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Busicom Corp
Nippon Calculating Machine Corp

Business Computer Corporation (Busicom Corp.), Osaka and Tokyo, Japan.

Originally the Nippon Calculating Machine Corporation (NCM), the name was changed to Busicom Corp. (Business Computer Corporation) in the late 1960s.
Busicom was a very technically progressive company, and was involved with Intel in the development of the Intel 4004, the first commercial microprocessor, for use in calculators.

Busicom also produced one of the first hand-held calculators, the Busicom LE-120A, which is small enough to be called the first pocket calculator.  This made use of the Mostek MK6010 integrated circuit, which was the first "calculator on a chip", which was developed by Mostek and Busicom.  The company also made prototypes of an LCD display version of this calculator, which would have been the first LCD calculator, but there were worries about the life of the liquid crystal and it never went into production.

Unfortunately the company's business acumen was not as advanced as its technology, and with the intense competition in the calculator industry it got into financial difficulties and ceased production in early 1974[1].  However the rights to the Busicom name were bought by Broughton's of Bristol in Britain and calculators with the Busicom label, produced by different manufacturers, continue to be marketed.

See the article "Busicom of Japan and Broughtons of Bristol: Pioneering calculator company and the company which carries on the name" in the Collecting Calculators section of this site, and the Broughtons of Bristol section of the associated British Vintage Calculators site for later calculator models under the Busicom name distributed by Broughtons.

Some Busicom calculators were labelled for sale by other companies, including NCR (National Cash Register) of the U.S.A. and Privileg of Germany.

Examples of Busicom and Nippon Calculating Machine calculators

NCM/Busicom HL21


NCM/Busicom HL21.

This mechanical, pin-wheel, calculator can be found with both an NCM label and a Busicom label.

Dating from the 1960s, this is a featured calculator on this site.

Busicom Junior / NCR 18-16

NCR 18-16 (Busicom Junior)

Busicom Junior / NCR 18-16

This version of the Busicom Junior, which was launched in late 1970/early 1971, was the first calculator to use a single 'Calculator on a Chip', the Mostek MK-6010 LSI (Large Scale Integration) chip.

The Busicom Junior was also sold by National Cash Register, as shown here, as the NCR 18-16.

This is a featured calculator on this site.


Inside, showing the Mostek MK-6010 'Calculator on a Chip'.

Busicom LE-120A 'HANDY-LE'

Busicom LE-120S “handy”

Busicom LE-120A 'HANDY-LE'.

This highly innovative calculator claims several firsts:

  • The first pocket-sized calculator.
  • The first calculator to use an LED display.
  • The first hand-held calculator to use a 'calculator on a chip' integrated circuit.

It was the first of a range of similar calculators introduced by Busicom in January 1971.

This is a featured calculator on this site.


Inside the Busicom LE-120A showing the innovative use of the Mostek MK6010 'calculator on a chip' and the LED display modules.

Busicom LE-80A 'handy'

Busicom LE-80A “handy”

Busicom LE-80A 'handy'.

This incredibly tiny calculator for the year (~1972) was developed by limiting the display to 8 LED digits and using four size N batteries (half the size of AA cells).  It measures 55x81x21 mm (2.2"x 3.2"x 0.8").

This is a featured calculator.

Busicom 141-PF / NCR 18-36

Busicom 141-PF / NCR 18-16

Here shown badged for NCR as its 18-36, the Busicom 141-PF was the first commercial product to incorporate a microprocessor, the Intel 4004.  It dates from 1971.

This is a featured calculator.

The circuit board of the Busicom 141-PF.
The integrated circuits of the MCS-4 chipset used here are:

The fascinating story of the development of the microprocessor for this calculator is told in The calculator that spawned the microprocessor on this site.

Busicom 'exec' 80-DA

Busicom “exec” 80-DA

Busicom 'exec' 80-DA

Dating from about 1972 this small desktop calculator has a flip-up display cover and a pull out carrying handle.


Inside is a Texas Instruments TMS 0105BNC 'calculator on a chip'.

Busicom PA-80S

Busicom PA-80S

Busicom PA-80S

This tiny calculator under the Busicom name is reminiscent of the Busicom LE-80A, above.

However, since the integrated circuit in this example is date-coded 1975, which is after the Japanese Busicom company had ceased trading, it appears to be from another manufacturer and labelled Busicom, probably by the U.S. distributor.  The same calculator is also found under the names Pico PA 90D and Vista Z48P.

Busicom/Colex 812-SL

BusicomColex 812SL

Busicom-Colex 812-SL

This is a Colex 812-SL calculator, made in Hong Kong, with a Busicom label simply stuck on the front.  There is another label on the back indicating that it is distributed by Broughtons of Bristol, in the UK, after it had acquired the rights to the Busicom name in Britain.

Further photographs can be found on this site of:



  1. Milton, R., Beaumont, A.J. (1974), Electronic Calculator Markets and Suppliers, 2nd. ed., Finresearch Series, London: Ovum, 5.

Vintage Calculators

Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.