Comments below this answer to the question Why was SpaceWire designed with nine wires? involve the history of Ethernet.
Did the earliest forms of Ethernet allow complete bidirectional communication over a single coaxial cable or a single twisted pair (possibly/probably with a shield)?
I've looked at the Wikipedia article on Ethernet and while it appears very well written and informative, I'm a networking noob and I'm having a hard time being sure I'm understanding anything there clearly. I searched for the terms bidirectional
and bi-directional
without result. In this particular case, I'm turning to Electronics Stackexchange for a concise yes or no, plus perhaps a bit of history.