Some interrupts are fixed, others can be re-assigned. The following
table lists the interrupts used by the computer and shows which may
be available for use by expansion cards.
With the BIOS Set-up utility IRQs 3 and 4 are available if you
disable serial ports 2 and 1 respectively. Similarly, if you have no
intention of using the parallel port, you can disable it with the BIOS
Set-up utility, freeing IRQ7. Do not disable ports unless you have
no intention of using them.
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 DMA7.
PIC daisy chain
Serial port 2
Serial port 1
Real time clock
Primary ATA/IDE interface
Secondary ATA/IDE interface
*If SCSI controller card fitted
S Y S T E M E X P A N S I O N