A: Weimar, Thüringen, Germany, B: Liechtenstein, Vaduz, Vaduz
In 1947 Contina Ltd of Vaduz, Liechtenstein began production of the Curta Model 1 pocket mechanical calculator. The most advanced small mechanical calculator ever built, the Curta was designed by Curt Herzstark, a calculating machine manufacturer, while he was a prisoner in Buchenwald concentration camp from 1943 to 1945. The Nazis operating the concentration camp encouraged Herzstark to complete the design while he was in Buchenwald, and produced a prototype by the end of the war. The Curta calculator was manufactured until 1973.