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
Digital electronic computer machines for computation and communicating using natural language. A digital computer can perform its operations in the decimal system, in binary, in ternary or in other numeral systems. As of 2014, all digital electronic computers commonly used, whether personal computers or supercomputers, are working in the binary number system and also use binary logic. A few ternary computers using ternary logic were built mainly in the Soviet Union as research projects. A digital electronic computer is not necessarily a transistorized computer: before the advent of the transistor, computers used vacuum tubes. The transistor enabled electronic computers to become much more