Editing Punched tape (section)

=== Communications ===
[[file:Teletype_33_ASR.jpg|thumb|right|[[Teletype Model 33|Teletype 33]] Automatic Send and Receive teleprinter with paper tape in both the reader and the punch]]
[[file:Honolulu IFSS Teletype1964.faa.jpg|thumb|right|Paper tape relay operation at US [[Federal Aviation Administration|FAA]]'s Honolulu flight service station in 1964]]

Punched tape was used as a way of storing messages for [[Teleprinter|teletypewriters]]. Operators typed in the message to the paper tape, and then sent the message at the maximum line speed from the tape. This permitted the operator to prepare the message "off-line" at the operator's best typing speed, and permitted the operator to correct any error prior to transmission. An experienced operator could prepare a message at 135 words per minute (WPM) or more for short periods.

The line typically operated at 75&nbsp;WPM, but it operated continuously. By preparing the tape "off-line" and then sending the message with a tape reader, the line could operate continuously rather than depending on continuous "on-line" typing by a single operator. Typically, a single 75&nbsp;WPM line supported three or more teletype operators working offline. Tapes punched at the receiving end could be used to relay messages to another station. Large [[store and forward]] networks were developed using these techniques.

Paper tape could be read into computers at up to 1,000 characters per second.<ref name="Hult"/> In 1963, a Danish company called [[Regnecentralen]] introduced a paper tape reader called RC&nbsp;2000 that could read 2,000 characters per second; later they increased the speed further, up to 2,500&nbsp;cps. As early as [[World War II]], the [[Heath Robinson (codebreaking machine)#Tape reading|Heath Robinson tape reader]], used by Allied codebreakers, was capable of 2,000&nbsp;cps while [[Colossus computer|Colossus]] could run at 5,000&nbsp;cps using an optical tape reader designed by Arnold Lynch.