The 3Com 509 ISA card. Getting ISA to work is always a pain, but not with this card.
Look at the list of taken IRQs and select one that isn't taken.
modprobe 3c509 irq=x
Where x is the interrupt you have free. You may have to try multiple interrupts to get this to work.
ifconfig ethx up
Where x is the number of what NIC this is in the machine. If its the only one: eth0.
'netconfig' should help you set its IP address however you want to, but I don't go in for the cute RH tools, so you might want to just use ifconfig for this or dhcpcd depending on what you want it to do.