characters in the C0 and C1 locations (00 16 through 1F 16 and 80 16 through 9F 16 ) as control characters to execute. When you select display controls mode, these characters are displayed on the screen. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 310 Operating in PC TERM Mode How the VT420 Operates in PC TERM Mode PC character sets have displayable characters mapped into all 256 character locations. When you select a PC character set in PC TERM mode, C0 locations can have both control characters and display characters. Table 15-1 lists the C0 codes that the terminal treats as control functions to execute. All other C0 and C1 locations always select a display character. Table 15-1 Control Codes for PC Character Sets ------------------------------------------------------------ Code Code Code ------------------------------------------------------------ ENQ 0/5 LF 0/A DC1 1/1 BEL 0/7 VT 0/B DC3 1/3 BS 0/8 FF 0/C ESC 1/B HT 0/9 CR 0/D ------------------------------------------------------------ The table also applies to PC character sets selected in VT mode with a PC keyboard. To send the display characters that also occupy the locations in Table 15-1, you send the character as the second half of a byte pair: ESC character 11 10 xx The xx character value can be in the 00 10 to 127 10 range. See the PC character sets in this chapter. Enabling or Disabling PC TERM Mode You can enable and disable PC TERM mode from the General Set-Up screen or by using the change emulation mode sequence. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode Change Emulation Mode 311 ------------------------------------------------------------ Change Emulation Mode In this mode, the terminal can use only one PC character set at a time. Format ESC 1/11 [ 5/11 ? 3/15 Ps 3/n ; 3/11 Pc 3/n r 7/2 Parameters Ps selects the operating mode. Ps Operating Mode 0 (default) VT mode with a PC keyboard 1 PC TERM mode Pc selects one PC character set or a UPSS character set. Pc Character Set 0 (default) default 1 PC Multilingual 2 PC International 3 PC Danish/Norwegian 4 PC Spanish 5 PC Portuguese 6 UPSS DEC Supplemental 7 UPSS ISO Latin-1 Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 312 Operating in PC TERM Mode Enabling PC Keyboard Commands Enabling PC Keyboard Commands When you select PC TERM mode, the PC keyboard enables one local keyboard command, for entering and leaving set-up. Other local keyboard commands are disabled. You can control these commands by an escape sequence from the host. You can also control some commands from the set-up screens. Table 15-2 lists each command and its key sequence. Table 15-2 PC Keyboard Commands in PC TERM Mode ------------------------------------------------------------ Can Be Controlled By ------------------------------------------------------------ Command Key Sequence Escape Sequence Set-Up Screen ------------------------------------------------------------ Enabled in PC TERM Mode ------------------------------------------------------------ Set-Up ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ p p ------------------------------------------------------------ Disabled in PC TERM Mode ------------------------------------------------------------ Switch session ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ p p Print screen ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Print Screen ------------------------------------------------------------ ------------------------------------------------------------ p p Windows ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ p p Pan down, one line ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ " ------------------------------------------------------------ ------------------------------------------------------------ p Pan up, one line ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ # ------------------------------------------------------------ ------------------------------------------------------------ p Hold screen, Session 1 ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ p Hold screen, Session 2 ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ p Size up ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ " ------------------------------------------------------------ ------------------------------------------------------------ p Pan down, one line ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ # ------------------------------------------------------------ ------------------------------------------------------------ p ------------------------------------------------------------ Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode Enabling PC Keyboard Commands 313 Data and Commands Sent from the Host to the Terminal Screen formatting (data) commands follow the ANSI standard in PC TERM mode. In PC TERM mode, the terminal processes most commands from the host as it does in VT mode. The terminal processes the following commands normally: clear the screen, move the cursor, and pan. However, the terminal ignores query commands that normally cause the terminal to send a reply. Secondary DA--PC Keyboard See Chapter 12, ``Device Attributes (DA),'' for a description of the secondary device attribute (DA). DSR--PC Keyboard Status See Chapter 12, ``Device Status Report (DSR),'' for the PC keyboard device status report (DSR). Using PC Character Sets This section describes 8-bit PC character sets and how you can select them. PC character sets only operate in the 8-bit character mode. The VT420 worldwide terminal with PC TERM mode has five built-in PC character sets. You can select these character sets in PC TERM mode and VT mode. · PC International (Figure 15-2 and Figure 15-3) · PC Multilingual (Figure 15-2 and Figure 15-4) · PC Danish/Norwegian (Table 15-3) · PC Portuguese (Table 15-3) · PC Spanish (Table 15-3) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 314 Operating in PC TERM Mode Using PC Character Sets Figure 15-2 PC International and PC Multilingual Character Sets (CO and GL) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode Using PC Character Sets 315 Figure 15-3 PC International Character Set (C1 and GR) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 316 Operating in PC TERM Mode Using PC Character Sets Figure 15-4 PC Multilingual Character Set (C1 and GR) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode Using PC Character Sets 317 National PC Character Sets The National PC character sets are the same as the PC International character set, except as indicated in the following table: Table 15-3 National PC Character Sets ------------------------------------------------------------ PC Character Set Hexadecimal Value ------------------------------------------------------------ 86 89 8B 8C 8E 8F ------------------------------------------------------------ PC International å ë ï î Ä Å PC Danish/ Norwegian PC Spanish À È PC Portuguese Á Ê Í Ô Ã Â ------------------------------------------------------------ 91 92 93 94 96 98 99 ------------------------------------------------------------ PC International æ Æ ô ö û ý Ö PC Danish/ Norwegian PC Spanish Í Ó Á PC Portuguese À È ô õ Ú Ì Õ ------------------------------------------------------------ 9B 9D 9F A9 AA AF ------------------------------------------------------------ PC International ¥ : PC Danish/ Norwegian ø ¨ PC Spanish Ò Ú Ï PC Portuguese Ù Ó Ò ------------------------------------------------------------ Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 318 Operating in PC TERM Mode Using PC Character Sets Selecting PC Character Sets When you select a PC character set, the terminal ignores the select character set (SCS) escape sequences. The SCS is not necessary, because the terminal can place only one PC character at a time in the in-use table. In PC TERM mode or VT400 mode, there are two ways to select a PC character set: 1. From the General Set-Up screen 2. With the change emulation mode sequence The change emulation mode command sequence, which enables and disables PC character sets and PC TERM mode. See ``Enabling or Disabling PC TERM Mode'' in this chapter. PC Keyboard Codes This section describes the codes the terminal sends to the host in PC TERM mode, when you connect a PC keyboard. See Chapter 3 for a description of the codes the PC keyboard and terminal send in VT mode. The VT420 worldwide model with PC TERM mode can use different national keyboard dialects. Each keyboard dialect pertains to a different country or region of western Europe. You can select the appropriate dialect by setting the keyboard language feature in the Set-Up Directory. Scan Codes In PC TERM mode, the terminal maps the keyboard scan codes to IBM PC keyboard scan codes. The terminal sends a unique IBM PC scan code directly to the host each time you press a key and each time you release a key. The PC software in the host defines the key codes. Layout The PC keyboard has four groups of keys and three indicator lights. The keys are grouped by function. The PC keyboard also has two audible indicators, a keyclick and bell. