E x p a n s i o n C a r d s
If you disable the interrupt which has been assigned to serial port 2 you
will disable the IR sensor used for the optional infra-red remote control.
IRQ3 is available if you disable serial port 2 with the BIOS Setup utility.
IRQ4 is available if you disable serial port 1.
Do not disable either one unless you have no intention of using the
affected port. Similarly, if you have no intention of using the
parallel port, you can disable it with the BIOS Setup utility,
completely freeing IRQ7 for use by an expansion card.
Direct memory access (DMA) channel
Some hardware devices can use a DMA channel to access system
memory without directly burdening the processor. Computers have
DMA channels numbered DMA0 to at least DMA7.
The following table lists the DMA channels used by the computer
and shows which are available for use by expansion cards.
LS/VS 550 OWNER'S HANDBOOK
Primary ATA/IDE interface
Secondary ATA/IDE interface
Diskette/floppy disk controller