ISA network cards

[jleclair <jleclair@onlinesupport.com>]

I'm trying to set up an old 486 as router/nat/firewall server for home network. The 2 nics are dlink 220 isa. 
When I run modconf, I choose the NE net module with this parameter: 
           io=0x300
This works and the module loads for eth0. How do I load the module now for the second nic?
I dont know the io address of the 2nd nic and the module will only load once. I guess I could do something like:  io=0x240,0x300 when loading the module through modconf.
BTW, I guessed at the io address that DID respond and have since unloaded the module and tried every other io address to make the second nic work. Are there tools to probe for hardware responding on io addresses not listed      
in /etc/proc?
I know this is all quite vague, but I am completely PCI plug-n-play spoiled.
Thanks for any assistance!
James