Back to Walther Gallery

Walther RMKZ Simulator

Pre-war pinwheel calculator (1930s) • 10 rotors, 8 counter, 13 accumulator digits

Counter
Accumulator
Input Check
Clear Input
Clear Counter
Clear Accum.
Clear All

How to Use the RMKZ

  1. Set a number using the brass levers (drag up/down or click on track)
  2. Click Add (CW) to add the input to the accumulator (clockwise crank)
  3. Click Subtract (CCW) to subtract (counter-clockwise)
  4. For multiplication: Set multiplier, shift carriage, add repeatedly
  5. For division: Enter dividend in accumulator, set divisor, subtract until negative, then add back
  6. The counter register tracks how many operations were performed