punched card

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Related to Punched cards: Difference engine, Analytical engine

punched card

(esp US), punch card
(formerly) a card on which data can be coded in the form of punched holes. In computing, there were usually 80 columns and 12 rows, each column containing a pattern of holes representing one character

punched card

[′pəncht ‚kärd]
(computer science)

punched card

(storage, history)
(Or "punch card") The signature medium of computing's Stone Age, now long obsolete outside of a few legacy systems. The punched card actually predates computers considerably, originating in 1801 as a control device for Jacquard looms. Charles Babbage used them as a data and program storage medium for his Analytical Engine:

"To those who are acquainted with the principles of the Jacquard loom, and who are also familiar with analytical formul?, a general idea of the means by which the Engine executes its operations may be obtained without much difficulty. In the Exhibition of 1862 there were many splendid examples of such looms. [...] These patterns are then sent to a peculiar artist, who, by means of a certain machine, punches holes in a set of pasteboard cards in such a manner that when those cards are placed in a Jacquard loom, it will then weave upon its produce the exact pattern designed by the artist. [...] The analogy of the Analytical Engine with this well-known process is nearly perfect. There are therefore two sets of cards, the first to direct the nature of the operations to be performed -- these are called operation cards: the other to direct the particular variables on which those cards are required to operate -- these latter are called variable cards. Now the symbol of each variable or constant, is placed at the top of a column capable of containing any required number of digits."

-- from Chapter 8 of Charles Babbage's "Passages from the Life of a Philosopher", 1864.

The version patented by Herman Hollerith and used with mechanical tabulating machines in the 1890 US Census was a piece of cardboard about 90 mm by 215 mm. There is a widespread myth that it was designed to fit in the currency trays used for that era's larger dollar bills, but recent investigations have falsified this.

IBM (which originated as a tabulating-machine manufacturer) married the punched card to computers, encoding binary information as patterns of small rectangular holes; one character per column, 80 columns per card. Other coding schemes, sizes of card, and hole shapes were tried at various times.

The 80-column width of most character terminals is a legacy of the IBM punched card; so is the size of the quick-reference cards distributed with many varieties of computers even today.

See chad, chad box, eighty-column mind, green card, dusty deck, lace card, card walloper.
References in periodicals archive ?
When I was working at a weave workshop, I was extremely fascinated by the punched cards and their use in weaving machines.
I played with these transformations for creating the punched cards with the help of musician and composer BEilint TEirkEiny-KovEics as co-producer.
For her Soundweaving experiments, she has transferred folk embroidery patterns on to strips for a punched card box, which plays the traditional motifs as sounds - and the result is nothing less than music to the ears.
The insurance industry looks completely different than it did when policies were handwritten and information was collected on punched cards at the dawn of the 20th century.
The first tape drives implemented a 7-track recording format on an eight-inch diameter reel and had a linear recording density of 100 bits per inch and had a capacity of 1MB or the equivalent of 12,500 punched cards.
Data storage media have evolved from punched cards, punched paper tapes, magnetic drums, magnetic tapes and disks to today's technology--optical storage.
Punched cards were adopted in the 1820s by an eccentric genius named Charles Babbage, who hoped to use them to program a steam-driven mechanical computer.
Based on Babbage's idea, punched cards were adopted by Herman Hollerith to automate the 1890 U.
Magnetic disk storage made random access of data possible, allowing technological advances that were previously impossible with the old methods of using magnetic tape or punched cards.