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From: "robin" <robin51@dodo.com.au>
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Subject: Re: How would Ariane 5 have behaved if overflow checking
 werenotturned off?
Date: Thu, 17 Mar 2011 10:39:02 +1100
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Date: 2011-03-17T10:39:02+11:00
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Martin Krischik wrote in message ...
>Am 16.03.2011, 11:41 Uhr, schrieb robin <robin51@dodo.com.au>:
>
>> That was the major blunder that they made,
>> namely, treating a programming error as a hardware error.
>
>Let me repeat: There was no programming error.

Let me repeat:  The major blunder made was in treating
a programming error as a hardware error.
The error was in assuming that there was no possibility of a
programming error, and therefore it must be hardware error.
This error was made in the Ariadne 4.

This attitide that "it can't happen" therefore there's no need to test for it
is responsible for run-time failures from the early days of programming.

Remember Robert's Law: "Even if it can't go wrong, it will".

In a real-time system, EVERY possibility must be tested for.

> The software was correct
>for the Ariane 4.

No it wasn't.
It had unchecked overflow.

> If at all it was a deployment or management error in
>installing Ariane 4 software on the Ariane 5.
>
>> By doing that, they guaranteed failure of the mission.

Quite so.