ScrewtapelloMar 31, 2025

Free42, the Free Software re-implementation of the classic HP 42s RPN calculator, supports using custom skins, a bit like WinAmp skins but more complex - instead of just a bunch of bitmaps, you get to define the size and location of each button and graphical element.

I have discovered that it its parsing of the layout file is not very strict, so I can wrap some HTML, CSS, and JavaScript around it and get a polyglot file that I can load into Free42 to test, and also load into a browser to visualise the coordinates as I edit them.

(the attached screenshot depicts a skin for Free42's slightly more capable cousin Plus42, but the skin files are interchangeable)

#free42 #hp42s #hpcalc

josFeb 8, 2025
#free42 et #plus42 sur #debian
#geek hp#
josFeb 8, 2025
#free42 une super calculatrice HP #rpn customisable ! Et quelle puissance !
Ça nous replonge dans les années d'autrefois !
#geek #calculators #linux
Show threadJon MollerJan 21, 2025
@csepp Yeah I was thinking something like ia16-elf-gcc plus PV specific libraries. I'll see if I could somehow contribute to that. Very cool! Forth would be incredible! I was hoping to port #free42 to the PV though there is a #sim48. Thanks so much!!
Stefan Wolfrum May 3, 2024
Did you know that you can actually upgrade your #DM42 #calculator’s #Free42 version? #SwissMicros hasn‘t updated Thomas Okken‘s awesome #HP42S simulator that runs on their DM42 hardware, it‘s still on version 3.0.15 and was last updated in October 2022.
The current Free42 version is 3.1.8, dated 2024-04-24. And guess what: GitHub user Regis Verpillot accepted the challenge to bring this latest version to the DM42 hardware! 🎉🍾🥳💃🕺 👉 https://github.com/rverpillot/free42
GitHub - rverpillot/free42: Free42 fork to use with Swissmicros DM42

Free42 fork to use with Swissmicros DM42. Contribute to rverpillot/free42 development by creating an account on GitHub.

GitHub
Show threadataffanelApr 22, 2024

It works! #Free42 in a #RaspberryPiPico takes about 300KB of code and seems to work fast enough. The Pico C/C++ sdk is quite pleasant to work with, and Free42 compiled near out-of-the-box.

Next steps are to clean up the project to make it public (it is currently a bit of a hack) and find a way to design a decent home-made keyboard for the calculator.

ataffanelApr 21, 2024

I am looking at making my (physical) #rpn calculator. I am investigating using #free42, an #hp42s re-implementation. So far it seems very easy to port! It is always fun to hack around and then suddenly get a coherent display.

Next step will be to see if it fits in a #raspberrypipico ...