System Specifications B-11
Interrupt Requests (IRQs)
Interrupt Assignments
IRQ
NORMAL ASSIGNMENT
NMI
I/O channel check
0
Reserved, interval timer
1
Reserved, keyboard controller
2
Reserved, cascade interrupt from slave PIC
3
COM2*
4
COM1*
5
LPT2 (Plug and Play option)/audio/user available
6
Diskette drive controller
7
Parallel Port 1 (LPT1)*
8
Real time clock
9
Reserved
10*
User available
11*
Windows Sound System*/user available
12
PS/2 mouse port if present, else is user available
13
Reserved, numeric processor
14
Primary IDE channel if present, else is user
available
15
Secondary IDE channel if present, else is user
available
*Default, but can be changed to another IRQ
