FCO DWBUA-R001 Rev B, Current Ucode fails

This document is Field Change Order (FCO) DWBUA-R001 Revision B, issued to address "Current Ucode fails" and other issues on DWBUA options for VAX 82X0/83X0/85X0/8700/8800 series systems. The FCO mandates retrofitting all DWBUA options to Revision Level "B1" by incorporating three Engineering Change Orders (ECOs: T1010-LK004, -LK005, -LK008) that fix problems such as microcode failures, incorrect bus responses, and unibus interface issues. The solution involves upgrading the T1010 BUA Module to revision "F1-F6" and replacing microcode ROMs (23-081L1-00 and 23-314F4-00). The installation, estimated to take 1 hour, requires a field service tool kit and detailed procedures are provided for different VAX models, including system shutdown, module and ROM replacement, power-up, and running diagnostics like EVCBB. This revised FCO supersedes Revision A released on June 22, 1987, and affects an estimated 3,600/2,800 systems.