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode PC Keyboard Codes 319 ! Main keypad " Editing keypad # Numeric keypad $ Top-row function keys -- Predefined keys -- Programmable keys % Escape key & Indicator lights Main Keypad The layout of the main keypad is similar to a typewriter keyboard with standard keys, such as alphanumeric characters, punctuation marks, and ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ keys. The main keypad also has a number of keys not found on a typewriter, such as the top-row function keys and the ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ and ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ keys. Key Assignments The following sections list the scan codes sent by each PC keyboard key in PC TERM mode. Keys are referred to by number. There are two models of the PC keyboard: · North American, with 101 keys (Figure 15-5) · Worldwide, with 102 keys (Figure 15-6) The figures show the number assigned to each key. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 320 Operating in PC TERM Mode PC Keyboard Codes Figure 15-5 North American PC Keyboard (101 Keys) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode PC Keyboard Codes 321 Figure 15-6 Worldwide PC Keyboard (102 Keys) Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 322 Operating in PC TERM Mode PC Keyboard Codes Standard Keys The standard keys send scan codes for the alphanumeric characters. Table 15-4 lists the scan codes sent to generate the alphanumeric characters and other symbols. The key numbers in the table correspond to the key numbers in Figures 15-5 and 15-6. Table 15-4 Scan Codes Sent by Standard Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ 1 29 A9 2 02 82 3 03 83 4 04 84 5 05 85 6 06 86 7 07 87 8 08 88 9 09 89 10 0A 8A 11 0B 8B 12 0C 8C 13 0D 8D 15 0E 8E 16 0F 8F 17 10 90 18 11 91 19 12 92 20 13 93 21 14 94 22 15 95 23 16 96 24 17 97 25 18 98 26 19 99 27 1A 9A 28 1B 9B 29  2B AB 30 3A BA ------------------------------------------------------------  This key is on the PC keyboard with 101 keys only. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode PC Keyboard Codes 323 Table 15-4 (Cont.) Scan Codes Sent by Standard Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ 31 1E 9E 32 1F 9F 33 20 A0 34 21 A1 35 22 A2 36 23 A3 37 24 A4 38 25 A5 39 26 A6 40 27 A7 41 28 A8 42+ 2B AB 43 1C 9C 44 2A AA 45+ 56 D6 46 2C AC 47 2D AD 48 2E AE 49 2F AF 50 30 B0 51 31 B1 52 32 B2 53 33 B3 54 34 B4 55 35 B5 57 36 B6 58 1D 9D 60 38 B8 61 39 B9 62 E0 38 E0 B8 64 E0 1D E0 9D ------------------------------------------------------------ +This key is on the PC keyboard with 102 keys only. ------------------------------------------------------------ Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 324 Operating in PC TERM Mode PC Keyboard Codes Editing Keypad The editing keypad includes editing and arrow keys. Table 15-5 lists the scan codes sent to generate editing key functions. Key numbers correspond to Figures 15-5 and 15-6. Table 15-5 Scan Codes Sent by Editing and Arrow Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ Unshifted, or Shifted with Num Lock On ------------------------------------------------------------ 75 E0 52 E0 D2 76 E0 53 E0 D3 79 E0 4B E0 CB 80 E0 47 E0 C7 81 E0 4F E0 CF 83 E0 48 E0 C8 84 E0 50 E0 D0 85 E0 49 E0 C9 86 E0 51 E0 D1 89 E0 4D E0 CD ------------------------------------------------------------ Shifted  ------------------------------------------------------------ 75 E0 AA E0 52 E0 D2 E0 2A 76 E0 AA E0 53 E0 D3 E0 2A 79 E0 AA E0 4B E0 CB E0 2A 80 E0 AA E0 47 E0 C7 E0 2A 81 E0 AA E0 4F E0 CF E0 2A 83 E0 AA E0 48 E0 C8 E0 2A 84 E0 AA E0 50 E0 D0 E0 2A 85 E0 AA E0 49 E0 C9 E0 2A 86 E0 AA E0 51 E0 D1 E0 2A 89 E0 AA E0 4D E0 CD E0 2A ------------------------------------------------------------  When you press the right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key, the make/break action sends the scan code B6/36 instead of AA/2A. When you press the right and left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ keys, both scan codes are sent. ------------------------------------------------------------ Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Operating in PC TERM Mode PC Keyboard Codes 325 ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ Num Lock On ------------------------------------------------------------ 75 E0 2A E0 53 E0 D2 E0 AA 76 E0 2A E0 54 E0 D3 E0 AA 79 E0 2A E0 4B E0 CB E0 AA 80 E0 2A E0 47 E0 C7 E0 AA 81 E0 2A E0 4F E0 CF E0 AA 83 E0 2A E0 48 E0 C8 E0 AA 84 E0 2A E0 50 E0 D0 E0 AA 85 E0 2A E0 49 E0 C9 E0 AA 86 E0 2A E0 51 E0 D1 E0 AA 89 E0 2A E0 4D E0 CD E0 AA ------------------------------------------------------------ Numeric Keypad Table 15-6 lists the scan codes sent to generate the numeric keypad characters. Key numbers correspond to Figures 15-5 and 15-6. Table 15-6 Scan Codes Sent by Numeric Keypad Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ 90 45 C5 91 47 C7 92 4B CB 93 4F CF 95 E0 35 E0 B5 Shifted  Shifted  E0 AA E0 35 E0 B5 E0 2A 96 48 C8 97 4C CC 98 50 D0 99 52 D2 100 37 B7 101 49 C9 102 4D CD ------------------------------------------------------------  When you press the right ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ key, the make/break action sends the scan code B6/36 instead of AA/2A. When you press the the right and left ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ keys, both scan codes are sent. Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 326 Operating in PC TERM Mode PC Keyboard Codes Table 15-6 (Cont.) Scan Codes Sent by Numeric Keypad Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ 103 51 D1 104 53 D3 105 4A CA 106 4E CE 108 E0 1C E0 9C ------------------------------------------------------------ Top-Row Function Keys Table 15-7 lists the scan codes sent by the top-row function keys. Key numbers correspond to Figures 15-5 and 15-6. Table 15-7 Scan Codes Sent by Programmable Function Keys ------------------------------------------------------------ Key Make Code Break Code ------------------------------------------------------------ 110 01 81 112 3B BB 113 3C BC 114 3D BD 115 3E BE 116 3F BF 117 40 C0 118 41 C1 119 42 C2 120 43 C3 121 44 C4 122 57 D7 123 58 D8 124 E0 2A E0 37 E0 B7 E0 AA ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ , Shifted ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ , Shifted E0 37 E0 B7 ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Alt ------------------------------------------------------------ ------------------------------------------------------------ 54 D4 125 46 C6 ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ 126  E1 1D 45 E1 9D C5 E0 46 E0 C6 ------------------------------------------------------------  This key is not typematic. All associated scan codes occur on the make of the key. ------------------------------------------------------------ Chapter 15 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ A VT52 Mode Control Codes ------------------------------------------------------------ The VT52 mode lets the VT420 terminal operate like a VT52 terminal. You use VT52 mode with applications designed for the VT52. NOTE VT52 mode may not be included in future Digital terminals. Programmers should only write new software for the ANSI operating mode. Software should avoid switching indiscriminately between ANSI and VT52 modes. In VT52 mode, the terminal ignores many features and settings used in the ANSI environment. To avoid confusion, write all new software for the ANSI operating mode. VT52 Mode You use the DECANM control function to change the terminal to the VT52 mode of operation. In VT52 mode, the VT420 acts like a VT52 terminal. This mode lets you use applications designed for a VT52 terminal. CSI 9/11 ? 