Fixing IO Base and IRQ

["Scott Davis" <scottd@techniquestassociates.com>]

I need some advice.

At present, the application depends on a fixed Base IO address and IRQ.  The
card is an ISA card and the OS is DOS.  Since the ISA bus has disappeared
from current PCs, a PCI equivalent card needs to be designed.  To minimize
the impact on the software it is desired that the Base IO address and IRQ be
the same as that on the ISA card.  From Tom Shanley's book, the Base IO
address can be fixed by using a legacy class code and omitting the Base
Address Registers on the card.  What I can't figure out is how to fix the
IRQ.  I believe that the BIOS selects the IRQs to associate with PCI
interrupts and the application has no control over that.

Does anybody out there have any idea how to fix the IRQ and Base IO address
on a PCI system?

Thanks,

Scott Davis

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Scott Davis
Principal Engineer
TechniQuest Associates
P.O. Box 1822
Nevada City, CA 95959
(530) 263-1314
(530) 265-9589 (FAX)
scottd@techniquestassociates.com
www.techniquestassociates.com