Computer science development of sophisticated computing equipment. Wilhelm Schickard designed and constructed the first working mechanical calculator in 1623. In 1673, Gottfried Leibniz demonstrated a digital mechanical calculator, called the Stepped Reckoner. He may be considered the first computer scientist and information theorist, for, among other reasons, documenting the binary number system. In 1820, Thomas de Colmar launched the mechanical calculator industry when he released his simplified arithmometer, which was the first calculating machine strong enough and reliable enough to be used daily in an office environment. Charles Babbage started the design of the first "automatic mechanical calculator", his Difference Engine, in
History of computing The 1937 Atanasoff–Berry computer design was the first digital electronic computer (though not programmable), and the Z3 computer from 1941, by German inventor Konrad Zuse was the first working programmable, fully automatic computing machine. Alan Turing modelled computation in terms of a one-dimensional storage tape, leading to the idea of the Turing machine and Turing-complete programming systems. During World War II, ballistics computing was done by women, who were hired as "computers." The term computer remained one that referred to mostly women (now seen as "operator") until 1945, after which it took on the modern definition of machinery it presently