VT520/VT525 Video Terminal

This document serves as a comprehensive technical manual for advanced users, consultants, and programmers working with the Digital VT520 and VT525 video terminals, published in July 1994. It provides in-depth details on the terminals' features, configuration, and programming interfaces across various operating modes.

Key information provided includes:

• Terminal Capabilities: An overview of the VT520/VT525 as low-cost, multi-session (up to four sessions), text-video terminals with enhanced keyboard and communications flexibility. The VT525 model offers color display capabilities.
• Set-Up and Configuration: Detailed instructions on using the menu-based Set-Up utility to configure terminal operating features, covering display settings (lines, columns, cursor, colors, windows), keyboard language and key definitions, communication protocols (baud rates, flow control, modem control), and printer port settings. It also explains session management, power-on defaults, error messages, and context-sensitive features.
• Desktop Productivity Features: Information on built-in desktop tools such as a calculator, a time-of-day clock, character set tables, banner messages, and copy/paste functionality.
• ANSI Control Functions: A detailed guide for programmers on ANSI escape and control sequences, including their formats, parameters, and mnemonic references. It covers functions for terminal management, window control, audible/visual attributes, editing, text processing, graphic character sets, and keyboard processing.
• Emulation Modes: Specifics on SCO Console emulation, including its keyboard and control sequences, and various ASCII emulation modes (e.g., WYSE, Televideo, ADDS) with their unique escape sequences for communications, terminal management, keyboard processing, and screen display.
• Character Set Support: Descriptions of supported VT graphic, PCTerm graphic, and dynamically redefinable soft character sets, along with procedures for designing, coding, loading, and designating custom fonts.
• Hardware Interface Details: Comprehensive coverage of keyboard layouts, keystroke processing, LED control, various communication port types (RS-232, EIA-423 MMJ, Centronics parallel), flow control mechanisms, and printer port operations.

The manual aims to enable effective understanding, configuration, and programming of these terminals in diverse application environments.