The HP-50G is a good calculator. Probably the best RPL available before the Prime (non-RPL alas). When I watched the HHC 2016 videos, my curiosity was triggered by the report on the newRPL – CL50NR by Gunter Schink. He was reporting on the work done by Claudio L available at In the short, it is about the HP-50G RPL rewrite from scratch into native ARM code using 99% C and the reminder 1% in ASM. In other words, blazing-fast, and be finally able to use the HW of the 50G (and not being poised by the emulation layer). Other improvements are better UI, better numbers support and a bunch of new functionalities.

New RPL for HP-50G - (1)

However, this is not a final release, so beware that not all are available. Nonetheless, you can get an HP-50G for a bit more than $50, so why hesitate? While I am waiting for some parts to advance on my WE project, I decided to give it a try. It happened that I have a spare HP-50G. The installation of the new firmware is straight forward. Copy the firmware image onto an SD card, add a file named update.scp referencing it. Insert the SD card, reset the HP-50G while depressing the + and – keys. Et voila! You are in the update menu. It takes less than 2 minutes and you can reboot under the NewRPL! It is pretty cool, and indeed very fast. The UI seems also more intuitive (but with the 50G, does it really mean anything?). Enjoy the pics & videos.