From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,FREEMAIL_FROM autolearn=ham autolearn_force=no version=3.4.4 X-Google-Thread: 103376,ac9405996d0dcb7f X-Google-Attributes: gid103376,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!postnews.google.com!not-for-mail From: snarflemike@yahoo.com (Mike Silva) Newsgroups: comp.lang.ada Subject: Re: Would You Fly an Airplane with a Linux-Based Control System? Date: 25 Nov 2004 10:28:24 -0800 Organization: http://groups.google.com Message-ID: <20619edc.0411251028.3e249bf3@posting.google.com> References: <2004112218292016807%david@bottoncom> NNTP-Posting-Host: 67.8.58.78 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1101407304 13257 127.0.0.1 (25 Nov 2004 18:28:24 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Thu, 25 Nov 2004 18:28:24 +0000 (UTC) Xref: g2news1.google.com comp.lang.ada:6475 Date: 2004-11-25T10:28:24-08:00 List-Id: David Botton wrote in message news:<2004112218292016807%david@bottoncom>... > For a real understanding of the Ariane 5 event, see the Ada FAQ: > > http://www.adapower.com/index.php?Command=Class&ClassID=FAQ&CID=328 A small but, I think, important correction. The hardware at the center of the failure was apparently built around the Motorola 68020/68881 chips, not the MIL-STD-1750. The "Operand Error" that triggered the failure is a hardware exception generated by the FPU when, among other conditions, a float-to-integer conversion exceeds the capacity of the integer, exactly as occurred. The reason this is important is because it shows that the exception was not generated by the Ada compiler code but by the hardware, and would therefore have occurred regardless of the programming language used. If that's the case then the "it wouldn't have exploded if it were written in C" argument evaporates, unless they want to argue that the exception handler behavior would have been specified differently if the implementation language was C -- not likely!