Compaq AP500 User Manual
Page 136
7-3
Compaq Professional Workstation AP500 Maintenance and Service Guide
Table 7-2
System Interrupts
Hardware IRQ
System Function
IRQ 0
System timer
IRQ 1
Keyboard (not on ISA Bus)
IRQ 2
Used by Interrupt Controller 2
IRQ 3
Serial port (COM 2)
IRQ 4
Serial port (COM 1)
IRQ 5
ESS sound chip
IRQ 6
Diskette drive
IRQ 7
Parallel port (LPT 1)
IRQ 8
Real-time clock
IRQ 9
Unavailable (used for ACPI support)
IRQ 10
Unused
IRQ 11
PCI Interrupts
IRQ 12
Mouse
IRQ 13
Non-catastrophic errors/CPU error
IRQ 14
Primary IDE controller
IRQ 15
Secondary IDE controller
Table 7-3
System Direct Memory Access (DMA)
Hardware DMA
System Function
DMA 0
Business audio (default)
DMA 1
Business audio (default)
DMA 2
Diskette drive
DMA 3
ECP Parallel port LPT1 (default)
DMA 4
DMA Controller cascading (not on ISA Bus)
DMA 5
Unused
DMA 6
Unused
DMA 7
Unused