RPN calculators

Guido's RPN calculator

RPN calculators are not so common because it takes a bit of learning until you can use them. However once you have understood the logic and used them for a while you would never want a different calculator again.

I have been using HP RPN calculators since the beginning of my university years. Now that PCs and Laptops are one every office table I have been looking for a good calculator that just runs independent of the operating system on any computer out there. I did not find one so I wrote one my self. Beginning of 1997 I started to write rpnjcalc. I have used it once in a while but it never really felt like a real HP pocket calculator. I always found my self looking for a real HP pocket calculator when I had to do some calculations. So finally in March 2008 I decided that it must be possible to write a really usable calculator in Javascript and I developed gsrpn

The gsrpn calculator

I am continuing to improve it but I am very satisfied with it. It is almost as good as a real pocket calculator and it works proably on any office PC in the world. It just needs a modern webbrowser.

My collection of RPN pocket calculators

I don't collect RPN calculators for the purpose of collecting them. I have them because I use them and I like them.

HP-15c

I bought this hp15c in 1988 and it was my first RPN calculator. It is light and robust. It had been heavily used for many years but it is still as good as new.

HP-33c

This HP33c was my second RPN calculator and I got it second hand from a friend who did not want to use it anymore. Unfortunately I don't have the original battery pack.

HP-42s

I bought the HP42s in 1991. A very powerful calculator with a lot of functions.

HP-48sx

I bought the HP48 in 1992 but I did not use it too much. It was good at the time but has too many function for which you would not use a pocket calculator but rather a Math-software on a PC. Over time I found that a pocket calculator has to be just handy and compact.

HP-35s

This is a 2008 hp-35s in 2008. For many years HP did not produce anymore any good scientific RPN calculators. They had only bulky graphing calculators in ugly metallic design. This is, after many years, the first scientific RPN calculator which comes close to the successful classic RPN calculators. I like it.