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The Perfect EE Undergrad Calculator: HP-15c

Posted by Steven Staton on 17 Feb 2007, 2:02 a.m.

I attended Rensselaer Polytechnic Institute in the early 1980s, working on a Computer Engineering degree. In the fall of 1983, I had the good sense to spend \$135 (a princely sum at the time) on an HP-15c calculator.

I wanted an HP-41CV, but the price was simply too high, especially given the tuition at RPI at the time (today, it's utterly ridiculous). I had to "compromise" on the 15c, and while in my heart I wanted the 41CV, I knew I was still getting an HP.

A high school friend used to rub his HP calculators in my face, and so for three long years, I ached for an HP-67, and then an HP-41C. I couldn't justify spending the money on these machines, since they cost more than my car! (It turns out that his father was the one buying these HPs -- the friend could no more afford them than I.) When I got to RPI, the HP was still just a glint in my eye.

So in the fall of 1983, I discovered the recently unveiled 15c, and the new price point that was just barely affordable (like two expensive textbooks). I bit, and got the Advanced Programing manual, too.

The machine was just magic. I was taken with how much effort was put into helping the user compute the error of the calculation! That was amazing to me, until I started having to deal with error in my courses. Then I understood. HP made tools for engineers. I was learning how to be an engineer, and I had selected the Right Tool.

The 15c was a pinnacle of pocket calculators and engineering school. It did exactly the mathematical operations a EE or CSE would have to do, and nothing more. It was simply the best calculator for electronic engineering ever made. It did complex arithmetic as well as real. It could compute determinents. It could find roots, compute definite integrals. It just did it all, and in a tiny package that sipped power from watch batteries, virtually guaranteeing that it would not fail during a test. And you could program it, too!

After all those years, I still have my 15c. It's my favorite calculator, and I expect it to be functioning the day I stop. Hats off to the Hewlett-Packard of the 1980s for achieving perfection!