Asus P5A-B - Manual (Page 24)

24 ASUS P5A-B User’s Manual
III. INSTALLATION
Expansion Cards
III. INST
ALLA
TION
To simplify this process, this motherboard complies with the Plug and Play (PNP)
specification which was developed to allow automatic system configuration when-
ever a PNP-compliant card is added to the system. For PNP cards, IRQs are as-
signed automatically from those available.
If the system has both Legacy and PNP ISA cards installed, IRQs are
assigned to PNP cards from those not used by Legacy cards. The PCI and PNP
configuration of the BIOS setup utility can be used to indicate which IRQs are being
used by Legacy cards. For older Legacy cards that do not work with the BIOS, you
can contact your vendor for an ISA Configuration Utility.
An IRQ number is automatically assigned to PCI expansion cards after those used by
Legacy and PNP ISA cards. In the PCI bus design, the BIOS automatically assigns an
IRQ to a PCI slot that has a card in it that requires an IRQ. To install a PCI card, you need
to set something called the INT (interrupt) assignment. Since all the PCI slots on this
motherboard use an INTA #, be sure that the jumpers on your PCI cards are set to INT A.
Assigning DMA Channels for ISA Cards
Some ISA cards, both legacy and PnP, may also need to use a DMA (Direct Memory
Access) channel. DMA assignments for this motherboard are handled the same way
as the IRQ assignment process described earlier. You can select a DMA channel in
the PCI and PnP configuration section of the BIOS Setup utility.
IMPORTANT: To avoid conflicts, reserve the necessary IRQs and DMAs for legacy
ISA cards (under PNP AND PCI SETUP of the BIOS SOFTWARE, choose Yes in IRQ
xx Used By ISA and DMA x Used By ISA for those IRQs and DMAs you want to reserve).
ISA Cards and Hardware Monitor
The onboard hardware monitor uses the address 290H-297H, so legacy ISA cards
must not use this address or else conflicts will occur.
Accelerated Graphics Port
This motherboard provides an accelerated graphics port (AGP) slot to support a new
generation of graphics cards with ultra-high memory bandwidth, such as an ASUS
3D Hardware Accelerator.
P5A-B Accelerated Graphics Port (AGP)
R
NOTE: You must first install the AGP Mini Port Driver (see
support CD) to avail of the motherboard’s AGP features.