System interrupt specifications, Intel
Hardware IRQ System function
IRQ0 System timer
IRQ1 Standard 101-/102-Key or Microsoft® Natural Keyboard
IRQ2 Cascaded
IRQ3 Intel 82801DB/DBM USB2 Enhanced Host Controller—24CD
IRQ4 COM1
IRQ5* Conexant AC—Link Audio Intel 82801DB/DBM SMBus Controller—24C3 Data Fax
Modem with SmartCP
IRQ6 Diskette drive
IRQ7* Parallel port
IRQ8 System CMOS/real-time clock
IRQ9* Microsoft ACPI-compliant system
IRQ10* Intel USB UHCI controller—24C2
Intel 82852/82855 GM/GME Graphic Controller
Realtek RTL8139 Family PCI Fast Ethernet Controller
IRQ11 Intel USB EHCI controller—24CD
Intel USB UHCI controller—24C4
Intel USB UHCI controller—24C7
Intel Pro/Wireless 2200BG
TI OHCI 1394 host controller
TI PCI1410 CardBus controller
IRQ12 Synaptics PS/2 TouchPad
IRQ13 Numeric data processor
IRQ14 Primary IDE channel
IRQ15 Secondary IDE channel
*Default configurations are IRQ5, IRQ7, IRQ9, IRQ10, or none.
NOTE: PC Cards may assert IRQ3, IRQ4, IRQ5, IRQ7, IRQ9, IRQ10, IRQ11, or IRQ15. Either the infrared or the serial port
may assert IRQ3 or IRQ4.

System interrupt specifications, Intel 93