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
Marconi Transistorised Automatic Computer (T.A.C.) Marconi Transistorised Automatic Computer (T.A.C.) The Marconi Transistorized Automatic Computer was Marconi Company's first computer, designed and manufactured from around 1959. They employed Germanium transistors which by this time were sufficiently reliable with room temperatures kept below about 23 degrees C. Apart from transistor failure other common faults included Power Supply capacitors 'drying out' resulting in excess ripple and poor connections on the computer input output highway. Paper tape peripherals had their own poor reliability influenced by degree of operator usage. The type S3301 was a 500 kHz clocked 20 bit word machine with two Mullard core memory stores providing