Jaap Scherphuis | The Portable Adding Machine @jaapsch2 | Uploaded April 2024 | Updated October 2024, 2 hours ago.
The Portable Adding Machine was designed by Glenn J. Barrett in 1923. It was renamed the Corona Adding Machine in 1925, so my machine is about a century old. It is an incredibly clever simplified design.

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

0:00 History
1:26 Simplified design
2:42 Printing mechanism
3:52 Control buttons
5:08 Demonstration
5:58 The printout
6:29 Outro