CONTEST II

CONTEST II is a maintenance program designed for the PDP-1 computer, released on May 1, 1963, by J. M. Graetz. Its primary purpose is to perform a comprehensive operational check of the computer's core functionalities. The program tests the central processing unit's instructions, memory (including a checkerboard pattern test), the system clock, program interrupt capabilities, and various input/output devices such as the reader, punch, and teleprinter.

The program is structured as a collection of small subroutines, each dedicated to testing specific instructions or components. It includes routines for register tests, interrupt tests, clock tests, punch tests, and print tests. After all instructions are tested, a checkerboard memory test is performed, followed by tests for program interrupt, reader, punch, and teleprinter operations. The entire sequence then repeats. The document provides detailed lists of potential halts and error messages, indicating specific failures with memory addresses, to assist in diagnosing issues. It also references other library programs that offer more rigorous testing for specific components, such as a dedicated checkerboard, clock interrupt test, and I/O tests for the reader, punch, and teleprinter.