Very good modern calculator with most of the appeal of the old HP-15C

For many years I greatly admired the classic HP-15C scientific calculator from the 80s and had wanted to buy one for some time.

But they were always too expensive when they came up for sale second hand, plus compared to modern calculators the originals are very slow and the display is quite limited.

Then when HP released the new Limited Edition of the 15C last year with a promised 100 times speed increase over the original and a recommended price tag of $100 it looked as though I would finally be able to afford one and it would as fast as a normal calculator.

Unfortunately the whole stock was bought by a few retailers who immediately increased the price to two to three times the HP RRP making them still too expensive.

This forced me to reassess what I actually liked about the 15C and wanted in a scientific calculator of this type.

The RPN entry system, classic HP angled key style, ability to write and store programs and work in different bases were all important plus these days the ability solve equations and have a more informative display would be a vast improvement over the 15C.

Hence I looked at other HP scientific calculators and found the 35S, which has all the above features and many more and the only drawbacks compared to the 15C are that it doesn't look quite as classy and is in a more normal portrait format compared to the 15Cs landscape.

It also has lots of other advantages over the 15C, it can be used in standard algebraic or RPN modes, it has many more functions available, far more memory, various conversion factors and constants built in, a two line modern LCD display and is a much more reasonable price.

So I bought a 35S and I am extremely happy with it.

It is a complicated calculator and takes some time to get to know, probably even more so than the 15C since it has so many more modes and functions.

In fact I would recommend that anyone who buys one should decide fairly early on whether they prefer to work in normal algebraic or RPN mode and stick with the one mode.

Although it is easy to switch modes on the 35S if you try to use it in both modes for certain jobs it does get very confusing since the key entry for most of the functions is completely different in the two modes.

A fair amount of time should be allowed to learn how to use this calculator, with frequent reference to the user manual, at least at first.

In fact reading the user manual is pretty much essential with the 35S when it first arrives as there are so many functions and methods which are not immediately apparent from the keyboard and work in a different way to scientific calculators from other manufacturers.

In conclusion I would recommend the HP-35S to anyone looking for a non-graphing scientific calculator and especially to anyone who wants a modern day replacement for the old 15C.

Don Stewart.

Great design... great capabilities... but flawed...

Very nice calculator, very good set of features. By design, this is exactly like a 20 year old calculator (a very advanced one). The programmability is not implemented in steps on any new calculator these days, but hp calcs are all about nastalgia (and I personally like it that way). There's one unbelievably ANNOYING bug that I found, and that is: if you have a number less than 1, say 0.543234234234234... and the the display mode is set to ALL (not fix or sci), it will show it in scientific notation (which is not a problem), but it truncates the the exponent... so it will show "7.654345345e-" or on the stack above it will show "5.423423432423E..." implying that the rest doesn't fit on the screen and then the exponenet will be off the screen... DRIVES ME NUTS, you literally can't tell what the magnitude of the answer is!!! and have to hit left-n-right buttons to see the rest of any answer that is less than 1, and everything that is greater than 10^12. I hope someone at HP gets fired over this, preferrably the whole QC team... it's simply retarded, that such a simple usability need got overlooked... It's as if, hp actually didn't EVEN TRY to use it, before making 1000000's of them...

HP 35s review

I am an engineer, and I find that a calculator that provides me with an RPN operating system is easier to use than an algebraic system. It works the way that I think and allows me to do more in less time.

Very good scientific calculator whit RPN mode

Very good scientific calculator. RPN mode helps make calculations quickly without extra keystrokes. Very good and sensitive keypad and easy to read high contrast display. Used in the calculations instead of daily model HP 50G.

FE exam calculator

- I bought this to use on the Fundamentals of Engineering exam. It was one of two HP calculators approved by NCEES (neither of which I'd used) and judging just on looks, I picked the 35s over the 33 because it more resembled my old HP48. So far, I'm happy with it.

- Good reference: HP's manual is easy to understand and well-organized. It took me about an hour to get the hang of storing formulas in memory, then calling them up and entering arguments and solving.

- One con: the buttons have a "clicky" feel to them, but it's misleading, because they have to be depressed fully to have an effect (i.e., wanting "209", you pressed 2-0-9-<enter>, but "29" is what gets entered). I like this calculator but this is a big downside.