The Jacquard Loom was a mechanical loom for cloth weaving, first demonstrated by Joseph Marie Jacquard in 1801. It used a chain of punched cards laced together to allow the loom to create complex patterns.
Any number of the cards could be chained together into a continuous sequence, with each card corresponding to one row of the design. Each position on the card corresponds to a ‘Bolus’ hook which can either be raised or stopped dependent on whether the hole is punched out of the position on the card or not. The hook raises or lowers the harness, which carries and guides the warp thread so that the weft will either lie above or below it.
Modern Jacquard looms are controlled by computers in place of the original punched cards, and can have thousands of hooks.
Charles Babbage was aware of Jacquard loom cards, and planned to use cards to store programs in his Analytical engine, first described in 1837. Later in the 19th Century, Herman Hollerith used the idea of storing information on cards to create the punched card tabulating machine which he used to input data for the 1890 US Census.