HelpPC 2.10 Quick Reference Utility Copyright 1991 David Jurgens

                Disk Partition Table (Fixed disk boot record)

     Offset        Represents:  (see format below)

       01BE        Partition 1 data table  (16 bytes)
       01CE        Partition 2 data table  (16 bytes)
       01DE        Partition 3 data table  (16 bytes)
       01EE        Partition 4 data table  (16 bytes)
       01FE        Signature  (hex 55 AA, 2 bytes)

       Offset from beginning of partition data shown above:

    Offset Size                Description

       00   byte   boot indicator
       01   byte   beginning sector head number
       02   byte   beginning sector (2 high bits of cylinder #)
       03   byte   beginning cylinder# (low order bits of cylinder #)
       04   byte   system indicator
       05   byte   ending sector head number
       06   byte   ending sector (2 high bits of cylinder #)
       07   byte   ending cylinder# (low order bits of cylinder #)
       08   dword  number of sectors preceding the partition
       0B   dword  number of sectors in the partition


       Boot indicator (BYTE)

       00  - non-bootable partition
       80  - bootable partition (one partition only)


       System Indicator (BYTE)

       00 - unknown operating system
       01 - DOS with 12 bit FAT, 16 bit sector number
       02 - XENIX
       04 - DOS with 16 bit FAT, 16 bit sector number
       05 - DOS Extended partition (DOS 3.3+)
       06 - DOS 4.0 (Compaq 3.31), 32 bit sector number
       51 - Ontrack extended partition
       64 - Novell
       75 - PCIX
       DB - CP/M
       FF - BBT


       Signature

       Hex 55AA marks the end of valid boot sector.     This is also
       required in each of the partition boot records.


       Sector/Cylinder

       2 bytes are combined to a word similar to INT 13:

       │7│6│5│4│3│2│1│0│ 1st byte  (sector)
        │ │ └─┴─┴─┴─┴─┴── Sector offset within cylinder
        └─┴───────────── High order bits of cylinder #

       │7│6│5│4│3│2│1│0│ 2nd byte  (cylinder)
        └─┴─┴─┴─┴─┴─┴───── Low order bits of cylinder #


       - all partitions begin on sector 1 head 0, except the first
         partition which follows the disk's master boot record and begins
         in sector 2
       - some of this information may vary with some variants of DOS 3.2
         and DOS 3.3 that use their own sectoring scheme for large disks

       - see  INT 21,32  Disk Partition Table

Esc or Alt-X to exit disk partition table Home/PgUp/PgDn/End ←↑↓→