The HP41cx+ calculator uses Reverse Polish Notation (RPN) which is an absolute must for me. The HP41cx+ program by Antonio Lagana faithfully replicates the original HP41 and adds all the bells and whistles which were later developed for the calculator all in one package. Not only do you get the fabulous HP calculator but you get all the overlays, the ability to run a tape with graphics, the extra memory, all the programming functions, the extreme precision and RPN. This program yields an excellently fully functioned, easy to use calculator. It is a joy to use!

This is the calculator that got me through engineering. Even better than the original with a built-in printer and CAS features. My only complaints are that the loading of ROM packs and overlays leaves much to be desired and the manual offers more of a continuous feature advertisement than a understanding of pages, the strange behavior when loading modules. The help is a mixed up mess when you consider docs for the simulation, docs for the calculator, and docs for the ROM packs are all to be found in different places and accessed different ways and are sometimes old versions or dependent upon other modules. But when it comes down to the number crunching this calculator really shines. It leaves me with the feeling of what a wonderful calculating device the developer could put together by taking the best ideas from this project and eliminating the irritating peculiarities of the HP41C. Perhaps I’ll stumble upon a way to access CAS and the I41CX-MATH module. It’s time to scrap old design traditions and think a bit about designing a tool to do what the user needs. A bit of thinking ala SpaceX-style could produce a much more usable tool than the emulation of a product of 40 years ago.

I cannot rave enough about the i41CX+ app. I have a real hp41CV from college and grad school days (mint condition). I use it rarely so that it doesn't wear out. First HP I owned was a model 67 and I was hooked. This 41cx app keeps the entire 41 product and accessories, and then some, in my pocket. Couldn't be more happy with the performance and user experience. Well done !! Please keep it going. It's bad enough HP has abandon these gems. I'd like to know that this app will remain for years to come. Thanks for the great work.

The emulation works perfectly. Bells and whistles are available but don’t interfere with the functionality. I haven’t tried any of the bells and whistles so I can’t speak to their utility. But I am happy to testify that the full functionality of my beloved old Hewlett-Packard calculator now runs flawlessly on my iPods and iPads. No doubt it works on an iPhone also, but I don’t use an iPhone. Thank you to the developer for this gem.