Random ISZ Test

This document serves as the technical documentation and source code for the PDP-8E "Random ISZ Test." This diagnostic program is designed to verify the correct operation of the Increment, Skip if Zero (ISZ) instruction on the PDP-8E computer.

Key features of the program include:

• Functionality: It tests the ISZ instruction by placing it at specific memory locations and validating that it correctly increments operands and triggers the expected "skip" or "no-skip" conditions.
• Testing Methods: The program operates in two parts: Part 1 uses a random number generator to select memory locations and operands, while Part 2 allows for fixed-value testing to isolate specific scenarios.
• Operation: It requires a PDP-8E with a teletype. Operators can control the execution via the Switch Register to set test modes, halt on errors, or suppress printouts.
• Error Reporting: The program provides detailed teletype output if an error is detected, identifying the specific instruction, the operand address, the values involved, and the nature of the failure (e.g., skip vs. no-skip).
• Recovery: It includes procedures for error recovery, allowing an operator to isolate and re-run specific failing conditions in a "scope mode" for deeper hardware analysis.