What is a Master Boot Record (MBR)?
At the end of the ROM BIOS bootstrap routine (which occurs when your PC first boots up), the BIOS reads and executes the first physical sector of the first boot device (floppy, hard disk, CD-ROM, or DVD-ROM) on the system. This first sector is called the Master Boot Record (also known as the partition table, or master boot block). At the start of this sector is a small program. This program uses the partition information (or partition table) stored at the end of the sector to determine which partition is bootable (usually the first primary DOS partition), and then attempts to boot from it. The values in the partition table (contained in the MBR) depend directly on the size of the physical disk and on the logical partitioning on that disk. The DOS Boot Record (DBR) holds the Boot Parameter Block (BPB), which contains the logical mapping information for that particular partition. The values in the Boot Parameter Block are absolutely dependent on the size of the partition and the type of
At the end of the ROM BIOS bootstrap routine (which occurs when your PC first boots up), the BIOS reads and executes the first physical sector of the first boot device (floppy, hard disk, CD-ROM, or DVD-ROM) on the system. This first sector is called the Master Boot Record (also known as the partition table, or master boot block). At the start of this sector is a small program. This program uses the partition information (or partition table) stored at the end of the sector to determine which partition is bootable (usually the first primary DOS partition), and then attempts to boot from it. The values in the partition table (contained in the MBR) depend directly on the size of the physical disk and on the logical partitioning on that disk. The DOS Boot Record (DBR) holds the Boot Parameter Block (BPB), which contains the logical mapping information for that particular partition. The values in the Boot Parameter Block are absolutely dependent on the size of the partition and the type of
