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From: ch...@butler.UUCP (David Chinn)
Newsgroups: net.unix,net.unix-wizards
Subject: Unix History
Message-ID: <212@butler.UUCP>
Date: Sat, 31-May-86 11:05:31 EDT
Article-I.D.: butler.212
Posted: Sat May 31 11:05:31 1986
Date-Received: Wed, 4-Jun-86 00:08:22 EDT
Organization: Butler - Controls Div., Kirkland WA
Lines: 13

Sorry if this has been asked before....

Could anyone give me a short run down on lineage
of the major lines of UNIX? Perhaps a brief narration 
or a family tree showing how sys V and 4.3 and such 
are all related.  I am primarily interested in AT&T and
Berkley, VAXEN and PDP's;  where do 3b2 and 2.9 fit in?  
			
				Thanks in advance;

    ... uw-beaver                                david m chinn
	   !tikal!dataio                         box 639
	       !butler!chinn     	         redmond,  wash 98073

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Path: utzoo!henry
From: he...@utzoo.UUCP (Henry Spencer)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <6780@utzoo.UUCP>
Date: Fri, 6-Jun-86 14:32:06 EDT
Article-I.D.: utzoo.6780
Posted: Fri Jun  6 14:32:06 1986
Date-Received: Fri, 6-Jun-86 14:32:06 EDT
References: <212@butler.UUCP>
Organization: U of Toronto Zoology
Lines: 23

> Could anyone give me a short run down on lineage
> of the major lines of UNIX? Perhaps a brief narration 
> or a family tree showing how sys V and 4.3 and such 
> are all related...

If you want a *very* brief version, draw a line of development marked "V1"
through "V8".  Between V6 and V7, draw a branch starting out "PWB" and
proceeding on through "SysIII" and "SysV" to "SysV.3.2.4.etc".  Between
V6 and V7, draw another branch starting out "1BSD" and going on to "2BSD"
and "2.nBSD".  Draw a branch from V7 and another from somewhere in the 2.xBSD
series, and merge them into a line starting "3BSD" and going on into the
4BSD series.  That's roughly right.

Then cover the whole drawing with a dense tangle of lines indicating
variants, independent sub-lines of development, and cross-fertilization in
various directions.  There were several *major* independent lines (tangles)
of development within AT&T alone.  Some friends of mine tried to draw up
an accurate family tree; it took them a long time and considerable research
and there were still gray areas and question marks.
-- 
Usenet(n): AT&T scheme to earn
revenue from otherwise-unused	Henry Spencer @ U of Toronto Zoology
late-night phone capacity.	{allegra,ihnp4,decvax,pyramid}!utzoo!henry

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Path: utzoo!watmath!clyde!cbosgd!ihnp4!oddjob!mrl
From: m...@oddjob.UUCP (Scott R. Anderson)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <1345@oddjob.UUCP>
Date: Tue, 10-Jun-86 02:07:07 EDT
Article-I.D.: oddjob.1345
Posted: Tue Jun 10 02:07:07 1986
Date-Received: Sat, 14-Jun-86 00:40:53 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP>
Reply-To: m...@oddjob.UUCP (Scott R. Anderson)
Organization: University of Chicago, Department of Physics
Lines: 17

In article <6...@utzoo.UUCP> he...@utzoo.UUCP (Henry Spencer) writes:
>> Could anyone give me a short run down on lineage
>> of the major lines of UNIX? Perhaps a brief narration 
>> or a family tree showing how sys V and 4.3 and such 
>> are all related...
>
>Between V6 and V7, draw a branch starting out "PWB" and
>proceeding on through "SysIII" and "SysV" to "SysV.3.2.4.etc".

