Abit AX5 Instruction Booklet page 67

Introduction of BIOS
BIOS Auto-Config PCI IRQ:
This option enables or disables the BIOS capability to automatically assign
IRQs. The BIOS default is Disable.
When you select Enable, the BIOS will automatically assign the correct IRQ
to the interrupt number (INT#) of the PCI slots. When this option is disabled,
you have to assign IRQs used by the interrupt number (INT#) of the PCI
slots.
Xth Available IRQ:
You can select four IRQs out of the 10 listed (IRQ3, 4, 5, 7, 9, 10, 11, 12,
14, 15) to be assigned for use by the interrupt number (INT#) of the PCI
slot
.
1st Available IRQ:
This means that the first interrupt number (INT#) found on the PCI bus will
use this IRQ. That is, this IRQ will be assigned to the first interrupt number
(INT#) found on the PCI bus.
2nd Available IRQ:
This means that the second interrupt number (INT#) found on the PCI bus
will use this IRQ. That is, this IRQ will be assigned to the second interrupt
number (INT#) found on the PCI bus.
The third and the fourth available IRQ will be assigned in sequence to
the third and the fourth interrupt numbers (INT#) found on the PCI
bus.
PCI IDE Card 2nd Channel:
This option can be enabled or disabled. BIOS default is Enable.
Since this channel uses IRQ15, if you want to use this channel, you have to
enable this option to make the BIOS assign IRQ15 to this channel.
PCI IDE Card IRQ Map to:
Three options are available for this item: PCI Auto, PCI-slotX and ISA.
ä PCI-Auto: The onboard BIOS auto-detects which PCI slot has an IDE
card inserted in.
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