Hand-held Calculators

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Commodore 776M & 796M

Examples of two typical low-cost, basic LED calculators of the mid-1970s from Commodore.

Commodore 776M

Commodore 776M

Commodore (cbm) 776M

Distinctive features: A popular, low-cost, basic calculator.

Technical details:
Display is 7 digits, red LED.

4-function, %, memory.

Main integrated circuit - Commodore GRBP-67, here dated 1975 week 45.

9v (PP3).

63 x 135 x 24 mm. (2.5" x 5.3" x 0.95").

1975.

Made in UK (though the circuit board is marked "Made in Japan").

Here the casing has been opened to reveal the circuit board with the LED display and just two integrated circuits, the Commodore GRBP-67 'calculator-on-a-chip' and the ITT 546A-5N display driver.

Commodore 796M

Commodore 796M

Commodore (cbm) 796M

Distinctive features: A popular, low-cost, basic calculator.

Technical details:
Display is 8 digits, red LED.

4-function, %, memory.

Integrated circuit - MOS MPS 7560 or Commodore 3D-98MT.

9v (PP3).

63 x 135 x 24 mm. (2.5" x 5.3" x 0.95").

1976.

Made in England and in Hong Kong  (though the circuit board is marked "Made in Japan").

A popular low-cost calculator, available in various colours.

Inside Commodore 796M

Here the case of the Commodore 796M has been opened to reveal the circuit board with just the single Commodore 3D-98MT integrated circuit which is able to directly drive the LED display.

Commodore (also known as Commodore Business Machines, cbm) sold mechanical adding machines in the late 1960s, and had early electronic calculators made for them (see Commodore C110). They started to manufacture calculators in the USA, UK, Japan and Hong Kong, and in 1976 took over the chip manufacturer MOS Technology Inc. of Pennsylvania, though also continued to subcontract designs around the world.
In the late 1970s Commodore left the calculator market, when prices and profits were very low, to concentrate on personal computers.

By 1975 the components required for a basic calculator with % and memory were minimal and mass produced so the cost was very low and this model was very popular.
There were other models, superficially similar but with different features and model numbers.

Hand-held Calculators

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2021  except where noted otherwise.