Interesting... Horton's timing sounds right because  I'm pretty sure we had some sort of Berkeley shell @ before CMU had 2BSD on the v6++ systems in 1978 - (I have to ask him, Klone must have been the one that brought it over to Mellon Institute ). I state that because I remember trying to play with it as well as another hacked shell V6 (I think from Harvard) around that time.  I was fascinated by the idea of being able to change the default command system, which no other OS I was using I could do same (TOPS*, VMS, TSS, Exec/8).   But I remember I didn't like some of choices of the Berkeley shell's syntax and tended to avoid it/could not figure it out.    Within a year or so V7 showed up there after with Bourne shell and I was happy with that.

A few years later, I did switch to typing to the csh when I got to UCB, but that was not until after the MIT job control stuff had been spliced into the BSD kernel (Horton & Kleckner were probably the ones that convinced me to learn it).  With job control I became a fan, but never warmed up to the programming syntax.   I picked up the mantra that I still consider wise -- "type to Joy and program to Bourne."   This is comfortable for the ROMS in the muscles of my fingers, but my scripts are portable.

Clem

PS To this day (like about a month ago), if I need to hack on my .login script when I move sites (I have some site specific stuff in .login and .profiles), I have to grab the cshell man page so I don't screw up the syntax.