User`s manual

4. BIOS SETUP
according to the type of IDE interface(s) installed in your system (PCI or ISA).
Standard ISA interrupts for IDE channels are IRQ14 for primary and IRQ15 for
secondary.
Primary/Secondary IDE INT#
Each PCI peripheral connection is capable of activating up to 4 interrupts: INT# A,
INT# B, INT# C and INT# D. By default, a PCI connection is assigned INT# A.
Assigning INT# B has no meaning unless the peripheral device requires two interrupt
services rather than just one. Because the PCI IDE interface in the chipset has 2
channels, it requires 2 interrupt services. The primary and secondary IDE INT# fields
default to values appropriate for 2 PCI IDE channels, with the primary PCI IDE
channel having a lower interrupt than the secondary.