PDP-15 VT15 Graphic Processor

This document is Volume 1 of a two-volume Maintenance Manual for the Digital Equipment Corporation (DEC) PDP-15 VT15 Graphic Processor, identified by document number EK-0VT15-MN-002, with editions dating from December 1970 to January 1974.

The manual provides a basic understanding of the VT15 Graphic Processor's operation and capabilities, which functions as the digital-to-analog interface for the Graphic-15 Display System (comprising the VT15 and a display console).

Key areas covered include:

1. Basic Description: General overview, functional and physical characteristics, system options, and specifications.
2. Installation: Procedures for unpacking, connecting power cables, initial setup, and system power-up, including customer acceptance checks and diagnostic programs.
3. System Operation: Detailed description of the VT15's major functional groups (I/O control, data collectors, timing and control, main registers, digital-to-analog converters, and analog function generator) and their interactions.
4. Instruction Flow Analyses: A comprehensive discussion of Input/Output Transfer (IOT) commands and VT15 Graphic Processor instructions (e.g., parameter/skip, vector, plot, jump, save/restore, character operations), detailing their formats and operational flows.
5. Special Modules: In-depth descriptions of unique hardware modules found within the VT15 Graphic Processor.
6. Maintenance: Procedures for preventive and corrective maintenance, including equipment requirements, diagnostic programming, and troubleshooting guidelines at the system, functional group, and module levels.

Volume 2 of the manual contains the complete set of engineering drawings for the VT15 Graphic Processor.