Awesome Mechanical Calculator July 7th, 2011 It’s time to geek out to a retro calculator. The Curta Mechanical Calculator was invented in the 1940’s by an inmate in a Nazi concentration camp. Given the limited resources he had to work with, it’s amazing he was able to pull this off. Get the latest Flash Player to see this player. [Javascript required to view Flash movie, please turn it on and refresh this page]