[comp.arch] Plessy 250

mo@messy.bellcore.com (Michael O'Dell) (11/16/90)

I've seen this machine referenced many times, but I've never seen
a description of the machine and its operating system.  Is there such
a description available??

jones@pyrite.cs.uiowa.edu (Douglas W. Jones,201H MLH,3193350740,3193382879) (11/16/90)

From article <1990Nov15.183201.23217@bellcore.bellcore.com>,
by mo@messy.bellcore.com (Michael O'Dell):
> I've seen this machine referenced many times, but I've never seen
> a description of the machine and its operating system.  Is there such
> a description available??

Read:  D.C. Cosserat, "A Capability Oriented Multiprocessor System
         for Real-time Applications."  First International Conference
         on Computer Communication, Stanley Winkler, Ed., pages 282-289.
         Oct. 1972, Washington DC.

       D. Halton, "Hardware of the System 250 for Communication Control."
         International Switching Symposium Record, MIT, June 1972, pages
         530-536.

       K.J. Hamer-Hodges, "Falult Resistance and Recovery within System
         250."  First International Conference on Computer Communication,
         Stanley Winkler, Ed., pages 290-296.  Oct. 1972, Washington DC.

       C.S. Repton, "Reliability Assurance for System 250, A reliable
         real-time control system."  First International Conference on
         Computer Communication, Stanley Winkler, Ed., pages 297-305.
         Oct. 1972, Washington DC.

pcg@cs.aber.ac.uk (Piercarlo Grandi) (11/16/90)

On 15 Nov 90 23:36:43 GMT, jones@pyrite.cs.uiowa.edu (Douglas W.
Jones) said:

jones> From article <1990Nov15.183201.23217@bellcore.bellcore.com>,
jones> by mo@messy.bellcore.com (Michael O'Dell):

mo> I've seen this machine referenced many times, but I've never seen
mo> a description of the machine and its operating system.  Is there such
mo> a description available??

jones> [ ... some references to rare conference proceedings ... ]

I think that the best introduction is the book by Levvy, published by
Digital Press, on capability systems. It is facinating reading, even for
those that (like me...) are already familiar with the subject. It is
(almost) all condensed there, and fairly well.

This book is the most obvious illustration that computer/OS architecture
is going in circles since the late sixities, and the only novelties are
slightly different approaches, as technological tradeoffs shift, to the
same ideas (OK, ok, this is a gross generalization, but it is fairly
credible, isn't it? :->).
--
Piercarlo Grandi                   | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk
Dept of CS, UCW Aberystwyth        | UUCP: ...!mcsun!ukc!aber-cs!pcg
Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk

gillies@m.cs.uiuc.edu (11/16/90)

"Capability-Based Computer Systems", by Henry Levy, Digital Press,
1984.

This book has a chapter on the protection scheme in Plessy/250.  This
is a very good book if you're interested in capabilities -- it is the
only source I've seen that fully explains the implementation of
several capability-based systems (most conference papers have holes
and gaps in the explanations).

colwell@omews35.intel.com (Robert Colwell) (11/27/90)

In article <3300217@m.cs.uiuc.edu> gillies@m.cs.uiuc.edu writes:
>
>"Capability-Based Computer Systems", by Henry Levy, Digital Press,
>1984.
>
>This book has a chapter on the protection scheme in Plessy/250.  This
>is a very good book if you're interested in capabilities -- it is the
>only source I've seen that fully explains the implementation of
>several capability-based systems (most conference papers have holes
>and gaps in the explanations).

It's also a good example of the "classic" computer architecture book, which
covers mechanisms and bit positions with absolutely no regard to how
expensive these mechanisms will be to implement nor what their performance
implications would be.  I think it would be a good exercise to read this
book and then Patterson/Hennessy; quite a contrast in attitudes and styles.

Bob Colwell  mipon2!colwell@intel.com  503-696-4550
Intel Corp.  JF1-19
5200 NE Elam Young Parkway
Hillsboro, Oregon 97124