System Configuration 2-3

Interrupt Level Assignments*

Interrupt Priority Interrupt Device
NMI I/O Channel Check
IRQ00 System Timer
IRQ01 Keyboard
IRQ02 Programmable Interrupt Cascade
IRQ03 COM2*
IRQ04 COM1*
IRQ05 LPT2 (plug and play option)/Audio integrated on system
board/User available
IRQ06 Diskette Drive Controller
IRQ07 Parallel Port 1
IRQ08 Real-Time clock
IRQ09 User Available
IRQ10 User Available
IRQ11 User Available (used by network board if present)*
IRQ12 Mouse
IRQ13 Reserved, Math Coprocessor
IRQ14 Primary IDE
IRQ15 Secondary IDE
* In Plug and Play s ystems, these interr upts are typical but may vary by configur ation.
Parallel Port Interrupts

The parallel p ort I/O inte r rupts are give n in the follo w ing table. T he table lists

all of the possible configurations but the port only uses one set. Any interrupts

used for the built-in parallel port are not available for ISA parallel ports.

Parallel Port Interrupts

Port Interrupt
LPT1 IRQ05
LPT2 IRQ05
LPT3 IRQ05
LPT1 IRQ07
LPT2 IRQ07
LPT3 IRQ07