erstood by the BIOS
INT 0x13 low-level disk interface: e.g. 0x00 for the first floppy disk or
0x80 for the first hard disk.<P>

The three remaining bytes specify the boot partition.  'part1' specifies
the "top-level" partition number, 'part2' specifies a "sub-partition" in
the top-level partition, etc.  Partition numbers always start from zero.
Unused partition bytes must be set to 0xFF.  For example, if the disk is
partitioned using a simple one-level DOS partitioning scheme, then 'part1'
contains the DOS 