Technical information

Appendix C. IRQ and DMA Channel Assignments
Appendix C. IRQ and DMA Channel Assignments
The following tables list the interrupt request (IRQ) and direct memory access (DMA) channel
assignments.
Table 53. IRQ Channel Assignments
IRQ System Resource
NMI Critical system error
SMI System/power management interrupt
0 Reserved (internal timer)
1 Reserved (keyboard)
2 Reserved (interrupt controller) timer in APIC mode
9
3
8
Infrared
4
8
Serial port
5 Available
6 Diskette
7
8
Parallel port
8 Real-time clock
9 Available
10 Available
11 Available
12
8
Mouse
13 Coprocessor
14 IDE drives (0, 1) if installed
15 IDE drives (2, 3) if installed
8
Can be modified to alternate settings or disabled.
9
With dual processing, the advanced programmable interrupt controller (APIC) manages hardware interrupts to the system BIOS.
The following interrupts are available only in the dual-processing APIC mode.
IRQ System Resource
16 PCI device
17 PCI device
18 PCI device
19 PCI device
20 Not available
21 Not available
22 Not available
23 Not available
24 SMI
46  Copyright IBM Corp. 1996, 1997