Texas Instruments Exactra 20 Handheld Electronic Calculator (TI-20)

Object Details

Texas Instruments

Description

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.

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.

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.

References:

[Advertisement], New York Times, May 2, 1974, p. 18. Exactra 20 selling for $39.99.

[Advertisement], Chicago Tribune, Dec 15, 1974, p. T17. Texas Instruments Exactra 20 selling for $19.88.

[Advertisement], New York Times, September 10, 1975, p. 6. Exactra 20 calculator, regularly $29.99, now $14.99.

Online Datamath Museum, accessed June 2, 2015.

Location

Currently not on view

Credit Line

Gift of John B. Priser

1974

ID Number

1986.0988.323

catalog number

1986.0988.323

accession number

1986.0988

Object Name

electronic calculator

Physical Description

plastic (overall material)

metal (circuitry material)

paper (sticker material)

Measurements

overall: 1 3/8 in x 2 5/8 in x 5 in; 3.4925 cm x 6.6675 cm x 12.7 cm

See more items in

Medicine and Science: Computers

Computers & Business Machines

Handheld Electronic Calculators

National Museum of American History

Record ID

nmah_1363779

Metadata Usage (text)

CC0

GUID (Link to Original Record)

https://n2t.net/ark:/65665/ng49ca746af-428d-704b-e053-15f76fa0b4fa