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RedGrittyBrick

Background

Dumb Terminals

Once upon a time, before personal computers, before microcomputers, there existed mainframe and minicomputers. These were big expensive things and the use of each one was typically shared by many people. more...

Standards

One of the dominant computer makers was the Digital Equipment Corporation, Known as DEC. I'm ignoring IBM who had their unique standards (3270). Their earliest terminal in widespread use was the VT52. This was superceded by the VT100 which did all the VT52 did and more. The VT100 inherited a lot of legacy features from the VT52. It still had a keyboard layout you'd not recognise from today's PCs. more...

Programming

It would have been pretty tedious to code variations in each applications for each terminal: "order entry for vt52", "order entry for vt100", "order entry for Wyse 50" and so on. So I guess, people wrote terminal handling libraries to insulate the actual application coding from whatever terminal was in use. The "curses" library must have arisen from this. Curses defines abstract functions for moving the cursor around. It translates these into the control codes that have to be sent to a specific type of terminal. On Unix, the library finds out what sort of terminal from an environment variable "TERM" that is set in the login scripts. more ...