As I commented a while ago, I got a Macintosh Performa 630. Fortunately for me, it came with a regular Ethernet network card; it kinda worked with the Mac OS that came installed with the machine (7.something). However, since I zapped the disk and installed MacOS 8.1, I haven't been able to get the card working again... until today.
I've been pointed out that I could be lacking the drivers. Oh, drivers... how is that I never realized that? (May it be because I rarely use Windows? ;-) Anyway, I took out the motherboard and watched at the NIC's labels to see which one I have. According to multiple diffferent inscriptions, I concluded that its name is DaynaPORT E/CS-T. So a quick search in Google revealed several links pointing to Intel. I was surprised to see that, but later I realized that Intel bought Dayna Communications Inc. a while ago.
Once in the page, I downloaded the drivers and installed them on the Mac OS 8.1. Surprise surprise, it works! Now I have network (and Internet!) access from the Macintosh, which means I can easily copy files to it; i.e., NetBSD's installation files (what I'm playing with ATM).