On Sun, Jun 6, 2021 at 3:18 PM <arnold@skeeve.com> wrote:

> For example? As I remember it, it was essentially a super-bug-fixed version
> of 4.2. Nothing more.
>
To be honest I've forgotten all of the details, but the big one was the
ability to (optionall) have the old 4.1 signal semantics and I think there
were a couple of more.   The stuff that went into 4.3 was heavily driven by
the Arpa advisory board.  Many people in the Arpa community had felt that
CSRG was not supplying what they needed.  There were some compromises.  As
part of that the team put much of the CMU Mach memory system at some point
(I thought at 4.3) and as Paul pointed out, that's when mmap was finally
added [which is part of why I think that's when the CMU changes came].   I
also where the great line (whom I wish IO knew who first said it),
described "new BSD system was full of other folks' ideas, but had been peed
on to smell like UCB).

BTW: the other thing that was happening at UCB by then was that while the
CSRG project was funding a lot of stuff, it was not seen as research, but
more of a development for hire by then.  There started to be a lot of
resentment.
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