struc BPB
 bpbBytesPerSec         dw ?    ; Bytes per sector
 bpbSecPerClust         db ?    ; Sectors per cluster
 bpbResSectors          dw ?    ; No. of reserved sectors
 bpbFATs                db ?    ; No. of file allocation tables
 bpbRootDirEnts         dw ?    ; No. of root-directory entries
 bpbSectors             dw ?    ; Total no. of sectors
 bpbMedia               db ?    ; Media descriptor
 bpbFATsecs             dw ?    ; No. of sectors per FAT
 bpbSecPerTrack         dw ?    ; Sectors per track
 bpbHeads               dw ?    ; No. of heads
 bpbHiddenSecs          dd ?    ; No. of hidden sectors
 bpbHugeSectors         dd ?    ; No. of sectors if bpbSectors = 0
ends