3/15 2 3/2 l 6/12 Table A-1 lists and describes all the escape sequences you can use when the terminal is in VT52 mode. Notes on DECANM · ANSI private control functions are not available. · The DEC Supplemental Graphic, ISO Latin-1 supplemental, and NRC sets are not available. · C1 control characters are not available. · The ASCII character set defaults to G0. Appendix A 327 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 328 VT52 Mode Control Codes Exiting VT52 Mode Exiting VT52 Mode You can exit VT52 mode by using the following escape sequence. ESC 1/11 < 3/12 When you you exit VT52 mode, the terminal returns to the mode it was in before entering VT52 mode. Table A-1 VT52 Escape Sequences ------------------------------------------------------------ Sequence Action ------------------------------------------------------------ ESC A Cursor up. ESC B Cursor down. ESC C Cursor right. ESC D Cursor left. ESC F Enter graphics mode. ESC G Exit graphics mode. ESC H Cursor to home position. ESC I Reverse line feed. ESC J Erase from cursor to end of screen. ESC K Erase from cursor to end of line. ESC Y Pn Move cursor to column Pn. ESC Z Identify. (host to terminal) ESC / Z Report. (terminal to host) ESC = Enter alternate keypad mode. ESC > Exit alternate keypad mode. ESC < Exit VT52 mode. (Enter VT100 mode.) ESC ^ Enter autoprint mode. ESC _ Exit autoprint mode. ESC W Enter printer controller mode. ESC X Exit printer controller mode. ESC ] Print screen. ESC V Print the line with the cursor. ------------------------------------------------------------ Appendix A ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ B Communication ------------------------------------------------------------ This appendix provides information on how the VT420 communicates with a host computer and a printer. The appendix describes how XON and XOFF characters help control the data flow between the terminal and the host system or the printer. For information on cables, see the ``Communication'' appendix in Installing and Using the VT420 Video Terminal. The terminal operates only on full-duplex asynchronous lines, with eight possible transmit and receive speeds. You can transmit at one speed and receive at another, but you must use the same speeds as your host system or printer. To match your host system's speed, use the Communications Set-Up screen. To match the printer 's speed, use the Printer Set-Up screen. Installing and Using the VT420 Video Terminal describes the set-up screens. You can connect the terminal directly to a local host system, using a cable. You can also connect the terminal to a remote system, as follows: · In VT mode: You can use (1) a terminal server, or (2) a modem or acoustic coupler connected to public-switched or dedicated telephone lines. · In PC TERM mode: You can use a modem, but not a terminal server. If you use a modem, the modem's XON and XOFF points must match the terminal's XON and XOFF points, as described in this appendix. Appendix B 329 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 330 Communication Standards Standards The VT420 operates in accordance with the following national and international communication standards from the Electronic Industries Association (EIA) and the Comite Consultatif International de Telegraphique et Telephonique (CCITT). EIA 232-D CCITT V.24 CCITT V.28 CCITT V.10 ISO 2110.2 Host System and Printer Port Interfaces The VT420 has two asynchronous serial ports available for communication with a host computer: Comm1 and Comm2. The Comm1 port is for communication with the primary host computer. The Comm2 port is for connecting to a local printer, or to a secondary host computer. Comm1 Connectors (Primary Host) · 25-pin subminiature D-type (EIA RS-232/RS-423) connector that connects the terminal to a local or remote host system (worldwide model only) · 6-pin DEC-423 connector that connects the terminal to a local host system On the worldwide model, you select which Comm1 connector is active by using the comm port selection feature in the Global Set-Up screen. See Installing and Using the VT420 Video Terminal. Comm2 Connector (Printer or Secondary Host) · 6-pin DEC-423 connector DEC-423 cabling lets you run your terminal at higher speeds and over longer distances than the RS-232 standards. When you use the RS-232 connector, you are limited to 50 feet of cable between the host system and terminal. When you use the DEC-423 connector, you can use up to 1000 feet of cable between the host system and printer. The ``Communication'' appendix in Installing and Using the VT420 Video Terminal lists the pin assignments for all VT420 connectors. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Communication Modems 331 Modems The VT420 can operate with all modems conforming to the national and international standards listed at the beginning of this appendix. However, the modem at the terminal must be compatible with the modem at the host system. NOTE In PC TERM mode, the modem's XON and XOFF points must match the terminal's XON and XOFF points. In PC TERM mode, the XON point is 65 16 characters, and the XOFF point is 67 16 characters. You can use Digital's DF124, DF212, DF224, and DF242 modems with the VT420. You can also use compatible modems and acoustic couplers, such as the AT&T 103, 113, and 212A types. The terminal must be certified for connection to non-AT&T type modems used outside of continental North America. Your local Digital Field Service office has detailed information on terminal certification and use of non-AT&T type modems. Printers You can connect the terminal to a local asynchronous serial printer by using a null modem cable. Here are some of the Digital printers you can use with the VT420: ------------------------------------------------------------ LA Series Letter-Quality Laser Plotter ------------------------------------------------------------ LA12 LA50 LQP02 LN01 LJ250 + LA34 LA75 LQP03 LN03  LJ251+ LA35 LA100 /LA210 DEClaser 1100+ LA36 LA324 DEClaser 2100+ LA38 DEClaser 2200+ ------------------------------------------------------------  With an H8751-A adapter. +With an H8751-E adapter. ------------------------------------------------------------ Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 332 Communication Character Format Character Format The VT420 can send and receive characters in a 7-bit or 8-bit format. The asynchronous character format consists of a start bit (space), the data bits (1 = mark, 0 = space), the parity bit (if present) and 1 or 2 stop bits (mark). The data bits represent a character, with the least significant bits leading. You can set the parity bit to even, odd, or none, using the data bits /parity feature in the Communications Set-Up screen. For more information on the asynchronous character format, see ANSI X3.15-1976, ``American National Standard for bit sequencings of the American National Standard Code for Information Interchange in Serial- by-Bit Data Transmission.'' Terminal-to-Host Data Flow Control Normally, the VT420 processes and displays characters as fast as it receives them. If the host system sends data faster than the terminal can display it, the terminal can use XON/XOFF flow control to tell the host to wait until the terminal has caught up. The VT420 stores incoming characters in a 254-character input buffer. When the buffer fills to a predetermined level (XOFF point), the terminal sends an XOFF character to stop the host system from sending more characters. When the buffer empties to an appropriate level (XON point), the terminal sends an XON character to tell the host to resume sending characters. If the terminal is set up to run one session in VT mode, you can select a first XOFF point of 64 or 128 characters (Communications Set- Up screen). The XON point is 32 characters. If the host system fails to respond to the first XOFF character, the terminal sends another XOFF character when the buffer fills to 220, and when the buffer is completely full. NOTE In PC TERM mode, the XON point is 65 16 characters, and the XOFF point is 67 16 characters. If you use SSU software to run two sessions in VT mode, you can select a first XOFF point of 64, 256, or 1792. SSU provides its own credit-based flow control, so XOFF is not needed. