ADDO X SERIES 20

The Addo X Series 20 is a calculator invented by the swedish company Addo AB.
The Addo calculator series includes different models, all of which provided both a purely mechanical and an electromechanical version.
Models differ from each other mainly for their capacity.
It must be noted that some machines with lower capacities have been produced with the Model 21 frame, presumibly to recycle unused parts and to allow subsequent upgrades.
Another difference is in the naming of the calculators: the fullkeyboard models were named “Addo”, while calculators that had keyboards with just 10 keys were named “Addo X”.

Insights

The Addo AB firm was founded in 1918 in Malmo by destist Hugo Agrell, who later founded in 1950 a subsidiary of the company in Cirencester, United Kingdom. In 1966, Addo was purchased by the swedish rival company Facit, but it was kept as a separate subsidiary.
After the Addo-Facit merging, the calculators started being produced not only in Sweden, but also in the US and in Japan. Meanwhile, in Italy, electromechanical Addo calculators started being
produced and distributed from 1936 onwards by the Lagomarsino company, headquartered in Milan, which previously was responsible only for distributing them.

Technical Data

Category: two species machine
Manufacturer: Addo
Modelli: 20-21-22-21 (by hand); 20E-21E-22E-23E (electronic motor)
Place of origin: Malmo, Sweden
Periodo di produzione: dal 1918 al 1959
Sistema: grid, pin slides
Calculator: simplex machine
Data insertion: by numeric keypad
Edition printing unit edition
By using a manual-traction lever o un electric engine
Processo di calcolo: not automatic
Value elaboration: between two phases
Colore: black
Dimensions: 25 x 30 x 23 cm
Weight: 9,8 (20E : 13,5) kg
Numero di cifre: 9 x 9