Vintage British Calculators



Decimo marketed a confusing number of similar and similarly named hand-held calculators.

Known Decimo calculators, pre-1980 :-

Mechanical Desk Calculators


Electronic Desk Calculators


Electronic Hand-held Calculators

Calculators supplied by Decimo to W.H. Smith, a British national chain of newsagent, book, stationery, and music stores.  See also the standard versions above:


Many Decimo calculators have 'Vatman' in their name.  Explanation of the significance of the name 'Vatman' -

      In April 1973, about the time that pocket calculators were becoming common, Purchase Tax was abolished in Britain, to be replaced by Value Added Tax (VAT).  Instead of being applied solely at the point of retail, this tax is applied at all points during the manufacture and distribution of most items when value is added to a product.

      As may be imagined, this caused great confusion and difficulties for many companies and stores, resulting in newspapers carrying many stories of raids by tax inspectors on those who had not paid their VAT properly.  The name which the popular newspapers have given to these despised inspectors is 'vatman', in headlines such as "The vatman demands unpaid tax of x0,000 from XYZ company or the owner will go to jail".

      So the name VATMAN on a calculator can give you an idea of what it will be useful for, and also makes you smile at its incongruousness.


Click on an image for a larger picture and technical details -

10-key add-lister


Decimo 2001-e
Decimo Handy M
Decimo Handy
Decimo Handy M
Decimo International (type 1)
Decimo International (type 2)
Memory Man
Memory Man II
Decimo Ready Reckoner
Decimo Strand Memory
Super Vatman
Super Vatman II
Super Vatman  M
Super Vatman  SSI
Super Vatman  SSII
Super Vatman  V.Sc. I
Vatman Boss

Vatman Executive (red LED and green VFD versions)

Vatman Executive
Vatman Executive
Vatman Executive
Vatman Extra M
Vatman Extra S
Vatman Mini
Vatman Mini II
Vatman Mini M
Vatman mini office

Vatman Popular

Vatman Popular
Vatman Scientific
Vatman Spy
Vatman Student
Vatman Super Spy
Vatman  V.Sc. II
Vatman  V.Sc. II

Vatman  X


Calculators supplied to W.H. Smith

Strand for W.H. Smith
Strand Memory for W.H. Smith

Information about Decimo Ltd.

Grateful thanks to Ian Travis for the following information about the company:

Decimo was founded by Douglas Dorsett in Luton, Bedfordshire, England.  The company  had about 50 employees and marketed a wide range of office products, apparently just in the UK.

Products included cash registers, photocopiers, dictating machines, electronic safes, electronic scales, and also some of the early digital watches (Blue Max).  If I remember correctly, a company called Phoenix in Japan was one of the main suppliers of calculators.

Douglas Dorsett semi-retired some time around 1990 and his son-in-law John Hadjipourou took over control.  However, although turnover was very large, revenue dropped, and the company closed down in about 1992.

Vintage British Calculators

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