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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 holes in the card ...
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 ...
Tape for punching was usually 0.00394 inches (0.100 mm) thick. The two most common widths were 11 ⁄ 16 inch (17 mm) for five bit codes, and 1 inch (25 mm) for tapes with six or more bits. Hole spacing was 0.1 inches (2.5 mm) in both directions. Data holes were 0.072 inches (1.8 mm) in diameter; sprocket feed holes were 0.046 inches (1.2 mm). [7]
The ten rules are: [ 1] Avoid complex flow constructs, such as goto and recursion. All loops must have fixed bounds. This prevents runaway code. Avoid heap memory allocation. Restrict functions to a single printed page. Use a minimum of two runtime assertions per function. Restrict the scope of data to the smallest possible.
Keypunch. IBM 026 Keypunch. Keypunch operators at work at the U.S. Social Security Administration in the 1940s. Operators compiling hydrographic data for navigation charts on punch cards using the IBM Type 016 Electric Duplicating Key Punch, New Orleans, 1938. A keypunch is a device for precisely punching holes into stiff paper cards at ...
The memory is magnetic-core memory with a cycle time of 1.5 microseconds (0.667 MHz), so that a typical two-cycle (Fetch, Execute) memory-reference instruction runs at a speed of 0.333 MIPS. The 1974 Pocket Reference Card for the PDP-8/E gives a basic instruction time of 1.2 microseconds, or 2.6 microseconds for instructions that reference memory.
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 ...
A fallstreak hole (also known as a cavum, [ 1] hole punch cloud, punch hole cloud, skypunch, cloud canal or cloud hole) is a large gap, usually circular or elliptical, that can appear in cirrocumulus or altocumulus clouds. The holes are caused by supercooled water in the clouds suddenly evaporating or freezing, and may be triggered by passing ...