https://www.bell-labs.com/usr/dmr/www/
https://www.bell-labs.com/usr/dmr/www/hist.html
A long while ago, I once had the fortune to exchange emails with Dennis Richie. He was a wonderful man, extremely helpful and kind.
I've found younger devs / sysadmins struggle hard due lack of context. Most systems work as they do today for historical, not technical reasons.
https://www.amazon.com/Quarter-Century-UNIX-Peter-Salus/dp/0...