Capturas de pantalla del iPhone


Free42 is a re-implementation of the HP-42S calculator and the HP-82240 printer.
It is a complete rewrite, not using any HP code, and it does not require an HP-42S ROM image.
Free42 is an Open Source project. The executables and source code are released under the terms of the GNU General Public License, version 2.
All third-party code used in Free42 is either in the public domain, or licensed under terms compatible with GPLv2, or used with the authors' permission.


Versión 2.5.24

Improved user-defined function support. The changes are rather substantial; please check the Free42 web site for details.

The previous release introduced a bug when pasting a program without line numbers, causing numbers to be mangled. Fixed.

Valoraciones y reseñas

4.7 de 5
171 valoraciones

171 valoraciones

Tyyp ,


I believe the HP 42s was the best scientific calculator ever made. And this APP is a fantastic representation of it. If you appreciate the benefits of RPN logic and a calculator that has all the capabilities appropriate for a hand held device, you will enjoy this APP. I have been using the APP for more than a year. The transition from the calculator to the APP was seamless. While there are some minor differences necessitated by the the smartphone platform, they are essentially inconsequential. And the APP has a few major advantages over the calculator such as not loosing programs when the batteries run down.

And the developer has been great. Miscellaneous enhancements and updates required by iOS revisions are very timely and bug free.

I write very few reviews and only when the product is either very good or very bad. If you are looking for a RPN calculator, do yourself a favor and get this APP.

MQ-9 ,

Wish it would make loud click

I love this app so much that I don’t have to carry my HP-32S with me to work( had it for so many years) but I wish it would make a loud click as mentioned also by another reviewer. You get a feel of the click as you press the key on the real one but it would help a lot to make the click sound louder confirming that your entry was entered. It makes you always verify that you have entered it correctly making the process a little slower. That function was my only complaint since I downloaded this app about 5 years ago.

Respuesta del desarrollador ,

Version 2.5.7 has an option for a louder click.

Atlanta Traveller ,

Double love for this app!

My wife and I are both educated as engineers. She got me hooked on RPN after I stubbornly stuck to TI and AOS through undergrad. Then in grad school I started using her HP and before I knew it I was reprogrammed for RPN. We started buying "his and her" calculators as the physical models wore out. When she was complaining about using her iPhone calculator to balance the check book, I selected this app because we had both owned a 42S along the way and loved them. With this outstanding app, well supported with updates, our favorite calculator never wears out. Five stars and a donation. It's well worth it!

Privacidad de la app

El desarrollador, Thomas Okken, ha indicado que las prácticas de privacidad de la app pueden incluir la gestión de datos que se describe a continuación. Para obtener más información, consulta la política de privacidad del desarrollador.

No se recopilan datos

El desarrollador no recopila ningún dato en esta app.

Las prácticas de privacidad pueden variar, por ejemplo, en función de tu edad o de las funciones que uses. Más información


Thomas Okken
8.6 MB

Requiere iOS 9.0 o posterior. Compatible con iPhone, iPad y iPod touch.





  • En familia

    Hasta un máximo de seis miembros de tu familia podrán usar esta app si tienes En familia activado.

También te puede interesar