Index

Description

This is an example of the first model of a scientific calculator marketed by Texas Instruments. The handheld electronic calculator has a black and ivory-colored plastic case with an array of twenty-three plastic keys. Twenty-one of these are square, the 0 and the total keys are rectangular. In addition to ten digit keys, a decimal point key, a total key, and four arithmetic function keys, the calculator has a reciprocal key, a square key, a square root key, a change sign key, an enter exponent key, a clear key, and a clear display key. Text above the keyboard, just below the display and to the left, reads: SR10. Behind the keyboard is a 12-digit LED display. Numbers larger than eight digits are displayed in scientific notation. A mark behind the display reads: TEXAS INSTRUMENTS. An on/off switch is right and slightly above this.

The back edge of the calculator has a jack for a recharger/adapter. A sticker on the back gives extensive instructions. It also gives the serial number SR10 275812.

Unscrewing screws near the top and bottom of the back reveals the workings of the calculator. It has a total of five chips. The largest of these is marked TMS 0120 NC (/) C7333. This is a TMS0120 chip, manufactured in mid-1973. Also in the case is space for three AA nickel-cadmium batteries.

The leather zippered case has both a loop and a hook for attaching the calculator to a belt. It also holds an instruction pamphlet entitled Texas Instruments electronic slide rule calculator SR-10, copyrighted 1973. A warranty registration on the inside of the back page indicates these instructions were originally sold with an SR-10 calculator with serial number 170334, purchased on September 27, 1973.

Texas Instruments described the SR-10 as an “electronic slide rule calculator,” hence the “SR” in the name. The first version of the device, introduced in 1972, did not have the mark SR-10 on the keyboard. The second version (introduced 1973) and the third (introduced 1975) did. This is an example of the first version. According to Ball & Flamm, it initially sold for $149.95.

Compare 1986.0988.351, 1986.0988.354, and 1986.0988.356.

References:

Guy Ball and Bruce Flamm, The Complete Collector’s Guide to Pocket Calculators, Tustin, CA: Wilson/Barnett, 1997, p. 153.

The online Datamath Museum includes versions of the SR-10 from 1972, 1973, and 1975.

date made

1972

Date made

1973

maker

Texas Instruments

ID Number

1986.0988.354

catalog number

1986.0988.354

accession number

1986.0988

Description

This handheld electronic calculator comes in a checkbook and is designed to assist in balancing checking accounts. It has a total of thirty-one plastic keys. On the left side are ten digit keys, a clear entry/clear key, a decimal point key, and four arithmetic function keys. At the center are a % key, a total key, an off key, an on key, and a DB key. On the right is a row of keys for a checking account for entering checks and deposits, and finding balances. A second row of three keys is for indicating charges, payments, and balances in a charge account. A third row of keys for a second charge account. At the bottom right corner is a grand total key.

Behind the keyboard is an eight-digit LCD display. To the right of it are three brightly colored dots. Text to the left reads: NSC National Semiconductor 103A.

The back of the calculator is riveted to the calculator, so marks there were not recorded. A mark on the circuit board reads: NS-103B-1 (/) A=5 (/) B=10.

Text on the inside of the checkbook reads: MADE IN TAIWAN. The checkbook also includes space for a pen.

Compare 1986.0988.227 and 1986.0988.336.

References:

Frank Macias, “Calculating Friends: Delegate That Everyday Balancing Act to These Little Guys with Big Brains,” Los Angeles Times, November 19, 1978, p. O64.

[Advertisement], Washington Post, February 13, 1981, p. A41. On sale for $29.95, regularly $34.95.

date made

1978-1981

maker

National Semiconductor Corporation

ID Number

1986.0988.148

catalog number

1986.0988.148

accession number

1986.0988

Description

This prototype handheld electronic calculator was built in the Semiconductor Research and Development Laboratory at Texas Instruments in Dallas, Texas, by a team led by Jack Kilby (1923–2005), co-inventor of the integrated circuit. By the mid-1960s, TI was building microchips for industrial and military applications. The company president, Pat Haggerty, sought a consumer product that would use chips, just as earlier TI transistors had found wide use in transistor radios. Haggerty proposed a variety of possible products, and Kilby and his colleagues settled on making a small electronic calculator. TI had given an earlier development program the code name Project MIT. The calculator work, also confidential, was dubbed Project Cal Tech.

Machines that performed basic arithmetic had sold from the mid-19th century, for use in business and government. Desktop electronic calculators with vacuum tubes sold from 1961, and with transistors from 1964. Kilby envisioned something much smaller that would be roughly the size of a book. This required a smaller keyboard, a new form of display, a portable power supply, and a new memory and central processor. Kilby assigned design of the keyboard to James Van Tassel, and gave work on the memory and processor to Jerry Merryman. He took responsibility for the output and power supply himself.

By September 1967 Kilby, Merryman, and Van Tassel had made enough progress to apply for a patent. The submitted a revised patent in May 1971 and a further revision in December 1972. This final application received U.S. Patent No. 3,819,921 on June 25, 1974.

The prototype resembles the “miniature electronic calculator” shown in the patent drawings. It has a metal case painted black and an array of seventeen keys and a zero bar. In addition to nine digit keys, there are keys for a decimal point, four arithmetic functions, clear (C), error (E), and print (P). The on/off switch is at the back right and a thermal printer with a thin strip of paper at the back left. The power supply plugs into the back of the calculator and into the wall.

