What is needed

  • HP 50g (although this calculator was discontinued by HP in 2015, used calculators can, of course, always be found on Ebay). It is recommended to have fresh batteries installed.
  • SD card (2 GB, formatted with FAT16)
  • ROM file: newrplfw.bin (get the latest from here)
  • Text file: update.scp

newRPL ROM installation Instructions

  1. The update.scp text file contains only the name of the ROM file, newrplfw.bin. Note that the text file must be a plain text file, so it cannot have embedded codes that frequently accompanies documents created with, for example, Microsoft Word. The text file can be created on a Mac using TextEdit, Windows using Notepad, or on linux using Vi (or any text editor of choice). Put both the update.scp and newrplfw.bin files in the root filesystem of the SD card. Insert the SD card into the calculator.
  2. Enter the Boot/Self Test Mode: Power the calculator OFF, press and hold the plus(+) and minus(-) keys simultaneously, insert a paper clip into the reset hole on the back of the calculator, remove the paper clip and then release the plus/minus keys after a few seconds. The screen will have two options when in this mode: 1. UPDATE CODE, and 2. SELFTEST (the Boot version and the serial number appear at the bottom of the screen).
  3. Enter mode 1. UPDATE CODE
  4. Choose 2. CARD

(Figure shows screen shots of the installation as it proceeds)

ROM Installation

The ROM update will take about 2 minutes during which time a series of Hex values will scroll down the screen. At the end of the update the total size of the ROM will be printed, press ENTER. If all goes well you will be presented with the newRPL display interface. Since the ROM filename itself doesn't contain its version, use the command VERSION to return the installed version information.

Warning! Installing newRPL will overwrite the entire 2MB of flash in the calculator. This includes the ROM, and also all user flash banks in Port 2. Using newRPL for the first time will also erase all RAM, including TEMPOB, USEROB, PORT 0 and ERAM 1. Remember to backup everything, including your libraries in Port 2 before installing the newRPL ROM.

How to revert to the stock ROM

To revert back to the stock HP ROM that came with the HP50g, just follow the directions above for loading the newRPL ROM, the only difference being the ROM file used. In this case, use the stock HP50g ROM file. For this case, the contents of the update.scp file would need to be changed to reflect this new ROM filename.

The ROM update will take about 2 minutes during which time a series of Hex values will scroll down the screen. At the end of the update the total size of the ROM will be printed, press ENTER. If all goes well you will be presented with the stock HP50g screen.

The latest HP50g stock ROM file (if you don't already have it) is currently available on the hpcalc.org website: http://www.hpcalc.org/details/7097

The downloadable ZIP archive contains another zip file, 2MB FIX.zip, which contains a ROM image that can fix problems with port 2. Because newRPL overwrites all of Port 2, this ROM file, 2MB_215f.bin, is required in order to revert back after the newRPL ROM was installed.