The answer is that it does one job both inexpensively and exceptionally well. And that helps explain the persistence of devices whose roles might long ago have been taken over by the PC.
The pocket-sized HP 12C has been an indispensible tool to a generation of financial analysts, accountants, investment advisers, and others who run complex financial calculations. And HP is sticking with what works: The new version, the HP 12C Platinum, offers only minor changes, including a better battery and easier data entry.
Nearly all 12C users have access to computers with Microsoft Excel or another spreadsheet program. Many who do complicated math could use powerhouse computer algebra systems such as Wolfram Research's Mathematica or Waterloo Maple. But a calculator is often the tool of choice.
PCs do many things splendidly. If I had to use a financial model or run a complicated financial calculation repeatedly with only minor variations, I would fire up a spreadsheet. But spreadsheet models or calculation templates take a lot of time and effort to create, and they are very inefficient for a one-time calculation. That's where calculators shine.
The 12C is not easy to use, though. It has 39 keys, and nearly all have two or three functions assigned to them. Although such complicated calculations as the internal rate of return of an investment and sum-of-years-digits depreciation are built-in functions, you can't expect to use them without spending time with the manual.
The biggest change in the 12C, expected in stores around June 1, is a choice between HP's traditional reverse Polish notation -- you add 3 and 4 by tapping 3, Enter, 4, + instead of 3, +, 4, = -- and the much more familiar algebraic entry. But that won't change the need to study the manual to become proficient. The 216-page Owner's Handbook and Problem-Solving Guide, which includes step-by-step instructions for a large number of computations, betrays its Carter Administration origins by using eye-popping double-digit interest rates in many examples.
Once you've learned the tricks, specialized calculators have large advantages over computers in a lot of settings. Unlike a laptop, you never have to decide whether having it along is worth the trouble of carrying it. The 12C, about the size of an index card and just over a half-inch thick, will travel all but unnoticed in a briefcase or a purse. You don't have to worry about power, because the 12C will run for up to three years (assuming an hour of use a day) on one easily replaceable lithium battery. And it does not create the sort of psychological or physical barrier that a laptop can impose between you and a client.
The 12C Platinum carries a list price of $105 but should be discounted to $90 or less. The older 12C, widely available for around $70, will remain on the market.
Beyond the ubiquitous four-function units, specialized calculators continue to play important roles. Graphing calculators, especially Texas Instruments' TI-81 and its successors, have probably been more influential than any other technology, and far more important than PCs, in high school and college math and science education. Although they are out of production, many engineers still swear by HP 48 and HP 49 engineering calculators.
The calculator holds a special place in tech history. TI's Jack S. Kilby, who shared a Nobel prize for the invention of the integrated circuit, built the first pocket calculator to demonstrate a practical use for his creation. Apple Computer founder Steve Wozniak famously sold his HP 35 to help finance the first batch of Apple I's -- and he credits his experience in HP's calculator division for giving him the skills and engineering discipline he needed for the job.
With all the software tools at my disposal, I usually turn to a calculator when there are numbers to be crunched. The handy and deceptively simple tools are going to be around for a long time to come. By Stephen H. Wildstrom