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: 27 Nov 2004 11:36:42 -0800 Organization: http://groups.google.com Message-ID: <20619edc.0411271136.66f56ee2@posting.google.com> References: <20619edc.0411251028.3e249bf3@posting.google.com> <20619edc.0411261258.7eb4a32b@posting.google.com> NNTP-Posting-Host: 67.8.58.78 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit X-Trace: posting.google.com 1101584202 10768 127.0.0.1 (27 Nov 2004 19:36:42 GMT) X-Complaints-To: groups-abuse@google.com NNTP-Posting-Date: Sat, 27 Nov 2004 19:36:42 +0000 (UTC) Xref: g2news1.google.com comp.lang.ada:6558 Date: 2004-11-27T11:36:42-08:00 List-Id: Marius Amado Alves wrote in message news:... > Mike Silva wrote: > > What was the bug? Since there wasn't one, your answer should prove interesting! > > Did they fix the hardware or the software? The inevitable conclusion > from your answer should prove interesting! They fixed the match between the hardware, the software and the flight profile. To do so they removed correct software (correctly implemented to a correct specification for Ariane 4) and replaced it with software correctly implemented to a correct specification for Ariane 5. They did not fix the software because the software was not broken. They modified correct software for one specification to correct software for a new specification. There was no _software_ bug, as you assert. There was a reuse error, or if you like, a reuse bug, but not a software bug. The software no more failed by correctly reacting to the new H-bias value according to its design spec than the H-bias sensor failed by correctly reacting to the new flight path of the rocket according to its design spec. The situation is similar to correctly using a 5 Amp fuse in a particular circuit, and then changing the circuit (the hardware) so that it draws 10 Amps. The 5 Amp fuse then blows, but was the 5 Amp fuse defective? Or was it simply the wrong part for the new circuit?