Trigonometry in the Plane  Electronic Calculators for Plane Trigonometry
Electronic Calculators for Plane Trigonometry
The introduction of the transistor and then the microprocessor in the late 1960s and 1970s made it possible to build electronic calculators that could compute trigonometric functions directly. These calculators quickly replaced slide rules and mathematical tables.
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HP9100 Prototype Desktop Electronic Calculator
 Description
 This transistorized electronic calculator is the prototype for the first electronic calculator sold by HewlettPackard Company, the HP 9100. The machine was notable for its ability to compute transcendental functions at the push of a button, and for the range of values that could be computed.
 The prototype has a metal case painted gray. At the right center is an array of nine digit keys and a 0 bar, with clear display, enter exponent, and change sign keys above these. To the right of these keys is an array of fourteen programming keys. Left of the digit keys are keys for arithmetic operations, square roots, and shifting the position of variables within the x, y, and z registers of the calculator . The fifteen further keys to the left are for a variety of trigonometric, hyperbolic, and exponential functions.
 Above these keys are four switches. The leftmost determines whether angles entered and computed are in radians or degrees. The second switch from the left determines whether the decimal point is floating or fixed. The third switch turns the power on or off. The rightmost switch sets the mode as run or program. A display and a dial that may be set between 0 and 9 are behind the keyboard and switches. At the back are a power cord and a connector.
 The prototype brought together ideas of Thomas Osborne, Malcolm McMillan, and others at HewlettPackard. For Osborne’s earlier prototype, see 19780311.01 and 1978.0311.02. For a production model of the HP9100B, see 2012.0044.01.
 Bernard M. Oliver, “How the Model 9100A Was Developed,” HewlettPackard Journal, September, 1968. A copy of this article is at the HP Museum website.
 Location
 Currently not on view
 date made
 ca 1966
 date received
 1978
 maker
 HewlettPackard Company
 Osborne, Thomas E.
 ID Number
 1978.0311.03
 accession number
 1978.0311
 catalog number
 1978.0311.03
 Data Source
 National Museum of American History

HewlettPackard 9100B Desktop Electronic Calculator
 Description
 This programmable desktop electronic scientific calculator has a beige metal case, a cathode ray tube display, a keyboard with four groups of keys, and a slot for a magnetic program card. The leftmost set of 15 tan keys includes coordinate conversion, logarithmic, exponential, trigonometric, and absolute value function keys. A switch above it can be set at degrees or radians.
 The set of 15 ivory and dark brown keys second from the left allows for the positioning and storage of numbers in different registers. Next to the right is a set of 20 brown and ivory keys to enter numbers and to specify machine functions. The rightmost set of 14 tan keys is used for programming.
 Five handwound circuit boards are inside the case, and three smaller circuit boards are inside the lid. There is a white power cord. A sticker on the back of the machine reads: SERIAL NUMBER (/) 93802147.
 The Crocker Nuclear Laboratory of the University of California at Davis acquired this machine in May of 1970 for a price of $5,195.00. Funds came from the Atomic Energy Commission’s Experimental Nuclear Physics program.
 For related prototypes, see the green machine of Thomas Osborne (198.0311.01, 1978.0311.02) and the prototype HP9100A (1978.0311.03).
 Reference:
 Accession File.
 Location
 Currently not on view
 date made
 1970
 date received
 2012
 maker
 HewlettPackard Company
 ID Number
 2012.0044.01
 accession number
 2012.0044
 catalog number
 2012.0044.01
 Data Source
 National Museum of American History

Wang 700 Electronic Calculator
 Description
 In March of 1968, An Wang saw a prototype of HewlettPackard’s HP9100 programmable desktop calculator. This machine reduced the task of finding many scientific functions from programming to pushing a key. In response, Wang Laboratories announced plans for a new set of calculators for the scientific and engineering communities, the series 700 advanced programming calculator. The instrument came on the market in mid1969.
 A large keyboard at the front of the machine includes keys for entering digits, carrying out arithmetic operations, and finding squares, square roots, and reciprocals. A separate key enters the number pi. Another set of keys performs operations for both logarithms and exponents in base e and base 10. Special function keys above the digit keys are set for trigonometric and hyperbolic functions. A tape cassette on the right above the keyboard allows for entering programs via magnetic tape. Left of the tape drive is a Nixie tube display that shows up to twelve digits in two registers, followed by the sign of the exponent and the exponent.
 A mark on the front left of the calculator reads: WANG. A metal tag at the back reads: Wang Laboratories, Inc. (/) ELECTRONIC CALCULATOR (/) MODEL NO. 700C (/) SERIAL No. 811055C (/) TEWKSBURY, MASS. U.S.A. Marks on the rightmost column of keys confirm that is a model Wang 700C, having debugging features characteristic of that machine. It was released in 1972. A paper sticker on the right back reads: JUL 8 1970 [sic]. The July date is scribbled over one reading JUN 3. Hence the object dates from at least 1970, most probably about 1972.
 Documentation received with the calculator dates from 1969, 1970, and 1972.
 Reference:
 An extensive discussion of the Wang 720C advanced programming calculator is at The Old Calculator Web Museum.
 Location
 Currently not on view
 date made
 ca 1972
 maker
 Wang Laboratories
 ID Number
 1983.0171.01
 catalog number
 1983.0171.01
 accession number
 1983.0171
 Data Source
 National Museum of American History

