Discussion 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

https://news.ycombinator.com/item?id=46544610