RD31-A Disk Drive Technical Description

This document, titled "RD31-A Disk Drive Technical Description" (EK-RD31A-TD-001) and published in November 1985 by Digital Equipment Corporation, provides a comprehensive guide for the installation, operation, and maintenance of the RD31-A 5-1/4 inch fixed disk drive.

The manual is structured into six chapters covering:

1. General Information: Introduces the RD31-A drive and details its specifications, including performance (e.g., 65ms average seek time, 3600 rpm spindle speed), physical dimensions (approx. 3.5 lbs), storage capacity (20.15 MB formatted), environmental requirements, and a general description of its mechanical and electronic components.
2. Installation: Provides instructions for unpacking, configuring the drive (including jumper settings for drive addressing and various modes), connecting termination resistors, and detailing the electrical interfaces (power, control, and data connectors).
3. Mechanical Description: Describes the physical components of the drive, such as the Head/Disk Assembly (HDA), magnetic disks, spindle motor, and head positioner, highlighting the sealed clean environment.
4. Theory of Operation: Explains how the drive functions, covering the drive interface signals and timing, system requirements (like track format and media defect handling), the functional overview of seek, read, and write operations, the positioner servo system, spindle motor control, and the read/write channel, as well as fault detection.
5. Maintenance: Outlines procedures for preventive and corrective maintenance, including a troubleshooting flowchart and detailed steps for removing and replacing field-replaceable components.
6. Parts List: Provides a list of field-replaceable parts for the drive.

In essence, the document serves as a detailed technical manual for service personnel, providing all necessary information for the successful setup, understanding, and upkeep of the RD31-A disk drive.