Troubleshooting
ROBO-8112VG2AR User’s Manual
5-3
Improper disable operation
There are too many occasions where users disable a certain device/feature in one
application through BIOS setting. These variables may not be set back to the original
values when needed. These devices/features will certainly fail to be detected.
When the above conditions happen, it is strongly recommended to check the BIOS
settings. Make sure certain items are set as they should be. These include the COM1/
COM2 ports, USB ports, external cache, on-board VGA and Ethernet.
It is also very common that users would like to disable a certain device/port to release
IRQ resource. A few good examples are
Disable COM1 serial port to release IRQ #4
Disable COM2 serial port to release IRQ #3
Etc…
A quick review of the basic IRQ mapping is given below for your reference.
Interrupt Request Lines IRQ
IRQ#
Current Use
Default Use
IRQ 0
Unused
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
Unused
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
It is then very easy to find out which IRQ resource is ready for additional peripherals. If
IRQ resource is not enough, please disable some devices listed above to release further
IRQ numbers.
