I like how having the old hardware gives physical "witness" and "evidence" that all the old stories are true - people did invent and create these things, they didn't just appear from aliens.
Indeed. I am teaching a security class on TCP/IP and I recently got my AT&T 7300 PC up and running with its Ethernet card and Wollogong TCP stack.
Granted the system doesn't have resolver/DNS libraries but even though it is almost 40 years old it still can connect to the most modern PC system, transfer data, and work using the same TCP/IP protocol.
I plan to show it to my students (along with how insanely easy it is to hack). But still, tat's stability over time.
CZ