Game Boy Advance¶

NX Redux ships two Game Boy Advance cores, gpSP and mGBA. You choose one per game by which Roms folder the game is in:

	gpSP	mGBA
Folder	`Roms/Game Boy Advance (GBA)/`	`Roms/Game Boy Advance (MGBA)/`
Strength	Faster	More accurate, better for ROM hacks
Netplay (GBA Link)	Yes, for link and wireless adapter games	No
BIOS	Recommended: `Bios/GBA/gba_bios.bin`	Optional: `Bios/MGBA/gba_bios.bin`
File types	`gba` `bin` `agb` `gbz`	`gba`

Which one to use¶

Start with gpSP in the GBA folder. It is the faster core, and the right choice for most games.

Use mGBA in the MGBA folder for ROM hacks, and for any game that glitches, crashes or runs incorrectly on gpSP. mGBA trades some speed for accuracy, so it handles games that gpSP gets wrong.

Netplay needs gpSP, and a game that supports link play

Only gpSP can play over Netplay, so move a game to the GBA folder to play together. Netplay only works with games that support the GBA link cable or wireless adapter, such as trading and versus modes.

More detail: netplay

A game in the MGBA folder shows no Y NETPLAY hint. Netplay emulates the GBA link cable and wireless adapter, so games without link play have nothing to connect.

gpSP and the BIOS

gpSP has a built-in replacement BIOS, so games start without one. The real gba_bios.bin in Bios/GBA/ improves compatibility. See Cores & BIOS Files.

Using both¶

You can keep the same game in both folders. The game list then shows it twice with the emulator tag, Advance Wars (GBA) and Advance Wars (MGBA). Pick the core each time you play (see duplicate names).

Game Boy Advance game list showing Advance Wars twice, tagged (MGBA) and (GBA)

Saves are kept per folder, in Saves/GBA/ and Saves/MGBA/. To carry your progress across, copy the game's save file from one folder to the other. Save states cannot move between the two cores.

More detail

Battery saves are written in the RetroArch-compatible .srm format by default, which is why the save file can be copied between the folders.

Super Game Boy¶

The Super Game Boy (SGB) folder runs Game Boy games on mGBA as a Super Game Boy. sgb_bios.bin in Bios/SGB/ is optional and gives full Super Game Boy accuracy.

Like the MGBA folder, it has no netplay. Use the Game Boy (GB) folder for Game Boy link cable games.