How do you use gba and n64 roms together?

To use Game Boy Advance (GBA) and Nintendo 64 (N64) ROMs together, you typically need an emulator that supports both systems. Some emulators, like RetroArch with the appropriate cores, allow you to play multiple console games within one interface. Alternatively, you can use separate emulators for each system, loading the respective ROMs into their designated software. Ensure you have the correct ROM files and check the emulator settings for optimal performance.