Disk Cartridge Memory - RK08/RK01

This document provides a comprehensive engineering specification and operational guide for the Digital Equipment Corporation RK08 disk cartridge memory system used with PDP-8 family computers.

System Overview: The RK08 is a removable disk storage system capable of supporting up to four RK01 drives, providing a total capacity of over 3.3 million words. The system utilizes an aluminum platter coated with magnetic oxide, which is accessed by read/write heads positioned by a stepping motor across 203 tracks.

Technical Specifications:

• Capacity: 831,488 words per cartridge.
• Transfer: Single cycle Data Break with a transfer rate of 16.7 µs per word.
• Access Times: 133 ms average, 400 ms maximum.
• Formatting: Each track contains 16 sectors, with each sector containing header and data regions. The system supports specialized sector formatting for optimization.

Programming and Operations: The document details the command structure, including specific mnemonics for operations such as loading the command register, reading/writing disk addresses, checking parity, and controlling status registers. It includes detailed bit-level definitions for the Command, Status, and Maintenance registers, as well as an explanation of error flags (e.g., parity error, time-out, write lock, sector non-existence).

Acceptance Procedure: A significant portion of the document (starting on the second to last page) outlines the mandatory acceptance procedures. These include running data reliability diagnostics, testing power failure sequences, verifying write-lock switches, and confirming software compatibility with PDP-8, PDP-12, and other system environments before the equipment is accepted for operational use.