Addiator Arithma
Brunsviga 13RK
Calculator "Superautomat SASL"
Mechanical calculator MADAS
Mellita, Model V/16
Original PRODUX calculator
XxX calculator





XxX calculator
Seidel&Naumann (Dresden), 1906
Dimentions: 50 x 22 x 14 cm
Capacity: 9 (w cr) x 8 (w/o tc) x 13 also 9 x 9 x 16 and 11 x 11 x 20
Weight: 11 kg
Colour: black/silver
The working principle of the XxX calculator is stepped drum. It represents an early attempt of proper designing and serially producing this kind of machines.