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Communication Terminal-to-Host Data Flow Control 333 For normal interactive use, you should use the default XOFF point of 64 characters. This setting prevents the host system from getting too far ahead of what is displayed on the screen. In some cases, using an XOFF point greater than 64 characters may improve the average speed for processing characters, since the host does not have to wait as often. NOTE If you select No XOFF in set-up, the terminal does not send an XOFF character to the host system when the input buffer fills. Selecting No XOFF also disables the ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ( ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ) Hold key function. If XOFF is disabled, there is no way to ensure that data will not be lost. When XON/XOFF Flow Control is Enabled If you set the XOFF feature to 64, 128, 256, or 1792 in VT mode, you enable XON/XOFF flow control. The terminal recognizes received XON and XOFF characters. When the terminal receives XOFF, the terminal stops sending data (except XON and XOFF characters). If the keyboard data buffer overflows, the keyboard locks and the Wait indicator appears on the keyboard indicator line at the bottom of the screen. The terminal resumes transmission when it receives an XON. When XON/XOFF flow control is enabled, the terminal sends XON and XOFF characters under the following conditions: Conditions that Send XON · The number of characters in the input buffer reaches the XON point (32 characters) and the last flow control character sent was XOFF. · The power self-test is completed (Chapter 7). · You perform a Clear Comm operation, either from the Set-Up Directory or with a hard reset (RIS) function. · You perform a Recall operation, either from the Set-Up Directory or with a hard reset (RIS) function. · You press the ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ ( ------------------------------------------------------------ ------------------------------------------------------------ Scroll Lock ------------------------------------------------------------ ------------------------------------------------------------ ) Hold key to release the screen when the input buffer is at or below the XON point. Conditions that Send XOFF · The number of characters in the input buffer reaches the first XOFF point (64 or 128 characters, selected from the Communications Set-Up screen) for the first time since the last XON was sent. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 334 Communication Terminal-to-Host Data Flow Control · The number of characters in the input buffer reaches the second XOFF point (220 characters) for the first time since the last XON was sent. · The terminal receives a character when the input buffer is full (256 characters). Using Fill Characters Software that does not support XON and XOFF characters from the terminal can still use all terminal features, by using fill characters. In some applications, you can use the terminal without XON/XOFF support or fill characters. However, the bit rate must be limited to 9600, and the software must not send the ESC (escape code), or use slow scrolling or the printer port. Transmit Rate Limiting When you enable this feature, the VT420 limits the rate at which it sends data to the host to 150 to 180 characters/second, with even spacing. Some host systems can only keep up with the relatively slow input of keys typed manually from the keyboard. Rate limiting simulates this condition and reduces the interrupt burden on the host. When this feature is disabled, the terminal sends all messages and keystrokes as fast as possible, limited only by the current transmit speed setting. ------------------------------------------------------------ Transmit Rate Limiting (DECXRLM) Applications can control the transmit rate limiting feature through the DECXRLM control function. Default: Unlimited Format CSI 9/11 ? 3/15 7 3/7 3 3/3 h 6/8 Set: limited transmit rate. CSI 9/11 ? 3/15 7 3/7 3 3/3 l 6/12 Reset: unlimited transmit rate. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Communication Transmit Rate Limiting (DECXRLM) 335 Modem Connections and Disconnections When the VT420 makes a connection to the host system through a modem, the terminal performs the following operations to ensure it is ready to send and receive. · Unlocks the keyboard (if it was locked). · Clears any transmission in progress. · Clears the keyboard buffer and all message buffers. · Clears the input buffer. · Clears XOFF sent and XOFF received. Any of the following conditions will disconnect the connection to the host system in VT mode: · You press ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ( ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Break ------------------------------------------------------------ ------------------------------------------------------------ ). · You use the Recall or Default fields in the Set-Up Directory. · Worldwide model : You change the host port you are using (from the RS-232 port to the DEC-423 port, or from the DEC-423 port to the RS-232 port). · The terminal loses the data set ready (DSR) signal. · The terminal loses the received line signal detect (RLSD) signal for a peiod of time you defined in set-up. See the disconnect delay feature in the Communications Set-Up screen. · The terminal does not receive an RLSD signal within 30 seconds after DSR. · The terminal receives a self-test command from the host system. The usual way to disconnect communications is to type ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ ( ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Break ------------------------------------------------------------ ------------------------------------------------------------ ). The host system's response to the disconnect signal depends on the system and the software. Terminal-to-Printer Data Flow Control The VT420 sends only data characters to the printer. The terminal does not send XON and XOFF characters. The terminal recognizes only XON and XOFF characters from the printer. Any other characters from the printer are ignored. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 336 Communication Terminal-to-Printer Data Flow Control When the terminal receives XOFF from the printer, the terminal stops sending data. The terminal starts sending data again when it receives an XON, or when a clear comm operation is performed. Using C1 Control Characters Using an 8-bit setting for the printer port implies the use of 8-bit C1 control characters. Using a 7-bit setting implies the use of the 7-bit ESC [ form of C1 control characters. You select the setting by using the data bits/parity feature in the Printer Set-Up screen. For more information on control characters, see Chapter 2 in this manual. NOTE Older printers may not recognize the 8-bit form of C1 control characters. With these printers, you must set the printer port to 7-bits for correct operation. Appendix B ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ C Related Documentation ------------------------------------------------------------ You can order the following VT420 manuals from Digital: Installing and Using the VT420 Video Terminal with PC Terminal Mode EK-VT42A-UU Provides information to install, operate and maintain the VT420 worldwide model that includes PC terminal (PC TERM) mode. Describes the ANSI, short ANSI, and PC keyboard keys and indicators, set-up screens, and compose sequences (used to select characters not otherwise available from the keyboard). Installing and Using the VT420 Video Terminal Worldwide Model EK-VT420-UU North American