I have FC4 and I was wondering how to control those things. Preferably from the desktop (gnome) but if no method exists, the shell will do.
I was recently trying to install an old ISA sb16 and, eventhough I compiled alsa and modprobed the module it was still not working correctly. Alsaconf detected the card though and did the additions to the modprobe.conf. Even alsamixer worked, I could simply get no sound.
Furthermore, the network card refused to activate until I plugged the soundcard out, at which point it worked again.
I'm guessing it has to do with a resource conflict but I have no clue how to control these things on linux.
Any help will be welcome.

It's a while since I had to deal with an ISA card. There are several ways to deal with IRQ/DMA/IO assignment.

If your card is hardwired or jumpered you can pass the values as arguments when loading the module (irq=11 dma=... etc) or set as options in /etc/modules.conf

For a PnP card there is a linux tool called isapnp which lets you play with the card settings. Then maybe you have to pass the assigned values to the module when loading.

There are also various BIOS settings for reserving IRQs which can help avoid conflicts.

Sorry to be so vague but it's a long time since I used any of these things. There are also useful linux HOWTOs for PnP, ISA and Soundblaster I think.