## Hewlett Packard's Cult Calculator Turns 30 318

Hugh Pickens writes

*"The Wall Street Journal reports that Hewlett Packard's HP-12C financial calculator has remained outwardly unchanged since its introduction in 1981. 'Once you learned it on the 12C, there was no need to change,' says David Carter, chief investment officer of New York wealth-management firm Lenox Advisors, who has owned his 12C for 22 years and still keeps it on his desk. 'It's not like the math was changing.' The 12C, which costs $70 on HP's website, is HP's best-selling calculator of all time, though the company won't reveal how many units it has sold over the years. The 12C still uses an unconventional mathematical notation called 'Reverse Polish Notation,' which eschews parentheses and equal signs in an effort to run long calculations more efficiently."*
## Unconventional? (Score:5, Interesting)

The 12C still uses an unconventional mathematical notation called 'Reverse Polish Notation,'

I still use the HP-41CV I bought new, made in Corvallis, Oregon ($400 or so at the time, with a card reader). Iâ(TM)ve never been able to do any significant math on a calculator that

did notuse RPN.At least in the courses I took, most people preferred RPN.

## Re:Unconventional? (Score:2, Interesting)

## Like a screwdriver (Score:4, Interesting)

This calculator is like a screwdriver: a perfect fit for the task.

The Platinum shipped with a bug. The 12C...well, there are no bugs.

RPN is great. Once you get used to it, you never look back. BTW, RPN is what the Forth programming language uses.

When doing financial calculations or shopping I always take it with me. Also to the bank. It creates an instant bonding between you and the manager (those initiated in HP 12C's RPN).

HP calculators, IIRC, were used to calculate the orbits in some early space program missions (YouTube). I think it's safe to say that the 12C is more numerically trustworthy than some Pentiums that came out....

## RPN hand calc is not the best way anymore. (Score:4, Interesting)

As long as calculus isn't involved, a spreadsheet is best. I did an Astronomy masters (finished 2002) and significantly cut down my time doing assignments involving simple algebra by using a spreadsheet. It was a distance course. We also had open book exams, and were permitted to use any calculation tools we wished. The only rule for assignments and exams was no collaboration.

Advantages of a spreadsheet: Repeatable. You can see your work and modify or correct mistakes at will. Graphs are limited but easy. Both statistical and scientific functions. Time saved can be used to do simple checking (plugging the answer back into the question).

Reverse polish is good on old style calculators for exactly 2 reasons:

1) You have the limited input and output of a calculator keyboard and screen.

2) You more closely mirror what a turing machine/computer is doing, so if you're trying to understand one it's a good way to get closer to the architecture

Reason 1 disappears if you spend most of your time sitting in front of a relatively modern computer.

Reason 2 has less to do with the calculation than it has to do with IT and computer science. And once you have a good understanding, you're just reinforcing that same knowledge.

Spreadsheets are excellent but have no native ability to solve or graph calculus equations. For that I would use a math package. Octave and SciLab can be had for free. Matlab, Maple, and Mathematica for more money if you're serious.