Unix v4 program found cleaning out an office at the University of Utah [video]
youtube.comDiscussion at the time: https://news.ycombinator.com/item?id=45840321 And more developments and analysis since:
An initial analysis of the discovered Unix V4 tape
https://news.ycombinator.com/item?id=46367744
Unix v4 (1973) – Live Terminal
https://news.ycombinator.com/item?id=46468283
Fixing a Buffer Overflow in Unix v4 Like It's 1973
The video (~13m) was posted after those discussions, but it's an excellent local news report and features several charming interviews from inside the lab at the University of Utah.