From The National Academy of Science:
The world’s first large-scale electronic computer, ENIAC — shorthand for Electronic Numerical Integrator and Computer — just turned 60. ENIAC was developed and built for the U.S. Army to calculate ballistic firing tables. It was unveiled on Feb. 14, 1946, at the University of Pennsylvania.
ENIAC was programmed and operated using punch cards, and the machine took up 1,800 square feet, weighed 30 tons, used 150 kilowatts of power, and contained 17,468 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors, and around 5 million hand-soldered joints. In one second, it could calculate 357 10-by-10 digit multiplication problems or 35 division or square root problems. It had less memory and processing power than a typical cell phone today.