SEAC ("Standards Eastern Automatic Computer") (1950)

("Standards Eastern Automatic Computer") 1950

The National Bureau of Standards completed the SEAC in April 1950. Some of the design of the SEAC (also known as the "Standards Electronic Automatic Computer") was based on the EDVAC computer, which was built at the Moore School of Engineering at the University of Pennsylvania.

The SEAC utilized sixty-four mercury filled glass tubes with a quartz crystal at each end. One crystal was used as a transmitter and one as a receiver in this acoustic delay line memory storage unit. The acoustic delay line had a capacity of eight words. Information traveled in the form of sound waves through the mercury in the tubes.

The SEAC was the only fully functional computer available to the NBS and other government agencies in 1950. Demands on it were very high, and it was in operation 24 hours a day, 7 days per week. In a given month, the SEAC would be used to solve more than 50 different unrelated scientific problems for a variety of users.

In addition to NBS staff and staff from other government agencies, private universities and laboratories would also make use of the SEAC's computing ability. In order to monitor the operation of the computer, its operators connected an amplifier and speakers to one of the machine's registers.

The SEAC operators could tell from any change in the SEAC's familiar operating sounds if there was a malfunction in the computer. Samuel N. Alexander was chief of the NBS section that produced the SEAC. He later became Chief of the NBS Information Technology Division. John Todd was chief of the Computation Section when the SEAC came on line. Some of the others involved in the SEAC project or in later improvements to the design are listed in the following table provided by the U.S. Government's Institute of Standards and Technology.

(Other SEAC photos below.) See also the other NBS computer, the SWAC 1950.

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