_ DEC-O-LOG for RZ57

_ DOL, RZ57-F001, Firmware bug

MAR 94

APPLICABILITY: This FCO applies to RZ57-E Rev. 
"C01" and below on VS4000   Model 60, VS4000 VLC 
and VS4000 Model 90.

This FCO incorporates ECO SHR RZ57-E-SH001 and 
after  installation  brings   RZ57-E  up  to  Rev.  level 
"D01".  This  kit  may  also  be  purchased  by  Alpha   
system  customers  who wish to upgrade and migrate 
RZ57s below Rev. level "D01"  to Alpha platforms. For 
Alpha  customers,  this  kit may  be  purchased  from   
Digital Assisted Services (DAS) and installed by either 
the customer or by   an MCS engineer on a per call ba
sis.  No charges for materials or labor  required  to up
grade Alpha customers should be charged to this FCO.	
Exceptional customer situations should be worked in 
consultation with the local account team.	

PROBLEM & SYMPTOM: RZ57 disk drives with 
Rev. 5000 microcode and below configured with 
VS4000 Model 60, VS4000 VLC,and VS4000 Model 90 
have experienced under certain conditions, a write 
fault that is not recovered   properly, such that data is 
not written and not reported. A bug was dicovered in 
the interrupt service routine (ISR) where the ISR does 
not   properly initialize a variable necessary for the er
ror recovery routine   (ERR). When initialized to a spe
cific two-byte word, the ERR exits without   being im
plemented and without reporting an error to the host. 
This translates into a false recovery from a write-fault 
or, simply, data not being  written.	

SOLUTION: The firmware bug has been corrected 
with drive microcode Rev. 6000   which is RZ57 hard
ware Rev. "D01". Replace firmware EPROM on RZ57	
below hardware Rev. "D01" configured with VS4000 
Model 60, VS4000 VLC,   and VS4000 Model 90.	
QUICK CHECK: RZ57-E Rev. "C01" or below requires 
kit installation.	

FCO KIT ORDERING:
 EQ-01695-01
      1  29-31520-01 Packaged Firmware, Rev. "D01"	
      1  36-19209-04 Label, Wire Marker "D"	
      1  36-19208-01 Label, Wire Marker "1"	
	
 FA-05032-01 
      1  FA-05032-01 FCO FA Document