DEC-10-HDCAA-B-D DC10 Data Line Scanner Maintenance Manual Oct73

This document is the "PDP-10 Maintenance Manual" for the "DC10 Data Line Scanner," produced by Digital Equipment Corporation (DEC) between 1967 and 1973.

The DC10 Data Line Scanner is a modular, option-based peripheral designed to provide a time-sharing, two-way interface between a PDP-10 central processor and up to 64 teletype-like stations. It can accommodate devices using 5-level or 8-level serial teletype codes at speeds up to 100 kilobaud, supporting various data line modes including full-duplex, half-duplex, and send/receive-only. Data and commands are transferred via the PDP-10's I/O bus, utilizing program control and a priority interrupt system where the scanner identifies lines requiring service.

Key components (available as options) include:

• DC10A Control Unit: The essential unit, providing the I/O bus interface, a scanning logic to find data lines needing attention, and cabinet space for other modules.
• DC10B 8-Line Group Unit: Handles serial-to-parallel and parallel-to-serial data conversion for eight lines, offering interfaces for EIA standard RS-232-B or 20 mA local loops.
• DC10C Telegraph Relay Assembly: Provides relay buffering for long or "dirty" telegraph lines, supporting 20 mA or 60 mA circuits up to 300 baud, and half-duplex operation.
• DC10D Telegraph Power Supply: A dedicated 125 Vdc power supply for the telegraph relay assembly.
• DC10E Expanded Data-Set Control: Enables the computer to control data-sets more extensively, including automatic calling units.
• DC10F Expander Cabinet: Provides additional mounting space for larger DC10 configurations.

The manual is primarily intended for maintenance personnel, covering:

1. Introduction: Scope, general description of the DC10, and reference materials.
2. Operating Information and Installation: Details on controls, indicators, power application, device selection, I/O instructions, programming notes, and extensive option card adjustments (e.g., clock frequencies, device numbers, duplex modes).
3. Theory of Operation: A comprehensive explanation of how the DC10 and its various optional components function, from block diagrams to circuit-level descriptions.
4. Maintenance: Procedures for preventive maintenance (mechanical checks, power supply checks, timing adjustments) and corrective maintenance (troubleshooting using diagnostic programs, signal tracing, module replacement, and repair).