The University of Pennsylvania inaugurated the ENIAC (Electronic Numerical Integrator And Computer) on Feb 16th 1946. It is an electronic computer many times more complex than any previous. Eckert and Mauchly formulated the plans for the machine in 1943, and it runs its first trials in Nov 1945. It’s structure covers over 650 square feet, and had 300 neon lights. Built into a basement room, it had vacuum tubes that produced 150 kw of heat. This required the use of two twenty horsepower fans to help keep it cool! Everything about the machine is large, except the time it takes to compute. Performing 5,000 calculations per second, it’s a thousand times faster than the Harvard Mark I.
Developed and built by the U.S. Army for the Ballistics Research Laboratory, it was called Project PX and was commisioned on May 17th, 1943. It was built at the Moore School of Electrical Engineering at a cost of $500,000. It sported 17,468 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 capacitors and around 5 million hand-soldered joints. The ENIAC had to be rewired to run a new program. It operated continuously until October, 1955.