[TUHS] Copyright notices in Edition 5, removed in Edition 6

[norman@nose.cs.utoronto.ca (Norman Wilson)]

Larry J. Blunk:

     Apologies if this has been answered before, but I noticed
  that there are AT&T copyright notices in the kernel sources
  for Unix Edition 5, but they were removed in Edition 6.
  [...] I noticed that USL registered Editions 5, 6, 7 and 32V in
  1992.  I would assume that Editions 4 and earlier are free
  and clear [...]
  As I understand it, Editions 7 and 32V could have had copyright
  protection without registration since they were released after
  1978.  However, because they lacked copyright notices when
  released, they may very well be considered public domain.  It was
  not until 1989 that the requirement for including
  copyright notices was dropped.

========

Notwithstanding other comments about the history, for practical purposes
none of this matters for Seventh Edition and 32V and anything earlier,
because Caldera (as it then was) open-licensed them in January 2002;
see http://www.tuhs.org/Archive/Caldera-license.pdf.  To be precise,
that license covers

   32-bit 32V UNIX
   16 bit UNIX Versions 1, 2, 3, 4, 5, 6, 7

with specific exclusion of System III and System V and successors.

That is why source code for the Seventh Edition system (for example)
is openly accessibly on the TUHS web server.

Among those whose dog work produced first a hobbyist-specific per-person
license, then the current BSD-like license, was Warren Toomey, who manages
that web server and this mailing list.  I don't think it will give him
a swollen head (or a wooden leg) to thank him now and then, and I do so here.

Long-time readers know all that, but those who have joined us recently
might not.

Norman Wilson
Toronto ON