ENIAC
The first large general-purpose electronic computer in the United States, built to calculate artillery firing tables for the US Army.
ENIAC, the Electronic Numerical Integrator and Computer, was built at the University of Pennsylvania's Moore School of Electrical Engineering for the US Army Ordnance Department. J. Presper Eckert was chief engineer and John Mauchly led the concept. Work began in 1943. The machine ran its first problems in late 1945 and was dedicated to the public in February 1946.
ENIAC had no stored program. Programmers set switches and plugged cables to wire a problem into the machine, a job that could take days. Six women, Kay McNulty, Betty Jennings, Betty Snyder, Marlyn Wescoff, Fran Bilas and Ruth Lichterman, were the first programmers. They learned the machine from its wiring diagrams. Later changes in 1948 let it run from a stored table of instructions.
Why it matters
ENIAC proved that a large electronic computer could work, and it ran about a thousand times faster than the electromechanical machines that came before. Its design problems led directly to the stored-program EDVAC design and to the early commercial computers that followed.
Key facts
- About 17,500 vacuum tubes and around 5 million hand-soldered joints.
- Weighed about 30 tons and filled about 1,800 square feet.
- Performed roughly 5,000 additions per second.
- Six women programmed it, often without credit at the time.
- Decommissioned in October 1955.
Sources
- Campbell-Kelly, Martin, and William Aspray, et al. Computer: A History of the Information Machine. 3rd ed. Westview Press, 2013.
- McCartney, Scott. ENIAC: The Triumphs and Tragedies of the World's First Computer. Walker, 1999.
- Fritz, W. Barkley. "The Women of ENIAC." IEEE Annals of the History of Computing 18, no. 3 (1996).