Comment by lproven

I think you are misremembering.

Coax Ethernet with BNC connectors was absolutely the norm for LANs from the late 1980s to mid 1990s. Then, slowly, UTP took over, as 10base-2 was replaced by 10base-T, then 100base-T, then switches instead of hubs, then Gigabit Ethernet: 1000base-T.

I worked with Token Ring in the '80s and never ever even heard of a coax version. It was D9 connectors on the card to fat IBM connectors on the MAU, as pictured here:

https://en.wikipedia.org/wiki/Media_access_unit

I think you're switching TR and thinnet Ethernet in your head.