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* Re: [TUHS] Fwd:  Public access multics
@ 2018-09-01 23:25 Noel Chiappa
  2018-09-02  4:05 ` Will Senn
  0 siblings, 1 reply; 23+ messages in thread
From: Noel Chiappa @ 2018-09-01 23:25 UTC (permalink / raw)
  To: tuhs; +Cc: Greenwald, thvv, osibert, jnc

    > From: Will Senn

    > I was thinking that Multics was a failed predecessor of unix
    > ... straighten me out :)

I'd start with:

  https://multicians.org/myths.html


    > From: Clem Cole <clemc@ccc.com>

    > https://www.quora.com/Why-did-Unix-succeed-and-not-Multics/answer/Clem-Cole

Clem, I think that's too limited in scope.

Like a lot of 'big' 'failures' (defined in Multics' case as 'failure to grow
to significant market share, and continue in the long term'), I don't think
Multics 'failed' for a single reason.

In general, in large failures, there are a number of causes, all doing their
bit. Now, if there are M causes, ranked in priority, maybe the first N1 are
_each_ big enough that _any one_ of them could have led to that outcome. Or
maybe not; maybe it needed the first N2, all acting in concert.


My crystal ball isn't that accurate. But here's my take on _some_ of Multics'
main issues.

- Management: if you look at:

  https://multicians.org/hill-mgt.html

it's clear that Honeywell top management didn't understand Multics, and
didn't understand that it had a long-term potential. They terminated
investment in new hardware, and that was what finally killed Multics.

- Non-portability: the system was too tied to a specific platform; it
couldn't really be moved elsewhere. (E.g. the code is riddled with 'fixed bin
18'; yes, that could be changed with a program to edit the source, but there
are lots of dependencies on the specifics of the machine's architecture.) It
would be possible to re-write it to run on, say, a 386, but you'd pretty much
have to start from scratch.

- Built for the wrong future: a key assumption was that people would continue
to get their computes from large centralized machines. Clearly, that was
wrong (and it played into the issues with Honeywell management)>. Multics
_could_ have made the transition to today's 'small' (physically) machines, in
which case it would have been really good to have - e.g. if we could run
browsers in AIM boxes a lot of malware simply would not be an issue. But the
point above prevented that.


Those are some of the big ones; I may come up with more. I've CC'd a couple
of Multicians - perhaps they can add additional insight.

	Noel

^ permalink raw reply	[flat|nested] 23+ messages in thread
* Re: [TUHS] Public access multics
@ 2018-09-03 13:29 Doug McIlroy
  2018-09-03 23:41 ` Dave Horsfall
  0 siblings, 1 reply; 23+ messages in thread
From: Doug McIlroy @ 2018-09-03 13:29 UTC (permalink / raw)
  To: arnold, tuhs

> Was Algol 60 any kind of viable alternative at the time?

The operating system for the Burroughs B5000 had been written in
Burroughs Algol. That punctured the widespread belief that OS's
were so particular to the hardware that they had to be written
in machine language. I don't recall how far Burroughs Algol
went beyond Algol 60, nor why Multics did not want to follow
that lead.  ("Viable" is a slippery concept when choosing
among Turing-complete alternatives.)

Doug

^ permalink raw reply	[flat|nested] 23+ messages in thread
* Re: [TUHS] Public access multics
@ 2018-09-02 21:47 Doug McIlroy
  2018-09-03  6:18 ` arnold
  0 siblings, 1 reply; 23+ messages in thread
From: Doug McIlroy @ 2018-09-02 21:47 UTC (permalink / raw)
  To: tuhs, jpl.jpl

Caveat: As a member of the PL/I committee, and the person who brought
the new and unimplemented language to the attention of Multics, let a
disastrous contract for a compiler, and finally helped cobble together
a rudimentary compiler that got the project off the ground, I am not
exactly an unbiased observer.

A ground tenet of Multics was that it would be programmed in a higher
level language. A subsidiary requirement, which was generally agreed
upon, was language-level access to the logical operators and address
manipulation inherent in the hardware.  No widely used language of the
time met this requirement.  And they didn't want to get sidetracked into
language design.

