Eniac (Electronic Numerical Integrator and Computer)

(Detail Panel – 200 words)
ENIAC (Electronic Numerical Integrator and Computer)

1944 Moore School of Electrical Engineering, University of Pennslyvania, USA

ENIAC was originally designed to calculate firing tables for WWII artillery, but it wasn’t completed until 1946. Although the ENIAC was not finished in time for the war effort, it was used to do calculations for the hydrogen bomb as well as other classified military applications.

Photo Caption: The ENIAC at the Ballistics Research Laboratory. Presper Eckert at the Function table and John Mauchly watching the machine.

Photo Credit: Ballistics Research Laboratory.

With about 18,000 vacuum tubes, 1,500 relays, 70,000 resistors, and 10,000 capacitors, ENIAC was the largest electronic vacuum tube device to have been produced to that time. Consuming enough power for 50 homes and capable of 5,000 operations per second. The principal designers were J. Presper (Pres) Eckert and John Mauchly with Herman Goldstine acting as the Army liaison.

The ENIAC was not a stored program computer, but had to be rewired for each new job. The rewiring problem led the team to think about storing the wire configuration as a “program” in memory, but it was too late to change the design of the machine under construction.
The panel on exhibit here is one of 40 that make up the ENIAC. It was used to read the constants set on switches of the function units and transmit these along the data bus lines that ran around the whole of the machine. The function table was connected via the large plug receptacle on the front. In later years the function tables were changed to store simple read-only programs in addition to constants.
Until it was struck by lightening in 1955, ENIAC probably did more computation than had been done in all human history to that point.

Photo Caption: Women checking the plugboard wiring and switch settings on the function units of the ENIAC.

Photo Credit: Ballistics Research Laboratory.


Photo Caption: Herman Goldstine (left) and Prespert Eckert holding the electronics needed to store a single decimal digit.

Photo Credit: Ballistics Research Laboratory.