The figure given next shows the MBR of a Disk with FAT32 partitions. The highlighted area of 64 bytes in the end of the figure represents the Master Partition Table of the MBR.
00H (Byte At Offset 03H) |
01H (Byte At Offset 02H) |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
0 |
1 |
Bits 7 to 0 For Cylinder Number |
Cylinder Bits 9, 8 |
Sector Bits 5 to 0 |
Cylinder Number = 0000000000 (B) = 0 |
Sector Number = 000001(B) = 1 |
Thus Starting C-H-S of the partition= 0-0-1.
Similarly the Head number for the Ending of the partition is FE (Hex), which is 254 and the Encoding for the Ending Cylinder and Sector number of the partition have been given in the next table:
BDH (Byte At Offset 07H) |
BFH (Byte At Offset 06H) |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
7 |
6 |
5 |
4 |
3 |
2 |
1 |
0 |
1 |
0 |
1 |
1 |
1 |
1 |
0 |
1 |
1 |
0 |
1 |
1 |
1 |
1 |
1 |
1 |
Bits 7 to 0 For Cylinder Number |
Cylinder Bits 9, 8 |
Sector Bits 5 to 0 |
Cylinder Number = 1010111101 (B) = 701 |
Sector Number = 111111 (B) = 63 |