Model EK-VT420-UG Provides information to install, operate and maintain the VT420 models that do not include PC terminal mode. Describes the ANSI keyboard keys and indicators, set-up screens, and compose sequences (used to select characters not otherwise available from the keyboard). VT420 Service Guide EK-VT420-PS Provides qualified service personnel with information to troubleshoot and repair all VT420 models. Appendix C 337 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ D Compatibility with Other Digital Terminals ------------------------------------------------------------ This appendix compares the VT420 video terminal to Digital's VT320 and VT220 video terminals. ------------------------------------------------------------ Feature VT420 VT320 VT220 ------------------------------------------------------------ Character Attributes Blinking Yes Yes Yes Bold Yes Yes Yes Double height Yes Yes Yes Double width Yes Yes Yes Reverse video Yes Yes Yes Underline Yes Yes Yes Character Sets ASCII Yes Yes Yes DEC Special Graphic Yes Yes Yes DEC Supplemental Graphic Yes Yes Yes Downloadable Yes Yes Yes ISO Latin-1 Yes Yes No National replacement Yes Yes Yes 338 Appendix D ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Compatibility with Other Digital Terminals 339 ------------------------------------------------------------ Feature VT420 VT320 VT220 ------------------------------------------------------------ DEC Technical Yes No No Communication Speed up to 38.4K Yes No No Composite video output No No Yes 6-pin DEC-423 serial port Yes Yes No 25-pin RS-232 serial port Yes Yes Yes 20 milliampere port No No Yes Optional integral modem No No Yes Printer port 6-pin DEC-423 6-pin DEC-423 9-pin RS-232 Bidirectional printer port Yes Yes Yes Two session capability with SSU (VT mode) Yes No No Compatibility VT52 Yes Yes Yes VT100 Yes Yes Yes VT102 Yes Yes Yes VT220 Yes Yes Yes VT320 Yes Yes No Conformance Level 4 3 2 Display Features Overscan Yes No No Variable screen height Yes No No Default character cell 80 columns 132 columns 10  16 6  16 15  12 9  12 10  10 6  10 Appendix D ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 340 Compatibility with Other Digital Terminals ------------------------------------------------------------ Feature VT420 VT320 VT220 ------------------------------------------------------------ Cathode ray tube size 359 mm 14 inch 359 mm 14 inch 307 mm 12 inch Display type Flat Flat Convex Nonglare screen Etch Etch Coated Pixel shape Square Square Rectangular Terminal status line Yes Yes No Host status line Yes Yes No Keyboard indicator line Yes No No Extra display line when status line disabled Yes No No External Features Keyboard LK401 108 keys LK201 105 keys LK201 105 keys Tilt-swivel base Yes Optional No Other Features User windows Yes No No Off screen page memory Yes No No Macro feature Yes No No Rectangular area operations Yes No No Local copy and paste Yes No No Terminal state inquiry Yes Yes No Screen adjustment from set-up Yes No No Secure terminal environment Yes No No Function key controls Yes No No ------------------------------------------------------------ Appendix D ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary ------------------------------------------------------------ 7-bit code extension technique A method for expressing 8-bit control characters as 7-bit escape sequences. Active position The location on the screen where the next typed character will appear. The cursor indicates the active position. Active session The session that is currently accepting input from the keyboard. Alias response A sequence used by the terminal to identify itself to the host as some other type of terminal. You can select these responses in set-up. Each response corresponds to a certain operating level. ANSI American National Standards Institute ANSI character types There are two types of ANSI characters, graphic and control. Graphic characters are alphanumeric characters that you can display on the screen. These characters include letters, numbers, punctuation, and any other characters you can display. Control characters are characters you do not usually display. They make the terminal perform specific functions in data communication and text processing. Carriage return (CR), form feed (FF), and escape (ESC) are examples of control characters. Glossary 341 ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 342 Glossary ANSI key layout A setting in VT mode that allows the terminal's PC keyboard keys to work like the corresponding keys on the ANSI keyboard. This feature is useful if you are using a PC keyboard, but are more familiar with the ANSI keyboard layout. ANSI keyboard A name for Digital's LK401 and LK402 keyboards, indicating that the keyboards follow the ANSI standards for transmitting data. See also Short ANSI keyboard. Application A computer program designed to perform a specific task, such as a word processor. Applications are usually coded using high-level programming languages, such as FORTRAN or Pascal. ASCII American Standard Code for Information Interchange. A set of 7- or 8-bit binary numbers representing the alphabet, punctuation, numerals, and other special symbols used in text representation and communications protocol. Autorepeat A VT420 feature that makes most keys send their character repeatedly when you hold the key down. You can turn the autorepeat feature on and off by using the Keyboard Set-Up screen or the DECARM control function (Chapter 11.) Auxiliary keypad See numeric keypad. Baud rate The speed at which the terminal communicates with the host system or a printer. The baud rate is measured in bits/second. Bit The smallest unit of storable information in a digital machine. A bit can assume one of two values, 0 (on) or 1 (off). CCITT Comite Consultatif International de Telegraphique et Telephonique (International Telegraph and Telephone Consultative Committee). A standards committee for the communication industry in Europe. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 343 Character cell The pixel area on the screen that the terminal uses to display a single graphic character. Character encoding All terminals and computers encode information as binary digits, or bits. Older systems use 7 bits to encode each character. Newer systems such as the VT420 use 8 bits, which provide more codes. The newer systems can also use the 7-bit codes. The VT420 uses an 8-bit character encoding system and a 7-bit code extension technique. Character-coding format There are two types of character-coding formats, 7-bit and 8-bit. The 7-bit coding format uses 7 bits to store each character in the terminal's memory. The ASCII character set uses a 7-bit coding format. The 8-bit coding format uses 8 bits to store each character in the terminal's memory. The DEC Supplemental Graphic character set uses an 8-bit format. Character set There are two types of character sets, hard and soft. A hard character set is any one of the terminal's built-in character sets. Hard character sets in the VT420 include the ASCII, DEC Supplemental Graphic, ISO Latin-1 supplemental graphic, DEC Special Graphic, DEC Technical, national replacement character (NRC) sets (worldwide model only). The VT420 with PC TERM mode includes PC character sets, and all of the VT420's character sets. A soft character set is any character set that you define using a DECDLD device control string (Chapter 5). Soft character sets are also called downloadable sets and dynamically redefinable sets (DRCS). Code table A list of all characters in a character set with their codes. Most standard character sets put similar characters into groups, so they have similar codes. A code table lets you see groups of characters and their relative codes clearly. Column A vertical row of character positions on the screen. You can display 80- or 132-column lines. