Insert the SD card into your M3, then insert the M3 into your Nintendo DS (or DS Lite).
Do you know the printed inside your device? sup m3 custom firmware verified
Budget handhelds like the SUP M3 often undergo silent hardware revisions, meaning units bought months apart might use different internal chipsets (e.g., specific variations of Actions or Allwinner chips). Check the readme file of your chosen custom firmware to ensure your specific board version is supported. Step 2: Format the MicroSD Card Insert the SD card into your M3, then
To connect the card to your PC or Mac.