Hello,
I am wondering how I should specify the RetroAchievement credentials on the mgba's port for 3DS.
Unless you mean the RetroArch build of mGBA, you don't. That's not a feature that mGBA has. And if you mean the RetroArch build, I have no idea. You're on the wrong forum.
Thank you for the answer.
Can you explain more this statement (from the 0.5.0 release log) :
Quote:Libretro: Memory map and achievement support (leiradel)
It's a feature written by leiradel that is exclusive to the libretro core, as used in RetroArch. The official frontends do not have this feature.