This raises the burning question:  whatever happened to
Systems I and II, and, especially, IV?  I never hear them
discussed.  Were they ever released commercially, and if
not, why not?
-- 

					Scott Anderson
					ihnp4!oddjob!kaos!sra

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Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!caip!topaz!uwvax!geowhiz!larry
From: la...@geowhiz.UUCP (Larry McVoy)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <449@geowhiz.UUCP>
Date: Sat, 14-Jun-86 02:54:34 EDT
Article-I.D.: geowhiz.449
Posted: Sat Jun 14 02:54:34 1986
Date-Received: Tue, 17-Jun-86 21:19:13 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP>
Reply-To: la...@geowhiz.UUCP (Larry McVoy)
Organization: UW Madison, Geology Dept.
Lines: 21

In article <6...@utzoo.UUCP> he...@utzoo.UUCP (Henry Spencer) writes:
>> Could anyone give me a short run down on lineage
>> of the major lines of UNIX? Perhaps a brief narration 
>> or a family tree showing how sys V and 4.3 and such 
>> are all related...
>
>If you want a *very* brief version, draw a line of development marked "V1"
>through "V8".  Between V6 and V7, draw a branch starting out "PWB" and
[etc, etc]

The best picture I've seen is by John Quartermain (sp?) in the chapter on Unix
in the *second* edition of the Peterson & Silberschatz book "Operating System
Concepts".  I think it's just what the patient ordered.
-- 
Larry McVoy
-----------
Arpa:  mc...@rsch.wisc.edu                              
Uucp:  {seismo, topaz, harvard, ihnp4}!uwvax!geowhiz!larry      

"Just remember, wherever you go -- there you are."
 	-Buckaroo Banzai

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Path: utzoo!henry
From: he...@utzoo.UUCP (Henry Spencer)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <6807@utzoo.UUCP>
Date: Mon, 16-Jun-86 21:01:30 EDT
Article-I.D.: utzoo.6807
Posted: Mon Jun 16 21:01:30 1986
Date-Received: Mon, 16-Jun-86 21:01:30 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP>, <1345@oddjob.UUCP>
Organization: U of Toronto Zoology
Lines: 31

> This raises the burning question:  whatever happened to
> Systems I and II, and, especially, IV? ...

Adam Reed and Matt Perez have already answered this moderately well, but
I'll throw in a few more tidbits.  System I was, approximately, PWB, which
was released.  System II was an improved PWB, incorporating some useful
things like a souped-up shell; it was never released because just then
AT&T was not sure it wanted to continue distributing useful new goodies
to potential competitors.  After the decision to continue with distribution
was made, System III was released, well after it was in use internally.
System IV never made it out because it was already in use when SysIII came
out, and the decision to bring external releases into sync with internal
ones overtook it.  System V was then released.  Since "System V" has now
become a magic marketing buzzword, the top-level numbering is absolutely
frozen for external purposes, and all future releases will be V.something
rather than VI, VII, etc.

Fortuitously, this happens to avoid 4, 6, and 7, which correspond to other
well-known flavors of Unix.

If you want to get a look at what System IV was like, check out the PDP11
distribution of System V.  PDP11 SysV is really SysIV.  Although AT&T won't
admit it in so many words, they effectively abandoned work on PDP11 Unix a
long time ago.  For example, although some of the SysV performance work
wouldn't fit on the 11, *some* of it would.  None of it was applied to
PDP11 SysV.  The PDP11 SysV shared-memory stuff is also different from and
incompatible with the regular SysV version.
-- 
Usenet(n): AT&T scheme to earn
revenue from otherwise-unused	Henry Spencer @ U of Toronto Zoology
late-night phone capacity.	{allegra,ihnp4,decvax,pyramid}!utzoo!henry

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From: k...@hropus.UUCP (Kenneth Almquist)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <513@hropus.UUCP>
Date: Thu, 19-Jun-86 15:46:01 EDT
Article-I.D.: hropus.513
Posted: Thu Jun 19 15:46:01 1986
Date-Received: Sat, 21-Jun-86 07:33:19 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP>, <1345@oddjob.UUCP> <6807@utzoo.UUCP>
Organization: Bell Labs, Holmdel, NJ
Lines: 80

> > This raises the burning question:  whatever happened to
> > Systems I and II, and, especially, IV? ...

Back in 1978, I think it was, a grand new numbering scheme for UNIX releases
put out by USG was devised.  Release numbers were set back to 1.0 and the
operating system was renamed UNIX/TS.  (The "TS" stands for time sharing.)
At the same time, MERT, a different operating system whose primary use was
to run a UNIX emulator, was renamed UNIX/RT (the "RT" stood for real time)
and also had its release numbers set back to 1.0.  The idea was that com-
patable releases of UNIX/TS and UNIX/RT would have the same release numbers.
UNIX/RT proceeded to bite the dust and the name of UNIX/TS gradually shifted
back to plain "UNIX".

