Confused from reading!
Does each IPL device have a MBR? And, each partition a boot sector? Is the MBR OS independent and the boot sector OS dependent?
I assume the BIOS boot loader looks at the IPL devices to load the primary, then loads the MBR from that device. At that time the Active partition in the MBR is identified and the Boot Sector from that partition is loaded at which time the second stage Boot loaders (NTLDR, LILO, etc..) begin to load the OS into RAM.
Is any of this right?