mov byte ptr [BootDrive], dl
// Now check if this computer supports extended reads. This boot sector will not work without it
-CheckInt13hExtensions:
+CheckInt13hExtensions:
mov ah, HEX(41) // AH = 41h
mov bx, HEX(55aa) // BX = 55AAh
int HEX(13) // IBM/MS INT 13 Extensions - INSTALLATION CHECK