ASUS P4SGX-MX motherboard user guide
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1.10 Expansion slots
The motherboard has three PCI slots and one Accelerated Graphics Port (AGP) slot.
To install and configure an expansion card:
1. Install an expansion card following the instructions that came with the chassis.
2. Turn on the system and change the necessary BIOS settings, if any. See
Chapter 2 for BIOS information.
3. Install the drivers and/or software applications for the expansion card
according to the card documentation.
1.10.1 Standard interrupt assignments
IRQ Priority Standard Function
0 1 System Timer
1 2 Keyboard Controller
2 N/A Programmable Interrupt
3* 11 Communications Port (COM2)
4* 12 Communications Port (COM1)
5* 13 IRQ holder for PCI steering
6 14 Floppy Disk Controller
7* 15 Printer Port (LPT1)
8 3 System CMOS/Real Time Clock
9* 4 IRQ holder for PCI steering
10* 5 Advance AC’97 CODEC
11* 6 Standard PCI Graphics Adapter (VGA)
12* 7 PS/2 Compatible Mouse Port
13 8 Numeric Data Processor
14* 9 Primary IDE Channel
15* 10 Secondary IDE Channel
* These IRQs are usually available for ISA or PCI devices.
1.10.2 IRQ assignments for this motherboard
ABCDEFGH
PCI slot 1 — used — — — — — —
PCI slot 2 — — shared — — — — —
PCI slot 3 — — — shared — — — —
AGP slot shared — — — — — — —
Onboard USB controller 1 — — — — used — — —
Onboard USB controller 2 — — — — — used — —
Onboard USB controller 3 — — — — — — used —
Onboard USB 2.0 controller — — — — — — — used
Onboard LAN (optional) — — — shared — — — —
Onboard audio — — shared — — — — —
Onboard VGA shared — — — — — — —
When using PCI cards on shared slots, ensure that the drivers support “Share
IRQ” or that the cards do not need IRQ assignments. Otherwise, conflicts will
arise between the two PCI groups, making the system unstable and the card
inoperable.