Reviewing System Features 3-7
Interrupt Level Assignments
INTERRUPT PRIORITY
INTERRUPT DEVICE
IRQ00
Counter/Timer
IRQ01
Keyboard
IRQ02
Cascade (INT output from slave)
IRQ03
COM2*
†
IRQ04
COM1
IRQ05
LPT2 (Plug and Play option)/
Audio/User Available
IRQ06
Diskette Drive Controller
IRQ07
Parallel Port 1
IRQ08
Real-time clock
IRQ09
Reserved
IRQ10
Windows Sound System
IRQ11
User Available
IRQ12
PS/2 mouse
IRQ13
Coprocessor
IRQ14
Primary IDE
IRQ15
Secondary IDE
* Default, but can be changed to another IRQ.
† Disabled by default in some systems.
PCI Local Bus
The 32-bit industry-standard PCI bus is a highly integrated
input/output (I/O) interface that offers the highest
performance local bus available for the Pentium-based
processor. The PCI bus supports burst modes that send
large chunks of data across the bus, allowing fast displays
of high-resolution images.