USG started producing top level releases once a year.  Second level releases
were used to make features available as they were written.  Third level
releases were limited to bug fixes.  For example, UNIX 3.0 was followed by
UNIX 3.0.1, which was basicly UNIX 3.0 with a few bug fixes.  (It was also
followed by UNIX 3.1, which may or may not have come out before UNIX 3.0.1.)

The first two versions of USG UNIX that were release externally to AT&T
were UNIX 3.0.1 and UNIX 5.0.1.  They were called System III and System V
externally.  There were no systems named System I, II, and IV.

> System I was, approximately, PWB, which was released.

PWB UNIX was not developed by USG.  One of the goals enunciated in the
switch to the new release naming scheme was to eliminate the various special
versions of UNIX floating around.  SCCS was included in UNIX/RT 1.0.  The
PWB code didn't make it into USG UNIX until release 2.0.

I don't know much about the version of PWB UNIX that was released externally,
but I think that predated UNIX/TS 1.0 significantly, so there were probably
UNIX/TS 1.0 features not in the external version of PWB UNIX, as well as vice
versa.

> System II was an improved PWB, incorporating some useful
> things like a souped-up shell.

The Borne shell (which was in UNIX/TS 1.0) did not undergo any major changes
between UNIX/TS 1.0 and UNIX 5.0.

> Since "System V" has now
> become a magic marketing buzzword, the top-level numbering is absolutely
> frozen for external purposes, and all future releases will be V.something
> rather than VI, VII, etc.

The real horror is that the internal numbering system has been abandoned,
so that even those of us inside AT&T have to suffer with names like
"System V Release 2 Issue 2".  Does driving people up the wall with a
chaotic numbering scheme really encourage them to buy from AT&T?

> If you want to get a look at what System IV was like, check out the PDP11
> distribution of System V.  PDP11 SysV is really SysIV.

Not really.

> Although AT&T won't admit it in so many words, they effectively
> abandoned work on PDP11 Unix a long time ago.

Most new features made it to the PDP11.  The major exception is the news
object module format, which makes SDB possible.  SDB is a UNIX 3.0 feature
which did not make it to the PDP11.  The UNIX 4.0 and UNIX 5.0 releases
for the PDP11 were pretty complete.

> For example, although some of the SysV performance work wouldn't fit
> on the 11, *some* of it would.  None of it was applied to PDP11 SysV.

The PDP-11 uses hashing to implement the sleep/wakeup facility in the kernel
under System V.  I don't know of any other System V performance work that
was applied to the PDP11 (but then if it had been it would probably would not
have helped a machine the size of a PDP-11 much.)

>  The PDP11 SysV shared-memory stuff is also different from and
> incompatible with the regular SysV version.

Right, but it is present, which is a difference from UNIX 4.0.  The IPC
stuff was first released in UNIX 4.2.
				Kenneth Almquist
				ihnp4!houxm!hropus!ka	(official name)
				ihnp4!opus!ka		(shorter path)

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glacier!mips!mash
From: m...@mips.UUCP (John Mashey)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <524@mips.UUCP>
Date: Sat, 21-Jun-86 12:48:26 EDT
Article-I.D.: mips.524
Posted: Sat Jun 21 12:48:26 1986
Date-Received: Tue, 24-Jun-86 03:45:50 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP> <1345@oddjob.UUCP> <6807@utzoo.UUCP> 
<513@hropus.UUCP>
Reply-To: m...@mips.UUCP (John Mashey)
Organization: MIPS Computer Systems, Sunnyvale, CA
Lines: 41

In article <5...@hropus.UUCP> k...@hropus.UUCP (Kenneth Almquist) writes:
>.... generally accurate description of release history...
>
>PWB UNIX was not developed by USG.  One of the goals enunciated in the
>switch to the new release naming scheme was to eliminate the various special
>versions of UNIX floating around.  SCCS was included in UNIX/RT 1.0.  The
>PWB code didn't make it into USG UNIX until release 2.0.
>
>I don't know much about the version of PWB UNIX that was released externally,
>but I think that predated UNIX/TS 1.0 significantly, so there were probably
>UNIX/TS 1.0 features not in the external version of PWB UNIX, as well as vice
>versa.

