Unitrex Scientific 21 Handheld Electronic Calculator
date: label: date made
content: ca 1976
name: label: maker
content: Eiko Business Machine Company
notes: label: Description
content: This handheld scientific calculator has a black and off-white plastic case with an array of twenty rectangular plastic keys with rounded corners. Many of the keys have dual functions, one indicated on the key and one above it. Hence the ten digit keys also may represent three trigonometric functions, three inverse trigonometric functions, square root, natural log, exponent, and pi. The decimal point key may represent an inverse function while the EE (enter exponent) key also denotes clear number. The red function key is pressed to activate these secondary functions. It also serves to clear functions. Three of the four arithmetic function keys, as well as the total key, serve as memory keys. The calculator also has clear memory and clear keys.
label: Description
content: Behind the keys is the on/off switch. Behind it is an eight-digit green vacuum fluorescent display. Text on the display cover reads: UNITREX (/) Scientific 21.
label: Description
content: The back of the calculator has a compartment for two “penlight” batteries at the top. A sticker below give operating instructions. It also reads in part: MADE IN THAILAND.
label: Description
content: Unitrex had sold a scientific calculator as early as March, 1974,, when it offered the Unitrex 80SR as competition for the HP-35, but at a much lower price.
label: Description
content: References:
label: Description
content: [Advertisement], <I>Washington Post</I>, March 28, 1974, p. E3. This advertisement for the Unitrex Mini Handy 80SR, offered as an alternative to the HP-35.
label: Description
content: [Advertisement], <I>Chicago Tribune</I>, October 24, 1976, p. S10. Unitrex Scientific 21 sold by Zayre’s for $19.98.
label: Description
content: [Advertisement], <I>Biddeford-Saco Journal [Biddeford, Maine]</I>, October 16, 1976, p. 43. Scientific 21 on sale for $19.98.
label: Location
content: Currently not on view
place: label: place made
content: Thailand
setName: label: See more items in
content: Medicine and Science: Computers
label: See more items in
content: Computers & Business Machines
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content: Handheld Electronic Calculators
creditLine: label: Credit Line
content: Gift of John B. Priser
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1986.0988.242
label: catalog number
content: 1986.0988.242
label: accession number
content: 1986.0988
objectType: label: Object Name
content: electronic calculator
physicalDescription: label: Physical Description
content: plastic (case; keys material)
label: Physical Description
content: metal (circuitry material)
label: Physical Description
content: paper (sticker material)
label: Measurements
content: overall: 1 in x 3 in x 5 7/8 in; 2.54 cm x 7.62 cm x 14.9225 cm