HP-10C series

The HP-10C series calculators were introduced by Hewlett-Packard in 1981.cite_web|url=http://www.vcalc.net/hp-date.htm|title=HP Calculators by Date of Introduction|author=Rick Furr|work=the Calculator Reference|updaded=January 22, 2003] Also known as the "Voyager" series, all are programmable and use Reverse Polish Notation. Nearly identical in appearance, each model provided different capabilities and was aimed at different user markets.

The HP calculators 10C series consisted of five models (with original retail price and years of production):
*HP-10C – basic scientific calculator. ($80 1982-1984)
*HP-11C – mid-range scientific calculator. ($135 1981-1989)
*HP-12C – business/financial calculator. ($150 1981-present)
*HP-15C – advanced scientific calculator. ($135 1982-1989)
*HP-16C – computer programmer's calculator. ($150 1982-1989)

The HP-12C remains in widespread use today.

The HP-10C

The HP-10C is the last and lowest-featured calculator in this line even though its number would suggest an earlier origin. The 10C was a basic scientific programmable. While a useful general purpose RPN calculator, the HP-11C offered twice as much for only a slight increase in price. Designed to be an introductory calculator, it was still relatively expensive compared to the competition, and many looking at an HP would just step up to the better HP-11C. Poor sales led to a very short market life.

The HP-12C

The HP-12C is a popular financial calculator. It was such a successful model that Hewlett-Packard redesigned it from scratch,cite_web|url=http://www.brouhaha.com/~eric/hpcalc/voyager/variants.html|title=HP Voyager Calculator Variants|author=Eric Smith|work=HP Voyager Calculator Variants|updaded=August 16, 2007] added several new functions, and introduced it as the HP-12C Platinum in 2003.

The HP-12C is HP's longest and best-selling product, in continual production since its introduction in 1981. Due to its simple operation for key financial calculations, the calculator long ago became the de facto standard among financial professionals – for example, Goldman Sachs and Bear Stearns issue HP-12Cs to the members of each incoming class of its investment banking analysts and associates. Its popularity has endured despite the fact that even a relatively simple, but iterative, process such as amortizing the interest over the life of a loan--a calculation which modern spreadsheets can complete almost instantly--can take over a minute with the HP-12C.

Later HP financial calculators are many times as fast with more functions, but none has been as successful. The HP-12C's programing mode is very intuitive and works like a macro operation on a computer. Basically, the keys you would press in the calculating mode to arrive at a solution are entered in the programing mode along with logical operaters (if, and, etc.) applicable to the solution. After the programing is complete the macro will run in the computation mode to save the user steps and improve accuracy. There are 99 lines of programmable memory on the HP-12C, but 400 lines of program memory are available on the HP-12C platinum.

Over its lifespan, the processors technology has been improved in order to integrate all the circuitry in a single chip and to refresh the manufacturing process (as the foundry could no longer manufacture the necessary chips, having moved on to making higher-density chips). However, HP's market research found in the late 1980s that the users did not trust results obtained too quickly and so the CPU speed was never improved from the original 200 or so kHz.Fact|date=February 2007 In the late 1990s, the CPU was changed to a 3V process and the battery was changed to a single 3V cell.

The HP-12C is one of only three calculators permissible in the Chartered Financial Analyst exams, the others being the Texas Instruments BA II Plus and BA II Plus Professional.

There are two versions of the HP-12C Platinum. The early versions did not have parentheses. This often led to awkward key-sequences to solve problems in algebraic mode. Newer versions of the HP-12C Platinum have parentheses, as blue-shifted functions of the STO and RCL keys.

Hewlett Packard makes an HP-12C / HP-12C Platinum solutions book available as a PDF on their website.

The HP-11C and HP-15C

The HP-11C is a mid-range scientific programmable. The HP-15C is a high-end scientific programmable with a root-solver and numerical integration. It is able to handle complex numbers and matrix operations. Although out of production, its popularity has led to high prices of US$200-400 on the used market [Completed sales of HP-15C on eBay, March 8, 2008] and a [http://www.hp15c.org/ petition] asking HP to restart production.

The HP-16C

The HP-16C is a computer programmer's calculator, designed to assist in debugging. It can display numbers in hexadecimal, decimal, octal, and binary and convert numbers from one base to the other. To accommodate long binary numbers, the display can be 'windowed' by shifting it left and right. For consistency with the computer the programmer is working with, the word size can be set to different values from 1 to 64 bits. Binary-arithmetic operations can be performed as unsigned, 1's complement, or 2's complement operations. This allows the calculator to emulate the programmer's computer. A number of specialized functions are provided to assist the programmer, including left- and right shifting, masking, and bitwise logical operations. Sales were poor.

A competitor to HP, Casio, did make a Computer Math Calculator, model CM-100, that had many of the same computer programmer functions as the HP-16C. It had no battery and ran on ambient light with a solar cell. While not nearly as complex as the HP-16C, it was an excellent value for about $15 (in the mid 1980's).

Arithmetic

One of the least-known features of this calculator series is the quality of the arithmetic inside them. Hewlett-Packard retained the well-known numerical analyst Prof William Kahan, from UC Berkeley, the architect of the IEEE 754 standard for floating-point arithmetic, to design the numerical algorithms implemented by the calculators. He also wrote parts of the manuals.

Emulators

Several individuals and companies make software emulators of the 15C and 12C calculators for Microsoft Windows, PalmPilots, PDAs, and smartphones.
* [http://code.google.com/p/hpcalc-iphone/ hpcalc-iphone] for the iPhone
* [http://www.3grtech.com/ MXCalc ] from 3grtech
* [http://www.lygea.com/index.htm Lygea]
* [http://www.sourceforge.net/projects/finanx Finanx FX-12C Java]
* [http://epx.com.br/ctb/hp12c.php HP-12C emulator in Javascript]

References

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* Cite_web|url=http://mycalcdb.free.fr/main.php?l=0&id=809|title=HP-11C|work=, Cite_web|url=http://mycalcdb.free.fr/main.php?l=0&id=810|title=HP-12C|work=, Cite_web|url=http://mycalcdb.free.fr/main.php?l=0&id=876|title=HP-12C platinum|work=, Cite_web|url=http://mycalcdb.free.fr/main.php?l=0&id=815|title=HP-15C|work=and Cite_web|url=http://mycalcdb.free.fr/main.php?l=0&id=816|title=HP-16C|work=pictures on MyCalcDB, pocket calculators made in 70s and 80s
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