An inscription on the front of the calculator reads: THE FIRST CAL TECH (/) PRESENTED TO P. E. HAGGERTY (/) MARCH 29, 1967.

Depressing a button on the front edge of the machine releases the cover and reveals an intricate “integrated circuit array” (to use the terminology of the patent description) and three chips. The array contained four integrated circuits, each the size of a wafer usually made with several chips on it.

Further refinement of the Cal Tech led to the commercial Pocketronic calculator, introduced by Canon in Japan in 1970 and in the United States in 1971. Texas Instruments began selling calculators under its own name in 1972.

References:

Kathy B. Hamrick, “The History of the Hand-Held Electronic Calculator,” American Mathematical Monthly, 102, October 1996, pp. 633–639.

Jack Kilby, Oral History with Arthur L. Norberg, June 21, 1984, Charles Babbage Institute, University of Minnesota, Minneapolis, Minnesota. A transcript is available online. Accessed June 18, 2015.

T. R. Reid, The Chip: How Two Americans Invented the Microchip and Launched a Revolution, New York: Simon & Schuster, 1985.

Jeffrey Zygmont, Microchip: An Idea, Its Genesis, and the Revolution It Created, Cambridge, MA: Perseus Publishing, 2003.

date made

1967

maker

Texas Instruments

ID Number

CI.336000

catalog number

336000

accession number

319050

Description

The HP-35 was the first handheld electronic calculator to display all the functions represented on a slide rule. It has a black plastic case and a total of thirty-five square or rectangular plastic keys. These include ten digit keys, a decimal point key and a pi key, all colored tan. In addition there are four arithmetic function left of the digit keys, a relatively long enter key, a change sign key, an enter exponent key, a clear x key, and a clear key, all in blue. Additional black keys are for powers, logs to base ten, natural logs, exponents, square roots, trigonometric functions (sine, cosine, tangent and the inverses of these), simple inverses, exchange, roll down, store, and recall. Above the keys is an on-off switch. There is no hole next to the switch to indicate that the display is on, as there was in the very first HP-35 calculators. Behind the switch is a red LED display that shows results. Numbers with absolute value between one hundredth and 10 billion are given in decimal form. Smaller or larger figures appear in scientific notation, with the appropriate power of ten occupying the three rightmost digit places (two for digits, one for a sign). The negative sign for the result, if needed, is at the far left. A mark on the front edge of the calculator reads: hp HEWLETT•PACKARD.

The back of the calculator has a plug for a three-prong power adapter, a compartment for a battery pack, four rubber feet, and a sticker entitled: HEWLETT•PACKARD MODEL 35 INSTRUCTIONS. Text below the sticker reads: HEWLETT-PACKARD (/) 3.75V 500MW (/) MADE IN USA PATENT PENDING. A sticker inside the battery pack reads: HEWLETT-PACKARD (/) SER.NO. 1249A 11780. The portion 1249 of the serial number indicates that it was made in the forty-ninth week of 1972. A red sticker on the lid of the battery pack reads: CAUTION (/) USE ONLY H. P. BATTERY PACK (/) MODEL NO 82001A (/) OTHER BATTERIES MAY DAMAGE CIRCUITS. A sticker on the outside top of the calculator reads: PROPERTY OF (/) Dr. R. E. Zupko.

In addition to the calculator, the gray plastic case contains a power adapter (1991.0210.01.2) labeled in part: HEWLETT - PACKARD (/) MODEL 82002A. It also has a carrying pouch (1991.0210.1.3). For the related manual, see 1991.0210.02.

In this and a few other early HP-35 electronic calculators, entering the function 2.02 ln (e ^x) gave a result of 2 rather than 2.02. In this example, the owner chose not to have the error fixed.

The donor, Ronald E. Zupko, was an historian of weights and measures and a professor at Marquette University in Milwaukee, Wisconsin.

References:

W.A.C. Mier-Jedrzejowicz, A Guide to HP Handheld Calculators and Computers , Tustin, California: Wilson/Burnett Publishing, 1997, pp. 36–39, 132.

David G. Hicks, The Museum of HP Calculators, http://www.hpmuseum.org/, accessed July, 2014.

Thomas M. Whitney, France Rodé, and Chung C. Tung, “The ‘Powerful Pocketful’: an Electronic Calculator Challenges the Slide Rule,” Hewlett-Packard Journal, June 1972, pp. 2-9.

Accession file.

date made

1972

maker

Hewlett-Packard Company

ID Number

1991.0210.01.1

catalog number

1991.0210.01.1

accession number

1991.0210

Description

Introduced in mid-1976, the Little Professor is a non-printing electronic calculator modified to present simple arithmetic problems. A correct answer prompts another problem on the eight-digit display. An error delivers the message, "EEE." The colorful keyboard shows a professor with whiskers and glasses. The red light-emitting diode screen, in combination with the top of the instrument, looks like a mortar board.

This example has buttons that allow one to set the level of problems, as well as an on/off button on the front rather than the side of the machine. These features were introduced in a version of the machine made from 1978 onward.

Reference:

P. A. Kidwell, A. Ackerberg-Hastings, and D. L. Roberts, Tools of American Mathematics Teaching, Baltimore: Johns Hopkins University Press, 2008, pp. 261–262.

date made

ca 1978

maker

Texas Instruments

ID Number

1986.0988.197

accession number

1986.0988

catalog number

1986.0988.197