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Keypunch

A keypunch is a device for precisely punching holes into stiff paper cards at specific locations as determined by keys struck by a human operator. Other devices included here for that same function include the gang punch, the pantograph punch, and the stamp.'Alphabetical duplicating keypunches recorded alphabetic information in tabulating cards so that complete words and names, together with numerical data, could be later printed by an alphabetical accounting machine. The Type 31 Alphabetical Duplicating Punch was introduced by IBM in 1933, and it automatically ejected one card and fed another in 0.65 second. These machines were equipped with separate alphabetical and numerical keyboards. The alphabetical keyboard was similar to a conventional manual typewriter except that the shift, tab, backspace and character keys were eliminated, and a skip, release, stacker and '1' key were provided.' – IBM Archives(manufactured by British ICT) (1960s) A keypunch is a device for precisely punching holes into stiff paper cards at specific locations as determined by keys struck by a human operator. Other devices included here for that same function include the gang punch, the pantograph punch, and the stamp. For Jacquard looms, the resulting punched cards were joined together to form a paper tape, called a 'chain', containing a program that, when read by a loom, directed its operation. For Hollerith machines and other unit record machines the resulting punched cards contained data to be processed by those machines. For computers equipped with a punched card input/output device the resulting punched cards were either data or programs directing the computer's operation. Early Hollerith keypunches were manual devices. Later keypunches were electromechanical devices which combined several functions in one unit. These often resembled small desks with keyboards similar to those on typewriters and were equipped with hoppers for blank cards and stackers for punched cards. Some keypunch models could print, at the top of a column, the character represented by the hole(s) punched in that column. The small pieces punched out by a keypunch fell into a chad box, or (at IBM) chip box, or bit bucket. In many data processing applications, the punched cards were verified by keying exactly the same data a second time, checking to see if the second keying and the punched data were the same (known as two pass verification). There was a great demand for keypunch operators, usually women, who worked full-time on keypunch and verifier machines, often in large keypunch departments with dozens or hundreds of other operators, all performing data input. In the 1950s, Remington Rand introduced the UNITYPER, which enabled data entry directly to magnetic tape for UNIVAC systems. Mohawk Data Sciences subsequently produced an improved magnetic tape encoder in 1965, which was somewhat successfully marketed as a keypunch replacement. The rise of microprocessors and inexpensive computer terminals led to the development of additional key-to-tape and key-to-disk systems from smaller companies such as Inforex and Pertec. Keypunches and punched cards were still commonly used for both data and program entry through the 1970s but were rapidly made obsolete by changes in the entry paradigm and by the availability of inexpensive CRT computer terminals. Eliminating the step of transferring punched cards to tape or disk (with the added benefit of saving the cost of the cards themselves) allowed for improved checking and correction during the entry process. The development of video display terminals, interactive timeshared systems and, later, personal computers allowed those who originated the data or program to enter it directly instead of writing it on forms to be entered by keypunch operators. Jacquard cards were said to be stamped or cut (not punched). The first Jacquard cards were stamped by hand, sometimes using a guide plate. An improvement was to place the card between two perforated metal plates (hinged together), insert punches according to the desired pattern, then pass the assembly through a press to cut the card. These essentially manual processes were replaced by machines; piano machines (the name taken from the keys), operated by keyboards and comparable in function to unit record keypunches, becoming the most common. Herman Hollerith's first device for punching cards from the 1890s was ...any ordinary ticket punch, cutting a round hole 3/16 of an inch in diameter. Use of such a punch was facilitated by placing the holes to be used near the edges of the card. Hollerith soon developed a more accurate and simpler to use Keyboard Punch, using a pantograph to link a punch mechanism to a guide pointer that an operator would place over the appropriate mark in a 12 by 20 matrix to line up a manual punch over the correct hole in one of 20 columns.

[ "Computer hardware", "Operator (computer programming)", "Operating system", "Programming language", "Engineering drawing" ]
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