paper tape I/O

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paper tape I/O An obsolete but once widely used means of entering data into and extracting it out of a processor system using punched paper tape as the medium. Paper tape I/O was adopted for many of the early computers: tape punches and tape readers were already in use for telex and were lower in cost than punched card equipment.

Early tape readers operated at about 10 characters per second (cps) by moving the tape in discrete steps, and sensed the holes by pressing a row of pins against the tape. The next generation of machines moved the tape continuously and sensed the holes via star-shaped wheels that rotated only when the points engaged a punched hole. Photoelectric sensing allowed speeds of up to 1500 cps to be achieved by 1975. There have been higher-speed readers but they were not able to stop within a character pitch. Tape punches as fast as 300 cps have been available but 110 cps was the more usual speed for volume output.