FCO CIBCA-1001, CIBCA microcode inefficiency

This document is a Field Change Order (FCO) detailing an upgrade for the CIBCA Option microcode (CIBCA.BIN) to Version V5.3 on VAX 82X0, 83X0, 85X0, 8700, 8800, and 897X console media.

The upgrade addresses two primary issues:

1. Microcode Inefficiency: Previous CIBCA.BIN V4.3 could cause HSCX0/CIBCA virtual-circuits to close during disk/tape backups or high disk I/O rates due to inefficient processing of the RETDAT (Return-Data) function.
2. Data Corruption Bug: A microcode bug in CIBCA could lead to data corruption in VMS memory when buffer-transfers of less than 16 bytes occurred at exact octaword boundaries, potentially overwriting entire 16-byte buffers. This issue primarily affected third-party applications.

The FCO also includes enhancements for future products and an update of the CIBCA EEPROM "Self-Test" microcode to V3, using the EVGDA EEPROM Program Utility. Installation is estimated to take 1 hour and involves copying the new CIBCA.BIN file and, if necessary, reprogramming the EEPROM. The document provides detailed installation procedures for different VAX configurations and media types, along with optional verification steps for the new microcode.