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Addo

Addo and Addo-X

 

Anthea Agrell has kindly provided the following information about Addo:

"My grandfather, Hugo Agrell, founded Addo AB in Malmö, Sweden in 1918. My father took it to the US in 1950. As far as I know the company in the UK, in Cirencester, was a subsidiary of the Swedish company where my uncle became the MD.

What I do know with certainty is that my grandmother received the ceremonial keys to the town of Cirencester - where the factory which manufactured the machines was located - as a token of their enthusiasm that jobs were being created. I also remember the name of the British agents as being Ian Bulmer and his brother. They were located in London. I believe they did a pretty good job since as late as 1990 Addo-X's were still in use !"

Addo are mainly known for their mechanical calculators. The full-keyboard machines have the name Addo and the 10-key machines have the name Addo-X (X from the Roman numeral for 10, maybe).

Some electronic calculators under the Addo-X range were manufactured by Sharp in Japan, but a few models were made in Britain:

ADDO Mod 9

ADDO Mod 9

Addo Mod 9

Hand operated mechanical calculator.

Full-keyboard add-lister for the old sterling currency (£sd).

Intended for addition and subtraction with the result printed as a listing on the paper, though multiplication is posible using repeated addition.

Manufactured by Agrell.

Photographs kindly provided by David Edwards.

Keyboard

The Addo Mod 9 has 1/4, 1/2, and 3/4 keys for entering 1 farthing, 1 half-pence, and 3 farthings, respectively.

ADDO Mod 16

ADDO Mod 16

Addo Mod 16

Hand operated mechanical calculator.

Full-keyboard add-lister for the old sterling currency (£sd).

Intended for addition and subtraction with the result printed as a listing on the paper, though multiplication is posible using repeated addition.

Made in England by Agrell Manufacturing Co. Ltd.

Distributed by Bulmer's (Calculators) Ltd., 7-8 Poultry, London E.C.2.

Photograph kindly provided by Roger Bilder.

ADDO Sabatronic

ADDO Sabatronic

Addo Sabatronic

The magazine Office Methods & Machines of April 1967 has details of this machine being exhibited at the Business Efficiency Exhibition[1]:

"New.  Sabatronic electronic printing calculator with 20-digit capacity for addition, subtraction and multiplication and 19-digit capacity for division.  4 registers are flexible for constants and/or storage and back transfer is possible between all registers and keyboard.  Positioning of decimal point in print-out is automatic."

ADDO Ten/3

ADDO Sabatronic

Addo Ten/3

The magazine Office Methods & Machines of December 1968 had an article about this machine[2].  It is illuminating to see that it includes a description of how to use one of these new-fangled electronic calculators:

"Addo confidently expect their new Ten/3 electronic calculator, which uses large scale integrated circuitry to keep the price low and reliability high, to present a major threat to Japanese domination of this market.

Instead of writing a mathematical problem on paper, the problem is pressed out on keys in the same sequence and a series of calculations takes place in the machine.  When an equals key is pressed, the answer appears on the screen.  If a decimal point is involved, the machine places it in the correct position automatically.

... The new calculator, called the Addo Ten/3, was nicknamed SAM - Simple Applied Mathematics - by Addo and the General Intrument Co. (U.K.) Ltd. who pooled their expertise to perfect it.  General Instrument's major contribution was the large-scale integrated circuitry which has helped to keep down costs and improve reliability. ...

... The calculator is highly portable measuring only 240 x 320 x 135 mm and weighing 6Kg. ... The price is £360 [GBP] [about US$900] ... ."

 

Addo Ten/3 Mark II

In April 1970 the magazine Management in Action had an advertisement[2]:

"For £320 you can posses our new model.
This is Addo's new Ten/3 Mark II. Our very calculating model - comes electrified - with even more integrated circuits. An unfailing memory that doubles as a third register.  A ten digit display. And is British all over. ..."

ADDO-X 9354J

ADDO-X 9354J

Addo-X 9354J

Power source - AC.

Display is 8-digits, stylised green Vacuum Fluorescent Display (Itron VFD) tubes, with half-height zeros.

4-functions.

Main integrated circuits made by Rockwell, in this example date-coded to mid-1970.

245 x 132 x 70 mm. (9.6" x 5.2" x 2.75").

Made in Japan.

Manufactured by Sharp, and is a version of the Sharp QT-8D.

In May 1970 this model was advertised at a price of £199 (GBP)[3] [about US$500].

ADDO-X 9364

ADDO-X 9364

Addo-X 9364

Power source - rechargeable battery pack containing six AA cells.

Display is 8-digits, stylised green Vacuum Fluorescent Display (Itron VFD) tubes, with half-height zeros.

4-functions.

Main integrated circuits made by Rockwell, in this example date-coded to mid-1970.

245 x 132 x 70 mm. (9.6" x 5.2" x 2.75").

Made in Japan.

Made about 1970 by Sharp, and is a version of the Sharp QT-8D.

ADDO-X 9675

ADDO-X 9675

Addo-X 9675

Power source - AC.

Display is 10 digits, "Nixie"- type tubes.

4-functions, %, memory.

Main integrated circuits - Plessey 7-item chipset with MP931B, MP932B, MP933B, MP934B, MP935B, MP936B, MP937B.

275 x 197 x 97 mm (11.8" x 7.75" x 3.8").

Made in the United Kingdom.

Made about 1972.

Inside

Here the cover has been removed to reveal the "Nixie"-type tubes, with display-driver board behind under the power supply, and the main calculating board right underneath.

Main circuit board

The main calculating board with the 7-piece chip-set manufactured by Plessey.

This is one of the few calculator chip-sets manufactured by Plessey. It looks to be quite costly since it requires 7 ceramic encased integrated circuits. This calculator is believed to date from about 1972, and by then both Mostek and Texas Instruments were putting the electronics of a 4-function calculator in one small plastic encapsulated integrated circuit. So a chip-set like this would then not have been competitive.

Plessey was a major company in Britain involved in radio and television-chassis production, but is especially noted for being at the forefront of developments in electronic telephone exchanges throughout the 1960s, 1970s, and 1980s. It was taken over by GEC-Siemens in 1989.

References:

  1. Office Methods & Machines, April 1967, p33.
  2. Management in Action, April 1970.
  3. Management in Action, May 1970.

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© Text & photographs copyright Nigel Tout   2000-2017  except where noted otherwise.