The Anita 811 was the first Anita hand-held electronic calculator, and was introduced in 1972. The Anita range of calculators had begun in 1961 with the Anita Mark VII and Mark VIII, which were the first all-electronic desktop calculators.

The Anita 811 was a four-function calculator with additional % and memory functions. It featured the Rockwell A1030PE integrated circuit and had an eight-digit red LED screen. The calculator was powered by three AA batteries, which could be either rechargeable or disposable, or mains power supply. The middle switch with the semi-circle icon allows you to switch between full floating decimal point or rounding your answer to two decimal places.

The calculator's operation is a little odd by modern standards as it operates a partial version of reverse polish notation (RPN). When adding and subtracting, the numbers are keyed in as you would with a RPN calculator. However when multiplying or dividing, it acts more like a modern calculator, and the equals key is used.

Versions of this calculator were also supplied to the Litton Industries subsidiary TA Vertriebs, of Germany, as its Adler 81 and Triumph 81 models.

When released in 1973 it originally sold for £75 (£760 in March 2023). 

Manufacturer: Sumlock Comptometer Ltd
Date: 1972

This exhibit has a reference ID of CH31305. Please quote this reference ID in any communication with the Centre for Computing History.

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