Discussions finally boiled down to AED, developed at MIT by Doug Ross, and
PL/I. Ross was a brilliant software innovator with a mystical outlook that
made it difficult to distinguish his vision of what could be done from
what actually existed. AED was definitely a moving target. By contrast
PL/I had a written spec, so you knew exactly what could be done in it,
though not how well the compiler would do it.

PL/I  was very big; we deliberately (and explicitly) omitted about
half the spec. The remainder was definitely seen as a "plausible
systems programming language".

From the perspective of the time, why do you think the contrary?

Doug

^ permalink raw reply	[flat|nested] 23+ messages in thread
[parent not found: <5B48F6A3-374A-4579-AE8F-35BD328D07F9@reagan.com>]
* Re: [TUHS] Public access multics
@ 2018-09-01 23:33 Noel Chiappa
  2018-09-01 23:44 ` jcs
  0 siblings, 1 reply; 23+ messages in thread
From: Noel Chiappa @ 2018-09-01 23:33 UTC (permalink / raw)
  To: tuhs; +Cc: jnc

    > From: jcs

    > The real mystery is what it's running on. ... It's=20 probably a
    > simulator but I've never heard of one for the H6000.

Per:

  https://multicians.org/multics.htmlhttps://multicians.org/multics.html

"Harry Reed and Charles Anthony reached a major milestone on the Multics
simulator on Saturday 08 November, 2014. Their SIMH-based simulator booted
Multics MR 12.5, came to operator command level, entered admin mode, created a
small PL/I program, compiled and executed it, and shut down. Release 1.0 of
the simulator is now available."

    Noel

^ permalink raw reply	[flat|nested] 23+ messages in thread
* [TUHS] Public access multics
@ 2018-09-01 20:31 Will Senn
  2018-09-01 21:27 ` jcs
  0 siblings, 1 reply; 23+ messages in thread
From: Will Senn @ 2018-09-01 20:31 UTC (permalink / raw)
  To: tuhs

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So, it looks like someone has gone and started running a multics instance:

http://lists.nycbug.org/pipermail/semibug/2018-August/000288.html

That’s interesting, and y’all may even have been aware of it. But, I was thinking that Multics was a failed predecessor of unix and it’s craziness an inspiration for how unix isn’t multics... straighten me out :)

Will



Sent from my iPhone

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^ permalink raw reply	[flat|nested] 23+ messages in thread

end of thread, other threads:[~2018-09-04  2:48 UTC | newest]

Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-09-01 23:25 [TUHS] Fwd: Public access multics Noel Chiappa
2018-09-02  4:05 ` Will Senn
2018-09-02  4:25   ` [TUHS] " Jeffrey H. Johnson
2018-09-02 22:30     ` Will Senn
  -- strict thread matches above, loose matches on Subject: below --
2018-09-03 13:29 Doug McIlroy
2018-09-03 23:41 ` Dave Horsfall
2018-09-04  2:47   ` Jeffrey H. Johnson
2018-09-02 21:47 Doug McIlroy
2018-09-03  6:18 ` arnold
     [not found] <5B48F6A3-374A-4579-AE8F-35BD328D07F9@reagan.com>
2018-09-02  3:17 ` Jeffrey H. Johnson
2018-09-01 23:33 Noel Chiappa
2018-09-01 23:44 ` jcs
2018-09-01 20:31 Will Senn
2018-09-01 21:27 ` jcs
2018-09-01 23:24   ` John P. Linderman
2018-09-02 13:06     ` Dave Horsfall
2018-09-02 16:23       ` Charles Anthony
2018-09-02 18:18       ` Paul Winalski
2018-09-02 19:09         ` Paul Winalski
2018-09-02  0:57   ` Dan Cross
2018-09-02  2:06     ` Grant Taylor via TUHS
2018-09-02  2:32   ` Charles Anthony
2018-09-02  2:52     ` Larry McVoy

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