Asus M3A78 - Manual (Page 32)

1-20 Chapter 1: Product introduction
Interrupt assignments
IRQ Standard function
0 System timer
1 Standard 101/102-Key or Microsoft Natural Keyboard
2 Programmable interrupt controller
3 Standard OpenHCI USB Host Controller
4 Communications Port (COM 1)*
5 ACPI IRQ Holder for PCI IRQ Steering
6 (free)
7 (free)
8 System CMOS / Real Time Clock
9 SCI IRQ used by ACPI bus
10 Standard PCI Graphics Adapter (VGA)
11 (free)
12 Microsoft PS/2 Port Mouse
13 Numeric data processor
14 Primary IDE controller (single fifo)
15 Secondary IDE controller (single fifo)
* This IRQ is usually available for ISA or PCI devices.