Appendix B
RUBY-7720VG2A User’s Manual
Interrupt Request Lines (IRQ)
Peripheral devices can use interrupt request lines to notify CPU for the service
required. The following table shows the IRQ used by the devices on board.
IRQ#
Current Use
Default Use
IRQ 0
System ROM
System Timer
IRQ 1
System ROM
Keyboard Event
IRQ 2
[Unassigned]
Usable IRQ
IRQ 3
System ROM
COM2
IRQ 4
System ROM
COM1
IRQ 5
[Unassigned]
Usable IRQ
IRQ 6
System ROM
Diskette Event
IRQ 7
[Unassigne]
Usable IRQ
IRQ 8
System ROM
Real-Time Clock
IRQ 9
[Unassigned]
Usable IRQ
IRQ 10
[Unassigned]
Usable IRQ
IRQ 11
[Unassigned]
Usable IRQ
IRQ 12
System ROM
IBM Mouse Event
IRQ 13
System ROM
Coprocessor Error
IRQ 14
System ROM
Hard Disk Event
IRQ 15
[Unassigned]
Usable IRQ