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Sinclair Enterprise

Sincalir Enterprise calculator

Sinclair Enterprise.

Display is 8 digits, red LED.

4 functions, %, memory, square root.

9v (PP3 battery).

Integrated circuit - General Instruments C689G, here date coded mid 1977.

Made in England.


Notice the large size of the LED digits, which are among the biggest used on a hand-held calculator. By this late date the cost of LEDs had fallen considerably and large digits were cheaply available. They are further enhanced by the magnifying lenses in front, a common feature. Compare the display on this Sinclair Enterprise with the Enterprise Programmable which has the usual size LED digits.

New Scientist Magazine reported[1]:
"Customers like them big and red
The large, red display (the characters are nearly 6 mm high) on the latest Sinclair calculator may not look modern but the customers shoul be happy enough: both the display of the new "Enterprise" machine and the simplified keyboard are the result of market research. The study found that users do not like liquid-crystal displays (LCDs), and have previously bought green displays in large quantities because they had bigger digits - everything being equal most buyers would have preferred a red display. Most of those questioned eschewed even the prime advantage of LCDs - their long battery life - in favour of a brighter display."

Sincalir Enterprise calculator without cover

Unusually, like it's stablemate, the Enterprise Programmable, the whole of the front cover unclips to replace the battery.


With the keyboard removed, showing the larger than normal magnifying lens array in front of the LED digits.

The General Instruments C689G integrated circuit.


  1. "Customers like them big and red", New Scientist, 6th October 1977, p8.

Vintage British Calculators

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