Thank you! at least is more than I have since i didn't want to open it. I still don't fully understand the differences between modes (I only know that depending on the cartridge only one of them works, I believe it has something to do with the mapping maybe).
At least if I could find a compatible software to connect it to the PC that would make a huge difference, since i would be able to load a rom on a real cartridge.
anyway, thanks for investigating!