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 344 Glossary Compose sequence A series of keystrokes you can use to display a character that does not appear on any single key. Compose sequences start with the ------------------------------------------------------------ ------------------------------------------------------------ Compose Character ------------------------------------------------------------ ------------------------------------------------------------ key. The German model keyboard uses the ------------------------------------------------------------ ------------------------------------------------------------ Group Shift ------------------------------------------------------------ ------------------------------------------------------------ key. See Installing and Using the VT420 Video Terminal for details. Context The operating information for a session. For example, the settings of set-up features are part of a session's context. The terminal maintains a separate context for each session. Control characters Characters that make the terminal or host system perform specific functions in data communications and text processing. The terminal usually does not display control characters. The VT420 uses two groups of control characters, C0 and C1. C0 (control zero) and C1 (control one) characters The VT420 uses the ANSI definitions for the functions of C0 and C1 controls. C0 control characters are in postions 0/0 through 0/15 in the left half (GL) of the 8-bit code table. You can use C0 characters directly in a 7- or 8-bit environment. C1 control characters are in positions 8/0 through 9/15 in the right half (GR) of the 8-bit code table. You can use C1 characters directly in an 8-bit environment. You can use C1 controls in a 7-bit environment by coding them as 2-byte escape sequences (ESC final). Control functions Commands you use in your applications to make the terminal perform special functions. These functions range from the simple-- editing data-- to the complex--reporting on the terminal's operating state. Control functions include control characters, device control strings, control sequences, and escape sequences. Control sequence Any control function that begins with the C1 CSI control character. Coupled cursor A cursor that appears to pull the user window through the page. When the cursor tries to move beyond the borders of the window, it pans in that direction to keep the cursor visible. If the user window is the complete screen, the cursor looks like it is connected, or coupled, to the screen. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 345 Cursor An indicator that highlights the active position on the screen. The VT420 uses different cursor characters for (1) text, (2) set-up, and (3) the CRT saver feature. The default cursor for text is a blinking block. You can select other cursor characters. DA Device attributes. A report the terminal can provide to the host on request. A DA report can provide the host with information about the terminal such as conformance level, basic features, identification code, and firmware version level. The host can use this information to adjust the computing environment and make the best use of the terminal's features. DA exchange An exchange between the host and VT420 in which the host requests and the terminal responds with basic information about the terminal, such as the terminal's identification code. Data flow control The method used to synchronize communication between the terminal and the host system or a printer. Data processing keys Keys that have three or four characters on the top of their keycap, rather than the normal two. Every keyboard used with the terminal, except the North American keyboard, has some data processing keys. To use data processing characters, you must set the typewriter/data processing keys feature in Keyboard Set-Up screen to Data Processing Keys. DCS A C1 control character that introduces device control strings. DCS is in position 9/0 of the 8-bit code table. You can use the equivalent 7-bit escape sequence ESC P when coding for a 7-bit environment. DEC private control functions Private sequences created by Digital for specific families of products. ANSI sequences and DEC private sequences follow ANSI standards for character codes. In this manual, private control functions created by Digital have the prefix DEC in their mnemonic name. For example, column mode has the mnemonic DECCOLM. All other control functions are ANSI sequences. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 346 Glossary DEC Multinational character set The factory-default character set for the VT420. The left half of this set is the the 7-bit ASCII set (with C0 control characters), stored in the GL table. The right half is the 8-bit DEC Supplemental Graphic set (with C1 control characters), stored in the GR table. DEC Special Graphic character set A 7-bit character set with 94 graphic characters, built into the VT420. The DEC Special Graphic set has special symbols and line segments, plus many of the graphic characters found in the ASCII character set. Another name for this character set is the VT100 line drawing character set. DEC Supplemental Graphic character set An 8-bit character set with 94 graphic characters, built into the VT420. The graphic characters include letters with accents and diacritical marks, used in many European languages. There are also special symbols, such as currency signs. DEC Technical character set This 7-bit character set has 94 graphic characters and symbols often used in technical applications such as schematic and logic diagrams. Default A standard factory setting for a terminal feature. The VT420 uses default settings for features and control functions, until you change the settings. Many control functions use default values for parameters. If you omit a value, the terminal uses the default value. Designate Assign a character set to one of the terminal's four logical sets, G0 through G4. This is the first of two steps in selecting a character set for use. The second step is mapping the character set. Device control string (DCS) A special form of control function you can use for such operations as downloading character sets or defining user-defined keys. Device control strings begin with the DCS control character. Diacritical marks Marks or symbols that indicate a change in the standard pronunciation of a letter. Examples of diacritics are the acute accent ( ’ ), grave accent ( ‘ ), and tilde ( ~ ). On the worldwide model of the VT420, you can use diacritical marks in two-stroke compose sequences. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 347 Display The area of the video screen where the terminal can present visible data. Display controls mode A special operating mode that lets you display control codes as graphic characters, when you want to debug your applications. In this mode, the terminal does not perform control functions. Download Move data from the host system to the terminal. For example, you can download a soft character set into the terminal. Downloadable (soft) character set A character set that an application loads into the VT420 from the host system. The character set can have up to 96 graphic characters. You can design your own soft character set. You can use the set in the GL or GR table. The terminal stores soft characters in its DRCS buffer. When you turn off the terminal, the soft characters are lost. DRCS Dynamically redefinable character set. See downloadable character set. DSR (1) Device status report. The host system sends a DSR request to the terminal to ask for the operating status of several terminal features, such as operating status and cursor position. (2) Data set ready signal. The state of this signal indicates the status of the printer port. Echo To display characters on the screen, in addition to sending them to the host. Either the host or the terminal can echo characters. Editing keypad The group of 10 keys (including the arrow keys) to the right of the main keypad. Table 3-1 lists the codes sent by the editing keys, and Table 3-3 lists the codes sent by the arrow keys on the ANSI keyboards. The scan codes for the PC keyboard editing keypad are listed in Chapter 15. Normally, you use the arrow keys to control the cursor on the screen. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 348 Glossary Emulation A method that lets the VT420 operate like other VT series terminals. For example, you can operate the VT420 like a VT220 terminal to run applications designed for the VT220. Environment The coding scheme a system uses to encode characters. Today, most systems use an 8-bit coding scheme, where each character of data is represented by an 8-bit binary code. The VT420 can operate in a 7- or 8-bit environment. ESC The escape character. Introduces escape sequences. Escape sequences Control functions that begin with the C0 control character ESC. Firmware All commands and control functions that are built into the terminal, such as the editing functions. Font A set of graphic characters, all of one size and style. Full-cell fonts A font that can individually address all pixels in a cell because the margins separate adjacent characters. Usually, text fonts cannot individually address all pixels. Graphic left (GL) table The left half of the terminal's in-use table. The GL table can store up to 94 graphic characters for immediate use. You can store characters in the 2/1 through 7/14 range of character positions. You can use GL codes in 7-bit or 8-bit environments. Graphic right (GR) table The right half of the terminal's in-use table. The GR table can store up to 96 graphic characters for immediate use. You can store characters in the 10/1 through 15/15 range of character positions. Some 8-bit character sets only use 94 of these GR codes. You can use GR codes only in an 8-bit environment. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 349 Graphic characters Characters you can display on a video screen. Graphic characters include letters, numbers, punctuation, and any other characters you can display. Graphic rendition The appearance of a display character, including all of its visual character attributes. You use the select graphic rendition (SGR) control function to select visual character attributes. Hard character set One of the terminal's built-in character sets, such as the ASCII, DEC Supplemental Graphic, and ISO Latin-1 sets. Some models also have PC character sets. Home cursor position Usually the upper-left corner of the screen. However, home position can also be the upper-left corner of the scrolling region (that is, the area within the margins). See ``Origin Mode (DECOM)'' in Chapter 11. Host The computer or terminal server that you connect to the terminal. You cannot connect the VT420 to a terminal server in PC TERM mode. In-use table The area in the terminal's memory that defines the character set(s) the terminal is currently using. The in-use table comprises the C0, GL, C1, and GR logical tables. ISO International Standards Organization (ISO). ISO Latin Alphabet Nr 1 supplemental set (ISO Latin-1) An 8-bit character set with 96 graphic characters, built into the VT420. Like the DEC Supplemental Graphic set, the ISO Latin-1 set includes letters with accents and diacritical marks, used in many European languages. The ISO Latin-1 set also has other special symbols, not included in the DEC Supplemental Graphic set. The ISO Latin-1 set is specified in the ISO standard ISO 8859.1. Layers The different levels of data exchange between the VT420 and the host system. When you use SSU, there are three layers of data exchange between the terminal and the host: ANSI/VT52, SSU, and XON/XOFF flow control. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 350 Glossary Line attribute The visual attributes for a complete display line on the screen. Local An operating state in which data entered at the keyboard is sent to the screen, but not to the host. The terminal stores data received from the host, until you return the terminal to the on-line state. Locking shift A control function used to map a designated character set into the terminal's in-use table as GL or GR. When you use a locking shift, the character set remains in GL or GR until you use another locking shift. Map Move a designated character set into the terminal's in-use table as GL or GR. Mapping is the second of two steps in selecting a character set for use. The first step is designating the character set. After a set is mapped, it is available from the keyboard. Margins See scrolling margins. Mnemonic An abbreviated name for a control character or control function. For example, CR is the mnemonic for the carriage return control character. Modifier key A key pressed in combination with another key, to modify the function of that key. The ------------------------------------------------------------ ------------------------------------------------------------ Ctrl ------------------------------------------------------------ ------------------------------------------------------------ key is a modifier key. Multiple system communications (MSC) A method for managing sessions, using a separate communication line for each session. The other method for managing sessions is Digital's SSU software. National replacement character sets (NRCs) A general name for a class of 7-bit, 94-character sets created for different languages and dialects. The VT420 has several NRC sets for many European languages. The NRC sets are based on ISO standard 646. Numeric keypad A group of keys on the right side of the VT420 keyboard that can send numbers and punctuation marks, or special control functions defined by an application (Chapters 3 and 11). Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 351 NVR Nonvolatile RAM (random access memory). NVR retains information when power is turned off. The VT420 stores the factory-default and saved settings for set-up features in the terminal's NVR. On-line An operating state of the terminal in which the terminal can communicate with a host system. The terminal sends data entered at the keyboard to the host. The terminal displays data received from the host on the screen. Operating mode A functional state of the terminal that determines which VT420 features you can use. All VT420 terminals have the following operating modes: VT400, VT100, and VT52. Some models also have PC TERM mode. You can use VT400 mode to run VT320 and VT220 applications and PC TERM mode to run PC applications. You can select each mode from the keyboard (using set-up) or from the host (using control codes). The VT420 uses standard ANSI functions in all operating modes, except VT52 mode. See Chapter 1. Origin The home cursor position on the screen. You can set the home position at the upper-left of the screen or within the scrolling margins. Page A section of the terminal's page memory. Each page has left, right, top, and bottom scrolling margins. You can define the size and layout of a page by using set-up features or control functions. Page format The size and number of pages in the terminal's page memory. You can arrange page memory into 1 to 6 pages, depending on whether you use single or dual sessions. You can also define the margins of a page. Page memory A storage area in the terminal for displayed text, when operating in VT mode. The size of this memory is equal to 144 display lines by 80 or 132 display columns. You can divide page memory into one or more pages. The amount of page memory available depends on whether you use one or two sessions. Parameter characters Variable characters in a control function that define the action or limits of that function. See Chapter 2. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 352 Glossary PC character sets Character sets for use with PC applications, when operating the terminal in PC TERM mode. VT420 terminals with PC TERM mode have several 8-bit PC character sets with 127 graphic characters. The graphic characters include letters with accents and diacritical marks, used in many European languages. There are also special symbols, such as currency signs, and other symbols used with personal computers. PC key layout The normal setting for the terminal's PC keyboard, in which keys perform their labeled functions. You can change the setting to ANSI key layout. PC keyboard A name for Digital's LK443 and LK444 keyboards, indicating that they use PC standards for transmitting data. Compare to ANSI keyboard. PC TERM mode An operating mode available on some VT420 models that lets the terminal support a PC keyboard and run PC software applications. You can select PC TERM mode or VT mode from the General Set-Up screen or with a control sequence from the host. Pixel Picture element. The smallest unit of display on the video screen. All graphic characters are displayed in terms of pixels. Port A connector on the rear of the terminal that lets the VT420 communicate with another device or host system. Presentation state report A VT420 report that indicates the settings of the terminal's character attributes and cursor, or the settings of its tab stops. Report Operating information that the terminal provides the host system. The VT420 can provide the host with report information such as identification (type of terminal), cursor state, operating status, conformance level (1, 2, or 3), and extensions. Reset (1) To change the terminal's operating features to their default or saved settings. (2) To change the setting of an ANSI or DEC private mode to its reset state. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 353 Reset state One of two possible settings for an ANSI or DEC private mode. Modes are control functions that have only two settings. Reset to initial state A control function that resets many of the terminal's features to a group of saved settings. Also called a hard terminal reset. You can perform a reset to initial state by selecting the Recall field in the Set-Up Directory. Restore To set the terminal to the latest saved operating state. Restoring the terminal is not the same as resetting the terminal. See reset. RIS See reset to initial state. Scan code The code that a keyboard key generates when pressed and released. In PC TERM mode, the terminal remaps the keyboard scan code to an IBM scan code and sends it directly to the host computer. In VT mode, the terminal converts the scan code to a character code or control sequence before passing it to the host. Scrolling Moving data between the scrolling margins on the screen. Data scrolled past the margins is lost from the terminal's memory. Scrolling margins The top, bottom, left, and right boundaries on the screen, beyond which data cannot be written or scrolled. Session An electronic connection between the terminal and host. Set-Up A series of display screens that list the terminal's operating features. Each screen lists a group of features, such as communications or printing. You can examine and change the current settings. For example, you can select the transmit or receive speeds and supplemental character sets. Installing and Using the VT420 Video Terminal describes how to use set-up. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ 354 Glossary Single shift A control character (SS2 or SS3) used to map a designated character set into the terminal's in-use table for one character only. You use a single shift when you want to display the next character from a different character set. A single shift maps the G2 or G3 set into GL. The character set is active for only one character, then the terminal returns to the previous character set in GL. Short ANSI keyboard A compact version of Digital's ANSI keyboard, for those who make little use of the numeric and editing keypads on the ANSI keyboard. All keypad functions are still available, by typing a two-stroke ------------------------------------------------------------ ------------------------------------------------------------ Extend ------------------------------------------------------------ ------------------------------------------------------------ key sequence. Sixel A column of 6 pixels on the screen. When you load a soft character set into the terminal, you use sixel data to code each character. Soft character sets See downloadable (soft) character sets. SSU Digital's software protocol for managing two VT420 sessions over one communication line. The other method for managing sessions is multiple system communications (MSC). ST String terminator character. ST is a C1 control character. You can use the equivalent 7-bit sequence ESC \ (1/11, 5/12) when coding for a 7-bit environment. Status line A line of text that appears as reverse video below the user window. There are three possible status line settings: indicator, host-writable, and disabled (default). You select the setting by using the status display feature in the Display Set-Up screen. PC TERM mode does not have a status line. The indicator status line displays operating information about the terminal. The host-writable status line displays information provided by an application. When disabled, the indicator status line appears only when you use set-up. Terminal state report A report that indicates the complete state of the terminal, except for the current UDK definitions and the soft character set. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ Glossary 355 Top-row function keys The function keys on the top row of the keyboard. In VT mode, the first five keys-- ------------------------------------------------------------ ------------------------------------------------------------ F1 ------------------------------------------------------------ ------------------------------------------------------------ (Hold), ------------------------------------------------------------ ------------------------------------------------------------ F2 ------------------------------------------------------------ ------------------------------------------------------------ (Print), ------------------------------------------------------------ ------------------------------------------------------------ F3 ------------------------------------------------------------ ------------------------------------------------------------ (Set-Up), ------------------------------------------------------------ ------------------------------------------------------------ F4 ------------------------------------------------------------ ------------------------------------------------------------ (Session), and ------------------------------------------------------------ ------------------------------------------------------------ F5 ------------------------------------------------------------ ------------------------------------------------------------ (Break)--are predefined function keys. In PC TERM mode, only the ------------------------------------------------------------ ------------------------------------------------------------ Print Screen/SetUp ------------------------------------------------------------ ------------------------------------------------------------ key has a predefined function. You can change the function of the predefined keys from the Keyboard Set-Up screen. You can define the function of the other top-row function keys. See user-defined keys. Typewriter keys The keys on the main keypad. On the worldwide model of the VT420, some keys also have data processing characters. User-defined keys (UDKs) The function keys on the top row of the keyboard that you can define to send selected characters or control functions. To define the function of a key, you use a DECUDK device control string. To use a user-defined key, you must press ------------------------------------------------------------ ------------------------------------------------------------ Shift ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ defined key ------------------------------------------------------------ ------------------------------------------------------------ . User-preferred supplemental set A standby set you use to provide quick access to the supplemental set you use most. You can select this set to be ISO Latin-1 supplemental or DEC Supplemental Graphic. You can select the user-preferred set in the General Set-Up screen or with a DECAUPSS control function. Visual character attribute A quality assigned to a graphic character that highlights the way the character appears on the screen, without changing the actual character. For example, the bold character attribute makes a character appear brighter on the screen. VT mode Any of the terminal's operating modes for running VT applications. Compare to PC TERM mode. Glossary ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------ ------------------------------------------------------------