Server Scan Sequence - Digital Equipment Digital Server 3220 Series System Reference Manual

Installing Expansion Boards

Server Scan Sequence

If the boot device is neither the CD-ROM drive or the diskette drive, then the
operating system will be found on drive C. The location of drive C can be determined
as follows:
1. The search for a bootable device begins from a low ROM address to a high
ROM address (starting at C8000h through EFFFFh). The boot device with
the lower address is assigned higher priority (this is drive C).
2.
When the server BIOS detects PCI expansion boards with ROMs installed in
PCI slots, it copies all the ROMs of the expansion boards to C8000 - DFFFF
areas in ascending order. The first scanned PCI expansion board occupies
the address area starting from the first available area. This could be C8000
if C8000 is available. The second scanned PCI expansion board occupies
the second available address area behind C8000, and so forth.
3.
If a bootable ISA expansion board is configured to occupy the C8000 region,
the server BIOS puts the existing PCI devices behind that region. When the
ISA expansion board is configured to occupy the C8000 address, PCI
bootable devices are not the first bootable device drive C.
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