; ------------------------------------------ ; This will be where the floppy FAT12 header ; Bytes 3-61 ; https://technet.microsoft.com/en-us/library/cc976796.aspx ; Values are those used by IBM for 1.44 MB, 3.5" diskette ; ------------------------------------------ OEM_name db "DeanOS " ; Bytes 03-10 - OEM name (Original Equipment Manufacturer) The name for the bootloader/OS Bytes_per_sector dw 512 ; Bytes 11-12 - Number of bytes per sector (usually 512 bytes) Sectors_per_cluster db 1 ; Bytes 13 - Number of sectors per cluster, is 1 because in FAT12 a cluster is the same as a sector Reserved_sectors dw 1 ; Bytes 14-15 - For FAT12 is 1 FAT_tables db 2 ; Bytes 16 - Number of FAT tables (usually 2) Root_directory_size dw 224 ; Bytes 17-18 - Size of root directory entries 224 for FAT12 Sectors_in_filesystem dw 2880 ; Bytes 19-20 - Total number of sectors in the file system (usually 2880) Media_descriptor_type db 0xF0 ; Bytes 21 - Media descriptor: 3.5" floppy 1440KB Sectors_per_FAT dw 9 ; Bytes 22-23 - Number of sectors per FAT is 9 Sectors_per_track dw 18 ; Bytes 24-25 - Number of sectors per track is 12 but found to be 9 Head_count dw 2 ; Bytes 26-27 - Number of heads/sides of the floppy (usually 2) Hidden_sectors dd 0 ; Bytes 28-31 - Number of hidden sectors (usually 0) Total_sectors dd 0 ; Bytes 32-35 - Total number of sectors in file system Logical_drive_number db 0 ; Bytes 36 - Logical drive number (0) Reserved db 0 ; Bytes 37 - Reserved sectors Extended_signature db 0x29 ; Bytes 38 - Indicates that there 3 more fields Serial_number dd 0xA1B2C3D4 ; Bytes 39-42 - Serial number, can be anything Volume_lable db "OS bootdisk" ; Bytes 43-53 - Name of the volume, 11 characters Filesystem_type db "FAT12 " ; Bytes 54-61 - File system type (FAT12), 8 characters ; ------------------------------------------ ; End of FAT12 header ; ------------------------------------------