RM05 Disk Subsystem User Guide

This document is the "RM05 Disk Subsystem User Guide" (EK-ORM05-UG-002), published by Digital Equipment Corporation. It provides comprehensive information on the RM05 Disk Drive and its associated RM adapter, covering its capabilities, installation, operation, and programming.

Key aspects of the document include:

1. Purpose and Scope: The manual serves as a guide for operators and programmers, while explicitly stating that installation and servicing must only be performed by qualified field engineering and maintenance personnel due to hazardous voltages. It notes variations between VDE and NON-VDE versions of the drive.
2. General Information: The RM05 Disk Subsystem offers a formatted storage capacity of 256 megabytes, utilizing a 14-inch RM05P removable disk pack. It consists of the disk drive and an RM adapter, which converts MASSBUS signals for interface with high-speed controllers like the RH70 (for PDP-11/70) and RH780 (for VAX-11/780) computers. The system supports daisy-chaining up to eight RM05 drives from a single controller.
3. System Features and Capabilities: It includes error detection and isolation (ECC), program-controlled offsets for data recovery, and an integrated backplane for simplified MASSBUS connections. A significant feature is its dual-port capability, allowing access by two different RH controllers, though specific cabling restrictions apply.
4. Installation and Checkout Procedures: This section provides detailed steps for site preparation, unpacking, drive installation (including grounding, AC power wiring, and logical address plug setup), RM adapter cabling, and initial checkout (power-up, tests, head alignment, servo system adjustments, and diagnostic programs). It also defines error types and rates for field acceptance testing.
5. Operation Instructions: This part describes the operator controls and indicators on both the drive's front panel and the power supply control panels. It outlines procedures for disk pack loading, spin-up, removal, and spin-down, alongside critical operator maintenance precautions for disk pack storage and handling, emphasizing that inspection and cleaning should only be done by trained service personnel.
6. Programming Instructions: This section delves into how the processor interacts with the drive for data transfers, including decisions on drive selection, location, and data direction. It details the various registers (control, status, error, maintenance, etc.) used for communication and control, and outlines command codes for positioning (seek, recalibrate), data transfer (read, write, check), and housekeeping operations. It also explains the functioning of the Error Correcting Code (ECC) and the specifics of dual-port operation from a programming perspective.

The document is extensively supported by tables and figures illustrating disk pack format, physical layouts, cabling, control panels, and register bit assignments.