75 years of the ENIAC

February 15, 2021 marks the 75th anniversary of the dedication of the Electronic Numerical Integrator and Computer (ENIAC), which is generally regarded as the first general-purpose electronic digital computer capable of being reprogrammed to solve a range of computing problems. This notable date is commemorated at the ENIAC Day website.

The development of the ENIAC was financed by the U.S. Army as a secret project during World War II. Its purpose was to solve the differential equations that described the trajectory of a shell in flight, electronically and with unprecedented speed.

The ENIAC was designed and constructed at the University of Pennsylvania between 1943 and 1946 and was officially unveiled to the public on February 14, 1946. Press releases from the War Department and articles that appeared in popular magazines, such as Newsweek, attest to the widespread attention that the ENIAC received upon its public dedication.

Not mentioned at the unveiling event was the team of six women who, having previously functioned as human “computers,” became the behind-the-scenes experts in charge of configuring and wiring the machine to perform specific computations, handling the punch card equipment, and debugging its operations.

The ENIAC was conceived and designed by John Mauchly and J. Presper Eckert of the University of Pennsylvania. The team of design engineers assisting the development included Arthur Burks, who received his Ph.D. from the University of Michigan in 1941. Burks later joined the faculty at Michigan, where he cofounded the graduate program in computing in 1957 and the Department of Computer and Communication Sciences in 1965. He also served as the first chair of the department.

The ENIAC added and subtracted 10 decimal digit numbers in 1/5000 second, and multiplied numbers in 1/400 second. Besides its speed, the most remarkable thing about ENIAC was its size and complexity. ENIAC was composed of 40 panels 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. It weighed more than 27 tons, took up 1800 square feet, and consumed 150 kW of power. It operated until 1957.

Today, CSE hosts the third largest standing display of the ENIAC. This display includes four of the ENIAC’s original 40 panels. Other displays of significance are located at the US Army Field Artillery Museum and at the University of Pennsylvania. The Smithsonian has also preserved portions of the ENIAC, some of which are on loan to other institutions.

The panels in CSE’s display were reassembled at the University of Michigan in 1964 and were moved to the Bob and Betty Beyster Building in January 2006. The CSE Division is grateful to the late Professor Emeritus Arthur Burks, who passed away on May 14, 2008, for having procured and retained these ENIAC components, selected by him to capture the essence of that revolutionary machine.