In honor of the Unix 50 party tomorrow, I wrote an analysis of the
available data to conclude the first PDP-7 that Ken and Dennis used to
bring up Unix on was serial number 34. I've not seen this result elsewhere,
but if it's common place, please let me know.

https://bsdimp.blogspot.com/2019/07/the-pdp-7-where-unix-began.html

One surprise from the analysis: there was only one pdp-7 in the world that
could have run the original v0 unix. It's the only one that had the RB09
hard drive (though the asset list referenced in the article listed a RC09
on that system).

I hope you enjoy

Warner