Asus P/I-P55T2P4 - Manual (Page 23)

ASUS P/I-P55T2P4 User's Manual 17
III. INSTALLATION
(DMA Channels)
III. INST
ALLA
TION
Both ISA and PCI expansion cards may need to use IRQs. System IRQs are avail-
able to cards installed in the ISA expansion bus first, and any
remaining IRQs are then used by PCI cards. Currently, there are two types of ISA
cards. The original ISA expansion card design, now referred to as “Legacy” ISA
cards, requires that you configure the card’s jumpers manually and then install it in
any available slot on the ISA bus. You may use Microsoft's Diagnostic (MSD.EXE)
utility included in the Windows directory to see a map of your used and free IRQs.
For Windows 95 users, the "Control Panel" icon in "My Computer," contains a "Sys-
tem" icon which gives you a "Device Manager" tab. Double clicking on a specific
device give you "Resources" tab which shows the Interrupt number and address.
Make sure that no two devices use the same IRQs or your computer will experience
problems when those two devices are in use at the same time.
To simplify this process this motherboard has complied 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 does 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 above. You can select a DMA channel in
the PCI and PNP configuration section of the BIOS Setup utility.
IMPORTANT: Choose "Yes" for those IRQ's and DMA's you wish to reserve
for Legacy (Non-PnP) ISA expansion cards in “IRQ xx Used By ISA” and “DMA
x Used By ISA” of the PNP and PCI Setup in the BIOS SOFTWARE section,
otherwise conflicts may occur.