The original firmware in the HP 50g emulates a Saturn CPU
like the HP 48 and HP 49 had. However, the built-in ARM920T
processor has more power than the Saturn.
And now there's a firmware to unleash the power: newRPL
It's very usable at this point, but not all features are implemented yet. You can see the current
status on the detailed project status page.
Grav was with by Trilby Media.