Field Change Order for VAXBI Systems Using KDB50 Controller

This Field Change Order (FCO) details the procedure to update the KDB50 DSA disk controller on VAXBI systems (specifically VAX 8200/8300 and VAX 8500/8700/8800). The update is necessary to resolve three specific problems occurring during disk read and write operations related to non-aligned memory buffers and 64K memory address boundary crossings. The fix involves replacing the existing PROMs with a new set and potentially upgrading the T1002 module if it is below revision level D. The document includes detailed safety precautions regarding electrostatic discharge (ESD), step-by-step installation instructions for different VAX models, and diagnostic verification procedures.