TC-59 Utility Program

This document describes the TC59 Utility Program, a software tool designed for testing and debugging the TC59 Magnetic Tape Control and its associated TU20 7-track tape transports when used with a PDP-9 system.

Key features and operational aspects include:

• Requirements: A PDP-9 system with a minimum of 8K memory, the TC59 Magnetic Tape Control, and 1 to 8 TU20 tape transports. Prior successful execution of the TC59 control test is mandatory.
• Loading and Starting: The program, initially assembled in MACRO-9 format, is loaded using a PDP-7 DDT. Users can initiate operations by configuring control switches or by typing in programs via DDT, allowing for single operations, sequences, or custom routines.

• Command Set: The utility provides a comprehensive range of commands for various functions:

  • Tape Motion: Commands to write, read, or read/compare records; backspace or space forward records/files; write end-of-file markers; and rewind tapes.
  • Pattern Generation: Functions to fill the write buffer with specific data patterns, including zeros, ones, predefined values, count patterns, random data, or sliding bit/character patterns.
  • Control and Status: Commands to zero or dump error counters, set and check program indexes, sense the end of tape, compare read and write buffer contents, and select tape density (200, 556, or 800 BPI) and parity (even or odd).

• Error Handling: The program includes automatic error recovery procedures for both write and read errors. It attempts to retry operations up to three times, categorizing errors as recoverable or non-recoverable, and provides error status printouts.

• Customization: Advanced users can define their own operations by constructing specific command words (WORD 1, WORD 2, WORD 3) via DDT, allowing precise control over parameters such as unit selection, record/file counts, density, parity, starting/final memory addresses, and search masks.
• Output: The utility provides clear printouts for user prompts and detailed error status messages.
• Purpose: The TC59 Utility Program is primarily intended for generating simple or complex exercisers to thoroughly test and debug the tape drive system, particularly for applications like scope loops.