Carl Walther GmbH, better known today for firearms like the iconic Walther PPK, began as a gunsmith business in 1886 in Zella-Mehlis, Thuringia, Germany. The company's diversification into calculating machines came from an unlikely source: the Treaty of Versailles.
After World War I, the treaty severely restricted arms manufacturing. To survive, Walther partnered with Mercedes-Euklid (who made pinwheel calculators under the Melitta brand) and began producing calculators in 1924. By 1939, Walther offered 17 different models with worldwide distribution.
The calculators used the Odhner pinwheel mechanism — an ingenious design where rotating cylinders with adjustable pins could add any digit from 0-9 with each crank turn. The "Japanese calculator wars" of the 1970s ended Walther's mechanical calculator line in 1974.