KA640 CPU System Maintenance

This document, "KA640 CPU System Maintenance," is a comprehensive guide for DIGITAL Field Service personnel and qualified self-maintenance customers. It details the base system, configuration, ROM-based diagnostics, and troubleshooting procedures for systems incorporating the KA640 CPU.

The document is organized into four chapters and two appendices:

• Chapter 1: KA640 CPU and Memory Subsystem describes the hardware components, including the KA640 CPU (a VAX processor module with features like cache memory, floating point accelerator, Q22-bus, DSSI, and Ethernet interfaces), MS650 memory modules, the H3602-SA I/O Panel, and the RF30 disk drive, detailing their specifications and roles.
• Chapter 2: Configuration provides guidelines for setting up the system, covering module order in the backplane, DSSI (DIGITAL Small Storage Interconnect) bus configuration (node IDs, unit numbers, cabling, and dual-host capabilities), and power/bus load considerations for various options.
• Chapter 3: KA640 Firmware explains the system's resident firmware, which takes control upon a processor halt. It covers the firmware's features, halt entry and dispatch code, power-up sequences, bootstrap process, and an interactive console I/O mode with commands for system examination, alteration, and control (e.g., BOOT, DEPOSIT, EXAMINE, SET, SHOW).
• Chapter 4: Troubleshooting and Diagnostics outlines procedures for diagnosing and resolving system problems. It focuses on KA640 ROM-based diagnostics (including diagnostic tests, scripts, console displays, and error messages), acceptance testing, loopback tests for subsystems like Ethernet and DSSI, module self-tests, and specific diagnostics for the RF30 disk drive.
• Appendices A and B provide technical reference information, including KA640 address assignments and a list of related documentation.