Commodore SR-1400 Handheld Electronic Calculator

This handheld electronic calculator is designed for scientific use. It has an array of forty-two keys. In addition to ten digit keys, a decimal point key, clear and clear entry keys, four arithmetic function keys, and a total key. The lower portion of the keyboard has change sign and exponent (of two digits) keys. Function keys include squares, degrees converted to radians, radians converted to degrees, powers, common logs, natural logs, exponents (of more than two digits), square roots, trigonometric functions (which can also double as inverse trigonometric functions), inverses, exchange, memory, and parentheses.

The power switch is at the top right of the keyboard. Behind it is a fourteen-digit red light-emitting diode display. A mark above this reads: commodore. The socket for an adapter is along the top edge.

A metal tag on the back of the calculator reads in part: ELECTRONIC SLIDE RULE CALCULATOR (/) SR-1400 (/) Please Read Instruction Manual. It gives basic instructions. Further text near the bottom reads: Serial No. 015975 (/) Commodore Business Machines, Inc. U.S.A.

The calculator has two Mostek chips. A mark on one reads: MOS (/) MCS2525 (/) 001 2174. A mark on the other reads: MOS (/) MCS2526 (/) 001 2874.

A December 17, 1974, newspaper advertisement listed the calculator as selling for $99.95

References:

Los Angeles Times, November 15, 1974, p. G9. Advertised as selling for $99.95.

Los Angeles Times, August 31, 1975, p. C7. Advertised as on sale for $49.88.

The Day, December 17, 1974. Advertised as available for $99.95.

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