Uploaded February 2023 | Updated September 2026, 2 hours ago

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This is a stepped drum mechanical calculator. It was made from 1913 till 1929 in Germany, but only about 6000 were made.

Stephen Freeborn also has a video about this machine: youtu.be/uzzDaMPfmA0

For more information about this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc

0:00 Introduction, History
2:20 Keyboard
3:15 Keyboard mechanism
4:02 Crank
4:20 Mechanism
8:22 Outro