RM02/03 Adapter Technical Description Manual

This "RM02/03 Adapter Technical Description Manual" (EK-RM023-TD-001), published by Digital Equipment Corporation in 1978, provides a comprehensive technical overview of the RM02/03 Disk Drive Subsystem's adapter portion, which serves as the interface to the Massbus. It is intended for maintenance personnel and system programmers.

The document covers:

1. Introduction: Describes the RM02/03 disk drive as an 80MB (unformatted) random-access mass storage device, its compatibility with various DEC controllers (RH10, RH20, RH70, RH11), typical single and dual-port configurations, and detailed data formatting (pack and sector formats, including 16-bit and 18-bit word options).
2. Interface-Level Description: Details the primary signal interfaces, specifically the Massbus connection between the RM02/03 and the controller, and the internal interface between the adapter and the drive. It describes various data and control lines (e.g., RUN, OCC, EBL, EXC, SCLK, WCLK, ATTN, INIT, FAIL) and their functions.
3. Operation and Programming: Provides information relevant to programming the RM02/03 system, including descriptions of the 16 command operations (positioning, data transfer, and housekeeping commands), a comprehensive summary and bit-by-bit listing of the 22 controller and drive registers, available diagnostic programs, the operation of the Error Correcting Code (ECC) for data recovery, and the functionality of the dual-port option, including its various states and register access rules.
4. Technical Description: Offers an in-depth look at the adapter's internal workings. It describes its physical modules (Control Interface, Data Sequencer, Command Sequencer, Drive Interface, and Massbus Transceivers), outlines the power-up and initialize sequences, details device and register selection mechanisms, and explains handshake control for register read/write operations. The chapter also provides detailed block diagrams and flowcharts to illustrate command execution and circuit elements, with frequent references to the RM02/03 Field Maintenance Print Set.
5. Appendix A (Programmable Logic Arrays): Explains the use and organization of Field-Programmable Logic Arrays (FPLAs) within the adapter.