Close, but not quite.
1) A bunch of us [Haight, Wehr, me] moved from PWB to USG in early 1977,
to help the merging process as noted.
2] Research was doing V7 at this time, and one of the additional goals of
ours, working with them, was to get V7 to have the facilities found needed
elsewhere, but in a more elegant fashion, given hindsight.  For example,
that's where environment variables (a drastic generalization of a PWB 
feature) and process accounting came from.)
3] Many PWB features actually did make it into UNIX/TS 1.0: the Acknowledgments
say: '...; a large part ot its contents is descended from the UNIX Programmer's
Manual-Sixth Edition...and the PWB/UNIX User's Manual...'  Specifically,
from PWB in that round were a) Numerous minor commands and command extensions,
b) A few system calls,  c) -MM and -MV macros, d) Miscellaneous functions.
4] The general goal was for UNIX/TS 1.0 to let the USG & PWB kernels merge at
the transition to a V7 base, while integrating such user-level features as
were easy to do and of general use.
5] PWB/UNIX 2.0 took the 1.0 base and added in some of the remaining features,
that took more time and were more work, like: SCCS, RJE, LEAP, etc, etc.
As noted, there never was a SYSTEM II; this was it, in some sense;
of course, it was the last PWB release.
6] PWB/UNIX 1.0 was what was released outside, way back.  This was too bad,
there was a 1.2 release that was substantially cleaned up and tuned;
this was probably the highest-performance V6 time-sharing version in
any widespread use.
-- 
-john mashey	DISCLAIMER: <generic disclaimer, I speak for me only, etc>
UUCP: 	{decvax,ucbvax,ihnp4}!decwrl!mips!mash, DDD:  	408-720-1700, x253
USPS: 	MIPS Computer Systems, 930 E. Arques, Sunnyvale, CA 94086

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Path: utzoo!linus!philabs!cmcl2!harvard!caip!ut-sally!im4u!jsq
From: j...@im4u.UUCP (John Quarterman)
Newsgroups: net.unix
Subject: Re: Unix History
Message-ID: <979@im4u.UUCP>
Date: Sun, 22-Jun-86 14:19:31 EDT
Article-I.D.: im4u.979
Posted: Sun Jun 22 14:19:31 1986
Date-Received: Tue, 24-Jun-86 04:19:49 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP> <449@geowhiz.UUCP>
Reply-To: j...@im4u.UUCP (John Quarterman)
Followup-To: net.unix
Organization: U. Texas CS Dept., Austin, Texas
Lines: 188
Summary: Try ACM Computing Surveys December 1985

>The best picture I've seen is by John Quartermain (sp?)

There's actually no question about it:  you spelled it wrong.  :-)

>in the chapter on Unix in the *second* edition of
>the Peterson & Silberschatz book "Operating System Concepts".
>I think it's just what the patient ordered.
>-- 
>Larry McVoy

Glad you liked it.  However, there's a better version forthcoming in
``4.2BSD and 4.3BSD as Examples of the UNIX System'' by Quarterman,
Silberschatz, and Peterson in the December 1985 ACM Computing Surveys
(that's right:  forthcoming and 1985).  Those of you who are impatient
can try running the rest of this article through pic and ditroff.
No claims are made for accuracy or completeness of the information
or of its depiction.

PS:  this followup is going only to net.unix and I've directed further
responses there as well.

.KF
.nf
.ps -2
.PS
smallb = 0.5i
medb = 0.75i
bigb = 1i
biggerb = 1.5i
boxwid = smallb
boxht = smallb / 2
movewid = 0.5i

spacing=0.5i
sysv=spacing
mert=sysv + spacing
pwb=mert + spacing
cbunix= pwb + spacing
research=cbunix + spacing
v32=research + spacing
bsd4=research + (2 * spacing)
bsd2=bsd4 + spacing

boxwid = medb
D69: box invis "1969"
D73: box invis "1973"
boxwid = smallb
D76: box invis "1976"; move
D77: box invis "1977"; move
D78: box invis "1978"; move
D79: box invis "1979"; move
D80: box invis "1980"; move
D81: box invis "1981"; move
D82: box invis "1982"; move
D83: box invis "1983"; move
D84: box invis "1984"; move
D85: box invis "1985"
Label: box invis at D69

