Back when I was in MS, I was trying to find out how best I could add TCP/IP to the computer I had – we had LANMAN but that was it. No TCP/IP to the outside world. My “internet” email was firstname.lastname@example.org. Yes, it was a UUCP link to UUNET.
Sometime in 1987/88, I came across the KA9Q TCP/IP code that was used to allow ham radio operators to use the AX.25 network to do TCP/IP. What an awesome piece of engineering – the code was fully open sourced but copyrighted by Phil Karn KA9Q – but gave a very good insight into what was possible even on lowly 8088/80286 machines.