From: Jerry Petrey <gpetrey@earthlink.net>
Subject: Re: Ada in medical devices
Date: Thu, 28 Jun 2012 11:03:18 -0700
Date: 2012-06-28T11:03:18-07:00 [thread overview]
Message-ID: <ad6dnRoBUcn4AXHSnZ2dnUVZ_o6dnZ2d@earthlink.com> (raw)
In-Reply-To: <jsem69$o6c$1@news.ox.ac.uk>
On 6/27/2012 3:10 AM, Ian Clifton wrote:
> Jerry Petrey <gpetrey@earthlink.net> writes:
>
>> On 6/21/2012 3:37 PM, Jeffrey Carter wrote:
>>>
>>> I once knew a C coder, and a mediocre C coder at that, who was coding
>>> for pacemakers. I hope I never need one.
>> How true. Remember the Therac-25 incident in the 1980's where C
>> pointer problems killed a number of people with huge doses of X-rays?
>>
> To be fair, I believe the Therac-25 software was written in PDB-11
> assembler:
>
> http://sunnyday.mit.edu/papers/therac.pdf page 23
>
You are right. It was written in PDP-11 assembly language - I
remembered incorrectly. Nancy Leveson has an excellent coverage of the
Therac-25 accident in her book "Safeware: System Safety and Computers".
The problems were caused by coding errors and improper reuse attempts by
trying to reuse some of the Therac-6 and Therac-20 code in the newer
Therac-25. It was a very sad outcome.
Jerry
next prev parent reply other threads:[~2012-06-28 18:03 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-06-21 22:12 Ada in medical devices Jerry
2012-06-21 22:37 ` Jeffrey Carter
2012-06-26 22:58 ` Jerry Petrey
2012-06-27 9:56 ` RasikaSrinivasan
2012-06-27 17:39 ` Jeffrey Carter
2012-06-27 18:43 ` RasikaSrinivasan
2012-06-27 10:10 ` Ian Clifton
2012-06-27 10:18 ` Dmitry A. Kazakov
2012-06-28 18:03 ` Jerry Petrey [this message]
2012-06-21 22:38 ` Nasser M. Abbasi
2012-06-22 2:04 ` John B. Matthews
2012-06-22 2:16 ` Patrick
2012-06-22 4:04 ` tmoran
2012-06-22 4:56 ` Nasser M. Abbasi
2012-06-29 17:23 ` leonid.dulman
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