< hardware , history > Punched paper tape. An early input/output and storage medium borrowed from telegraph and teletype systems.
Data entered at the keyboard of the teletype could be directed to a perforator or punch which punched a pattern of holes across the width of a paper tape to represent the characters typed. The paper tape could be read by a tape reader feeding the computer. Computer output could be similarly punched onto tape and printed off-line.
As well as storage of the program and data, use of paper tape enabled batch processing .
The first units had five data hole positions plus a sprocket hole (for the driving wheel) across the width of the tape. These used commercial telegraph code ( ITA2 also known as Murray ), Baudot code , or proprietary codes such as Elliott which were more programmer-friendly. Later systems had eight data holes and used ASCII coding.
(2003-12-02)