If your SD card is larger than the firmware image, use a partition manager to ensure you can use the remaining space for games.
Most stock M3 units don't support save states. CFW allows you to save your progress anywhere in the game—a must-have for difficult retro titles.
Use a tool like BalenaEtcher or Win32DiskImager to write the custom firmware .img file to your new SD card.
The SUP M3 is a fantastic little device for its price, but the stock software barely scratches the surface of what it can do. By installing , you transform a "cheap toy" into a legitimate pocket-sized emulation station.
Drop your .nes , .gb , or .gba files into the designated "ROMs" folder.
The biggest draw. Custom firmware allows you to load your own ROMs via the microSD card, so you can finally play the specific titles you grew up with.
Some CFWs are mapped for different handheld layouts. Look for a mapping.cfg file in the system folder to remap your A/B and X/Y buttons.