IBM builds the Selective Sequence Electronic Calculator

27th January 1948
IBM builds the Selective Sequence Electronic Calculator

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:

  • 0.02 seconds for multiplication
  • 0.03 seconds for division
  • 0.2 milliseconds for addition or subtraction

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.

Related information:

Image:


 

 

 


 

IBM builds the Selective Sequence Electronic Calculator

Click on the Images
For Detail






 

Help support the museum by buying from the museum shop

View all items

Founding Sponsors
redgate Google ARM Real VNC Microsoft Research
Heritage Lottery Funded
Heritage Lottery Fund
Accredited Museum