This gray mechanical 10-key adding machine was manufactured by Johnston Adding Machine Company of California. It is a model A11 Adder with 10 white number keys and 6 red function keys. The machine could add, subtract, and multiply as well as print a paper tape. Its cover is hinged and opens to reveal the calculating mechanisms, the ribbon and platen for printing, and a red knob for advancing the printing paper. Stamped on a metal plate located on the inside right rear is the serial # 11766A11.
Johnston Adding Machine Company was acquired by the Marchant Calculating Machine Company in 1957. The Johnston plant was engaged to produce and distribute the Marchant 10-key adding machine.
See also: 1979.3084.128 Advertisement for Marchant's new adding machine.
1979.3084.023 - .025 Marchant Board of Directors Minutes of Meetings.
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