MP01286 RA80 Mar82

This document is a "Field Maintenance Print Set" (Part Number MP-01286) for Digital Equipment Corporation's RA80-C disk drive system, specifically covering the -CA and -CD variations as installed within an H9642-B cabinet. Copyrighted in 1982, it serves as a comprehensive engineering reference for the system's maintenance, troubleshooting, and repair.

The set contains a detailed Table of Contents and comprises various types of documentation for key subsystems and components, including:

• Assembly Drawings and Parts Lists: These provide detailed physical layouts, installation instructions, cable routing diagrams, and comprehensive component breakdowns. Covered assemblies include the overall RA80/H9642-B cabinet, Disk Drive Assembly (basic disk drive and HDA - Head/Disk Assembly with Read/Write modules), H766 Power Supply Assembly, Logic Chassis Assembly, Lower Chassis Assembly, Operator Control Panel Assembly, and Servo Board and Stiffener Assembly. Instructions for specific procedures like belt tension adjustment and shipping bracket installation are also included.
• Detailed Schematics: These present intricate circuit diagrams and logic flows for the system's electronic components. Key areas detailed in the schematics include:
  • The H766 Power Supply and its associated Regulator Board and Capacitor Board, showing comprehensive wiring, voltage distribution, and control logic.
  • The RA80 Microprocessor and its Personality Boards/Modules, illustrating complex data transmission/reception (SDI), control logic, command deserialization, synchronization, input/output registers, and diagnostic functions.
  • The Servo Control system, with detailed schematics for signal preamplification, filtering, position and phase detection, VCO (Voltage Controlled Oscillator) and gating, servo error detection, and motor drivers.
  • Specific Read/Write channel circuitry and the Head/Disk Assembly (HDA) Printed Circuit Board layouts.

The document is highly technical, providing the essential detailed prints necessary for in-depth field maintenance of the RA80-C disk drive system.