The PDP-7 Where Unix Began
https://bsdimp.blogspot.com/2019/07/the-pdp-7-where-unix-began.html [bsdimp.blogspot.com]
2019-10-10 06:44
In preparation for a talk on Seventh Edition Unix this fall, I stumbled upon a service list from DEC for all known PDP-7 machines. From that list, and other sources, I believe that PDP-7 serial number 34 was the original Unix machine.