Dorr Felt
The inventor who built the first practical key-driven calculator out of a macaroni box.
Dorr Eugene Felt (1862–1930) built his first prototype of the Comptometer in 1885 out of a macaroni box, rubber bands, wooden sticks and staples — the famous "macaroni box" model. The point of his design was that it was key-driven: you entered digits by pressing keys, and the machine added the moment the key went down. That made it dramatically faster than the crank-driven machines of Thomas de Colmar and Odhner.
Felt started the Felt & Tarrant Manufacturing Company in Chicago and sold the Comptometer from 1887. It became a standard fixture of offices and bookkeeping for more than sixty years, and created an entire profession — the "comptometer operator" — long before the word "programmer" existed.