Hand-held Calculators

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Casio Mini Card LC-78

Casio Mini Card LC-78

Casio Mini Card LC-78

Distinctive features: The first credit card-sized calculator.

Technical details:
Display is 8 digits, yellow LCD.

4-function, %, memory.

Integrated circuit - NEC D896G3 (here date coded 1978).

Batteries - 2x AG10 Silver button cells.

Credit card size (but a little thicker) - 91 x 55 x 5 mm (3.6 x 2.2 x 0.2").

Was the first credit card-sized calculator (though a little thicker), introduced in 1978. Cost £17 GBP (about US$34).

Made in Japan by Casio Computer Co. Ltd.

Casio Mini Card LC-78

Side view showing how thin the calculator is.

Inside

Removing the rear cover reveals the circuit board, with the integrated circuit mounted in a hole in the board.

Circuit board

The other side of the circuit board and the integrated circuit with the conductive rubber membrane of the keyboard.

By 1978 the use of LCD (Liquid Crystal Display) and C-MOS (Complementary Metal Oxide Semiconductor) integrated circuits with their very low power consumption allowed the production of a very small and thin calculator powered by two button cells giving a quoted life of 1000 hours.  See the bottom of this page for a comparison with one of the first hand-held calculators, the Sharp EL-8.

Casio Mini Card LC-78G

Casio Mini Card LC-78G

The LC-78G shown here looks identical to the LC-78.

Comparison of the Casio Mini Card LC-78 with the Sharp EL-8 hand-held calculator of 1970/1.

It is interesting to compare the size, electronics, battery life and cost of the Casio Mini Card LC-78 with the Sharp EL-8 below, one of the first hand-held calculators from just 7 years, or so, earlier.

This shows the incredible advances in electronics over these years.

Casio Mini Card LC-78

Casio Mini Card LC-78.

Sharp EL-8

Sharp EL-8

Comparison of the Casio LC-78 with the Sharp EL-8 hand-held calculator of 1970/1.

Functions:

Batteries:

Cost:

Sharp EL-8

Sharp EL-8 with the back removed showing the rechargeable battery pack containing 6x AA NiCad cells.

Sharp EL-8 board
Sharp EL-8 board

The display board of the Sharp EL-8 with the vacuum fluorescent display tubes and the display driver chips.

The calculating circuit board of the Sharp EL-8 with the 5 chips then required to give the standard 4 functions.

Hand-held Calculators

Vintage Calculators

Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.