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| Smart Computing® Encyclopedia |
| paper tape | ||
| Early computers, as well as other machines, read, stored, and output data fed by a narrow, continuous strip of paper in which punched holes represented coded letters and numbers. Sir Charles Wheatstone introduced paper tape in 1857. The electric telegraph,
invented in 1836, was the first business machine to use paper tape. The technology of paper tape caught on quickly, and a year after its introduction, a Morse tape reader-transmitter was developed that was capable of operating at a speed of 100 words per minute. Adding machines and cash registers were using paper tape by the end of the nineteenth century. Commonly used in twentieth century stock quoting machines, the tape was known as ticker tape. Tapes were typically produced in 1,000-foot rolls and varied in width from 7/8 of an inch to three inches. The code was punched across the width of the tape. Each row represented one character. The combination of punches signified a character, so five-track tape could handle combinations of 25, or 32 characters. A special character preceding the punches indicated if the code was a letter, numeral, or special symbol. Five-track tapes appeared early in the 20th century and were standard for computerized data processing during the 1930s and 1940s. As demand for more complex code combinations grew, advances in tape capacity continued until third-generation computers appeared in the mid-1960s. At that time the industry standard was set at eight tracks (seven code tracks and one parity-bit track) on one-inch-wide tape. At this time, formal standards for formatting code were adopted, which influenced the later development of ASCII (American Standard Code for Information Exchange) language, which became the standard for machine-readable data. In 1957, NCR (National Cash Register) partnered with General Electric to produce the first solid-state mainframe computer, the NCR 304. The NCR 315 followed the NCR 304 as the first mass storage device. Cash registers and bank teller machines, adding machines, and accounting machines could be fitted with paper tape recorders, which punched tape users could input to the 315. But the need for paper tape in banking was short-lived. In 1963, banks could interface teller machines to telephone lines and connect to the 315, enabling instant updating of customer accounts from branch offices. In manufacturing, slow-speed paper tape, coded with the instructions to make a particular part, may be used to guide CNC (computer numerically controlled) precision machining operations. Terms associated with paper tape: paper tape punch: The paper tape punch is an output device that translates computer data into paper tape code. paper tape reader: The paper tape reader is an input device with sensors that translates paper tape code into data for a computer to process. | ||
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