Ultima Eletac 10 Desktop Electronic Calculator

This lightweight, non-printing electronic calculator has an array of nine digit keys with a slightly larger 0 key and a decimal point key below these. On the right are keys for arithmetic operations. On the left are K, clear, and clear entry keys. The tubes above the keyboard show results up to ten digits in length.
A mark above the display on the right reads: ELETAC10. A sticker attached above the display on the left reads: Ultima. Letters attached to the front left read: MUDEN. A tag attached to the bottom reads: ELECTRONIC CALCULATOR (/) ELETAC 10. It also reads: SERIAL NO. 320636 (/) Ultima Electronics, Ltd. (/) Made in Japan.
Removing four screws from the bottom of the machine releases the cover. One circuit board is at the base, one holds the tubes that make up the display, and one lies under the keyboard. The calculator chip on the base has a Texas Instruments logo and reads: TMS0118NC (/) C7339. The "7339" is date code that refers to the 39th week of 1973, which is when the chip was manufactured.
A February 13, 1973, article in the New York Times lists Muden as one of several companies that sold electronic calculators. On August 17, 1976, Ultima Electronics, Ltd., in Melville, N.Y., filed trademarks for MUDEN (first used in commerce in the United States in June of 1976) and ULTIMA (first used in commerce in the United States in October of 1975). These trademarks were registered in 1978. By 1989 Ultima Electronics was in Taiwan. As the Eletac 10 never gained wide sales, it seems likely that this example was sold about 1976.
R.Metz, “Market Place,” New York Times, February 9, 1973, p. 46.
Images of another example of this machine, with detailed photographs, are at http://www.devidts.com/be-calc/, accessed April 2, 2013.
Yet another example of this machine, with a related Japanese advertisement, is in the Japanese virtual calculator museum at http://www.dentaku-museum.com/, accessed April 2, 2013.
Currently not on view
Object Name
electronic calculator
date made
ca 1976
Ultima Electronics, Ltd.
Physical Description
plastic (case, keys material)
glass (components material)
overall: 9 in x 7 in x 3 in; 22.86 cm x 17.78 cm x 7.62 cm
place made
ID Number
catalog number
accession number
See more items in
Medicine and Science: Computers
Desktop Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History, Kenneth E. Behring Center


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