Commodore MM-1 Handheld Electronic Calculator

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).

References:

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.”

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