Help with Pokémon Crystal save not recognized on Goose 2508.1 (Anbernic RG40XXV)

[LloydyGee]

Hello everyone,

I’m brand new to MustardOS and recently installed the Goose 2508.1 OS on my Anbernic RG40XXV — it’s fantastic so far!

I previously used the stock OS on my old MicroSD card, and I’ve now upgraded to a new MicroSD. I flashed the Goose 2508.1 image onto it and am trying to transfer my Pokémon Crystal save from the old OS.

Here’s what I’ve done so far:

• In the /ROMS folder, I created a subfolder called GBC.

• I placed all three files from my previous setup in there:

  • Pokemon Crystal.gbc (ROM)

  • Pokemon Crystal.sav (save file)

  • Pokemon Crystal.rtc (real-time clock)

• All filenames are identical to the original ROM.

• I’ve confirmed that the save file is compatible with Gambatte (the emulator core that muOS uses).

When I boot the OS, the .gbc and .rtc files appear, but the .sav file is hidden (as expected). However, when I launch the game, it does not recognize the save — it only offers “New Game.”

I’m unsure whether the .sav and .rtc files are in the correct location or if there’s something else I should try to make the save load properly.

Any advice or suggestions would be hugely appreciated. Thank you so much!

[TheWalruzz]

Saves should go to MUOS/save/file/{emulator_name} directory, unless you specifically changed that in RetroArch settings to be next to your roms

[LloydyGee]

I’ve made some progress getting my save files working, but I’ve run into a compatibility issue. I tested creating a new save in Pokémon Crystal and found that muOS stores it under:
/MUOS/save/file/Gambatte/

That helped me locate the correct directory, but I noticed muOS saves Game Boy/Color files with the .srm extension, whereas my original save (from the stock Anbernic OS) uses the .sav extension.

I’ve tried a few things — placing the .sav file in the same folder, renaming it to .srm, and confirming the filename matches the ROM exactly — but the game still doesn’t recognize the save.

Is there a proper way to convert or import .sav files so that muOS (Gambatte core) will read them? Or is there a particular setting or emulator core I should use to make it compatible?

Any guidance would be hugely appreciated — I really want to carry my old Pokémon Crystal progress forward.

Thanks in advance!

[TheWalruzz]

I didn’t test it, but this might help: Save File Converter

[LloydyGee]

@TheWalruzz That worked straight away! The initial way I was trying to do it was overtyping the .sav to .srm, and it did not like that. Using that file converter above, I pasted the converted .srm file into the right location, and it appears in game first time! Thank you!