Rockefeller Differential analyzer a one-hundred-ton machine with 2000 vacuum tubes and 150 motors, and weighed 100 tons It was an analog computer. An analog computer carries out an analogy of a real physical process It was invented 1942 (19 h 16 m, 26 nov 1860 ano – 14 h 5 m, 21 mar 1942 ano) (Linha do tempo)