KA660 CPU System Maintenance

This document, "KA660 CPU System Maintenance," is a technical guide published by Digital Equipment Corporation in December 1990. It is intended for Digital Customer Services personnel and qualified self-maintenance customers.

The guide provides comprehensive information on the KA660 CPU system, focusing on its base system components, configuration, ROM-based diagnostics, and troubleshooting procedures.

Key areas covered include:

• KA660 CPU and Memory Subsystem: Details the KA660, a quad-height VAX processor module for the Q22-bus, designed for high-speed, real-time, multiuser, and multitasking environments. It describes the integrated components like the SOC chip (containing the VAX central processor, floating-point accelerator, and cache memory), the CMCTL (memory controller for MS650-Bn memory modules up to 64MB), and the System Support Chip (SSC). The document also outlines the KA660's on-board DSSI (Digital Storage Systems Interconnect) and Ethernet interfaces, emphasizing DSSI's role in improving system performance by offloading disk traffic from the Q22-bus. The CPU cover panel (H3602-00) and its diagnostic/control features are also described.
• System Configuration: Provides guidelines for setting up KA660 systems, including recommended module order in the backplane, configuring device addresses and interrupt vectors (with the CONFIGURE command), and detailed instructions for DSSI configuration (node IDs, cabling for enclosures, bus termination, and dual-host system capabilities for VAXclusters). It includes a worksheet and power/bus load tables to assist in verifying system resource allocation.
• KA660 Firmware: Explains the resident firmware stored in ROM on the KA660 module. This firmware manages processor halts, power-up sequences (including language inquiry and initial self-tests), and handles system bootstrap and operating system restarts. It introduces the console I/O mode, detailing its command syntax, address specifiers, symbolic addresses, and various commands like BOOT, DEPOSIT, EXAMINE, FIND, SET, SHOW, TEST, UNJAM, and X (for binary load/unload).
• Troubleshooting and Diagnostics: This major section covers general troubleshooting practices and extensively details the KA660's built-in ROM-based diagnostics. It describes various diagnostic tests and how to utilize predefined and user-created scripts for testing. The document explains how to interpret console displays, system halt messages, console error messages, and VMB error messages. It also provides specific guidance on isolating memory failures, performing loopback tests for Ethernet, console, and DSSI interfaces, and diagnosing fuse problems. Additionally, it covers diagnostics for RF-series Integrated Storage Elements (ISEs), including tools like DRVTST, DRVEXR, HISTRY, ERASE, and PARAMS for setting and examining ISE parameters. A list of diagnostic error codes is also provided.

Appendices contain detailed KA660 CPU address assignments and procedures for programming parameters on RF-Series ISEs.