Ultra 1 problems...

I've got a Sun Ultra1 143MHz. For a while I had it on the internet. At one point, I swapped out my router, and my Ultra1 would no longer pick up an IP address. I recently put the old router back, but it still can't find it. I know the router works fine because I have 4 other computer connected to it. I know the cable is fine because I get connection lights when the system is on, or I get online when other computers are connected to that cable.

Does anyone know how to set a static IP on this system rather then let it try dynamically? Or maybe I did set up a static one with that other router. I don't know, I just need to change it

Anther question I've had is the rom. I don't recall what version I'm running(I'll check later, the system is put up ATM) but whatever it is, I can only Solaris in 32bit mode. Now I've read this system is one of the first 64bit systems, and upgrading the rom should allow me to run in 64bit mode. Anyone know where I can find this update? And how save is it? I REALLY don't want to mess this system up. It's got to be my favorite system in my collection