JMP-Self Test

This document describes the "JMP-Self Test" program, designed to verify the proper execution of the JMP instruction on a PDP-9 computer and to test all available memory.

The program works by repeatedly placing a JMP instruction at different memory locations, holding the computer in that instruction for a specified time interval (initially 16.6 msec), and checking for errors. If the JMP instruction fails, an error is indicated to the operator. The program occupies memory locations 17500 through 17762 and tests all memory locations below 17500. The entire test takes approximately 10 minutes to run from locations 0 to 17477 (octal).

To load the program, an HRI tape is placed in the reader, the ADDRESS SWITCHES are set to 17500, and the KEY READ-IN key is depressed. Starting involves setting ADDRESS SWITCHES to 17500 and ACCUMULATOR SWITCHES to desired positions (default 520000), depressing I/O RESET, ensuring the clock is enabled, and pressing START. Accumulator switches allow operators to configure error handling, such as halting on error, printing error messages, ringing a bell, looping on the current location, or repeating the entire test.

Errors are typically printed on the teleprinter unless disabled. The program can halt if a JMP instruction drops a bit or if the full test is not repeated. Error recovery involves resetting accumulator switches and pressing CONTINUE. Specific memory locations can be targeted for testing by storing the address in a designated location and restarting the program. Preliminary instruction tests (MAINDEC-9A-D01A-D and MAINDEC-9A-D02A-D) are required before running this self-test. There are no known starting or operating restrictions.