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Bell Punch / Sumlock / Anita

Bell Punch Company
Also Anita, Sumlock-Anita, Sumlock-Comptometer.

The Island, Uxbridge, Middlesex, UK.

The story of Bell Punch Co. and its associate companies, Control Systems, Sumlock Comptometer, Sumlock Anita, and the development of the first electronic desktop calculators is very complicated and is covered in the article Anita: the world's first electronic desktop calculator: A brief history of the complex Bell Punch company and its calculators on this site, and a full history is given in the sister site to this one,  "Bell Punch Company and the ANITA calculators".

Summary of the history of the Bell Punch Co., Sumlock, and Anita.

  • 1878 - Bell Punch Co., Limited, was established in London as a manufacturer of ticket punches for buses and trams.
  • July 1927 - Control Systems, Limited, was incorporated, as a holding company for the purpose of acquiring and consolidating the direction of the growing diverse activities of the Bell Punch Co.
  • Late 1930s - Bell Punch introduces its first mechanical calculator, the Plus Adder, which resembles a cut-down "Comptometer".
  • Early 1940s - London Computator, Limited, was incorporated to deal with the sales and distribution of the mechanical calculators manufactured by Bell Punch Co.
  • December 1957 - Lamson Industries acquired a controlling interest in Control Systems, and so its subsidiaries.
  • 1961 - Sumlock Comptometer Ltd formed from the amalgamation of the British operation of Comptometer Corporation of Chicago, U.S.A., with the calculator operation of Bell Punch Co.
  • 1961 - The Anita Mk VII and the Anita Mk 8 were launched as the world's first electronic desktop calculators.
  • 1966 - Sumlock Anita Electronics Ltd. was formed to take over the Bell Punch Co.'s former activities in the field of calculating machines. These were still distributed in Britain by Sumlock Comptometer Ltd.
  • 1973 - Rockwell International of the U.S.A. buys Sumlock Anita Electronics from Lamson Industries. The Bell Punch Co. continues manufacturing and selling its other products, such as taximeters.
  • About 1976 - Rockwell exits the calculator business. The rights to use the Sumlock Anita name were sold off and the name eventually disappears.
  • About 1986 - The Bell Punch Co. was broken up.


Examples of Bell Punch and Anita calculators

Plus Adder

Plus 509/D.

This "adder" is a "Comptometer" type machine and has an abbreviated keyboard. To enter a value greater than 5 in any column, you have to press one key and then another which add up to the required value.

Bell Punch started to manufacture machines similar to this in the late 1930s. The design was developed over the years and machines like this were made from the late 1950s to the early 1970s.

This calculator is featured on the Anita calculators site.

Sumlock Sterling currency (£sd) calculator

Sumlock 912/S.

This is a "Comptometer" type machine and has keyboards and mechanism for calculations with the old Sterling currency (£sd).

This calculator is featured on the Anita calculators site.

Sumlock 993s Comptometer

Comptometer 993s.

This Comptometer was made after Bell Punch took over the British rights to the Comptometer name. It is electrically driven and has storage register (similar to a memory).

This calculator is featured on the Anita calculators site.

Anita Mk VIII

Anita Mk 8.

This machine and the Anita Mk VII, which were introduced in late 1961, were the world's first electronic desktop calculators. It uses a Dekatron, cold-cathode, and thermionic tubes.

This is a featured calculator.

Anita 1011

Anita 1011.

Introduced in 1969, this model uses a mixture of integrated circuits and discrete transistors.

This is a featured calculator.

Anita 1011 LSI.

Anita 1011 LSI.

The distinctively styled LSI series was launched in 1971, and, as the name implies, uses Large-Scale Integration integrated circuits.

This is a featured calculator.

Anita 811

Anita 811.

This was the first hand-held calculator made by Sumlock-Anita Electronics, and was introduced in 1972.

This calculator is featured on the Anita calculators site.

Rockwell-Anita 1211

Rockwell-Anita 1211.

This desktop model dates from the mid-1970s, after Anita had been taken over by Rockwell.

This calculator is featured on the Anita calculators site.

Sumlock Compucorp 324G Scientist

Sumlock Compucorp 324G Scientist.

To fill gaps in its product range, Sumlock Anita sold a small number of models made by other companies, such as this Compucorp 324G. Often, as here, the Sumlock name was included on the label.

This is a featured calculator.

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