boxwid = smallb
V1: box invis "V1" at D69 + (0, research)
V5: box invis "V5" at D73 + (0, research)
V6: box invis "V6" at D76 + (0, research)
boxwid = bigb
V7: box "Version 7" at D78 + (0, research)
arrow from V1.e to V5.w
arrow from V5.e to V6.w
arrow from V6.e to V7.w

boxwid = smallb
V32: box invis "32V" at 1/4 <D78, D79> + (0, v32)
boxwid = bigb
V8: box "Version 8" at D83 + (0, v32)
arrow from V7.n to V32.s
arrow from V32.e to V8.w
arrow right from V8.e

"\fIBell Research\fP" ljust at Label + (0, research + (v32 - research) / 2)

boxwid = smallb
PWB: box invis "PWB" at 1/2 <V6, V7> + (0, pwb - research)
arrow from V6.s to PWB.nw
U30: box invis "3.0" at 1/2 <D79, D80> + (0, pwb)
arrow from V32.se to 4/5 <PWB, U30>
arrow from V7.sw to 1/2 <PWB, U30>
U40: box invis "4.0.1" at D81 + (0, pwb)
U301: box invis "3.0.1" at 1/2 <U30, U40>
U50: box invis "5.0" at D82 + (0, pwb)
U52: box invis "5.2" at D83 + (0, pwb)
U524: box invis "5.2.4" at D84 + (0, pwb)
arrow from PWB.e to U30.w
arrow from U30.e to U301.w
arrow from U301.e to U40.w
arrow from U40.e to U50.w
arrow from U50.e to U52.w
arrow from U52.e to U524.w
arrow right from U524.e

boxwid = bigb
CBUNIX: box invis "CB UNIX" at PWB + (0, cbunix - pwb)
arrow from 1/4 <V6, V7> to CBUNIX.n
spline -> from CBUNIX.e to U301 + (0, cbunix - pwb) then to 1/2 <U301, U40>

"\fIBell Columbus\fP" ljust at Label + (0, cbunix)

boxwid = medb
MERT: box invis "MERT" at PWB + (0, mert - pwb)
boxwid = bigb
UNIXRT: box invis "UNIX/RT" at D78 + (0, mert)
arrow from V6.s to MERT.nw
arrow from MERT.e to UNIXRT.w
arrow from UNIXRT.ne to 3/4 <PWB, U30>

boxwid = bigb
SysIII: box "System III" at D82 + (0, sysv)
SysV: box invis "System V" at D83 + (0, sysv)
oldht = boxht
boxht = oldht * 2
SysV2: box "System V" "Release 2" at D84 + (0, sysv)
boxht = oldht * 3
SysV24: box dotted "System V" "Release 2" "Version 4" at D85 + (0, sysv)
boxht = oldht
arrow from U301.se to SysIII.n
arrow from U50.se to SysV.n
arrow from U52.se to SysV2.n
arrow from U524.se to SysV24.n

"\fIUSG / USDL\fP" ljust at Label + (0, sysv + (pwb - sysv)/2)

boxwid = smallb
BSD3: box invis "3BSD" at 1/2 <D78, D79> + (0, bsd4)
arrow from V32.n to BSD3.s
boxwid = medb
BSD40: box invis "4.0BSD" at 1/2 <D79, D80> + (0, bsd4)
BSD41: box "4.1BSD" at 1/2 <D80, D81> + (0, bsd4)
BSD42: box "4.2BSD" at 1/2 <D83, D84> + (0, bsd4)
BSD41A: box invis "\s-14.1aBSD\s0" at 1/3 <BSD41, BSD42>
BSD41C: box invis "\s-14.1cBSD\s0" at 2/3 <BSD41, BSD42>
BSD43: box dotted "4.3BSD" at 1/2 <D84, D85> + (0, bsd4)
arrow from BSD3.e to BSD40.w
arrow from BSD40.e to BSD41.w
arrow from BSD41.e to BSD41A.w
arrow from BSD41A.e to BSD41C.w
arrow from BSD41C.e to BSD42.w
arrow from BSD42.e to BSD43.w
arrow right from BSD43.e

