How do I prioritize hard driver controllers?

[brxndxn]

I boot from a RAID 0 drive on the secondary controller that's built-on the Asus motherboard. I want to add another hard drive to my computer but I have all IDE channels on the motherboard full. But, when I plug in the Ultra Tx2 into the PCI slot and tell my motherboard to boot from the external controller (that usually boots from the RAID controller on the motherboard), it automatically tries to boot from the Ultra TX2.

How do I tell it to boot from the RAID controller on the motherboard and not the Ultra TX2?

 

[VirtualLarry]

Normally, if you have multiple add-in disk controller cards with BIOSes, you can re-arrange the cards in PCI slot order, to get one to boot before the other one. However, if one of the RAID controllers is built into the motherboard... that indeed could be a problem. If the onboard RAID is also based on a Promise chipset, then you might be able to flash the add-in PCI card with a "dummy" BIOS, or possibly vice-versa (obtain a version of the mobo BIOS sans the onboard RAID BIOS). The reason is, Promise BIOSes can control up to two cards/eight drives, but having two different Promise cards/BIOSes in the same system can sometimes cause problems.

My new-ish AMI BIOS on my MSI KT4V-L gives me the choice of the primary boot device explicitly and directly, I don't have to choose between "A:,C:,SCSI" or "CD-ROM,SCSI,C:" or whatever the older BIOSes used as possible boot-order choices.

If there's no other option in terms of mobo BIOS settings, then the only other possibility that I can see, is either: 1) boot off of a floppy, with a customized bootloader that "does the right thing", or 2) get a hold of a modded Promise controller BIOS that doesn't attempt to boot off of any of the drives connected to it, or get someone to mod a BIOS to do that. (Check Wim's BIOS page forums, maybe.)