Unisonic 21-P1 Handheld Electronic Calculator and Electronic Game

This colorful handheld electronic calculator also could be used to play the game of blackjack, with the calculator serving as the dealer and the user as a player.
The object has a metal case with plastic trim and keys. It has an array of twenty-five oval plastic keys. Four arithmetic function keys are on the left, in a column labeled: Calc. Ten digit keys, a decimal point key, and a total key are arranged in three columns in a section labeled: Bet. Eight gaming keys are arranged in two columns labeled: Play. Above this on the right is a shuffle/clear/clear entry key. Left of it are an on/off switch and a calculator/game switch. A mark below the keyboard reads: Unisonic 21. Another mark there reads: Blackjack. Behind the keyboard is a twelve-digit display that is labeled on the left: Player. On the right it is labeled: Dealer. Text behind this reads: Dealer draws on 16.
A sticker on the back describes the "A/C" adapter that may be used with the calculator. A jack for it is on the bottom edge. Text printed on the back gives calculation examples. One mark reads: Unisonic 21-P1. Another mark reads: SERIAL NO. (/) 078380 (/) MADE IN TAIWAN.
Below these marks is a compartment for three UM-4 batteries.
This calculator was actively discussed in early literature on electronic games.
Compare 1986.0988.295 (the Unisonic 21-P1) and 1986.0988.048 (the Radio Shack EC-21).
A copy of the instructions for the game is at the wass.net website, accessed July 2, 2015.
“Card Counter,” Texas Monthly, 7 #7, July, 1979, p. 16. Price of Unisonic 21 varies from $20 to $30, depending on model. Image shown appears to be the desktop version of the device.
Anne Douglas, “Game Shows Have Serious Aspects Too,” Chicago Tribune, June 18, 1977, p. 1B 11. Unisonic 21 available in both desktop and portable forms for $50 and up.
Kris Jensen, “New 1978 Electronic Games,” Modern Mechanix, January 1978, pp. 33–43. Mentions that the Unisonic 21 is available in both desktop and portable versions.
John Free, “Pocket Calculators for More than Math,” Popular Science, 214 #4, April 1979, p. 22, 24, 26, 29.
Currently not on view
Object Name
electronic calculator
date made
ca 1977
Physical Description
metal (case; circuitry material)
glass (display material)
paper (stickers material)
plastic (trim; keys material)
overall: 5/8 in x 3 in x 5 1/4 in; 1.5875 cm x 7.62 cm x 13.335 cm
place made
ID Number
catalog number
accession number
Computers & Business Machines
Handheld Electronic Calculators
See more items in
Medicine and Science: Computers
Handheld Electronic Calculators
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Gift of John B. Priser
Additional Media

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