JC Penney MM3R Handheld Electronic Calculator

JC Penney MM3R Handheld Electronic Calculator

<< >>
Usage conditions apply
This four-function calculator has a tan plastic case, an array of ten oval digit keys, and a decimal point key. It also has four blue arithmetic function keys to the right of these and has clear entry and clear keys to the left. A constant switch is above the clear keys. The on/off switch is on the right above the keyboard. A mark to the left of it reads: JCPenney. The eight-digit LED display is at the back. The back edge has a socket for a power adapter.
A sticker on the back reads: JCPenney (/) Electronic Calculator (/) VOLTAGE 6V CURRENT 0.2A (/) MODEL MM3R SERIAL No. 126131 (/) Made in U.S. A.
This model is similar to the Commodore MM3R and probably was made by Commodore.
J. C. Penney is a chain of American department stores.
Guy Ball and Bruce Flamm, The Complete Collector’s Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, pp. 81–82.
Currently not on view
Object Name
electronic calculator
date made
ca 1975
J.C. Penney Company
place made
United States
Physical Description
plastic (case; display cover; keys material)
gallium arsenide (display chips material)
metal (circuitry material)
paper (sticker material)
overall: 2.5 cm x 7.4 cm x 10 cm; 31/32 in x 2 29/32 in x 3 15/16 in
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Computers & Business Machines
Handheld Electronic Calculators
Data Source
National Museum of American History
Nominate this object for photography.   

Our collection database is a work in progress. We may update this record based on further research and review. Learn more about our approach to sharing our collection online.

If you would like to know how you can use content on this page, see the Smithsonian's Terms of Use. If you need to request an image for publication or other use, please visit Rights and Reproductions.


I have a JCPenney MM3R calculator which is tan colored and most of keys are tan colored.

Note: Comment submission is temporarily unavailable while we make improvements to the site. We apologize for the interruption. If you have a question relating to the museum's collections, please first check our Collections FAQ. If you require a personal response, please use our Contact page.