Manual IRQ allocation

[Wavy Davy]

How do you set manual IRQs for PnP PCI cards. I tried the INT Pin (1 thru 4) Assignment in the PnP PCI configuration setup menu, but it did not seem to work effectively. Does Pin 1 correspond to the first PCI slot (ie the one below the AGP slot)? Nothing in the manual on Pin allocation, so any help would be appreciated. At the momemt I my Geforce MX is IRQ 5 on auto!!!

Again, cheers!!!

Wavy

[bugblatt]

I had to do some pratting about when I got my Pro2A, it was a bit hit-and-miss but as far as I could tell pin 1 is the AGP slot. Some of the PCI slots seem to share the same pin, as changing the IRQ for some pins changed the IRQ for two cards. In the end I got it sorted by trying cards in different slots.

[bugblatt]

I had to do some pratting about when I got my Pro2A, it was a bit hit-and-miss but as far as I could tell pin 1 is the AGP slot. Some of the PCI slots seem to share the same pin, as changing the IRQ for some pins changed the IRQ for two cards. In the end I got it sorted by trying cards in different slots.

[Wavy Davy]

Did a little more fiddling last night, and I can confirm Bugblatt, you are right..... PIN 1 is AGP.
What I found out:

PIN 1 AGP
PIN 2 PCI SLOT 1
PIN 3 PCI SLOT 2
PIN 4 PCI SLOT 3

The other lower slots share IRQs with the above. I thought AGP and PCI SLOT 1 shared an IRQ normally, but on this mobo you can assign different IRQs to it. That is what threw me at first. I wonder why the lower PCI slots can not have IRQs manually assigned to them? If anyone knows I would love to know.....

Cheers,

Wavy

[dukla2000]

Wavy Davy et al are correct. I also found this a tad restrictive as in the good old days it was essential to avoid IRQ sharing. Fortunately this mobo seems stable even if you do share some IRQs.

Some more details from my explorations (I remember way back when a mapping table of 8h, 9h, Ah, Ch etc to IRQ but couldnt find it):

PIN 1 AGP
PIN 2 PCI SLOT 1 (shares with PCI Slot 4)
PIN 3 PCI SLOT 2 (shares with on board sound)
PIN 4 PCI SLOT 3 (shares with USB)
PIN 2 PCI SLOT 4 (shares with Slot 1)
PIN 3 PCI SLOT 5 (shares with on board sound)
PIN 4 PCI SLOT 6 (shares with USB)

So if you use the on board sound and USB (I do), then slot 4 (or 1, except too close to AGP for cooling) is the only one that picks up a free IRQ.

So my frustration is that although I free IRQ 3 (by putting both COM on IRQ4) and IRQ 7 (my printer is on the network), I still land up with my modem (in slot 3) on same IRQ as USB and IRQ 9 is unused.

BTW - make sure you set PnP OS = NO in BIOS/PnP, PCI settings, otherwise Windoze promptly 'fixes' the IRQ settings the BIOS made (usually for the worse).

Chris