punched card

[techspeak] (alt.: punch card ) The signature medium of computing's Stone
Age , now obsolescent. The punched card actually predated computers
considerably, originating in 1801 as a control device for mechanical looms.
The version patented by Hollerith and used with mechanical tabulating
machines in the 1890 U.S. 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 ,
code grinder.