Dunno if this is relevant or not, but here goes. I have a Tulip card too, the Linksys Network-Everywhere NC100 card. I got mine to work by making a 2.4.5 kernel with support for anything with "DecCHIP" listed in "Network" and "network devices", and by Enabling the "TULIP" driver in Network Devices, 10/100 MpBS cards (or somewhere like that.)
After you do that, check if eth0 is available. If not, try ./MAKEDEV eth0 in /dev. Then, try ifconfig -a and see if "lo" and "eth0" come up. If so, you're all set! :) Hope this helps, Deven Gallo
