RQDX1 Controller Module User's Guide

This user's guide, published by Digital Equipment Corporation in January 1984, details the RQDX1 Controller Module.

The document covers the following key areas:

1. Introduction & Specifications: Describes the RQDX1 module's function as an interface between RD51 Winchester fixed disk drives (11 MB) and/or RX50 diskette drives (800 KB) to LSI-11 bus systems (16-, 18-, or 22-bit). It highlights features like DMA data transfers, block mode transfers, 22-bit addressing support, and its ability to control up to four logical units (max two RD51s). Detailed specifications for the module, RD51, RX50, and the optional RQDX1-E extender module are provided.
2. Functional Description: Explains the internal workings of the RQDX1 controller module, including its major functional subsections such as oscillators, data recovery, serializer/deserializer, MFM encoder, various registers (Interrupt Vector, SA Read/Write, IP), QBus transceivers, and the control logic shared by the T-11 chip and a high-speed controller.
3. Configuration & Installation: Provides instructions for installing the RQDX1 module in an LSI-11 backplane (typically the last occupied slot), including how to configure jumpers for device address and logical unit number selection. It also details the installation and use of the RQDX1-E extender module for connecting external drives.
4. Registers & Commands: Describes the programmable registers accessible via the QBus (Initialize and Poll, Status and Address registers). It outlines the Mass Storage Control Protocol (MSCP), the message-oriented standard for host-controller communication, including a list of supported commands (e.g., Read, Write, Format, Erase, Get Status). The Diagnostics and Utilities Protocol (DUP) for diagnostic operations is also explained.
5. Error Detection: Covers the module's power-up selftest, how to interpret diagnostic LED error displays, and lists XXDP+ diagnostic software programs (e.g., RDRX Performance Exerciser, RDRX Formatter) used for testing and troubleshooting the controller and associated drives.
6. Disk Drives: Provides installation and operational information for the RD51 fixed disk drive (including DIP shunt jumper configuration and formatting procedures) and the RX50 diskette drive.

Appendices detail backplane pin assignments and cable signals for the RQDX1 and the disk drives.