It's about Punch Tape. Old Teletype terminals allowed P-tape to be "written" and read. If the typist made a mistake, they could back up the tape and type "Rub Out." That would write a DEL, effectively punching holes across the tape - effectively a bitwise OR. P-tape readers were designed to ignore the DEL.
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Fascinating, and makes perfect sense. The only character you could viably write over every other one without conflict ist 1111111, after all.
Incredibly obvious once you think about it. Very cool though. TIL!
Misread Dell for a second there and was wondering why were they screwing around with ASCII...
DEL is supposed to delete one row of text
It's not. It overrides a row on a punch card, i. e. one character.
As it's all 1s in binary you can overwrite any character by doing an or with DEL
That was a pretty solid reasoning path. Nice work! (Not sarcasm)