There are two known versions of casing for the Sinclair Executive calculator with different keyboard markings. Type 1 has a K (constant) two-way switch, rather than the button on the Type 2 version. On the Type 1 there is a decimal point switch on the right side of the calculator, which allows you to choose between Floating, 2, 3 and 4 decimal places, while the Type 2 is constantly set to floating point.

There are also at least five known variations of the Type 1 Executive calculator, including differences in LED display size, number of batteries required, and the chip. This board in our collection has the large LED display, a TMS 0103NC chip, and space for three button cells. The IC is date marked from week 5, 1972.

The Sinclair Executive calculator was the world's first slimline pocket calculator. It was released in 1972 and cost £79.95 +VAT. It was one third the size of any of its competitors in 1972 as it featured TI's new "calculator-on-a-chip" IC, and cost half as much. The calculator won a Design Council Award for Electronics in 1973.

Manufacturer: Sinclair Radionics
Date: 1972

This exhibit has a reference ID of CH70707. Please quote this reference ID in any communication with the Centre for Computing History.

Click on the Image(s) For Detail