PDP-9 High Speed Reader Test

This document describes a diagnostic program designed to test and verify the operational status of the PDP-9 High Speed Reader, including its associated control logic and mechanical components. The program is divided into two main parts:

1. Part 1: Test Tape Generator - This section can punch various test tapes required for the diagnostic tests, including alternate 1s and 0s, binary counts, or specific characters, controlled via ACS switches.
2. Part 2: Diagnostic Tests - This part consists of five sections that perform comprehensive checks:
   • Section 1 (Tests 1-7): Focuses on the reader's IOT (Input/Output Transfer) instructions, control logic response (with and without tape), motor delay timing, and interrupt handling.
   • Section 2 (Tests 9-10): Specifically tests the 45 ms motor delay of the reader logic and the response of the reader logic when no tape is present.
   • Section 3 (Basic Data Checks): Verifies the reader's ability to accurately read data from tape using all control IOTs, employing various tape patterns like binary count or specific characters.
   • Section 4 (Variable Reader Speed Test): Evaluates the reader's mechanical adjustments by allowing the operator to vary the motor speed using AC switches.
   • Section 5 (Random Read and Stall): Performs a stringent test by reading random block lengths with a fixed stall time between frames, and then reads at full speed.

The program occupies memory locations 000000 to 3362 and automatically detects the presence of the Memory Parity option, adjusting timing loops accordingly. Errors during testing typically result in a program halt, with the Program Counter (C(PC)) indicating the nature of the error for troubleshooting. Other I/O devices (besides Teletype, high-speed reader, and paper tape punch) must be turned off to prevent interference.