Troubleshooting
ROBO-8920VG2 User’s Manual
5-4
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 floppy
drive, COM1/COM2 ports, Parallel port, 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
Disable Parallel port to release IRQ #7
Disable PS/2 mouse to release IRQ #12,
Etc…
A quick review of the basic IRQ mapping is given below for your reference.
IRQ#
Description
IRQ #0
System Timer
IRQ #1
Keyboard Event
IRQ #2
Usable IRQ
IRQ #3
COM 2
IRQ #4
COM 1
IRQ # 5
Usable IRQ
IRQ #6
Diskette Event
IRQ #7
Usable IRQ
IRQ #8
Real-Time Clock
IRQ #9
Usable IRQ
IRQ #10
Usable IRQ
IRQ #11
Usable IRQ
IRQ #12
IBM Mouse Event
IRQ #13
Coprocessor Error
IRQ #14
Hard Disk Event
IRQ #15
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.
