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

Known Decimo calculators  :-

Mechanical Desk Calculators


Electronic Desk Calculators


Electronic Hand-held Calculators

Supplied to other companies:

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

International - 2 models

Decimo International (type 1)
Decimo International (type 2)
Memory Man
Memory Man 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 Popular
Vatman Scientific
Vatman Spy
Vatman Student
Vatman Super Spy
Vatman  V.Sc. II
Vatman  V.Sc. II

Vatman  X


Supplied to other companies

Strand Memory

Strand Memory

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, and the newspapers carried 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.


Decimo Ltd.

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). Many of the electronic calculators were manufactured by Phoenix in Japan.

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.

Grateful thanks to Ian Travis for information about the company.

Vintage Calculators

© Text & photographs copyright Nigel Tout   2000-2018  except where noted otherwise.