Historical information
This IBM card format, designed in 1928, had rectangular holes, 80 columns with 12 punch locations each, one character to each column. Card size was exactly 7-3/8 inch by 3-1/4 inch (187.325 by 82.55 mm). The cards were made of smooth stock, 0.007 inch (0.178 mm) thick. There are about 143 cards to the inch. In 1964, IBM changed from square to round corners. They came typically in boxes of 2000 cards.[20] (Reference and more information at http://en.wikipedia.org/wiki/Punched_card )
Early digital computers used punched cards, often prepared using keypunch machines, as the primary medium for input of both computer programs and data. (http://en.wikipedia.org/wiki/Punched_card)
Physical description
Yellow card with printed numbers. Used for feeding information into a computer.
