Texas Instruments SR-50A Handheld Electronic Calculator
date: label: date made
content: 1975
name: label: maker
content: Texas Instruments
notes: label: Description
content: This scientific calculator is a modification of the Texas Instruments SR-50. A handheld electronic calculator, it has a black plastic case with an array of forty small rectangular plastic keys. In addition to ten digit keys, a decimal point key, a change sign key, a total key, four arithmetic function keys, a clear entry key, and a clear key; the calculator has twenty-one further keys. Some are for entering exponents, pi, storage, recall, summation, exchange, powers, squares, square roots, reciprocals, factorials, general roots, hyperbolic functions, conversion between radians and degrees, natural logarithms, exponents, and common logarithms. Four keys are for trigonometric functions and inverse trigonometric functions.
label: Description
content: Text above the keys reads: TEXAS INSTRUMENTS SR-50A. Behind the keyboard is a switch that may be set at R (radians) or D (degrees). Next to it is an on/off switch. Behind the keyboard is an LED display that shows ten-digit positive and negative numbers and two-digit positive and negative exponents.
label: Description
content: The calculator has a jack for a recharger/adapter along the back edge. A sticker on the back gives instructions. It reads in part: TEXAS INSTRUMENTS (/) SR-50A. It also gives the serial number SR-50A 875346. It also reads: Assembled in USA. Above the sticker is a compartment for three batteries. A mark below the sticker reads: 3375DTA.
label: Description
content: Unscrewing three screws on the back reveals the workings of the calculator. It has six chips, two relatively large. One of the large ones is marked: TMC0521NL (/) ΔE7535-5. This is a TMC0521 chip, manufactured in 1975. The other is marked: TMC0501NL (/) DΔ7533-5. This is a TMC0501 chip, manufactured in the same year.
label: Description
content: The calculator comes in a black plastic, cloth-lined, zippered case with belt clip.
label: Description
content: References:
label: Description
content: [Advertisement], <I>Los Angeles Times</I>, June 28, 1975, p. C6. Gives a reduced price of $89.95.
label: Description
content: [Advertisement] <I>Boston Globe</I>, July 9, 1975, p. 22. Gives a price of $84.95.
label: Description
content: [Advertisement], <I>Los Angeles Times</I>, August 30, 1975, p. OC A5. Gives a price of $84.95.
label: Description
content: [Advertisement], <I>Los Angeles Times</I>, November 26, 1975, p. B5. Gives a reduced price of $79.76.
label: Description
content: [Advertisement], <I>Los Angeles Times</I>, April 10, 1976, p. C7. Gives a reduced price of $58.85.
label: Description
content: According to the online Datamath Museum, accessed May 15, 2015, the calculator was introduced in March of 1975 at an initial price of $109.50.
label: Description
content: Guy Ball and Bruce Flamm, <I>The Complete Collector’s Guide to Pocket Calculators</I>, Tustin, CA: Wilson/Barnett, 1997, p. 154. They give a 1975 price of $109.50.
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: 1986.0988.350
label: catalog number
content: 1986.0988.350
label: accession number
content: 1986.0988
objectType: label: Object Name
content: electronic calculator
physicalDescription: label: Physical Description
content: plastic (case; carrying case; keys material)
label: Physical Description
content: metal (jack; circuitry material)
label: Physical Description
content: paper (sticker material)
label: Physical Description
content: cloth (lining of carrying case 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