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Sharp Compet CS-10A

Sharp Compet CS10A

Sharp CS-10A, owned by Sharp Corporation.

Sharp Compet CS-10A

The first Japanese all-transistorised desk calculator, 1964.

Display is "Nixie-type" tubes.

4 functions & memory.

This has some similarities to the early Anita machines, and like them it has a full-keyboard similar to a mechanical "Comptometer".

It uses 530 germanium transistors and 2300 diodes.

Size 420 x 440 x 250 mm (16.5" x 17.3" x 9.8"), 25Kg (55lbs).

Cost 535 thousand yen (about US$1,490, at exchange rate of $1=360 yen).

Very large, and very heavy !


The following details of the development of the CS-10A are based on information kindly provided by Sharp Corporation:

In the early 1960s several companies around the world started to investigate the possibilities of transistor-based electronic calculators, which would have the advantage of quietness, speed, and long life.  Among these companies was Sharp, where in 1960, a project team of computer engineers, headed by Atsushi Asada, started to design logic circuits using fairly substantial quantities of discrete components such as transistors, diodes, resistors, and capacitors.  At that time  germanium transistors, used for consumer products like radios, were much cheaper than silicon transistors, used for high-tech products like large computers, and hence Sharp engineers decided to adopt the former.

Although the Germanium transistors were prone to reliability problems and manufacturing difficulties, after four years' struggling with various technical difficulties the project team succeeded in the commercialisation of an all-transistor electronic calculator, the Sharp Compet CS-10A.  This was launched in 1964, and even though it cost 535,000 yen (equivalent to US$1,490; @ $1=360 yen), weighed 25 Kg (55 pounds), and consumed 90 Watts of power (using 530 transistors and 2,300 diodes), the demand for this calculator grew so rapidly that soon the monthly production of three hundred could not keep up with demand.

By chance, on the same day as Sharp launched the CS-10A, Sony Corporation released to the press a details of a prototype all-transistor calculator, but this did not come onto the market until 1967.  Later in 1964 the Japanese manufacturers Canon and Ohi Electric also launched all-transistor calculators.

For further information about Sharp Corporation and its calculators visit the Calculator Companies section of this site.

Sharp Compet CS10A

Sharp CS-10A, photographed at the Science Museum, London (Note, on subsequent visits to the museum this machine was no longer on display).
For further information on the National Museums of Science and Industry see

The Sharp CS-10A, introduced in July 1964, is a contender (together with the Friden 130, the IME 84, and the Mathatron) for the accolade of the first all-transistorised desktop calcutor.

Sharp were calculator pioneers, rapidly improving and miniaturising.  In 1969 it introduced the first calculator using Large Scale Integrated Circuits (LSI) (QT8-D), followed by one of the first battery portable calculators (QT8-B) and one of the first hand-held calculators (EL-8).
In December 2005 Sharp Corporation was awarded the IEEE Milestone in Electrical Engineering and Computing for its pioneering work on electronic calculators, 1964-1973, by the Institute of Electrical and Electronics Engineers of the U.S.A.


An article in the journal New Scientist in 1975 stated "The Anita machine [the ANITA Mk 8]  was built under licence by numerous foreign firms, including Olympia in the United States and Sharp in Japan"[1].
It is possible that this machine was a transistorised development of the ANITA Mk 8.



  1. "Coming of age in the calculator business", Nicholas Valéry, New Scientist Calculator Supplement, 13 November 1975, p[II].

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© Text & photographs copyright Nigel Tout   2000-2022  except where noted otherwise.