Texas Instruments Exactra 20 Handheld Electronic Calculator (TI-20)
date: label: date made
content: 1974
name: label: maker
content: Texas Instruments
notes: label: Description
content: This handheld electronic calculator is one of a series of “exactra” calculators introduced by Texas Instruments in the spring of 1974. It has an off-white plastic case, an orange keyboard, and eighteen nearly square plastic keys. These include ten digit keys, a clear entry key, a clear key, a decimal point key, four arithmetic function keys, and a constant key. An on/off switch and a $/F (for dollars / floating point) key are on the left in the top row of keys. A mark at the top of the keyboard reads: exactra 20. Behind this is a six-digit red LED display.
label: Description
content: The calculator has no provision for a charger/adapter. A battery compartment at the top of the back would hold three AA alkaline or carbon-zinc batteries. A mark molded into the plastic on the back reads in part: TI-20 ELECTRONIC CALCULATOR (/) MADE BY TEXAS INSTRUMENTS INCORPORATED. It also gives instructions. Toward the bottom of the back is the stamp: 274. A tag below this reads: SERIAL NUMBER 2000036485.
label: Description
content: Unscrewing two screws on the back allow one to remove it. The calculator has two chips. The larger one is marked: TMS 0135 NC (/) C7422. This is a TMS0135 chip. The smaller one is marked: M7419 (/) SN27882.
label: Description
content: References:
label: Description
content: [Advertisement], <I>New York Times</I>, May 2, 1974, p. 18. Exactra 20 selling for $39.99.
label: Description
content: [Advertisement], <I>Chicago Tribune</I>, Dec 15, 1974, p. T17. Texas Instruments Exactra 20 selling for $19.88.
label: Description
content: [Advertisement], <I>New York Times</I>, September 10, 1975, p. 6. Exactra 20 calculator, regularly $29.99, now $14.99.
label: Description
content: Online Datamath Museum, accessed June 2, 2015.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Computers
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content: Computers & Business Machines
label: See more items in
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: 1986.0988.323
label: catalog number
content: 1986.0988.323
label: accession number
content: 1986.0988
objectType: label: Object Name
content: electronic calculator
physicalDescription: label: Physical Description
content: plastic (overall material)
label: Physical Description
content: metal (circuitry material)
label: Physical Description
content: paper (sticker material)
label: Measurements
content: overall: 1 3/8 in x 2 5/8 in x 5 in; 3.4925 cm x 6.6675 cm x 12.7 cm