some sd-cards have on MBR some not. MBR 512 Byte Byte Word $000 $00 .. $1C6..1c9 $e3 first sector of first partition (little endian) -------------------------- usage from goldmomo_endlos SD Card no MBR Block 0 (goldmomo ident) Block 1 data .... SD Card with MBR Block 0 MBR Block n (goldmomo ident) Block m data -------------------------- detection load block 0 check ident first eight byte are "goldmomo" yes -> next block (block 1) is data no -> next block is defined at $e3 -> check ident first eight byte are "goldmomo" -> yes next block (block 1) is data -> no ... no goldmomo :-(