Punch Cards - Herman Hollerith

Modern data processing began with the inventions of American engineer, Herman Hollerith.

In 1881, Herman Hollerith began designing a machine to tabulate census data more efficiently than by traditional hand methods. The U.S. Census Bureau had taken eight years to complete the 1880 census, and it was feared that the 1890 census would take even longer. Herman Hollerith invented and used a punched card device to help analyze the 1890 US census data. Herman Hollerith's great breakthrough was his use of electricity to read, count, and sort punched cards whose holes represented data gathered by the census-takers. His machines were used for the 1890 census and accomplished in one year what would have taken nearly ten years of hand tabulating. In 1896, Herman Hollerith founded the Tabulating Machine Company to sell his invention, the Company became part of IBM in 1924.



Herman Hollerith first got his idea for the punch-card tabulation machine from watching a train conductor punch tickets. For his tabulation machine he used the punchcard invented in the early 1800s, by a French silk weaver called Joseph-Marie Jacquard. Jacquard invented a way of automatically controlling the warp and weft threads on a silk loom by recording patterns of holes in a string of cards.

Hollerith's punch cards and tabulating machines were a step toward automated computation. His device could automatically read information which had been punched onto card. He got the idea and then saw Jacquard's punchcard. Punch card technology was used in computers up until the late 1970s. Computer "punched cards" were read electronically, the cards moved between brass rods, and the holes in the cards, created a electric current where the rods would touch.

Note: A chad is the small piece of paper or cardboard produced in punching paper tape or data cards; also can be called a piece of chad. The term originated in 1947 and is of unknown origin. In laymen's terms chad is the punched out parts of the card - the holes.