To all that are worried about the analog side of Ethernet, it's really
not a problem - You just follow the App note like the man says. Most
controllers provide an AUI (15 pin style) port. It is relatively trivial
to add on-board Twisted-pair or Thinnet connections. Some controllers like the
Nat Semi AT?LANTIC provide the twisted pair xcvr in the chip so you get
twisted-pair and AUI. Coax is extra. Also most PC ethernet controllers
are reasonable simple to hook to a 3051 if you are willing to ignore having
all the regisers in exactly the place you would expect them.
As for whoever said the solution could be under $30 on the motherboard
- NOT! most reasonable chips are $20-$30 in 1000s quantity - how are
we going to get the whole shot in $30?
I will volunteer to design the ethernet I/F, although it will be
tough to coordinate from CA. I would propose a AUI/coax system
with an optional twisted pair interface unless the ethernet of choice
has twisted pair on-board. I like the nat semi AT/LANTIC since it is
based on the venerable 8390 and has twited pair already.