7 Apr
2017
7 Apr
'17
3:12 a.m.
's/DNS/DNA/' - Not a problem. Thanks!
I'd come across Thoth mentioned in an OS book at the U of Canterbury (NZ) Science
Library; they also
had a copy of the Tunis book. But I never took the time to read them.
Getting them put into a time frame is useful - it gives an external perspective to
Salus' book, eg, this is
what some non-Unix folk thought of Unix at the time.
Wesley Parish
Quoting Clem Cole <clemc(a)ccc.com>:
s/DNS/DNA/ - dyslexia sucks....
On Thu, Apr 6, 2017 at 2:02 PM, Clem Cole <clemc(a)ccc.com> wrote:
note
"I have supposed that he who buys a Method means to learn it." - Ferdinand Sor,
Method for Guitar
"A verbal contract isn't worth the paper it's written on." -- Samuel
Goldwyn
âtry-II sorry about that...â
On Wed, Apr 5, 2017 at 9:18 PM, Wesley Parish
<wes.parish(a)paradise.net.nz>
wrote:
> The mention of UNOS a realtime "clone" of Unix in a recent thread
raises
a
question for me. How many
Unix clones are there?
âAn interesting question.... I'll take a shot at this in a second, there is a Wikipedia page:
https://en.wikipedia.org/wiki/Category:Unix_
variants that I don't fully agree with.
The problem with all of this question is really depends where you
place
which boundary on the following continuum:
non-unix add-unix ideas trying to be
unix might as well be unix research unix
stream
eg VMS eg Domain eg UNOS
eg Sys V, BSD/386 & Linux Vx & BSD VAX
Different people value different things. So here is my take from the
"cloned" systems I used/was basically aware....
Idris was a V6 clone for the PDP-11, which I saw 1978ish. I can say I
was able to recompile code from v6 and it "just worked" so from a
user's
standpoint it might as well has been. But the
compilers and
assemblers
were different and I never tried anything
"hard"
The first attempt to "clone" v7 that I knew about was in France, and
written in Pascal - I think at Ecole Tech in Paris? The name of the
project escapes me, but they presented the work in the 1979/80 winter
USENIX (Blackhole) conference in Denver. There were no proceedings in
those days. I believe it also ran on the PDP-11, but I never ran it
so; so
I have no idea how easy it was to move things
from Seventh Edition.
But I
also don't think they were working binary
compatibility, so I think
it
landed more toward the center.
The Cruds folks (Goldberg) wrote UNOS shortly there after (early 80s)
It was definitely not UNIX although it tried to have be mostly. We
had
CRDS box at Masscomp and before I arrived they
plan had been to use it
get
code working before the RTU was running. But the
truth was it failed
because it was not UNIX. The 68000 vs Vax issues were far, far less of
an
issue than UNOS != UNIX. To Goldberg's
credit, he did have a couple
of
cool things in it. I believe only system
commercial systems that used
Kanodia & Reed's Sequences and Eventcounts, were UNOS, Apollo Doman,
and
Stellar's Stellix (I'm not sure about
DG - they might have also at
one
point). But these were hidden in the kernel. Also
the driver model he
had was different, so there was no gain writing drivers there.
Mike Malcom & Dave Cheriton at Waterloo developed Thoth (Thoth -
Thucks),
which was written in B, IIRC. Ran on the PDP-11
and was very fast and
light. It was the first "ukernel" UNIX-like/clone system.. Moving
code
from V7 was pretty simple and there was attempt
to make it good enough
to
make it easy to move things, but it was not
trying to be UNIX so it
was
somewhere in the middle.
The Tunis folks seem to have been next. This was more in the left
side
of the page than the right. I think they did make
run on the PDP-11,
but
I'm not so sure how easy it was to move
code. If you used their
concurrent Pascal, I suspect that code moved. But I'm not sure how
easy it
was to move a raw K&R "White Book"
C code.
CMU's Accent (which was redo of Rochester's RIG) came around the same
time. Like Tunis the system language was an extended Pascal and in
fact
the target was the triple drip Perq (aka the
Pascalto). The C
compiler
for it was late, and moving code was difficult,
the UNIX influence
was
clear.
Apollo's Aegis/Domain really came next - about 82/83 ish. Like Accent
it
was written in hacked up Pascal and the command
were in
Ratfor/Fortran
(from the SW Tool User's Group). C showed up
reasonably early, but
the
focus did not start trying to be UNIX. In fact,
they were very
successfully and were getting ISV's to abandon VMS for them at a very
good
clip. UNIX clearly influenced the system, but it
was not trying to be
UNIX, although moving code from BSD or V7 could be done fairly
easily.
Tannebaum then did MINIX. Other than 8086 vs PDP-11-ism, it was a
pretty
darned good clone. You could recompile and most
things pretty much
"just
worked." He did not support ptrace and few
other calls, but as a basic
V7
system running on a pure PDP PC, it was
remarkably clean. It also had
a
large number of languages and it was a great
teaching system - which
is
what Andy created it be. A problem was that UNIX
had moved on by the
time Andy released it. So BSD & V8 were now pretty much the definition
of
"UNIX" - large address spaces were
needed. As were the BSD tools
extensions, such as vi, csh. Also UUCP was now very much in the
thing,
and while it was a pure v7 clone, it was the lack
of "tools" that made
it
not a good system to "use" and
it's deficiencies out weighed the
value.
Plus as discussed elsewhere, BSD/386 would
appear.
Steve Ward's crew at MIT created TRIX, which was a UNIX-like,
although
instead of everything being a file, everything
was a process. This
was
supposed to be the system that rms was originally
going to use for
GNU, but
I never knew what happened. Noel might. I thought
it was a cool
system,
although it was a mono-kernel and around this
time, most of the OS
research
had gone ukernel happy.
Coherent was announcement and its provenance is questioned, although
as
discussed was eventually released from the
AT&T official inquiry and
you
can look it your self. It was clearly a V7 clone
for the PC and was
more
complete than Minix. I also think they supported
the 386 fairly
quickly,
which may have made it more interesting from a
commercial standpoint.
It
also had more of the BSD tools available than
Minix did when it was
first
released.
CMU rewrites Accent to create Mach, but this time splices the BSD
kernel
inside of it so that the 4.1BSD binaries
"just work." So it's bit
UNIX
and a new system all in one. So which is it? This
system would begat
OSF/1 and eventually become Apple's Mac OS? I think its UNIX, but one
can
claim its not either....
By this point in time the explosion occurs. You have Lion's book,
Andy's
and Maury Bach's book on the street. he
genie is clearly out of the
bottle,
and there is a ton of code out there and the DNS
is getting all mixed
up.
Doug Comer does Xinu, Sheraton does V-kernel,
Thoth is rewritten to
become
QNX, and a host of others I have not repeated.
BSD's CSRG group would
break up, BSDi would be created and their 386 code come out. It was
clearly "might as well be" if it was not. Soon, Linus would start
with
Minix and the rest is history on the generic
line.
Clem