page_title: History of computing hardware
section_title: Punched-card data processing
hierarchical_section_title: History of computing hardware / Early devices / Punched-card data processing
caption_attribution_description: English: A scene from the U.S. Social Security Administration (SSA)'s early accounting operations in Baltimore circa 1936. The issuing of Social Security numbers and the creation of earnings records on all Americans covered by Social Security was the largest bookkeeping operation in the history of the world.
context_page_description: The history of computing hardware covers the developments from early simple devices to aid calculation to modern day computers. Before the 20th century, most calculations were done by humans. Early mechanical tools to help humans with digital calculations, like the abacus, were referred to as calculating machines or calculators. The machine operator was called the computer.
  The first aids to computation were purely mechanical devices which required the operator to set up the initial values of an elementary arithmetic operation, then manipulate the device to obtain the result. Later, computers represented numbers in a continuous form. Numbers could also be represented in the form of digits, automatically manipulated by a mechanism. Although this approach generally required more complex mechanisms, it greatly increased the precision of results. The development of transistor technology and then the integrated circuit chip led to a series of breakthroughs, starting with transistor computers and then integrated circuit computers, causing digital computers to largely replace analog computers.
context_section_description: In 1804, French weaver Joseph Marie Jacquard developed a loom in which the pattern being woven was controlled by a paper tape constructed from punched cards. The paper tape could be changed without changing the mechanical design of the loom. This was a landmark achievement in programmability. His machine was an improvement over similar weaving looms. Punched cards were preceded by punch bands, as in the machine proposed by Basile Bouchon. These bands would inspire information recording for automatic pianos and more recently numerical control machine tools.
  In the late 1880s, the American Herman Hollerith invented data storage on punched cards that could then be read by a machine. To process these punched cards, he invented the tabulator and the keypunch machine. His machines used electromechanical relays and counters.  Hollerith's method was used in the 1890 United States Census.  That census was processed two years faster than the prior census had been. Hollerith's company eventually became the core of IBM.
  By 1920, electromechanical tabulating machines could add, subtract, and print accumulated totals. Machine functions were directed  by inserting dozens of wire jumpers into removable control panels. When the United States instituted Social Security in 1935, IBM punched-card systems were used to process records of 26 million workers. Punched cards became ubiquitous in industry and government for accounting and administration.
  Leslie Comrie's articles on punched-card methods and W. J. Eckert's publication of Punched Card Methods in Scientific Computation in 1940, described punched-card techniques sufficiently advanced to solve some differential equations or perform multiplication and division using floating point representations, all on punched cards and unit record machines. Such machines were used during World War II for cryptographic statistical processing, as well as a vast number of administrative uses. The Astronomical Computing Bureau, Columbia University, performed astronomical calculations representing the state of the art in computing.
caption: IBM punched-card accounting machines, 1936
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