>typing something about ttys
>an last the kernel detects my second ethernet port
>ae0 at nubus0: ad...., type MacCon Ethernet 16kB mem

Well, I removed the Ethernet card now the system boots with problems. I 
had to reinstall the NetBSD Filesystem, because first I hadn't converted 
the A/UX swap to NetBSD swap. The last partition on my hd wasn't visible 
with Mkfs 1.4.3 Only a small junk partition 20k solved the problem - 
should be fixed.