OK, I dug something up.

There is this page:

https://sites.google.com/a/bostic.com/keithbostic/vi/

Where if you download the Nvi archive, you get 1.79 from 1996.

In the tarball's docs/ directory, there is a changelog which goes back to 0.92 -> 0.93 (Mon Dec 20, 1993). 0.94 went to 1.00 on January 10, 1994.

> nvi - 1980 for 4BSD

4BSD (same as 3BSD) had the original vi (at version 3.1). You can see the sources at TUHS.

Fun fact: AT&T adopted vi in System V UNIX, and advertised that fact without crediting UCB as required by the BSD license. So when AT&T sued, USB countersued, which is why AT&T settled for merely removing UNIX code from future releases.

Thank you for putting this together. The writing quality and comprehensiveness are excellent. It's amazing to think that vim's lineage stretches back over 50 years (older than UNIX, display terminals, and Apollo 11!)