> I'd like to program my own LAN without a network card. I think I need
> sample source, information about protocols and so on....
Have you seen the crynwr sources?  One in particular that I've used
is a PLIP interface to allow a DOS box on my family LAN out to the
internet. It's point-to-point tcp/ip using parallel ports. All code 
if I recall is in assembly. Try ftp.crynwr.com, but I'm sorry to say
that I've forgotten the filenames. Large files though, and the names
tied together.
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