arrow from 1/5 <V32, V8> to BSD41.sw

boxwid = smallb
BSD1: box invis "1BSD" at 1/2 <V6, V7> + (0, bsd2 - research)
BSD2: box invis "2BSD" at V7 + (0, bsd2 - research)
boxwid = medb
BSD28: box invis "2.8BSD" at D82 + (0, bsd2)
BSD29: box invis "2.9BSD" at D83 + (0, bsd2)
arrow from V6.n to BSD1.s
arrow from BSD1.e to BSD2.w
arrow from BSD2.e to BSD28.w
arrow from BSD28.e to BSD29.w
arrow right from BSD29.e

arrow from BSD2.s to BSD3.n
arrow from BSD41.ne to BSD28.sw
arrow from 1/2 <BSD41A, BSD41C> to BSD29.sw

"\fIBerkeley\fP" ljust at Label + (0, bsd4 + (bsd2 - bsd4)/2)

arrow from BSD41.se to 3/4 <V32, V8>
arrow from BSD41.s to U50.n

boxwid = medb
box dashed "PDP-11" at BSD1 + (-1, 0)
boxwid = smallb
box dashed "VAX" at 1/2 <V32, BSD3> + (-1, 0)
boxwid = medb
box dashed "PDP-11" at PWB.w + (-1, 0)
boxwid = biggerb
box dashed "PDP-11 / VAX" with .ne at 1/2 <U30, SysIII>

.PE
.ps +2
.FI "UNIX History"
.fi
.KE
.GI
-- 
John Quarterman, UUCP:  {gatech,harvard,ihnp4,pyramid,seismo}!ut-sally!im4u!jsq
ARPA Internet and CSNET:  j...@im4u.UTEXAS.EDU, j...@sally.UTEXAS.EDU

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Path: utzoo!henry
From: he...@utzoo.UUCP (Henry Spencer)
Newsgroups: net.unix,net.unix-wizards
Subject: Re: Unix History
Message-ID: <6865@utzoo.UUCP>
Date: Wed, 25-Jun-86 17:13:11 EDT
Article-I.D.: utzoo.6865
Posted: Wed Jun 25 17:13:11 1986
Date-Received: Wed, 25-Jun-86 17:13:11 EDT
References: <212@butler.UUCP> <6780@utzoo.UUCP>, <1345@oddjob.UUCP> <6807@utzoo.UUCP>, 
<513@hropus.UUCP>
Organization: U of Toronto Zoology
Lines: 46

> > Although AT&T won't admit it in so many words, they effectively
> > abandoned work on PDP11 Unix a long time ago.
> 
> Most new features made it to the PDP11...

But there weren't all that many new features.  A lot of what was new was
the performance work, which did *not* make it.

> > For example, although some of the SysV performance work wouldn't fit
> > on the 11, *some* of it would.  None of it was applied to PDP11 SysV.
> 
> The PDP-11 uses hashing to implement the sleep/wakeup facility in the kernel
> under System V...

It did under V7 too; this is nothing new.

> I don't know of any other System V performance work that
> was applied to the PDP11 (but then if it had been it would probably would not
> have helped a machine the size of a PDP-11 much.)

Nonsense.  Things like inode hashing make quite a substantial difference,
and are easy to put in, if anyone had bothered to *try*.  As for "the size
of a PDP-11"...  an 11/44 is fully the equal of a 750 on anything that
doesn't hit address-space problems, and an 11/70 approaches a 780.  The
neglect of the 11 was not because the machines wouldn't benefit from it,
but because AT&T had, as I indicated, effectively abandoned the 11.  (I
don't *blame* them, given how hard the address-space problem hits the
kernel, but they should stop lying about it.)

> > ... PDP11 SysV is really SysIV.
> 
> Not really.
> 
> >  The PDP11 SysV shared-memory stuff is also different from and
> > incompatible with the regular SysV version.
> 
> Right, but it is present, which is a difference from UNIX 4.0.  The IPC
> stuff was first released in UNIX 4.2.

I wasn't claiming that PDP11 SysV was identically equal to 4.00000, but
that it was largely one of the 4's, not really a 5.  (I should have been
clearer about this.)
-- 
Usenet(n): AT&T scheme to earn
revenue from otherwise-unused	Henry Spencer @ U of Toronto Zoology
late-night phone capacity.	{allegra,ihnp4,decvax,pyramid}!utzoo!henry