PDP-12 Maintenance Manual, Volume II

This document, Volume II of the PDP-12 Maintenance Manual, is a comprehensive guide for Field Service Engineers and other personnel involved in the installation, maintenance, adjustment, and repair of the PDP-12 Computer System.

Key areas covered include:

1. Installation: Detailed instructions for site planning, including space, floor construction, fire and safety, and environmental considerations. It describes system configurations and expansion, pre-delivery preparations, and step-by-step procedures for unpacking, installing, and inspecting the PDP-12 cabinet, Teletype units, and prewired options. Initial system checks, such as Teletype tests, memory tests, and running diagnostic programs (MAINDECs), are also outlined.
2. Maintenance: This section introduces the systematic maintenance program required for the PDP-12, which integrates both PDP-8/I and LINC functional subsystems. It specifies necessary maintenance equipment, the use of diagnostic and reliability test programs, and procedures for mounting LINCtape maintenance tapes.
3. Preventive Maintenance: Outlines scheduled tasks ranging from daily LINCtape head cleaning to weekly diagnostic program runs, and three-month inspections covering cleaning, lubrication, visual checks of wiring and components, module seating, and power supply verification.
4. Corrective Maintenance: Provides a logical troubleshooting process, starting with preliminary investigation and system-level fault isolation, progressing to detailed logic and circuit troubleshooting, repairs, and validation testing. The importance of meticulous log book recording for all maintenance activities is emphasized.
5. Adjustments: Offers specific, step-by-step adjustment procedures for critical system components. This includes memory current and strobe, power supply, extended memory, Teletype clock, LINCtape transport mechanisms (delays, brake, torque, head adjustments), and analog/display units (digital-to-analog, size, position, brightness, deflection, analog-to-digital, sample and hold, external analog channels).
6. Prewired Option Installation and Checkout: Details the unpacking, installation, and specific checkout procedures for various PDP-12 prewired options using relevant diagnostic programs.
7. Teletype Maintenance: Dedicated sections for the maintenance of Teletype Models ASR 33 and 35, covering necessary tools, preventive maintenance tasks, and corrective action guidance for common issues.
8. Service Options and Customer Acceptance: Provides information on Digital Equipment Corporation's service contracts (including on-call coverage and resident engineer plans), per-call coverage, depot repair services, and field installation of additional options. It also describes the customer acceptance process, which involves demonstrating machine operation with diagnostics and system software, and lists relevant forms and checklists.

The manual is an essential resource for ensuring the long-term reliability and proper functioning of the PDP-12 Computer System.