RX02 Floppy Disk System User's Guide

This document is the "RX02 Floppy Disk System User's Guide," first published in July 1978 by Digital Equipment Corporation (DEC). It serves as a comprehensive manual for setting up, operating, and programming the RX02 Floppy Disk System.

Key aspects covered include:

• System Overview: The RX02 is a low-cost, random-access mass memory device designed to store data on flexible, preformatted diskettes. It includes two flexible disk drives, a microprogrammed controller, read/write electronics, and a power supply, all housed in a rack-mountable chassis.
• Computer Compatibility: It interfaces with DEC's PDP-8, PDP-11, and LSI-11 computer systems through various interface modules (M8357, M7846, M8256, M7946, M8029), with specific configurations (e.g., RX8E, RX28, RX11, RX211, RXV11, RXV21) supporting different computers and recording densities.

• Recording Schemes & Data Capacity: The system supports two recording schemes:

  • Double Frequency (FM): Used for single-density recording, compatible with IBM 3740 devices and the RX01 Floppy Disk System.
  • Modified Miller Code (MFM): Used for double-density recording, compatible with DIGITAL double-density devices but not with other manufacturers. Data capacity varies by density, with up to 512K 8-bit bytes in double density and 256K 8-bit bytes in single density. Data integrity is ensured via IBM 3740-compatible Cyclic Redundancy Check (CRC).

• Installation: Provides detailed guidance on site preparation (space, cabling, AC power, environmental considerations like temperature, humidity, and cleanliness), unpacking, and the step-by-step installation process, including configuring controller switches and interface jumpers.

• User Operation: Emphasizes customer responsibility for maintaining environmental conditions and proper handling and storage of diskettes (e.g., avoiding dust, magnets, and extreme temperatures) to prevent data loss. It notes that the RX02 has no operator controls; all operations are initiated and managed by software. A troubleshooting guide for common operational issues is also included.
• Programming Information: Offers extensive details for developers, covering the device registers, instruction sets, function codes (such as Fill Buffer, Write Sector, Read Sector, Set Media Density, Read Status, and Error Recovery), and programming examples specific to the PDP-8 (RX8E/RX28), PDP-11 (RX11/RX211), and LSI-11 (RXV11/RXV21) interfaces, including instructions for programmed I/O and DMA transfers.

The manual highlights that careful attention to diskette handling and environmental factors is critical for reliable operation and data preservation.