1) no default
2) no default
3) A220 I5 D1 H5 P330 E620 T6 (maybe)

the first two wont have defaults since they're PCI devices, and PCI devices only have access to four IRQ's. A B C D. which get translated to other IRQ, which are set by the bios or the OS.
the last one might have that as default but since it's Plug 'n Pray, you might as well pray.

Yes, The motherboard bios I am using assigns IRQ’s to the PCI and ISA slots.
Which IRQs should I use ?

reserve 5 2 9 for the ISA
set NIC to 10 or 11
VGA none

Why do you want to reserve IRQs for the PCI cards in the first place?

And it is almost a 100% certainty that IRQs are going to be shared between onboard devices and the PCI slots.

Windows will take care of resource assignment.

Is this another troll thread?

cyclone3d wrote on 2021-09-19, 15:11:

Is this another troll thread?

I think it is. I almost fell for one when he was asking about which graphics card with 3D acceleration was good for Windows 95 and eventually stopped responding.

IRQ on PCI devices doesn't really matter at all.

Gmlb256 wrote on 2021-09-19, 15:22:

cyclone3d wrote on 2021-09-19, 15:11:

Is this another troll thread?

I think it is. I almost fell for one when he was asking about which graphics card with 3D acceleration was good for Windows 95 and eventually stopped responding.

IRQ on PCI devices doesn't really matter at all.

I was wondering why someone with almost 4000 messages was asking such a question.
Then again, screw'm.

weedeewee wrote on 2021-09-19, 14:37:

3) A220 I5 D1 H5 P330 E620 T6 (maybe)

the last one might have that as default but since it's Plug 'n Pray, you might as well pray.

It has. Creative Labs PnP cards have exactly the values you posted (well, no E620 on SB16 of course) as the one set of preferred resources. As long as a PnP manager initialzes the card at all (BIOS might skip initializing sound cards if "PnP OS installed: yes", because the BIOS expects the OS to reconfigure the resources anyway), it will always assign IRQ5 to the sound card unless it is "reserved by ISA" or another ISA PnP card also has IRQ5 as the single preferred IRQ.

mkarcher wrote on 2021-09-19, 15:50:

weedeewee wrote on 2021-09-19, 14:37:

3) A220 I5 D1 H5 P330 E620 T6 (maybe)

the last one might have that as default but since it's Plug 'n Pray, you might as well pray.

It has. Creative Labs PnP cards have exactly the values you posted (well, no E620 on SB16 of course) as the one set of preferred resources. As long as a PnP manager initialzes the card at all (BIOS might skip initializing sound cards if "PnP OS installed: yes", because the BIOS expects the OS to reconfigure the resources anyway), it will always assign IRQ5 to the sound card unless it is "reserved by ISA" or another ISA PnP card also has IRQ5 as the single preferred IRQ.

actually I googled for it, and that was one of the first meaningful results, which lead back right to a post on this site 😉
I guess the defaults can sometimes get messed up when the eeprom gets corrupted/broken.

On the old PCI / ISA IRQ mix boards, you want to keep 4 IRQs available for PCI, so that there is one each available for PCI INT A-D. If short of them, turn off unused serial / parallel ports.
You can get by with fewer, but then more will share - and on PCI, things SHOULD be able to share, but certain cards are better not to. PCI IRQ are level triggered, not edge, so when two devices share, the IRQ remains asserted until both are serviced, but the additional latency can be a problem for things like SCSI / RAID cards

Matth79 wrote on 2021-09-19, 16:03:

On the old PCI / ISA IRQ mix boards, you want to keep 4 IRQs available for PCI, so that there is one each available for PCI INT A-D. If short of them, turn off unused serial / parallel ports.
You can get by with fewer, but then more will share - and on PCI, things SHOULD be able to share, but certain cards are better not to. PCI IRQ are level triggered, not edge, so when two devices share, the IRQ remains asserted until both are serviced, but the additional latency can be a problem for things like SCSI / RAID cards

While this is important to do, I have seen PCI cards that doesn't even use IRQ at all especially early 3Dfx Voodoo cards and some video cards (I have two which gets NA on IRQ when the PCI device list is displayed).