From: jlothian@uk.ac.edinburgh.castle (J Lothian) Date: 8 Jan 93 18:59:15 GMT Here's some stuff about the M7856 (DL11-W) module (combined serial port/real-time clock), taken from the print-set. As far as I can remember, there are 5 sets of dip-switches on the board. Mode of operation is selected as follows: Mode 1: serial line and RTC can both be addressed. Serial line addresses are restricted to 77756X. [Standard console address]. Line clock is at 777546. Mode 2: Only serial line can be addressed. Address selection ranges from 774000 to 777777. Line clock is disabled. Mode 3: Only line clock can be addressed, serial line does not respond to any address. Line clock is at 777546. Mode selection & address bits: Address bit A10 A09 A08 A07 A06 A05 A04 A03 N/A N/A Switch S5-3 S5-2 S5-1 S5-4 S5-5 S5-6 S5-8 S5-7 S5-9 S5-10 Mode 1 Off Off Off On Off Off Off On Off On Mode 2 Off Off Off On Off Off Off On On Off Mode 3 Off Off Off On Off Off On On On On Mode 2 is shown for serial line addresses 77756X. For address bits in mode 2, switch off = 1 and switch on = 0. [Apparently, it is not possible to deviate from the specified address for the serial port in Mode 1 -- I have a feeling that if you fiddle with the address switches in Mode 1, the LTC address may move as well.] Note: remove R63 from DL11-W operating in Mode 2 to allow proper operation of a line frequency clock or other DL11-W in Mode 1 or Mode 3. [R63 goes from the BUS LTC L signal at pin CD1 on the backplane connector to (among other things) pin 9 on a 7414, and is a 330 ohm resistor. It should be easy enough to find -- I don't have a layout diagram for the board.] Vector Address Assignments Line clock is fixed at 100. Serial line assignments are floating vectors of the form XX0 (receiver) and XX4 (transmitter), where XX is 00 to 77. For console device, vector should be 060/064. Vector bit V8 V7 V6 V5 V4 V3 switch S2-8 S2-7 S2-5 S2-3 S2-6 S2-4 060/064 Off Off Off On On Off On=1, Off=0. Data Format Bits per Character S4-4 S4-3 Bits On On 5 On Off 6 Off On 7 Off Off 8 Parity S4-2 S4-6 Parity Off Off Off On Off Off Off On Even On On Odd Stop Bits S4-5 Stop bits On 1 Off 2 (or 1.5 if 5 data bits selected) Baud Rate Selection Rate Receiver Transmitter S3-2 S3-3 S3-5 S4-10 S3-1 S3-4 110 Off Off Off On On On 150 On Off Off Off On On 300 Off On On On Off Off 600 Off On Off On Off On 1200 Off Off On On On Off 2400 On On On Off Off Off 4800 On On Off Off Off On 9600 On Off On Off On Off Current Loop Active/Passive Selection Transmitter S1-1 S1-2 S1-3 S1-6 S1-7 Active On On Off Off On Passive Off Off On On Off Receiver S3-6 S3-7 S3-8 S3-9 S3-10 Active On Off On Off On Passive Off On Off On Off Reader Enable S1-4 S1-5 S1-8 S1-9 S1-10 Active On Off On Off On Passive Off On Off On Off [There is a spade lug on the board, near the front edge, which can be connected to one of the spade lugs on the M9301 bootstrap module, so that pressing BREAK on your terminal keyboard will cause the machine to bomb into the bootstrap module's console emulator.] So there you go. I've used one of these boards on my 11/40 for several years now, without much bother. I have an M9301 for bootstrap, and am good at avoiding BREAK when typing! The only thing that occurs to me about the problems you've been having is: is there another device (e.g. bootstrap board) in your system that includes an LTC circuit? See the note about R63 above. You can reset the 11/34 CPU by placing CONT/HALT in HALT position, then operating BOOT/INIT. Good luck. James --