RA7x/SA7x Pocket Reference Guide

This document is the RA7x/SA7x Pocket Reference Guide from Digital Equipment Corporation, designed to provide quick-reference information for their RA7x series disk drives (RA70, RA71, RA72, and RA73) and SA7x enclosures.

Key information provided includes:

• Drive Characteristics: Specifications such as total heads, data heads, servo heads, and formatted storage capacity for each RA7x model.
• Operational Procedures: Guidelines for thermal stabilization based on temperature, and instructions for setting the capacity indicator switch on RA71 and RA72 drives.
• Troubleshooting: General tips, a troubleshooting flowchart, and details on interpreting drive internal error logs.
• Parts and Diagrams: Lists of part numbers for RA7x components (ECM, HDA, shoe plate) and SA7x enclosure parts, accompanied by exploded views and simplified electronics block diagrams.
• System Compatibility: Minimum versions required for VAX diagnostics, operating systems (VMS, ULTRIX-32, VAXsimPLUS, VAXELN, VAX System V), and SDI controllers to support RA71-RA73 disk drives.
• Error Reference: Detailed breakdowns of RA7x drive status information (byte formats), OCP (Operator Control Panel) error codes with affected Field Replaceable Units (FRUs), and comprehensive drive error codes with specific fault numbers and their most probable causes (e.g., ECM, HDA, SDI controller, power supply, or cabling).