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From: atbowler@orchid.UUCP
Newsgroups: talk.bizarre,comp.misc
Subject: Re: What the world needs now [ is an exploding computer ]
Message-ID: <7775@orchid.UUCP>
Date: Mon, 25-May-87 13:48:32 EDT
Article-I.D.: orchid.7775
Posted: Mon May 25 13:48:32 1987
Date-Received: Tue, 26-May-87 01:15:19 EDT
References: <12067@topaz.rutgers.edu> <910@killer.UUCP> <170@auvax.UUCP>
Reply-To: atbowler@orchid.UUCP (Alan T. Bowler [SDG])
Organization: U. of Waterloo, Ontario
Lines: 30
Xref: utgpu talk.bizarre:1909 comp.misc:546

In article <170@auvax.UUCP> rwa@auvax.UUCP (Ross Alexander) writes:
>As far as this sort of thing in the mainframe world goes, I (fondly)
>remember that one of the hackers at the MFCF (U of Waterloo, about
>197[45]?), I believe it was C.J.  O'Donnel (corrections solicited,
>any of you guys still around???)  found out that if one could
>synchronously produce a tag fault, a lockup fault and some third
>fault which I forget (a derail??)  that the fault priority arbitrator
>would fry a diode or something and <*crash*> until the CE could fix
>it.  Of course, this was done more than once - it has to be
>repeatable to be a scientific experiment, right ;-) !!  So be careful
>about generating faults on an H6050.  And this is _not_ hearsay - I
>saw the code and experienced the crashes.
>
Ciaran O'Donnell was responsible for a lot of wierd and wonderful
GCOS crashes both in bugs he exposed, and bugs he introduced
(For those of you out there who still use GCOS systems, subsystem
wrapup in TSS is part of his legacy.)
   However, this particular item is not one I recall. It sounds unlikely.
There was a real hardware/software bug whereby the system could
be crashed by a program that caused a carefully timed lockup fault
to occur during the initial stages of fault processing while state
was still being saved from the first program induced fault.  This
would cause GCOS to crash, and was fixed by a hardware field change to
the lockup fault timing algorithm that removed the vulnerable window.
However, no-one here remembers anything that destroyed any electronics.
One of the people involved in exposing that likes feeding people tall
tales laced with just enough truth to make them seem plausible,
I think Ross, you got taken in.

                           Alan (are you still at Waterloo?) Bowler