Sharp Compet CS-10A Electronic Calculator

In 1964 the Japanese firm of Hayakawa Electric (later Sharp Corporation) announced the Compet CS-10A, its first electronic calculator. This is an example of the device.
The heavy full-keyboard, non-printing calculator has a metal case; ten columns of gray and white plastic keys; and keys for the arithmetic functions, equality, and clearance. The result register has 21 tubes and is covered with glass. Eleven dials and a red button stretch across the front. The cover is missing on the base.
A mark on the front of the calculator above the register reads: SHARP COMPET. A mark to the right of this reads: CS-10A. A metal tag on the back reads in part: SHARP COMPET (/) MODEL CS-10A. It also reads in part: SERIAL NO. 86314 (/) HAYAKAWA ELECTRIC CO., LTD.
According to Atsushi Asada, who led the team at Hayakawa Electric that developed the instrument, it included germanium transistors built by NEC and Hitachi instead of vacuum tubes. Circuits also used diodes. Early versions of the calculator had a total of some 5,000 components. The instrument was announced on the same day that Sony announced plans to sell a calculator using transistors (May 14, 1964). Sharp would go on to make much smaller and lighter electronic calculators.
Accession file.
Another example of the calculator is shown at the Vintage Calculators Web Museum at
Currently not on view
date made
ca 1964
Sharp Corporation
place made
Physical Description
metal (case material)
plastic (keys material)
glass (display material)
overall: 10 1/2 in x 17 in x 18 in; 26.67 cm x 43.18 cm x 45.72 cm
ID Number
catalog number
accession number
Credit Line
Sharp Corporation
See more items in
Medicine and Science: Computers
Desktop Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


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