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, LOTS_OF_MONEY autolearn=unavailable autolearn_force=no version=3.4.4 Path: eternal-september.org!reader01.eternal-september.org!reader02.eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Robert I. Eachus" Newsgroups: comp.lang.ada Subject: Re: Ada-Oriented GUI Date: Sun, 1 Apr 2018 13:37:59 -0400 Organization: Aioe.org NNTP Server Message-ID: References: <9ed9edb1-3342-4644-89e8-9bcf404970ee@googlegroups.com> <26a1fe54-750c-45d7-9006-b6fecaa41176@googlegroups.com> <656fb1d7-48a4-40fd-bc80-10ba9c4ad0a4@googlegroups.com> NNTP-Posting-Host: fZYVf2g/avGnWJvs1xVPEA.user.gioia.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:52.0) Gecko/20100101 Thunderbird/52.5.2 X-Notice: Filtered by postfilter v. 0.8.3 Content-Language: en-US Xref: reader02.eternal-september.org comp.lang.ada:51282 Date: 2018-04-01T13:37:59-04:00 List-Id: On 3/26/2018 6:29 PM, Randy Brukardt wrote: > Calling an avionics display a "GUI" is confusing at best; there is little > relationship because of the strict requirements on avionics software. > (Something like RX would be unlikely to fly - pun intended - there can't be > "unexpected" anything in avionics software.) Sorry Randy I think I know what you were intending to say, but I suspect that many readers here will get the wrong impression. Military Avionics software has to be written to minimize the effect of unexpected events, If a sudden hole appears through the fuselage--and the avionics, the pilot would very much like the controls to work until he (or she) is back over friendly territory. The government which paid $100 million plus for the aircraft would like it even more if the pilot can land the plane. Both F-15E and A-10 have been successfully landed "on a wing and a prayer" with one wing missing. To do this you need to design with most systems doing automatic fallbacks if some of its inputs are missing. (If one aileron is missing, it would be nice if the one on the remaining wing still worked.) More important, any system which is fubared (fouled up beyond all recovery) needs to tell the pilot that it has failed--and shut up. Diagnostics are for after landing. The A-380 passenger plane got this one wrong. It took the crew hours to shut down systems which were periodically saying that they were inoperable, so they could figure out what was working and what wasn't, and land the plane. I'd apologize for the rant, but I figure that if one person reads this and designs a system correctly it will have been worthwhile. And this audience is probably a target rich environment for avionics software designers. ;-)