Adbe, Am8e A to D Converter and Multiplexer Diagnostic

Summary This document is a technical manual and assembly listing for a diagnostic program (MAINDEC-8E-D6BB-D) designed to test the A/D (Analog-to-Digital) converter and multiplexer hardware for the PDP-8/E computer.

Key aspects of the document include:

• Purpose: The program performs basic functional tests on input/output control logic and the multiplexer, and provides calibration routines for the converter.
• Requirements: Requires a PDP-8/E with 4K memory, an ASR33 teletype, and the AD8E/AM8E hardware. Specific analog tests require an external high-quality voltage source or waveform generator.
• Operating Instructions: Details how to use the computer's switch register (SW0–SW11) to control program flow, such as suppressing error messages, halting on errors, selecting specific diagnostic tests, and setting loop parameters.
• Testing Capabilities: Includes control logic tests (checking interrupt flags, data transfers, and registers), miscellaneous system tests, and analog performance tests (monotonicity, resolution accuracy, noise, and conversion timing).
• Technical Content: The majority of the document consists of the PAL8 assembly source code listing, including I/O definitions, jump tables, subroutines for error reporting, and the logic routines for each specific diagnostic test.