Appendix D. Interrupt Request And Direct Memory Access Channel Assignments - IBM NetVista A21 User Manual

Appendix D. Interrupt request and direct memory access
channel assignments
The following tables list the IRQ and DMA channel assignments.
Table 4. IRQ channel assignments
IRQ System resource
NMI Critical system error
SMI System-management interrupt for power management
0 Timer
1 Keyboard
2 Cascade interrupt from slave PIC
3 COM2 (some models only)
4 COM1
5 LPT2/audio (if present)
6 Diskette controller
7 LPT1
8 Real-time clock
9 Video, ACPI
10 MIDI/joystick (some models only)
11 Available to user
12 Mouse port
13 Math coprocessor
14 Primary IDE (if present)
15 Secondary IDE (if present)
Note: The default settings for COM 1 (IRQ 4), COM 2 (IRQ 3), and LPT 1 (IRQ 7)
Table 5. DMA channel assignments
DMA channel
0
1
2
3
4
5
6
7
© Copyright IBM Corp. 2001
can be changed to another IRQ.
Data width
8 bits
8 bits
8 bits
8 bits
16 bits
16 bits
16 bits
System resource
Open
Open
Diskette drive
Parallel port (for ECP or EPP)
Reserved (cascade channel)
Open
Open
Open
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