VT62 DECscope

This technical manual details the VT62 DECscope, a 24-line, 80-character video display terminal primarily designed for commercial data entry and retrieval applications, suitable for users without specialized computer training. The terminal operates as an input/output (I/O) device for a host processor, supporting data transmission and reception up to 9600 baud. Key features include a standard typewriter-style keyboard with an auxiliary numeric/special function keypad, eight LED indicators for operational status, and a formatted split-screen display with host-controlled protected fields, menu selection, and local data validation capabilities to minimize operator errors.

The document provides a comprehensive technical description of the VT62's architecture, including its internal microprocessor (comprising Control ROM, Macro ROM, and Random Access Memory), video logic, communications interface, keyboard logic, and monitor circuits (CRT and deflection systems). It also covers the H7832 power supply and various communication options (EIA and 20 mA current loop).

A substantial part of the manual is dedicated to installation, operation, programming, and maintenance. It outlines installation procedures, off-line and on-line operating instructions, and user programming considerations. For servicing, it advocates a subassembly-level troubleshooting approach, detailing initial checks, voltage test points, monitor waveform analysis, and step-by-step replacement procedures for all major modules like the memory board, processor/video board, monitor board, keyboard, CRT assembly, and power supply. Additionally, it includes display adjustment instructions and extensive off-line acceptance tests and diagnostic modes, featuring a self-test with LED error displays and detailed fault-locating procedures for diagnosing component failures.