Texas Instruments Concept II Handheld Electronic Calculator

Texas Instruments continued to manufacture calculators sold by other companies. This example was marketed by the Zayre department store chain. The handheld electronic calculator has a black plastic case and a metal keyboard. It has an array of twenty-four rectangular black plastic keys. The meaning of the keys is indicated on the keyboard. There are ten digit keys, a decimal point key, a total key, four arithmetic function keys, a clear key, a clear entry key, a change sign key, and a percentage key. Above these is a row of four memory keys. The on/off switch is on the left edge. A mark above keyboard on the left reads: TEXAS INSTRUMENTS. Behind the keyboard is an eight-digit LED display. A mark below the keys reads: CONCEPT II.

A jack for a power outlet is along the back edge. A sticker on the back reads: US PAT 3819921 AND OTHER PATS PENDING (/) TEXAS INSTRUMENTS (/) Concept II (/) Serial No. 1027861. It also reads in part: ASSEMBLED IN USA. Below the sticker is a compartment for a nine-volt battery. A mark below it reads: 4276 LTA. Unscrewing four screws on the back of the calculator does not reveal the chip.

Compare the Concept II calculator with the TI-1250 (1986.0988.053). By 1977 Zayre stores sold different calculators under the Concept name.

References:

[Advertisement], Hartford Courant , June 6, 1976, p. 8O, Selling for $14.77, regularly $18.77.

[Advertisement], Hartford Courant , December 5, 1976, p. 25L. Selling for $13.88, regularly $16.88.

Online Datamath museum, accessed June 3, 2015.

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