Subject: Re: A report on implementing runlevels in NetBSD
To: NetBSD Userlevel Technical Discussion List <tech-userlevel@NetBSD.ORG>
From: Greg A. Woods <>
List: tech-userlevel
Date: 12/04/1999 19:06:35
[ On Saturday, December 4, 1999 at 22:01:34 (+0100), Ignatios Souvatzis wrote: ]
> Subject: Re: A report on implementing runlevels in NetBSD
> So what should be check... AMIX?

Any official AT&T or UNIX Press (i.e. as published by Prentice Hall)
documentation, such as the old blue AT&T manuals, or the newer red&white
"UNIX SVR4.2 MP for Intel Processors" reference manuals.  I don't have
complete sets of any manuals more recent than SysVr3.2, but I'm fleshing
out my sets -- we're starting to see them come up in the "Giant Book
Sale" remainder stores around here!  ;-) The more the merrier though --
I find it helps to understand the history of development to look at the
evolution of various facets of the system though from V7, PWB, SysV-III,
SysVr2.2, SysVr3.x, and SysVr4.x

Any of the original SysVr4 official reference porting bases are, by
definition the ones to look at for real examples (other than of course
the original AT&T releases for 3b2 and i386).  If I remember correctly
the Fujitsu folks did the SPARC port and NEC did the m68k port, but I
don't remember any of the rest.  I don't know how many of these
companies marketed their porting bases though.  When I was porting
software to all these machines we had a loaner NEC machine running the
reference port, but I had to go up to Fujitsu Canada's offices to work
on their SPARC server.

As I recall Motorola UNIX and Amiga UNIX are both very faithful ports
that were not official reference ports (Motorola used GCC instead of
AT&T's compiler, for example, but otherwise stayed true to the spirit).
Even Pyramid's DC-OS/x was a reasonable facsimile of the original (and
was certainly geared to being a true mainframe class production system,
true to the "Data Center" part of its name).

What are not good examples are those concoctions made up of various
generations of SysV releases all munged into one, often with lots of
more native BSD stuff thrown in on top.  SCO, the various incarnations
of AIX, what I know of HP/UX, DG/UX, etc. are such examples.  SunOS-5
started out being what AT&T took on as SysVr4, but as I understand the
history the political pressure on AT&T to divorce itself from Sun early
on caused the Sun folks to continue on their own, not wanting to restart
with the Fujitsu reference port when all the dust settled.  Obviously a
lot of independent development has happened to SunOS-5 since its first
release too, both on the outside and the inside.

							Greg A. Woods

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