M-AUDIO Delta RBUS - Manual (Page 56)

IRQ for each PCI slot on the motherboard. This may be very handy in
resolving IRQ assignments for PCI devices.
Also, sometimes a BIOS is configured to direct a particular IRQ to an ISA
legacy device (non-PnP ISA card), and needs to be told to look for a
PCI/ISA PnP device (some systems default to this, especially with IRQs
3 and 4). Consult your computer or motherboard manual for advice on
how to do this.
Finally, with some systems you will reach the dead-end realization that
you have no available IRQ’s – every one of them is assigned to some
device in the system. This most typically occurs with pre-packaged
computers made by the big-name O.E.M. computer companies. These
computers have so many features packed into them that every IRQ is
consumed. In this type of situation, some kind of reconfiguring or
reprioritizing your system is in order. Optionally, Windows may allow
you to create a second "hardware configuration" which disables some of
the installed devices and makes their resources available for general use.
See your Windows documentation for information on this subject.
56