VAX 4000 Model 105A Upgrade to Model 106A

This document, published by Digital Equipment Corporation in June 1995, provides detailed, step-by-step procedures for upgrading a VAX 4000 Model 105A system to a VAX 4000 Model 106A.

The core of this upgrade involves:

• Replacing the KA53 CPU module with a new KA54 CPU module.
• Replacing the DSSI cable and port cover.
• Applying a new system medallion.

The manual specifies a prerequisite OpenVMS operating system upgrade to version 5.5-2H4 or 6.1 before the hardware installation. It is intended for Digital services personnel and licensed self-maintenance customers, guiding them through unpacking the upgrade kit, system shutdown, careful disassembly, component removal, installation of new parts, reassembly, and reconnection of cables.

A crucial part of the document (Appendix A) outlines the mandatory return procedure for the original KA53 CPU module. It emphasizes that the original CPU must be returned to Digital Equipment Corporation, along with completed forms, to avoid a penalty charge. Customers are responsible for backing up their system software prior to the upgrade.