What exactly is newRPL?

newRPL is a re-implementation of the HP48/49/50 series calculators programming environment. The RPL scripting language is being redesigned and recreated with even more powerful features.

While this new implementation is written in portable C, initially, the target will be the HP50g hardware, consisting on the following:

  • ARM 920T processor running at up to 200 MHz
  • 512 KBytes of RAM
  • 2 MBytes of NOR flash memory.
  • 16-grays screen, 131x80 pixels

Simultaneously, a simulator for the PC environment is being used for development and also offered to the users for testing.

Being a complete firmware replacement, installing newRPL on a HP 50g calculator completely removes the old Operating System and transforms the calculator into a newRPL device. The installation process is no different from installing any other ROM updates, and is completely reversible: simply flash the original "stock" firmware from HP and the calculator will be back to normal.

The newRPL firmware provides a few advantages over the standard OS:

  • An order of magnitude faster
  • More RAM available to the user
  • Arbitrary numeric system precision up to 2000 digits
  • Dual soft-menu interface
  • Many keyboard shortcuts to work more efficiently
  • More powerful units
  • Faster support for SD cards, including SDHC cards
  • 8-level stack undo/redo
  • Unicode text support throughout for better exchange of information with other devices


The firmware is usable as a programmable scientific calculator. For more details refer to the Project Status page.

The firmware image can be downloaded from the Downloads page.