Although not all, a great number of retro computing enthusiasts seem focused on home system configurations. For the most part home networking didn't become a thing until the PCI era.

I have a Zenith/Heathkit Z-160 luggable, an 8-bit ISA bus system, which I installed an 8-bit ISA network card in. 8-bit ISA network cards are much more difficult to find than 16-bit ISA network cards but still it was only $20 on ebay.