I have 2 identical ethernet boards installed in an old computer with ISA bus. Running 'ifconfig eth0' and 'ifconfig eth1', Linux recognizes both boards, but it says they have the same port (220) and the same interrupt (5). Of course the two boards have different hardware addresses and they will have different IP addresses, but is it okay to have 2 NICs with matching ports and IRQs? I think I can set the NICs for different IRQs, right? But I think the ports are set in the hardware for ISA?

Also: what is a good source to learn about ports and IRQs and how they relate to one another and to the rest of the system (preferably on-line)?