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ASCII was very carefully designed. One feature I like is that you can neatly cut out a 64-character 6-bit all-uppercase encoding (like DEC's) if you don't need
by TazeTSchnitzel 10y ago
ASCII was very carefully designed.
One feature I like is that you can neatly cut out a 64-character 6-bit all-uppercase encoding (like DEC's) if you don't need lowercase.
Wikipedia covers some of the design choices here: https://en.wikipedia.org/wiki/ASCII#Internal_organization https://en.wikipedia.org/wiki/ASCII#Internal_organization
- AlecSchueler 10y agoFor a more detailed look at the design decisions in ASCII and its predecessors, check out Character Coding Sets: History and Development by Charles Mackenzie, one of the best technical books I've ever read.
- aap_ 10y agoHere is a nice history of ASCII: https://github.com/ericfischer/ascii https://github.com/ericfischer/ascii
- enf 10y agoThank you!
- kps 10y agoThe 1963 ASCII standard also lists many of the design considerations. http://worldpowersystems.com/archives/codes/X3.4-1963/index.html http://worldpowersystems.com/archives/codes/X3.4-1963/index....
- kps 10y ago> One feature I like is that you can neatly cut out a 64-character 6-bit all-uppercase encoding (like DEC's) if you don't need lowercase. And if you take the digits from the 0x3X column and the non-digits from the 0x2X column (flipping one bit), you get 0123456789*+,-./ which is enough to write numbers and the basic arithmetic operators. This too was deliberate.
- mdimec4 10y agoYes and on keybord shift+1 becomes
- breadbox 10y agoThe TRS-80s had the lovely feature that all of the punctuation above the digits were consistent with ASCII layout. shift-1 was !, as per usual, but also shift-2 was ", and ' was shift-7. On the Model I they even went so far as to make shift-0 produce a space! (On the Model III however, they reused shift-0 to toggle between uppercase and lowercase mode -- sort of a reverse caps-lock key.)
- kps 10y agohttps://en.wikipedia.org/wiki/Bit-paired_keyboard https://en.wikipedia.org/wiki/Bit-paired_keyboard
- mark-r 10y agoIn about 1978 I designed my own keyboard. The unique feature it had was that the key positions were used as address lines into a ROM, and I was free to assign any character to any key I wanted. Shift/Ctrl weren't required to be at all related to the base character. Today we take it for granted, but back then it was radical.
- ssdsa 10y agoHow many keys were there? I suppose there must have been a lot more keys than your ROM had address lines.
- kalleboo 10y agoMy Japanese keyboard still has that punctuation ordering.
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