[TUHS] Fwd: Public access multics

Noel Chiappa jnc at mercury.lcs.mit.edu
Sun Sep 2 09:25:37 AEST 2018

    > From: Will Senn

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

I'd start with:


    > From: Clem Cole <clemc at 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:


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.


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