Tu58 Engineering Specification

Summary This document provides the engineering specifications for the Digital Equipment Corporation (DEC) TU58, a low-cost, mass-storage device that utilizes a 3M DC-100A cartridge.

Key aspects covered in the document include:

• System Overview: The TU58 is a firmware-controlled system that uses preformatted cartridges storing 2048 records of 128 bytes each. It supports two drives but only operates one at a time.
• Interfaces: The system supports both a parallel interface for terminal integration and an asynchronous full-duplex serial interface (RS-232, RS-422, and RS-423 compatible) with user-selectable baud rates.
• Mechanical & Environmental: The documentation details configuration options, physical dimensions, and operational environmental limits (e.g., temperature and humidity).
• Logical Format: It describes the tape recording scheme (800 bits per inch, ratio encoding), track layout, and the structure of headers and data fields used for system operations.
• Software Interface (RSP): The TU58 utilizes the Radial Serial Protocol (RSP) for host communication. The document explains the packet structure (command, data, and end packets) and defines the instruction set, which includes commands for reading, writing, positioning, and status reporting.
• Error Handling: The specification outlines how the controller manages data integrity through checksums and retries, and how it communicates success or failure states back to the host system.