Handheld Electronic Calculator Homemade by John B. Priser

John B. Priser (1918–1997) was an astronomer by profession and a collector of electronic calculators by avocation. He donated much of his collection to the Smithsonian’s National Museum of American History in 1986 and 1987. Priser built this model calculator at home in Flagstaff, Arizona, in 1982.

The calculator has an array of thirty-two round plastic keys and a translucent plastic case with four rubber feet. In addition to ten digit keys, a decimal point key and a pi key, it has four arithmetic function keys, a clear key, a clear entry key, a memory key, and a total key. The row of keys behind these has an EEX key, a change sign key, and two parenthesis keys. Three further rows of function keys typical of scientific calculators are behind these. At the back is a thirteen-place display. What these places indicated is not clear—it seems likely that not all are for digits. The calculator used at least two Mostek chips. A jack for a power adapter is on the back edge.

A mark on the lower board of the calculator reads: DEVTRONICS (/) MODEL SR 55-1-A.

A sticker on the front reads: HOMEMADE (/) BY: JOHN B. PRISER (/) FLAGSTAFF, AZ. (/) MAY 1982.

Reference:

James Sanders, Hobbies: How Thirty-Seven Fascinating Hobbies Were Started, Middle Village, N.Y.: J. David, 1980, pp. 110–114.

Currently not on view