IDE hard disks in themselves have no organisation other than the sectors (512 bytes), all other organisation is down to the application using the drive (i.e Windows, Linux). If it's FAT32 info you are seeking then go to pjrc.com, linux is widely published. As for actually using a drive, it's basically a large memory accessed by 8 bit control and 16 bit data resister, and this has been widely discussed on this forum.