Texas Instruments TI-2550 III Handheld Electronic Calculator
date: label: date made
content: 1976
name: label: maker
content: Texas Instruments
notes: label: Description
content: In 1972 Texas Instruments began selling electronic calculators under its own name. The first of these was the Datamath or TI-2500. Over the next few years, TI sold modifications of the TI-2500 that had different forms of battery (such as the TI-2500B, the TI-2500II, the TI-2510, and the TI-2550III), a different color case (the TI-2510 and the TI-2550III), a key for taking percentages (the TI-2550, the TI-2550II, and the TI-2550III), and keys for additional functions (the TI-2550, the TI-2550II and the TI-2550III). This is an example of the TI-2550III.
label: Description
content: The calculator has an array of thirty-five rectangular plastic keys. These include ten digit keys, four arithmetic function keys, a clear key, a clear entry key, a decimal point key, and a total key. Also included are a change sign key, a percentage key, four memory keys, an inverse key, a square key, a square root key, and a reverse entry (RV) key. The RV key replaced an entry in the display with the immediately preceding entry.
label: Description
content: The on/off switch is above the keyboard on the right. A mark above it reads: TEXAS INSTRUMENTS TI-2550III. Behind this is an eight-digit blue vacuum fluorescent display.
label: Description
content: There is a jack for a power adapter along the back edge (according to instructions for the calculator found online, this would have part number AC9310A). The back has a battery compartment that would hold a rechargeable battery pack (according to instructions for the calculator, this would have model number BP-3).
label: Description
content: A sticker on the back of the calculator reads in part: US PAT 3819921 OTHER PATENTS PENDING (/) TEXAS INSTRUMENTS (/) TI-2550-III (/) electronic Calculator (/) Serial No. (/) 2550-III 075877. It also reads in part: ASSEMBLED IN USA. A mark below the label reads: 4576LTA.
label: Description
content: Unscrewing four screws from the back of the calculator reveals the circuit board. The largest chip is marked: TMS1043NL (/) KBSΔ7642.
label: Description
content: The calculator has a black plastic zippered case.
label: Description
content: References:
label: Description
content: [Advertisement], <I>Boston Globe</I>, November 25, 1976, p. 92. Selling for $29.95.
label: Description
content: [Advertisement], <I>Los Angeles Times</I>, January 29, 1977, p. C5. Advertised as selling for $28.95.
label: Description
content: Guy Ball and Bruce Flamm, <I>The Complete Collector’s Guide to Pocket Calculators</I>, Tustin, CA: Wilson/Barnett, 1997, p. 158. They give a 1976 price of $34.95.
label: Description
content: Online Datamath Museum.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Computers
label: See more items in
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: 1986.0988.347
label: catalog number
content: 1986.0988.347
label: accession number
content: 1986.0988
objectType: label: Object Name
content: electronic calculator
physicalDescription: label: Physical Description
content: plastic (case; keys; carrying case material)
label: Physical Description
content: metal (circuitry; zipper material)
label: Physical Description
content: paper (sticker material)
label: Measurements
content: overall: 1 1/4 in x 3 in x 5 3/4 in; 3.175 cm x 7.62 cm x 14.605 cm