DEC-00-HTU60-C-D TU60maint Oct73

This document is the Maintenance Manual for the TU60 DECassette Tape Transport (DEC-00-HTU60-C-D, 1st Edition December 1972, 3rd Printing October 1973).

The manual provides comprehensive technical information for the installation, operation, theory, and maintenance of the TU60, a solid-state, magnetic tape data storage device featuring two independent tape drives. It emphasizes the critical importance of using only DEC-certified Digital Tape Cassettes due to the device's specific drive tensions and operational characteristics, explicitly warning against the use of audio cassettes.

Key areas covered include:

• General Information: Introduction to the TU60, its major assemblies (tape drives, logic modules, H751 power supply), and detailed performance specifications (electrical, environmental, tape characteristics, read/write/search speeds, data transfer rates, and error rates).
• Installation & Operation: Procedures for unpacking, electrical installation, and normal operating procedures, including cassette loading/unloading and essential tape handling precautions.
• I/O Interface Signals: A detailed description of input and output signals used for communication and control between the transport and an associated processor's interface module.
• Theory of Operation: In-depth explanations of tape format, various motion control operations (rewind, block/file gap navigation), read/write data block operations (including phase encoding), programming restrictions, detailed logic descriptions, CRC character handling (derivation and validation), and analog circuit analysis (control motor servo system, phase lock loop, power supply operation).
• Maintenance: A complete guide to maintaining the TU60, listing recommended tools and test equipment, preventive maintenance schedules (quarterly, semi-annual, annual, biennial), step-by-step adjustment procedures for critical components (e.g., servo loop, tachometer, head skew, regulators), test programs, diagnostic routines, and troubleshooting steps for various electrical and mechanical issues.

The manual is intended for technical personnel responsible for the installation, operation, troubleshooting, and repair of the TU60 DECassette Tape Transport.