Documentation on the Standard Trigonometric Program for the Wang 700B Electronic Calculator
 Description
 Wang Laboratories not only sold desktop electronic calculators but also prerecorded tape cassettes that included useful programs. This yellow reference manual describes use of the standard trigonometric package program. The package included programs for converting between degrees and radians, finding standard trigonometric, inverse trigonometirc, hyperbolic trigonometric, and inverse hyperbolic trigonometric functions.
 For a related object, see 1983.0171.01.
 Location
 Currently not on view
 date made
 1970
 maker
 Wang Laboratories
 ID Number
 1983.0171.05
 catalog number
 1983.0171.05
 accession number
 1983.0171
 Data Source
 National Museum of American History

HewlettPackard HP35 Handheld Electronic Calculator
 Description
 The HP35 was the first handheld electronic calculator to compute all the functions represented on a slide rule. It has a black plastic case and a total of thirtyfive 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, and 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 HP35 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 ones 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 threeprong 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: HEWLETTPACKARD (/) 3.75V 500MW (/) MADE IN USA PATENT PENDING. A sticker inside the battery pack reads: HEWLETTPACKARD (/) SER.NO. 1302A 27645. The portion 1302 of the serial number suggests that it was made in the second week of 1973. 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.
 In addition to the calculator, the gray plastic case contains a power adapter labeled in part HEWLETT  PACKARD (/) MODEL 82002A. It also has a carrying pouch, battery packs, and a battery case.
 According to the donor, Nicholas Grossman, he ordered the calculator when it was first announced and received it, paying $395 plus shipping, six weeks later. The HP35 was first announced in early 1972.
 Received with the calculator were two documents, the HP35 Operating Manual and HP35 Math Pac.
 References:
 W.A.C. MierJedrzejowicz, 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,” HewlettPackard Journal, June 1972, pp. 2–9.
 Location
 Currently not on view
 date made
 19721973
 maker
 HewlettPackard Company
 ID Number
 1982.0222.01
 catalog number
 1982.0222.01
 accession number
 1982.0222
 Data Source
 National Museum of American History

APF Mark 55 Handheld Electronic Calculator
 Description
 This handheld electronic calculator is designed for scientific work. It has an array of digit keys with a decimal point key, keys for the four arithmetic functions, a sign change key, a reverse x and y key, a down key, an ENT key, and an EE key. At the top are shift, recall, standard deviation, natural log, and clear display keys. Below these are sine, cosine, tangent, summation, and power keys. The function keys all can assume a second function, allowing for evaluation of hyperbolic trigonometric function, decimal logarithms, mean values, square roots, and so forth. A few keys are devoted to converting decimal and standard units of weight and measure—centigrade and Fahrenheit temperatures, liters and gallons, centimeters and inches, and kilograms and pounds.
 The tendigit LED display is behind the keyboard. The device has space for a nickel/cadmium battery behind this, as well as an outlet for an adapter/charger.
 A mark above the keyboard, even with the on/off switch, reads: aPF MARK 55. A mark on the sticker on the back of the case reads: aPF mark 55 (/) ADVANCED SCIENTIFIC CALCULATOR. After brief operating instructions, futher marks read: MARK 55 (/) Model No.; J036646 (/) Serial No.; and: APF ELECTRONICS INC. (/) NEW YORK, N.Y. 10022 (/) MADE IN JAPAN.
 A March, 1976, advertisement compared the features of the APF Mark 55 with those of the HP45, noting that both calculators used reverse Polish notation for data entry, carried out a wide array of operations, and could store and recall nine registers of numbers. According to the advertisement, the HP45 cost $195 while the APG Mark 55 cost only $79.95.
 References:
 Los Angeles Times, March 14, 1976, p. V57.
 Los Angeles Times, June 8, 1976, p. 9.
 Location
 Currently not on view
 date made
 ca 1976
 maker
 APF Electronics
 ID Number
 1986.0988.171
 catalog number
 1986.0988.171
 accession number
 1986.0988
 Data Source
 National Museum of American History