I understand early versions of Unix were licenced from AT&T to Universities and ran on PDP computers. I read in Tanenbaum's book (operating systems) that the first versions of Unix were only a couple of thousands LOC. It is not detailed which functions came when. For example: When was the first version of Unix that could do pipelining with the shell?
Did the first versions even have a shell or was the interface to Unix just C and assembly?