What Happened on May 17th
ENIAC (Electronic Numerical Integrator And Computer), an early all-electronic computing system, was developed and built by the US Army for its Ballistics Research Laboratory. It was the first system to use vacuum tubes rather than electromagnetic switches. Its purpose was to calculate ballistic firing tables. ENIAC was designed by J. Presper Eckert and John William Mauchly of the University of Pennsylvania. Constructed at that university’s Moore School of Electrical Engineering, when first commissioned, the computer was known as Project PX. It cost almost $500,000 at the time. Unveiled on February 14, 1946, it operated until November 9, 1946. It was then refurbished, given a memory upgrade, and transferred to the Aberdeen Proving Grounds, Maryland, in 1947. On July 29th it was turned on again and ran continuously until 1955.