Enterprex Model 100M Desktop Electronic Calculator

This compact desktop electronic calculator has an ivory-colored plastic case, a brown plastic keyboard, twenty-two square plastic keys, and three rectangular plastic bars. In addition to nine digit keys, a zero bar and a decimal point key, there are bars for addition/sum and subtraction/total, keys for multiplication and division, and keys for exchange and clear/clear entry. To the left of the digit keys are six memory keys, a percentage key, and a Δ% key. Behind the keyboard are three switches and a ten-digit vacuum fluorescent display. A mark in front of the keyboard reads: ENTERPREX 100M.
The back of the calculator has a compartment for two large batteries. Below this is an indentation for a sticker, but the sticker has come loose. It reads in part: 10-DIGIT DESK-TOP (/) ELECTRONIC CALCULATOR (/) POWER SOURCE: TWO "D" CELL (/) BATTERIES. DC 3VOLT. It also reads in part: SERIAL NO. 64597 (/) PN 943014 MADE IN TAIWAN.
[Advertisement], Chicago Tribune, November 5, 1978, p. M7. Enterprex 100M advertised as on sale for $20.00.
[Advertisement], Los Angeles Times, February 24, 1979, p. C2. Enterprex 100M advertised as on sale for $29.95, with a list price of $40.00
Guy Ball and Bruce Flamm, The Complete Collector’s Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, p. 70.
BE CALC Vintage Electronic Calculators website (now www.calcuseum.com). This shows an example of the calculator, with a sticker indicating that it was made in Hong Kong.
Currently not on view
date made
ca 1978
place made
Physical Description
plastic (case; keys; display cover material)
metal (circuitry; switches material)
glass (tube material)
overall: 1 3/4 in x 6 1/2 in x 6 3/4 in; 4.445 cm x 16.51 cm x 17.145 cm
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Desktop Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History


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