SameBoy Core on iPhone & iPad | Retropa

What SameBoy can open

SameBoy comes from the project at https://github.com/LIJI32/SameBoy, and Retropa wires it up for a deliberately narrow slice of hardware. Only catalog entries count here, so treat upstream features as out of scope. A file extension in the list is a starting point, not a compatibility guarantee for a specific game. Nobody is bundling ROMs or BIOS images, so import your own files and stay within what you are allowed to use.

• Game Boy: .gb
• Game Boy Color: .gbc

Checking color with the filter off

Bring in a file you have saved locally and see whether the app reads it as Game Boy or Game Boy Color. Leave the display on its original setting, because a DMG treatment can drain the color out of a color title on purpose. Compare one scene you know changes palette, and compare that same scene both times rather than two different moments.

Timing, sound and the buttons

Start on the default skin and check the directional pad, A, B, Start and Select. When timing or sound feels off, note the exact moment it happens and whether it survives with display effects turned off. With Retropa Plus you can line the game up against another compatible core to narrow down where the difference lives, but seeing a difference does not prove which core matches real hardware.

When it is worth changing cores

Changing cores is a Retropa Plus feature, even though Game Boy and Game Boy Color play for free. It is worth doing only when you can name the problem: a specific sound, a specific frame, a specific button. Choose a core that supports both the system and the format, because a mismatch gets you nowhere. Retropa remembers the pick per game, so keep a copy of the in-game save and of any save states from the core you started on before you test the same scene twice.

• SameBoy save states describe SameBoy's running state and are not a portable format for another core.
• Verify the in-game save separately before comparing SameBoy with another core; migration is not automatic.
• Changing cores from SameBoy cannot rewrite the file or fill a missing BIOS.

A Game Boy core, not a GBA one

GBA files sit outside this core's remit: point one at a catalog's GBA-capable core instead, and do not expect an extension change to make SameBoy accept it. A save state written by a different core will not travel either. Hold on to the old state, and test an in-game save backup on its own before you rely on it.