TU80 Magnetic Tape Subsystem Pocket

This "Pocket Service Guide" is a concise manual designed for trained service personnel working with the TU80 Magnetic Tape Subsystem. The TU80 is a dual-speed, nine-track streaming tape data storage system integrated into an H9643 cabinet, connecting to a host CPU via an M7454 UNIBUS adapter. Up to four TU80 units can be connected to a single CPU, each requiring a dedicated M7454 adapter.

The document provides a product overview, including its functional components, cabling, and various power configurations. It lists essential tools, applicable documentation, and describes the TU80's control panel, detailing both operational switches (e.g., LOAD/REWIND, UNLOAD, ON LINE) and diagnostic controls (e.g., TEST, STEP, EXECUTE). A key aspect of maintenance is the ability to pivot the tape deck for easier access to internal components. The guide notes that the TU80 generally requires no mechanical/electrical adjustments for maintenance, only regular tape path cleaning.

Installation procedures cover configuring transport addresses and options via jumpers and DIP switches on the formatter/control module, and the step-by-step installation/replacement of the M7454 UNIBUS adapter, including internal CPU and external TU80 cabling.

Troubleshooting is a major section, outlining both resident (off-line) diagnostics initiated via the control panel and host-based (on-line) diagnostics for PDP-11 and VAX systems. It emphasizes using fault codes in conjunction with the TU80 Pathfinder for problem isolation. Detailed procedures are provided for power-up health checks, basic operator tests (Test 01, 02, 03), and M7454 module diagnostics.

The final section details removal, replacement, and verification procedures for all Field Replaceable Units (FRUs), covering components on the tape deck (e.g., magnetic head, tape cleaner, reels, sensors) and those inside the cabinet (e.g., motors, pump, power supply, various electronic modules). Instructions include how to safely rotate the tape deck into a maintenance position. Appendices offer module layouts and TU80 register summaries to further assist service.