Test - 14L

This document describes TEST-14L, a diagnostic program designed to thoroughly test a PDP-14L Computer System. The program runs on a PDP-8 I/L computer, which interfaces with the PDP-14L under test, including its processor, I-Boxes, O-Boxes, and S-Boxes.

TEST-14L provides error type-outs, error halts, and oscilloscope looping capabilities. It can be executed for a short duration (minutes) for initial checks or for approximately two hours for a comprehensive test of all logic circuitry. Key requirements for its operation include specific hardware connections: a PDP-8 I/L to PDP-14L interface module (M745), outputs of the O-Boxes electrically tied back to the inputs of the I-Boxes, and I-, O-, and S-Box cables occupying consecutive address slots.

The program is loaded using the standard PDP-8 Binary Loader. Switch register settings allow the operator to control various test parameters, such as looping on tests, halting on errors, printing errors, performing short or long tests, and testing memory logic. Initial setup involves answering questions about the PDP-14L's I/O/S box configuration and the presence of a Read-Only Memory (ROM) via the teletype keyboard.

Error messages produced by the program include a two-letter error designator and a description of the failing condition. These designators map to specific modules that might be faulty (e.g., IR Decoder, Major Registers, or the PDP-8 to PDP-14L Interface). The document also covers error recovery procedures and mentions non-diagnostic errors like "PDP-14 HUNG" or "PDP-14 STOPPED." The program description outlines a series of tests, checking various instructions (JMP, TRM, NOP, JFF), external and output register flag operations, and numerous I/O status conditions.