HP 15c

HP15C calculator – I have been using my HP-15C daily since I bought it new in 1988. On its third set of batteries :) The trig functions served me well until retirement. Now I do my checkbook with it. Could not be happier.

A classic calculator from Hewlett Packard – Even though you can't buy them any more except on the "vintage" market, I felt moved to second Cass's review of the HP15C calculator. I bought an original-model HP15C, without prior research of the HP calculator range, as an opportunistic purchase during a trip to Hong Kong in 1988. Fortunately, I bought the model that I would've chosen if I… Read more

*had* researched the range. I'd previously had an earlier-model HP scientific calculator, and wanted another HP scientific calculator specifically for their Reverse Polish Notation (RPN) keystroking logic, which has been almost unique to Hewlett Packard (scientific) calculators. Once you've got your head around RPN, you probably wouldn't go back to the algebraic keystroking logic of other calculators if your calculations entail multiple intermediate results or nested parentheses, because RPN eliminates or significantly reduces the need for explicit store-and-recall operations relating to intermediate results.

The HP15C was a beautifully presented calculator, featuring HP's trademark positive-feedback "clicky" keys, and a display the legibility of which I have not seen surpassed. It was accompanied by a getting-started guide together with an owner's handbook of nearly 300 pages.

A few years ago I bought an HP35s, the 15C's present-day successor, as a backup to my HP15C and ... well, for the pleasure of buying a new "toy" after all these years. I didn't particularly need to, though. The HP15C has worked flawlessly the whole time that I've owned it. The 15C was also a product of the time when Hewlett Packard manufactured their calculators in the US, before the era of offshoring production to cheap-labour facilities abroad.

Great calculator with good button feel – It is always handy to have a hand held scientific calculator instead of running Spreadsheet / turning the notebook/PC on. As a user of Hewlett Packard calculator for years and have purchased several models (eg HP-21 (1975), HP33C, HP32S etc) over the years. Missing out on HP15C (released 1981) but with petition of many people it was released… Read more

again as Limited Edition a few years back. I purchased one and it is probably the best unit with a nice compact form in your hand and great feel with the buttons (so impressed I bought another unit - still unopened, just in case I lose one). Have been using it over 3 yrs and love it. I did not have many problems with previous HP calculators neither, just old and the keys may be worn out a little after heavy usage.

This Limited Edition HP15C is much faster than the original release since the processor is more modern (eg testing with factorial) and it has an order higher of the upper numerical limit. Only small issue is that the key layout is different from those 33C, 32S etc... so need to familiarize with the layout.