I won't get to troubleshooting until much later tonight if at all unfortunately, but wanted to ask some clarification on both of your suggestions.

1. Would I be testing to see if I could ping the Powerbook 520 from another machine? And what is ICMP?

2. Would I be able to acquire a private IP address of some sort using EtherTalk or MacTCP? I'm really fuzzy on those concepts so I'm not sure what I would need to do and if I would require another 68k Mac to test those?

3. I don't think I have a crossover cable... but if I try hooking an Ethernet cable of some sort from my Powerbook G4 to the 520, what will happen and what do I need to do? Do I need to create a network or something in OS X to test communication/connectivity with the 520?

Thanks in advance :I