Commodore MM-1 Handheld Electronic Calculator

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This handheld electronic calculator has a white case with black trim and metal keyboard, and eighteen square plastic "Klixon" keys. Such keys have a design trademarked by Texas Instruments and make a distinctive click when pressed. In addition to ten digit and one decimal point key, the calculator has four keys for arithmetic functions. One serves as a total key for addition, another as a difference key for subtraction. The top of the keyboard has a constant switch, a D key for recalling the display (which turns off after fifteen seconds), a clear entry key, and a red clear key. The on/off switch is below the keyboard along with a switch for setting the position of the decimal point.
The eight-digit red LED display is behind the keyboard. A cord for recharging the battery attaches at the back of the top. (This example has no cord.)
The back has four plastic feet. A metal plate there gives operating instructions. Text near the bottom reads: COMMODORE BUSINESS MACHINES, INC. (/) MODEL MM-1 (/) SANTA CLARA, CALIFORNIA (/) MADE IN U.S.A.
This was one of the first models of a handheld calculator sold by Commodore. It was manufactured by Bowmar/Ali and is similar to the Bowmar 901B.
Compare 1986.0988.098 (the Commodore Minuteman 2) and 1988.0988.129 (the Bowmar 901B).
Guy Ball and Bruce Flamm, The Complete Collector’s Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, p. 57.
Los Angeles Times, March 14, 1972, p. C5. Advertised as selling for $179. “Now you can face this year’s taxes with confidence.”
Currently not on view
date made
ca 1972
Commodore Business Machines, Inc.
place made
United States
Physical Description
plastic (case; keys; display material)
glass (tube material)
metal (circuitry; keyboard material)
overall: 1 1/2 in x 3 1/2 in x 6 in; 3.81 cm x 8.89 cm x 15.24 cm
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History


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