RA80 Disk Drive User Guide

This document is the RA80 Disk Drive User Guide (EK-ORA80-UG-001), published by Digital Equipment Corporation in January 1982. It provides a comprehensive manual for the RA80 Disk Drive, covering its installation, checkout, and operational procedures. While primarily for users, detailed installation and checkout information is intended for qualified Field Service personnel.

Key aspects of the document include:

• RA80 Disk Drive Description: It is a rack-mountable disk drive using non-removable media, offering a storage capacity of 121 megabytes. It features dual-port capability and operates on the Standard Disk Interface (SI) bus, allowing up to four drives per controller. A sealed Head Disk Assembly (HDA) is a core feature, contributing to data protection and hardware reliability, with a peak transfer rate of 1.2 MB/s and an average positioning time of 25 ms. The drive includes internal microcoded diagnostics for error detection and fault isolation, run during power-up or via switch-selectable routines for Field Service.
• Specifications: Detailed performance, environmental, physical (e.g., 66.7 Kg / 147 pounds weight), and electrical characteristics are provided.
• Installation: This chapter outlines site preparation (environmental considerations, floor loading, power), equipment unpacking, and specific steps for RUA80 installation (joining CPU and disk drive cabinets, SI cabling, programming drive unit addresses) and RA80 add-on installation for additional drives (installing slide assemblies, mounting drives, cabling, power connection, and securing components). Safety warnings regarding hazardous voltages and the importance of data backup due to non-recoverable HDA failures are highlighted.
• Checkout Procedure: Steps for applying power and performing drive checkout using internal diagnostics via the microprocessor module controls and LED displays (a procedure primarily for trained maintenance personnel) are detailed.
• Operating Instructions: This section describes the front panel controls and indicators (RUN/STOP, FAULT, READY, WRITE PROTECT, Port-Select switches A and B), the function of circuit breakers, general drive operation (spin-up, spin-down), and basic customer care (e.g., air filter inspection and cleaning). Fault indications are also explained through specific lamp display codes.