Hamann Manus R


Although similar looking on the outside, the construction of the input register, a ratchet wheel,  is totally different from the widely used pinwheel.   This ratchet wheel construction has a big advantage: for both adding and subtracting the input register is turned in the same direction. This allowed the designers to automate division in a very early stage of calculator development (1925).

The red/white caps of this machine are not the original ones, nor is the bottom and the rubber feet.



As usual for this type of machine


Clear all registers.  Put the mode selector in the upper left of the machine in the position marked with a white “:”.    Move the carriage all the way to the right and press the “X<-->:” selector at the bottom of the carriage. The red line with the “-” sign should now point at the “8” on the base plate.  

Enter the dividend in the positions 13 to 8 of the result register. Enter the divisor in the main register. Start turning the main shaft.  The machine now starts subtracting until an underflow occurs. It then makes a small step, adds the divisor to correct the underflow, makes another small step and starts subtracting again. It continues until the carriage has reached its extreme left position.  The quotient is in the counter register (left), the remainder is in the result register (right).

Note:  If a machine works well, it runs very smoothly, also when underflow occurs and a step is made.

Function of some keys, switches etc

Calculator InfoRepair information & pictures of internals

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Video Assets: adverts, brochures, etc

Serial number:

Build in:


Rotation speed:


Production until:


45 575

Ca. 1955/1956

Addition, Subtraction, Manual Multiplication,  Automatic Division


Ca. 1959  (Known serial numbers range from 41 880 to 49 571)

DM 665,- in 1956  (Source: See assets: Price list )