Asus P55SP4 P/I-P55SP4 User's manual - Page 24

Upgrade Guide Any PCI expansion cards that need to use an IRQ have one automatically assigned from the IRQs remaining after Legacy and PNP ISA cards have had theirs assigned. 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" assignment. Since all the PCI slots on this mainboard use "INTA#", you only need to make sure that any PCI card you install is 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 mainboard are handled the same way as the IRQ assignment process described above. If you don't use an ICU program, you can select a DMA channel in the PCI and PNP Configuration section of the BIOS Setup utility. The MediaBus Slot The PCI4 slot is both a standard PCI slot and, combined with its slot extension, forms a proprietary MediaBus slot for ASUSTek MediaBus expansion cards. The slot extension is an ISA extension that allows combining of a PCI card and an 16-bit ISA card on one composite card. Review the documentation for a particular card for an explaination of how to install and set it up, including any IRQ use. 2 - 5