IBM builds the Selective Sequence Electronic Calculator
27th January 1948
In January 1948, IBM's Selective Sequence Electronic Calculator (SSEC) becomes operational. The SSEC was the first computer that could modify a stored program.
IBM built the SECC at its Endicott, New York facility based on specifications provided by Professor Wallace Eckert.
The SSEC contained over 21,000 electromechanical relays and 12,000 vacuum tubes, and occupied a room room 60 feet long by 30 feet wide. Typical calculation times for the SSEC were as follows:
The machine was first demonstrated to the public on January 27, 1948. The first use of the SSEC was to calculate the positions of the Moon and other planets.
The SSEC was in operation until August 1952.