I just bought a SanDisk 2 GB Micro SD Card for my Famicom EverDrive N8 , I don't need a big Card like a 4 or a 8 GB one I copied the OS in there from krikzz site..The lastest version is 13 I'm getting Error A7, Tried formatting in FAT, still the same thing..
Got another sd card to test with? What did you use to format the card? Have you tried unplugging the sd and plugging in again?
Your card is the problem. N8 isn't coded to handle or understand SD card smaller than 4GB. Get SDHC class cards (4GB to 32GB) and try those.