Texas Instruments TI-2500 II (Datamath II) Handheld Electronic Calculator

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This is an example of an early handheld electronic calculator marketed by Texas Instruments under its own name. The calculator has a tan plastic case with a dark brown keyboard. It has an array of nineteen keys, seventeen of them square and two rectangular. These include ten digit keys, a decimal point key, a total key, four arithmetic function keys, a clear key, a clear entry key, and a percentage key. The percentage key distinguishes it from the TI-2500B.
A mark above keyboard on the right reads: Datamath II. Behind the keyboard is an eight-digit LED display.
A jack for a power adapter is along the back edge. An on/off switch is on the left side.
The back of the calculator has a compartment for storing either two rechargeable nickel-cadmium batteries or two AA-sized non-rechargeable batteries.
A sticker on the compartment cover reads: TI-2500II electronic calculator (/) Texas Instruments Incorporated (/) P.O. Box 22288: Dallas, Texas 75222. It also reads in part: Serial Number (/) 2500II- 019756. The sticker indicates that the calculator should be recharged for twelve hours using an AC9130 adapter/charger.
Unscrewing three long screws on the back of the case does not reveal the chips.
This modification of the TI-2500 was introduced in 1974 and sold at least until 1975.
Compare 1986.0988.188, 1986.0988.189, 1986.0988.190, 1986.0988.342, and 1986.0988.359.
Guy Ball and Bruce Flamm, The Complete Collector’s Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, p. 157.
Online Datamath Museum, accessed May 13, 2015.
[Advertisement], Chicago Tribune, March 2, 1975, p. G27. Price given as $49.95.
Currently not on view
date made
Texas Instruments
Physical Description
plastic (overall material)
overall: 1 5/8 in x 3 7/8 in x 5 1/2 in; 4.1275 cm x 9.8425 cm x 13.97 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


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