This section contains 1,284 words (approx. 5 pages at 300 words per page) |
Tabulating machines, or punched card machines, were the earliest automated data processing devices. They include keypunch machines, collators, sorters, reproducers, and tabulators. By the late 1980s, virtually all tabulating machines had been replaced by digital computer systems.
A keypunch machine was a data entry device that punched holes in a lightweight piece of cardboard. A deck of blank cards was placed in a hopper. A keypunch operator signaled a punched card to be loaded into the punching station of the machine. As the operator typed on a keyboard, a series of dies punched predefined holes in the selected card column. One or more holes in a vertical column represented one character.
Earliest Punched Card Machines
The first machine to use punched cards was a loom designed in 1801 by a French weaver named Joseph-Marie Jacquard (1752–1834). It used punched holes in a card to direct the...
This section contains 1,284 words (approx. 5 pages at 300 words per page) |