https://github.com/memnoth/unix-v6/blob/master/sys/ken/nami....
https://github.com/memnoth/unix-v6/blob/master/sys/param.h#L...
i guess this 'edition zero' is from 01971, and 6th edition is 01975
1971 saw the port to the PDP-11/20, which was released as UNIX-11 and soon after, V1 UNIX.
1971 saw the port to the PDP-11/20, which was released as UNIX-11 and soon after, V1 UNIX.