VAX 11/780 Diagnostic System User's Guide

This document is the VAX-11/780 Diagnostic System User's Guide (2nd Edition, August 1979), published by Digital Equipment Corporation.

It serves as a comprehensive manual for customers and field service engineers on how to use, power-up, bootstrap, and maintain the VAX-11/780 Diagnostic System.

The guide outlines a hierarchical diagnostic system structured into six levels, ranging from high-level operating system (VMS)-based diagnostics to low-level console diagnostics (including microdiagnostics, Octal Debugging Technique (ODT), and ROM resident power-up tests). It details various execution environments for these diagnostics, whether standalone or under the VMS operating system.

Key areas covered in the document include:

• Microdiagnostic Program: Describes its function in isolating logic failures within the CPU, memory controllers, and Floating-Point Accelerator (FPA) through a bootstrapping test sequence, and how to interpret its error messages for module callout.

• Diagnostic Supervisor: Explains its role as the primary interface for controlling macro-level diagnostic program execution. It provides a detailed command set for:

  • Program/Test Sequence Control: Loading, running, attaching/selecting devices, and managing test flow.
  • Scripting: Automating diagnostic procedures using command files (e.g., CONFIG for system configuration and SYSTEST for system-wide testing).
  • Execution Control: Setting and clearing flags (like HALT, LOOP, TRACE) and event flags to modify diagnostic behavior.
  • Debug and Utility Functions: Examining and depositing data in memory, setting breakpoints, and single-stepping through instructions.

• Boot Procedures: Provides step-by-step instructions for power-up and console booting from floppy diskettes, including troubleshooting for console bootstrap failures and program crashes. It also covers booting the diagnostic supervisor from the system disk in both on-line and standalone modes, and running diagnostics from "load path" floppy diskettes when the system disk is unavailable.

• System Maintenance: Instructions for building and updating diagnostic disk packs from magnetic tape or floppy diskettes.
• Appendices: Offer detailed help files for console commands, error messages, remote access, and microdebugger commands, along with troubleshooting flowcharts for common console boot and power-up issues.

The manual emphasizes a "building block" approach to testing, starting with basic system components and progressively testing more complex elements.