DEC-00-HRTC-D TU56 Mantenance Manual Jan73

This document is a Maintenance Manual for the TU56 (Dual) or TU56H (Single) DECtape Transport, a solid-state, bi-directional, low-cost magnetic tape data storage device manufactured by Digital Equipment Corporation (DEC), with copyright dates ranging from 1970 to 1973.

The manual provides comprehensive information for the installation, operation, theory of operation, and maintenance of the TU56 DECtape Transport.

Key areas covered include:

• General Information: Detailed specifications (e.g., 93 inches per second tape speed, 33,300 3-bit characters per second data transfer rate, Manchester Phase Encoding, 2.7 x 10^6 unformatted bits capacity), descriptions of major assemblies, controls, indicators, and the power supply. It highlights the use of redundant track pairing for reliable data transfer and reduced tape skew.
• Installation: Step-by-step procedures for unpacking, mechanical mounting into various cabinet types, electrical connections, and initial tape loading and operating procedures.
• Theory of Operation: An in-depth explanation of the transport's functionality, including its interface with controllers (command and information cables), the read/write head design (with 10 paired coils for redundancy), the DECtape format, and the logical sequence of events for both local (off-line) and remote (on-line) tape motion, read, and write operations. It also describes the function of key logic modules.

• Maintenance: Provides a guide for servicing, including:

  • A list of recommended tools and test equipment.
  • Preventive Maintenance procedures (weekly and monthly checks, tape care and cleaning).
  • Corrective Maintenance for replacing and adjusting components such as control panel lamps, reel motors (including electronic brake adjustment), and read/write heads (including head output and skew checks).
  • Troubleshooting tables linking common malfunctions to their causes and corrective checks.
  • A list of recommended spare parts.

• Reference Drawings: An appendix contains detailed schematics and assembly diagrams.

The manual is intended for technicians and engineers responsible for the upkeep, repair, and configuration of the TU56 DECtape Transport, designed to support both standard and custom installations by detailing compatibility options with other DEC and non-DEC systems.