overall: 1/8 in x 3 3/8 in x 2 1/8 in; .3175 cm x 8.5725 cm x 5.3975 cm
In the second half of the 1970s, taking advantage of the introduction of liquid crystal displays, manufacturers of handheld electronic calculators designed and built ever-thinner products. In this Sharp calculator the usual keys have been replaced by a single thin membrane. This reduces the thickness of the calculator itself to about .3 cm (about 1/8”). Pushing numbers on such a calculator produces no tactile sensation. To give users a sense that they indeed had entered information, the calculator could be set so that a tone sounded whenever a digit or function was entered. Pushing the section of the membrane with a musical note on it (called the sensor key) activated this part of the calculator.
The credit card-sized calculator has a total of twenty-six “keys.” To the left are ten digit keys, a decimal point key, a % key, four arithmetic function keys, three memory keys, and a total key. Right of these are an off key, an on/clear key, a sensor key, a clear entry key, a STR key for storing a number in the memory, and a COMP key for computing conversions by multiplying the stored value by the value in the display. These last two keys are labeled: STORAGE COMPUTER.
Behind the key membrane on the left side is the eight-digit LCD display. Text next to it reads: SHARP EL-8145.
Text on the back of the calculator reads: SHARP (/) ELECTRONIC CALCULATOR U.S. Pats. 390169 & 3976994 (/) EL-8145 No. (/) 86408458. It also reads: SHARP CORPORATION MADE IN JAPAN. The most recent U.S. patent number listed, 3976994, was issued in 1976 and assigned to Sharp.
The calculator ran on two squat cylindrical silver oxide batteries.
The instrument fits into a black plastic wallet. A mark on the front of the wallet reads: SHARP (/) ELECTRONIC CALCULATOR. The wallet, in turn, fits into a blue cardboard box. One price tag on the box reads: FRED MEYER (/) $29.95. Another reads: FRED MEYER SALE (/) $19.99.
Sharp membrane calculators in the collections include 1997.0032.01 (Sharp EL-8152 or EL-8152A), 1987.0435.13 (Sharp EL-8130A) and 1986.0988.316 (Sharp EL-8145).
[Advertisement], <I>Washington Post</I>, September 1, 1978. p. C5. “Credit card calculator” advertised as on sale for $34.95.
[Advertisement], <I>Chicago Tribune</I>, November 12, 1978, p. N4. Price given is $32.95. Comparable (less expensive) credit card-sized calculators mentioned in the ad are the National Semiconductor NS 102 and the Casio LC-78.
[Advertisemnt], <I>Los Angeles Times</I>, October 20, 1979, p. D7. Price for calculator listed as $25.95.
[Advertisemnt], <I>Los Angeles Times</I>, February 17, 1980, p. C9. Price of calculator listed as $28.88.