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.
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.