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History
Notes on a seven-bit code
Where ASCII came from, and why its 128 characters sit where they do.
Articles
Origins
A short history of ASCII
How a committee of engineers turned telegraph habits into the seven bits every computer still speaks.
Control codes
ASCII control characters
Thirty-three codes built to drive teletypes, and the handful that still run your terminal.
Encodings
ASCII vs. UTF-8
Why every ASCII file is already valid UTF-8, and what changes above 0x7F.
Line endings
CR, LF and the CRLF wars
Two separate teletype motions, and why your diffs still argue about them.
Keyboards
Why Ctrl+[ is Escape
Ctrl clears the 0x40 bit, which turns [ (0x5B) into ESC (0x1B).
Characters
Why DEL is 127
Paper tape couldn’t be un-punched, so the erase character punches every hole.