Perfection: The HP-15C

HP's foray into consumer electronics began with pocket calculators. The golden era is debatable, but my favorite was and is the venerable HP15C

Way back, in the 1980's, Hewlett Packard made calculators. I had inherited my fathers 29C when he upgraded (he worked at Lockheed Missiles and Space) to the HP-41C. It was programmable, rechargeable, and it was amazing to the 16 year old me.

But, what I really wanted was the newly released HP15 series, the form factor was cool, it was vastly more capable than the 29C, and it had an LCD vs LED display, thus it was far stingier on power consumption.

I never got the 15C back then. When I graduated high school, bound for university to study physics and mathematics, my father acquired a used (but in excellent condition) HP-41CV the expanded version of the veritable HP-41C.

I never did drop that early lust for the 15C.

In the mid aughts, I got the hankering, so I paid way too much for an EBay HP15C. It was close to what the retail price in 1982 was, and I just closed my eyes and completed the purchase.

It arrived, and was serviceable, but it clearly wasn't a desk queen. It had a small dent in the aluminum fascia, and there was an annoying issue where it would drain the battery in about a week; definitely not how it was designed.

Opening it up, it was clear that some water had invaded, and that made a couple of the solder joints flaky. A quick clean up and touch up of the solder on a QFP package, and a fresh set of batteries later, I was off to the races.

This was circa 2008.

Since then, it has sat on my desk, used probably once or twice a week when a quick calculation is needed, I slide it out of its case, punch the numbers in, do the operations, and have a result.

Tres magnifique!

Then last week, the unthinkable happened. I got the blinking battery low indicator.

Holy forking cow, the batteries had lasted almost 14 years!!!!!

Of course, it doesn't get daily, or heavy use, but damn, did the EE's back then know how to design circuits that sipped power.

Hat's off to the designers of one of the finest calculators ever made, the HP-15C!

n.b: I still have my HP41CV in its case on a shelf. I mostly just use the 15C for the quick and dirty calculator needs.