VT100VT220

VT100 and VT220 are among the most influential lines of video terminals produced by Digital Equipment Corporation (DEC). The VT100, released in 1978, defined a widely adopted standard for remote terminal communication. It used a character-based display, typically 80 columns by 24 rows, and relied on RS-232 serial interfaces to connect to host computers. A core feature of the VT100 was its set of escape sequences, which allowed software running on a host computer to control cursor movement, screen erasure, text attributes, and basic locale and character-set changes. These DEC escape codes evolved into the de facto standard for terminal emulation and later influenced the ANSI escape sequences used by many operating systems and software applications.

The VT220, introduced in the early to mid-1980s as part of DEC’s VT200 series, expanded on the VT100’s capabilities. It offered enhanced keyboard input with more function keys, options for both 80- and 132-column display modes, and improved support for international character sets. The VT220 maintained VT100 emulation compatibility, ensuring that software designed for VT100 terminals could operate on the newer model, while also providing native VT200 features for more advanced terminal control. The device improved handling of 7-bit and 8-bit control codes, screen memory management, and more flexible screen editing and navigation, making it a versatile choice for professional and laboratory environments.

Legacy and impact: VT100 and VT220 influenced countless terminal emulators and remote access tools. Even today, many terminal programs preserve VT100 or VT100-compatible emulation for broad compatibility, while some emulators extend support to 132-column modes and VT200 features. The line’s emphasis on simple, programmable control sequences helped standardize remote terminal interaction across diverse computing platforms.