Texas Instruments TI-2500 (Datamath) Handheld Electronic Calculator

This is an example of the first model of an electronic calculator marketed by Texas Instruments under its own name. The handheld electronic calculator has a tan plastic case with a dark brown keyboard. It has an array of eighteen keys, sixteen of them square and two rectangular. These include ten digit keys, a decimal point key, a total key, four arithmetic function keys, a clear entry key, and a clear key. A switch at the right in the top row of keys may be set at “CHAIN” or “CONST.” A mark above this switch reads: Datamath. Behind the keyboard is an eight-digit LED display.

A jack for a power outlet is along the back edge. An on/off switch is on the left side. A sticker on the back reads: TI-2500 electronic calculator. It also reads in part: Datamath (/) electronic calculator (/) A Product of Texas Instruments Incorporated. It also reads in part: Serial Number (/) 2500 582951. The sticker indicates that the calculator had a built-in battery that gave four to six hours of portable operation and was fully recharged in ten hours.

Unscrewing three long screws on the back of the case allows one to remove the back. The inside has five chips. The largest reads: TMS 0119 NC (/) C 7335 (/) ZA 0072. This is a TMS0119 chip, manufactured in the thirty-fifth week of 1973. There is space for four soldered batteries.

This appears to be the second version of the TI-2500, introduced in February of 1973 for a price of $119.95. The calculator initially was introduced in 1972.

Compare 1986.0988.188, 1986.0988.189, 1986.0988.190, 1986.0988.342, and 1986.0988.359.

References:

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.

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