Uploaded May 2021 | Updated September 2026, 3 hours ago
The EOS calculator is identical to the Hannovera model CK, but was made for the Swiss market. It uses an oscillating toothed segment mechanism which was easier to manufacture and did not infringe on Brunsviga's patents, unlike Hannovera's previous models which were pinwheel machines. The mechanism is similar to that of the Demos, but better because it can do subtraction by turning the crank in reverse.
I show the mechanism of the EOS in another video: youtu.be/pWOyLou-uys
For more information on this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:28 Addition
2:58 Subtraction
3:21 Counter
3:50 Clearing
4:20 Shifting the carriage
5:39 Serial number
6:52 Outro
The EOS calculator is identical to the Hannovera model CK, but was made for the Swiss market. It uses an oscillating toothed segment mechanism which was easier to manufacture and did not infringe on Brunsviga's patents, unlike Hannovera's previous models which were pinwheel machines. The mechanism is similar to that of the Demos, but better because it can do subtraction by turning the crank in reverse.
I show the mechanism of the EOS in another video: youtu.be/pWOyLou-uys
For more information on this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc
0:00 Introduction, History
1:28 Addition
2:58 Subtraction
3:21 Counter
3:50 Clearing
4:20 Shifting the carriage
5:39 Serial number
6:52 Outro
