Ed64 Plus Firmware Here

by opening the cartridge (four screws) and checking the PCB silkscreen. If you have a v3.0, stick with stock firmware or test Alt64 carefully.

There are hardware revisions of the ED64 Plus PCB (Printed Circuit Board). Some revisions are compatible with the "Alt" OS versions used by the community, while others require the specific OS shipped by the seller. If you try to force an incompatible OS, the screen may remain black upon boot. ed64 plus firmware