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From: "Wayne L. Beavers" <wayneb@beyond-software.com>
Subject: Re: Ariane 5 failure
Date: 1996/10/01
Date: 1996-10-01T00:00:00+00:00	[thread overview]
Message-ID: <52s00v$oj1@beyond-software.com> (raw)
In-Reply-To: 3251322B.1076@lmtas.lmco.com


Ken Garlington wrote:

> That's actually a pretty common rule of thumb for safety-critical systems.
> Unfortunately, read-only memory isn't exactly read-only. For example, hardware errors
> can cause a random change in the memory. So, it's not a perfect fix.

  Your right, but the risk and probability of memory failures is pretty low I would think.  I have never seen 
or heard of a memory failure in any of the systems that I have worked on.  I don't know what the current 
technology is but I can remember quite awhile ago that at least one vendor was claiming that ALL double bit 
memory errors were fully detectable and recoverable, ALL triple bit errors were detectable but only some were 
correctable.  But I also don't work on realtime systems, my experience is with commercial systems.

  Are you refering to on-board systems for aircraft where weight and vibration are also a factor or are you 
refering to ground base systems that don't have similar constraints?

  Does anyone know just how good memory ECC is these days?

Wayne L. Beavers   wayneb@beyond-software.com
Beyond Software, Inc.      
The Mainframe/Internet Company
http://www.beyond-software.com/




  reply	other threads:[~1996-10-01  0:00 UTC|newest]

Thread overview: 105+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <agrapsDy4oJH.29G@netcom.com>
1996-09-25  0:00 ` Ariane 5 failure @@           robin
1996-09-25  0:00   ` Bob Kitzberger
1996-09-26  0:00     ` Ronald Kunne
1996-09-26  0:00       ` Matthew Heaney
1996-09-27  0:00         ` Ronald Kunne
1996-09-27  0:00           ` Lawrence Foard
1996-10-04  0:00             ` @@           robin
1996-09-28  0:00           ` Ken Garlington
1996-09-28  0:00             ` Ken Garlington
1996-09-29  0:00           ` Alan Brain
1996-09-29  0:00             ` Robert A Duff
1996-09-30  0:00               ` Wayne L. Beavers
1996-10-01  0:00                 ` Ken Garlington
1996-10-01  0:00                   ` Wayne L. Beavers [this message]
1996-10-01  0:00                     ` Ken Garlington
1996-10-02  0:00                       ` Sandy McPherson
1996-10-03  0:00                 ` Richard A. O'Keefe
1996-10-01  0:00             ` Ken Garlington
1996-09-27  0:00         ` Wayne Hayes
1996-09-27  0:00           ` Richard Pattis
1996-09-29  0:00             ` Chris McKnight
1996-09-29  0:00               ` Real-world education (was: Ariane 5 failure) Michael Feldman
1996-09-29  0:00             ` Ariane 5 failure Dann Corbit
1996-09-29  0:00             ` Alan Brain
1996-10-01  0:00             ` Ken Garlington
1996-09-28  0:00         ` Ken Garlington
1996-09-27  0:00       ` Ken Garlington
1996-09-27  0:00       ` Alan Brain
1996-09-28  0:00         ` Ken Garlington
1996-09-29  0:00       ` Louis K. Scheffer
1996-09-25  0:00   ` Michel OLAGNON
1996-09-25  0:00     ` Chris Morgan
1996-09-25  0:00     ` Byron Kauffman
1996-09-25  0:00       ` A. Grant
1996-09-25  0:00         ` Ken Garlington
1996-09-26  0:00         ` Byron Kauffman
1996-09-27  0:00           ` A. Grant
1996-09-26  0:00         ` Sandy McPherson
1996-09-27  0:00   ` John McCabe
1996-10-01  0:00     ` Michael Dworetsky
1996-10-04  0:00       ` Steve Bell
1996-10-07  0:00         ` Ken Garlington
1996-10-09  0:00         ` @@           robin
1996-10-09  0:00           ` Steve O'Neill
1996-10-12  0:00             ` Alan Brain
1996-10-04  0:00     ` @@           robin
1996-10-04  0:00       ` Joseph C Williams
1996-10-06  0:00         ` Wayne Hayes
1996-10-04  0:00       ` Michel OLAGNON
1996-10-09  0:00         ` @@           robin
1996-10-17  0:00       ` Ralf Tilch
1996-10-17  0:00         ` Ravi Sundaram
1996-10-22  0:00           ` shmuel
1996-10-22  0:00             ` Jim Carr
1996-10-24  0:00               ` hayim
1996-10-25  0:00                 ` Michel OLAGNON
1996-10-25  0:00                 ` Ken Garlington
1996-10-01  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-02  0:00 ` Robert I. Eachus
1996-10-02  0:00   ` Ken Garlington
1996-10-02  0:00 ` Matthew Heaney
1996-10-04  0:00   ` Ken Garlington
1996-10-05  0:00     ` Robert Dewar
1996-10-06  0:00       ` Keith Thompson
1996-10-10  0:00       ` Ken Garlington
1996-10-14  0:00       ` Matthew Heaney
1996-10-15  0:00         ` Robert Dewar
1996-10-16  0:00         ` Ken Garlington
1996-10-18  0:00           ` Keith Thompson
1996-10-18  0:00             ` Samuel T. Harris
1996-10-21  0:00               ` Ken Garlington
1996-10-18  0:00             ` Ken Garlington
1996-10-23  0:00           ` robin
  -- strict thread matches above, loose matches on Subject: below --
1996-10-01  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-02  0:00 ` Ken Garlington
1996-10-01  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-02  0:00 ` Alan Brain
1996-10-02  0:00   ` Ken Garlington
1996-10-02  0:00     ` Matthew Heaney
1996-10-04  0:00       ` Robert S. White
1996-10-05  0:00         ` Robert Dewar
1996-10-05  0:00         ` Alan Brain
1996-10-06  0:00           ` Robert S. White
1996-10-03  0:00     ` Alan Brain
1996-10-04  0:00       ` Ken Garlington
1996-10-03  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-03  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-03  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-14  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-15  0:00 ` Robert I. Eachus
1996-10-15  0:00   ` Robert Dewar
1996-10-16  0:00     ` Michael F Brenner
1996-10-16  0:00       ` Robert Dewar
1996-10-23  0:00 ` robin
1996-10-16  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-18  0:00 ` Ken Garlington
1996-10-19  0:00   ` Frank Manning
1996-10-21  0:00     ` Norman H. Cohen
1996-10-21  0:00 Marin David Condic, 407.796.8997, M/S 731-93
1996-10-22  0:00 ` Adam Beneschan
1996-10-28  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1996-10-28  0:00 Marin David Condic, 561.796.8997, M/S 731-93
1996-10-29  0:00 ` Ken Garlington
1996-11-08  0:00   ` robin
1996-10-31  0:00 Marin David Condic, 561.796.8997, M/S 731-93
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