ILLIAC - ILLIAC I

ILLIAC I

ILLIAC I was built at the University of Illinois based on the same design as the ORDVAC. It was the first von Neumann architecture computer built and owned by an American university. It was put into service on September 22, 1952.

ILLIAC I was built with 2,800 vacuum tubes and weighed about 5 tons. By 1956 it had gained more computing power than all computers in Bell Labs combined. Data was represented in 40-bit words, of which 1024 could be stored in the main memory, and 12800 on drum memory.

Immediately after the 1957 launch of Sputnik, the ILLIAC I was used to calculate an ephemeris of the satellite's orbit, later published in Nature.

ILLIAC I was decommissioned in 1963 when ILLIAC II (see below) became operational.