Vintage British Calculators



Rockwell International is a U.S. company.

Most Rockwell calculators were labelled "Assembled in Mexico.  U.S. and Foreign parts" or "Made in Hong Kong", but a few are found labelled "Made in Great Britain".

Models known to have been manufactured in Britain :-


Rockwell had bought the British calculator manufacturer Sumlock Anita Electronics Ltd. and the distributor Sumlock Comptometer in 1973.  The name of the distributor was changed to Sumlock Anita Ltd.

Some examples of some of the Rockwell models were manufactured at the Sumlock Anita Electronics factory at Portsmouth, Hampshire.  A company internal memo of October 1974[1] lists the Rockwell calculator models that the company will be dealing with after the takeover and says "For the first few months we will import machines from the U.S.A. but active steps are now being taken to ensure that production of this new calculator range will commence at Portsmouth early next year".

The journal 'Management in Action', in December 1974[2] reported on the Rockwell 'Answers' range of calculators:
Rockwell International, the firm which built America's Apollo moon rockets, is entering the British domestic market with a range of five calculators from a pocket model to advanced machines for engineers and scientists.  The company reckons it has worked out the answer to what prices the following people will pay: school-children doing sums; shoppers comparing prices and checking supermarket bills; housewives converting to metric for cooking, sewing and decorating measurements; holiday-makers checking currency; householders checking and saving on bills, HP interest, mortgage payments; college students doing maths, technical, engineering, professional or economic subjects; salesmen verifying quotations on the spot; shop-keepers calculating VAT; and businessmen budgeting.  The outcome is a new approach to the design and marketing of electronic calculators—the first of a new range of Rockwell consumer products that arrived in shops throughout Britain from the beginning of November.
    The machines are named Answers.  The company reckons to transform the rapidly developing calculator market by selling a full range of easily recognisable, reasonably priced machines, backed up with nationwide servicing.  Prices start at £16.95 including VAT, batteries and carrying case.  Rockwell International believes that in a few years' time calculators will be a normal part of every household, in general daily use like the telephone or television set.  Answers have been designed to meet the needs of various sections of the market from housewives and schoolboys to business executives.  For example, the tiny Answer 51R is a general-purpose calculator and an automatic converter from British to metric measurements, holiday currency conversions and sums involving fractions.  Available at Boots, Currys, Selfridges and other stores, it is being heavily promoted in time for Christmas.  The price is £55.95 including VAT.
    Answers will be manufactured at the Portsmouth, Hants, factory of Sumlock Anita Ltd, the British subsidiary of Rockwell.  All come with a one-year guarantee and are backed by full nation-wide after-sales service including local servicing in key major cities in addition to a centralised postal service depot in Hemel Hempstead."

The logo "Answer" was marked on the box but not on the calculator and may have been used just for the British market.


Rockwell also manufactured some models at the Portsmouth factory for House of Fraser, a British department store chain.  These can be found on the House of Fraser page.


  1. "Information Bulletin: Pre Product Release Information, Rockwell Consumer Range, 10R, 20R, 30R, 51R, 61R", Sumlock Comptometer Limited internal memo, section 1.0, 29th October 1974.
  2. "New Products: Answers", Management in Action, December 1974, p27.

Vintage British Calculators

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