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Punched card. A 12-row/80-column IBM punched card from the mid-twentieth century. A punched card (also punch card[ 1] or punched-card[ 2]) is a piece of card stock that stores digital data using punched holes. Punched cards were once common in data processing and the control of automated machines . Punched cards were widely used in the 20th ...
Punched cards. A punched card is a flexible write-once medium that encodes data, most commonly 80 characters. Groups or "decks" of cards form programs and collections of data. The term is often used interchangeably with punch card, the difference being that an unused card is a "punch card," but once information had been encoded by punching ...
Punched card input/output. A computer punched card reader or just computer card reader is a computer input device used to read computer programs in either source or executable form and data from punched cards. A computer card punch is a computer output device that punches holes in cards. Sometimes computer punch card readers were combined with ...
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Print/export Download as PDF; Printable version; This user remembers using punch cards This page was last edited on 14 July 2019, at 06:01 (UTC). ...
Signed overpunch. In computing, a signed overpunch is a coding scheme which stores the sign of a number by changing (usually) the last digit. It is used in character data on IBM mainframes by languages such as COBOL, PL/I, and RPG. [1] Its purpose is to save a character that would otherwise be used by the sign digit. [2]
A vacuum-tube computer, now termed a first-generation computer, is a computer that uses vacuum tubes for logic circuitry. While the history of mechanical aids to computation goes back centuries, if not millennia, the history of vacuum tube computers is confined to the middle of the 20th century. Lee De Forest invented the triode in 1906.
The term unit record equipment also refers to peripheral equipment attached to computers that reads or writes unit records, e.g., card readers, card punches, printers, MICR readers. IBM was the largest supplier of unit record equipment and this article largely reflects IBM practice and terminology.