Philadelphia City Council has officially declared Feb. 15 as “ENIAC Day,” celebrating the 65th anniversary of the historic computer’s dedication at Penn, and the beginning of the digital age that it helped to usher in.  

The Electronic Numerical Integrator and Computer, or ENIAC, was built to calculate ballistic trajectories for the Army during World War II, a time- and labor-intensive process that had previously been performed by teams of mathematicians working with mechanical calculators.

Under the direction of John Mauchly and J. Presper Eckert of Penn’s Moore School of Electrical Engineering (now the School of Engineering and Applied Science), construction of the 27-ton, 680-square-foot computer began in July 1943 and was announced to the public on Feb. 14, 1946.

As the first electronic general-purpose computer, ENIAC was a major step forward from its technological predecessors: calculating machines that had their roots in ancient math tools like the abacus.

ENIAC was electronic in that it stored numeric information as electrons in vacuum tubes, and was a computer in that it could be programmed to do any sort of calculation. Programming was done manually, by rearranging the wires that connected its various calculating components in a series of complicated steps.

Notably, the six original programmers, or “computers” as they were then called, were all women. In one of the only scientific fields that has seen an increase in gender disparity over the last two decades, Betty Snyder Holberton, Jean Jennings Bartik, Kathleen McNulty Mauchly Antonelli, Marlyn Wescoff Meltzer, Ruth Lichterman Teitelbaum and Frances Bilas Spence continued the pioneering tradition of Ada Lovelace, who wrote the first algorithm for Charles Babbage’s mechanical analytical engine and is considered to be the first computer programmer.

John Mauchly and Presper Eckert went on to found the first computer company, the Eckert–Mauchly Computer Corporation, and ENIAC served as an archetype for the room-filling vacuum-tube computers that immediately followed it, as well as the silicon microprocessors that can be found in almost every modern electronic device.

For ENIAC’s 50th anniversary, students working under Penn Engineering’s Jan van der Spiegel demonstrated just how far computers have come by replicating ENIAC’s design and functionality on a computer chip less than a tenth of the size of a postage stamp.

For more information on ENIAC, visit Penn Engineering’s ENIAC Museum at www.seas.upenn.edu/about-seas/eniac.