Bohn Omnitrex SR1 Handheld Electronic Calculator

This somewhat hefty handheld electronic calculator is an improvement on the Bohn Instant and the Bohn Omnitrex. It has ten digit keys, a decimal point key, keys for the four arithmetic functions, an equals or total key, and a clear key. In addition, it has a memory key, a square root/reciprocal key, a square/percentage key, and a position of the clear key that clears only the entry. The on/off switch is to the left of the digit keys and the key for shifting the function of the function keys is next to the top row of function keys. Behind the keyboard is an unusually large eight-digit fluorescent display. A mark between the keyboard and the display reads: Bohn omnitrex SR1. A connection for an adapter is on the right side at the top.
The back of the calculator has a compartment to hold five batteries. At present it has no batteries and no cover. It has four plastic feet. A sticker attached to the back reads: BOHN REX ROTARY (/) MODEL BOHN OMNITREX SR1 (/) VOLTAGE-7.5 VOLTS D. C. POWER: 1.5 V. A. (/) SERIAL NO. 3708649-I (SERVICE CENTERS (/) 475 S. DEAN ST. (/) ENGLEWOOD N. J. 07631 (/) MADE IN TAIWAN. The address of the second service center, also indicated on the sticker, is: 121 S. PALM ST. (/) ALHAMBRA CAL. 91801.
The Bohn Duplicator Company had distributed Danish adding machines and Rex-Rotary duplicating machines. For an example of one of the adding machines, see 1995.0018.01.
The date of about for the Bohn SR1 is given by Ball and Flamm, who indicate that it sold for $99.95. A January 1974 advertisement in the Chicago Tribune indicates that the calculator had a list price of $129.95 and was on sale for $79.88.
Guy Ball and Bruce Flamm, The Complete Collector's Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, p. 34.
Chicago Tribune, January 31, 1974, p. 18.
Currently not on view
date made
ca 1974
place made
Physical Description
plastic (case; screen; keys; feet material)
metal (circuitry material)
paper (sticker material)
overall: 1 1/2 in x 4 1/8 in x 6 1/2 in; 3.81 cm x 10.4775 cm x 16.51 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, Kenneth E. Behring Center


Add a comment about this object