17
3
Crtl and alt have become common place on just about any computer keyboard sold anywhere in the world (I even saw a picture of them on a typewriter...). But what were these sacred modifier keys first used for? What's the difference between them and other keys used as modifiers? How has their used evolved into what it is today?
Not really "the earliest days". As indicated, the Ctrl key was a feature on ASCII teletypewriters, following the ASCII standard (originally published in 1963). But there were a lot of years of computing before that. Computers of that era commonly stored printable characters in 6-bit fields and printers and keypunches could typically only handle about 48 different glyphs; there were no "control codes". – Jamie Hanrahan – 2019-03-05T06:36:35.810
Alt and Alt Gr were also used a lot in MS-DOS application shortcuts, before they were all standardised in Windows (by copying the MacOS keyboard shortcuts). I seem to remember Alt Gr being printed in green on AT keyboards, so I always thought it stood for Alt Green. – paradroid – 2010-12-02T08:47:23.287