Abstract : This article presents Jean-Baptiste Schwilgué's 1844 adding machine, which was equipped with a number of unique features, in particular with what was apparently the first numerical keyboard.
Denis Roegel. An Early (1844) Key-Driven Adding Machine. IEEE Annals of the History of Computing, Institute of Electrical and Electronics Engineers, 2008, 30 (1), pp.59-65. ⟨10.1109/MAHC.2008.1⟩. ⟨inria-00336086⟩