Random JMP-JMS Test

Summary

This document is a technical manual for a diagnostic program designed to test the JMS (Jump to Subroutine) instruction on the PDP-8 computer.

Key features of the diagnostic:

• Purpose: It verifies the functionality of JMS instructions by testing random memory addresses for both the starting ("FROM") and target ("TO") locations.
• Mechanism: The test utilizes the PDP-8 interrupt function. After placing a JMS instruction at a chosen "FROM" address, the program executes it and checks the interrupt to verify that the program counter was stored correctly at the "TO" address.
• Error Handling: The program provides specific printouts when it detects a failure, identifying the attempted instruction, the destination, the actual contents of the target address, and the location where the program counter was erroneously stored.
• Operation: Users can configure the test via control switches (SR2/SR3) to use either fixed or random addresses. It includes a "scope mode" feature to loop a specific test sequence for troubleshooting purposes.
• Requirements: The program requires a PDP-8 with a Teletype and follows a standard loading procedure using the Binary Loader. It assumes several prerequisite diagnostic programs (08-D01 through 08-D04) have already been run successfully.