Keystone 390 Handheld Electronic Calculator

<< >>
Some early manufacturers of electronic calculators began as makers of photographic equipment. One of these was the Keystone Division of Berkey Photo, Inc. Keystone Camera Company traced its origins to a company founded in Boston, Massachusetts in 1910. Early products included movie cameras and projectors. In 1966, Berkey Photo, Inc. acquired Keystone. By 1973, the Keystone Camera Division of Berkey, with its factory in Clifton, New Jersey, had expanded to making instant-load cameras with electronic flash. It also, from late 1972 until at least 1975, made handheld electronic calculators.
The Keystone 390 handheld electronic calculator has a black plastic case with gray trim, a metal keyboard, and twenty plastic keys. The keys are square with circular tops. In addition to ten digit keys, a decimal point key, a total key, four arithmetic function keys, and a cancel key, the calculator has a percentage key and two memory keys. Buttons above the keyboard can be used to set the display for numbers or dollars and cents and to turn on the memory. A mark next to these reads: Keystone (/) 390.
At the back is an eight-digit display. Text along the front edge reads: Made in U S A. The socket for a power adapter and the on/off switch are at the back edge.
A sticker on the back of the calculator gives operating instructions. It is marked at the bottom: Keystone (/) PARAMUS, NEW JERSEY 07652 SERIAL #C174364. The calculator has a black plastic zippered carrying case. A cloth tag on the inside reads: MADE IN TAIWAN.
Advertisements list the price of the calculator as $107.95 (1973) down to $47.50 (1974).
Compare 1986.0988.368.
[Advertisement], New York Times, September 15, 1973, p. 15. Ad lists Berkey Keystone calculators #350, #370, #390, and #395. Model 390 is on sale for $107.95.
[Advertisement], New York Times, March 30, 1974, p. 64. Ad lists Berkey Keystone calculators #350, #370, #390, and #395. Model 390 is on sale for $107.95.
[Advertisement], New York Times, September 8, 1974, p. 153. Ad lists Berkey Keystone calculators #350, #370, #390, and #395. Model 390 on sale for $69.50.
[Advertisement], New York Times, November 17, 1974, p. 193. Ad lists Berkey Keystone calculators #350, #370, #390, #395, #2030, 2040, and #2050. The ad indicates that the Model 390 is on sale for $47.50.
Currently not on view
date made
place made
United States: New Jersey, Paramus
Physical Description
glass (display material)
metal (keyboard; circuitry material)
plastic (case; keys; carrying case; trim material)
overall: 1 3/4 in x 3 in x 5 1/4 in; 4.445 cm x 7.62 cm x 13.335 cm
ID Number
catalog number
accession number
Credit Line
Gift of John B. Priser
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Computers & Business Machines
Data Source
National Museum of American History


I still have mine. My mom bought it for me after I got out of the Air Force in 1972 and started at Purdue University in 1973. I know she could not afford it, but got it for me anyway.

Add a comment about this object