Pdp-8 A/d Converter

Summary

This document provides the technical specifications, operating instructions, and diagnostic procedures for the Maindec 845 A/D Converter Test. This software is designed to assist maintenance personnel in debugging hardware issues and performing periodic confidence checks on the PDP-8 computer's A/D converter systems (models 138E/139E and 189).

Key features of the diagnostic test include:

• Functionality: It verifies data flags, interrupts, monotonicity, steady-state accuracy, and multiplexer operations.
• Operation: It supports both manual and automatic testing modes. It uses an Automatic A/D Converter Tester or a high-accuracy voltage standard for verification.
• Configuration: Users can select different test modes based on the bit length (10, 11, or 12-bit) and the specific hardware converter (138E or 189).
• Switch Register (SR) Controls: The document details specific switch settings that allow users to control multiplexer channels, inhibit printouts, loop tests, and set repeat functions.
• Error Reporting: The program provides clear printouts for identified faults, such as the inability to raise flags/interrupts, narrow voltage states, "DIP" (monotonicity) errors, and incorrect voltage limits.
• Documentation: The manual includes detailed memory storage requirements, entry point instructions, a full assembly language source code listing, and flow charts for the diagnostic routines.