Prehistory: 1906--1947
1906: Lee De Forest invents vacuum tube
1946: J. Presper Eckert and John Mauchly at U Pennsylvania invent ENIAC: boxcar size, 30 tons, 18,000 vacuum tubes, 150kW, computing power of 100 humans
1947: John Bardeen, William Shockley, and Walter Brattain invent transistor at Bell Labs