Addiator Arithma
ADDO Mod 16
ADDO-X 331
Brunsviga 13RK
Brunsviga 13ZK
Calculator "Superautomat SASL"
Facit 1004
Facit EK
Mechanical calculator MADAS
Mellita, Model V/16
Monroe Model L200-X
Nisa PK 5
Original Produx Calculator
Remington Rand Adding Machine
Walther DE 100
Walther RM
XxX calculator

ADDO-X 331
A.B. Addo, 1965
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”.