VT125 Programming Reference Card

This document is a comprehensive reference card for programming the VT125 terminal, detailing control characters, ANSI compatible sequences, and VT52 compatible sequences.

It covers:

• Control Characters: A list of basic control characters (e.g., Null, Bell, Backspace, Line Feed, Carriage Return, Shift Out/In, Device Control 1/3 for XON/XOFF) with their mnemonics, octal codes, and functions for fundamental terminal operations like cursor movement, bell tones, character set selection, and flow control.
• ANSI Compatible Sequences: Commands to set and reset various terminal modes, including line feed/new line, cursor key behavior, ANSI/VT52 mode, 80/132 column display, smooth scrolling, reverse screen, relative origin, auto wrap, and auto repeat. It also defines cursor key and keypad codes for both ANSI and VT52 modes, as well as character selection for alternate/numeric keypads.
• Character Sets & Attributes: Instructions for selecting different GO and G1 character sets (e.g., UK, USASCII, special characters, line drawing), using Single Shift 2/3 for character shifts, and applying graphic rendition attributes like bold, underline, blink, and reverse video.
• Display Control: Commands for managing the scrolling region, precise cursor movement, setting and clearing tab stops, and adjusting line attributes (e.g., double-height, single/double-width).
• Erasing & Protocols: Sequences for erasing parts of a line or the entire screen/display, along with communication and graphics protocol commands for entering ReGIS, DECwriter graphics, or VT105 emulator modes, and managing media copy operations.
• Reporting & Reset: Commands to request device status (VT125, cursor position), device attributes, and to identify the terminal, including the format of the attribute response. A command to reset the terminal to its initial state is also provided.
• Tests & Adjustments: VT100-specific commands for screen alignment, filling the screen, and various confidence tests (power-up, data loopback, EIA modem control) with options for continuous execution, noting that loopback tests require specific hardware.
• Keyboard Indicators: Commands to control the terminal's LED indicators.
• ReGIS Command Summary: A detailed section outlining ReGIS (Raster Graphics Instruction Set) commands for position, vector, curve, text, writing controls (modes, foreground planes, intensity, color, patterns), screen controls (scroll, display addressing, hardcopy, output mapping, time delay), macrographs, and character cell control.
• Report Command Summary: Commands to query and report on selected items, macrograph contents, storage usage, and cursor position.

The card serves as an essential technical reference for controlling the VT125 terminal's display, graphics, and interactive features.