The Sumlock Anita Comptometer was the world's first all-electronic calculator. It was developed by the Bell Punch Company, and the first models, the Mark VII and Mark VIII were both released in October 1961. The Mark VII was mostly sold in mainland Europe, while the Mark VIII was aimed at the British market. This example in our collection is the third model released, the Mark 9, which was introduced in 1964.

Development for the all-electronic calculator began in 1956, and was led by Norman Kitz. The Bell Punch Company, who were originally manufacturers of public transport ticketing machines, and later mechanical adding machines, had purchased the British rights to the Comptometer design and trademark in 1960. Kitz had written his dissertation in 1951 on automatic digital high-speed calculating machines, and had realised that the next important step in the development of the calculator was for it to become fully electronic. In 1956 Kitz had a chance meeting with some of the directors from Control Systems, the parent company of Bell Punch, and put forward his idea of an electronic calculator. The company had recently set up an electronics department, and asked Kitz to lead the development project.

The first prototype for the electronic calculator was ready by December 1958. Due to some running issues, the Mark VII was not ready for production until 1960. However the company's sales force believed the new skills required to operate the machine would cause confusion with the Sumlock operators. However, the export division did not see any issues with the machine, and the Mark VII was later launched at the Hamburg Business Equipment Fair in October 1961. Development had already begun on the Mark VIII and it was launched a week before the Mark VII at the 1961 Business Efficiency Exhibition in London, but orders were not being taken until January 1962. Despite initial manufacturing issues, the Anita calculators were the only all-electronic calculators for over two years and as a result were very popular, and sales were high.

Like the Mark VII and Mark VIII, the Mark 9 was a full-keyboard machine with a 12-digit Nixie tube display which used cold-cathode tubes, vacuum tubes, and a Dekatron decade counter. The Mark 9 is similar to the Mark VIII but with the additional capability of chain multiplication.

Manufacturer: Sumlock
Date: 1964

This exhibit has a reference ID of CH43909. Please quote this reference ID in any communication with the Centre for Computing History.

Click on the Image(s) For Detail