Digital Model TU-45 Dual Format Synchronous Read After Write Tape Transport

This document is an operating and service manual for the Digital Model TU-45 Dual Format Synchronous Read After Write Tape Transport, manufactured by Pertec Computer Corporation for Digital Equipment Corporation. It provides comprehensive instructions for the transport's operation, installation, and maintenance, including detailed electrical and mechanical adjustments, and troubleshooting procedures.

The TU-45 Tape Transport is capable of synchronously recording and reading 9-track digital data at 75 inches per second (ips). It supports two formats: 1600 cpi Phase Encoded (PE) IBM-compatible format and 800 cpi Non-Return-To-Zero-Inverted (NRZI) ANSI- and IBM-compatible format. A notable feature is its dual-gap head, which allows for simultaneous writing and immediate data verification (read-after-write), and an erase head. The transport operates on single-phase AC power (95-125V or 200-250V, 50/60Hz) and utilizes a vacuum column tape storage system, along with photoelectric sensors for Beginning of Tape (BOT) and End of Tape (EOT) detection.

The manual is structured into sections covering general description and specifications, installation and initial checkout, detailed operating procedures, the theory of operation for its functional subsystems (Capstan Servo, Reel Servos, Control Logic, Power Supply, Data Electronics), the theory of operation for its Printed Circuit Boards (PCBs), maintenance and troubleshooting, and finally, parts lists, logic levels, waveforms, and schematics. The document also includes specific instructions for upgrading from K1 to K2 modules for improved data reliability.