Facit Model CS1-13

Under the new model name CS1-13 the semi-automatic machine was sold until 1965. Maybe planned but probably never built has been a mechanism for rapid calculation of reciprocal values, which is described in patent DE1096652 or CH342385 from Erik Conrad Grip and Lars Gustav Hellström. (The idea: the machine is in the division position, so when slaked result works the setting dial is not step shown after the first underflow; the zeros in the result works are complemented by an invisible foreign one, ie the dividend 1 does not have to be keyed in, and one gains an additional decimal place in the result.)