Which brings me to one thing that puzzled me about the video. In the part starting from 10:37 https://youtu.be/f8PP5IHsL8Y?t=637 it describes STARLAN as specifying two pairs of wires, one for transmit and one for receive. But naturally you can't really have full duplex without a switch at the other end of the wire; and yet the STARLINK "Network Extension Unit" is described as a hub (and indeed it seems that the first Ethernet switches/multiport bridges didn't ship until 1989-1990). So when at 12:10 https://youtu.be/f8PP5IHsL8Y?t=730 the video seems to suggest that STARLINK being half-duplex was a step back from the original plan, I don't see how that can be the case: I assume that first-generation STARLINK was never intended to provide full duplex, and the two pairs of wires were just reserved for future upgrades. That seems compatible with what Richard Bennett says from 12:29 . That's still interesting, though, because it suggests that the STARLINK contributors must have had switches in mind back in 1983.