It's unclear, but possible. In 2BSD, 3BSD and 4BSD, there aren't very many copyrights,
but they are all Regents copyrights on pascal, assembler, termlib and some plotting
software. Well, there appeared to be two Bell Telephone Laboratories, Inc copyright
in lex.c and sed.c. The vast majority of files had no copyright attached to them at all,
even ones that were little changed from 32V or 7th edition.
Same was true for 4.1BSD.
4.2BSD had rcs which was Copyright Walter F. Tichy and Ken Harrenstien, SRI
International (mostly the former). fp which was Copyright Scott B. Baden, indent
which was copyright Board of Trustees of the University of Illinois. sccstorcs
copyright Kenneth L. Greer. and cpm which was copyright by Helge Skrivervik, UCB.
and was one of the few files to have a permissions grant "Permission granted for
use by UNIX* licencees." though many of these were for manual pages. And sccstorcs
did have the permission
* All rights reserved. No part of this software may be sold or distributed
* in any form or by any means without the prior written permission of the
* author.
on it, through several releases (though it was removed before 4.3BSD-Reno).
4.3BSD added a bunch more copyrights of various people:
Digital Equipment Corporation
Tektronix Inc
Advanced Computer Communications
and likely others.
Starting in 4.3BSD-Tahoe we see lots of
* This code is derived from software contributed to Berkeley by
* Excelan Inc.
which have Regent copyrights, and sometimes the original contributor copyright.
This was the time that we started also seeing the BSD license is a proto form. This
continues in 4.3BSD-Reno to a greater degree.
4.4BSD continues this to a ridiculous degree.
So, maybe it did happen, but I find no extant evidence of a copyright being
removed and replaced by Berkeley. If anything, once files started being marked
with a copyright notice, they seem to be retained over several releases and
on the 2BSD series where the code was merged into.
Now, it's not clear if all the code contributed by folks executed paperwork assigning
the copyright to the Regents or not. But it looks like in many cases credit was
given, at least in the time period starting with 2BSD. 1BSD lacks the word 'copyright'
but kirk's archive has all the files in .a archives which are grepable. It didn't
include any AT&T code.
Warner
It was a long time ago but it rankled at the time (and even came up in my Bell Labs interview): that copyright notice replaced whatever was there before. Code written and copyrighted by other institutions was absorbed into the Berkeley distribution and reattributed without credit. Joy told me later that the lawyers made them do it. He was probably telling the truth, but that didn't make it OK.
-rob
I hate myself a little bit, but I posted an answer to the 'BSD license origin' in this twitter thread
that people might find interesting.
Please note the caveats at the end of the thread: This is a bare outline hitting the high points taking only data from release files with no behind the scenes confirmation about why things changed, nor in-depth exploration of variations that I know are present, nor do I got into examples from various USENET postings from the time that stole the license for people's own different uses.
Nonetheless, I hope it's useful...
Warner