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=-0.3 required=5.0 tests=BAYES_00, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,da26f7e99d6cfcf3 X-Google-Attributes: gid103376,public X-Google-ArrivalTime: 2001-04-11 04:14:07 PST Path: supernews.google.com!sn-xit-03!supernews.com!nntp.cs.ubc.ca!news-spur1.maxwell.syr.edu!news.maxwell.syr.edu!newsfeed.icl.net!colt.net!newsfeed.esat.net!news.heanet.ie!Colin_Paul_Gloster From: Colin_Paul_Gloster@ACM.org (Colin Paul Gloster) Newsgroups: comp.lang.ada Subject: Re: software failure question Date: 11 Apr 2001 12:12:52 GMT Organization: Dublin City University Message-ID: References: <9Pxz6.992$ix4.198187@news1.rdc1.sfba.home.com> <4ZmA6.1693$Ak1.181271@newsread2.prod.itd.earthlink.net> Reply-To: Colin_Paul_Gloster@ACM.org NNTP-Posting-Host: ns.dcu.ie X-Trace: kenraki.heanet.ie 986991172 30456 136.206.1.3 (11 Apr 2001 12:12:52 GMT) X-Complaints-To: news@kenraki.heanet.ie NNTP-Posting-Date: 11 Apr 2001 12:12:52 GMT User-Agent: slrn/0.9.5.3 (UNIX) Cache-Post-Path: ns.dcu.ie!unknown@tolka.dcu.ie X-Cache: nntpcache 2.3.3 (see http://www.nntpcache.org/) Xref: supernews.google.com comp.lang.ada:6744 Date: 2001-04-11T12:12:52+00:00 List-Id: It was widely reported in Spring or Summer of the year 2000. I believe that the first time I heard about the beachballs is today. I had heard that they actually fired (in at least one report Stinger) missiles (well, technically beach balls can be missiles too). Apparently it did have basis in truth but a surprisng ommission from the commonly circulated urban legend as repeated earlier in the thread is that " [..]The head of the Defense Science & Technology Organization's LandOperations/Simulation division reportedly instructed developers to model the local marsupials' movements and reactions to helicopters. [..] Eager to demonstrate their flying skills for some visiting American pilots, the hotshot Aussies "buzzed" the virtual kangaroos in low flight during a simulation. The kangaroos scattered, as predicted, and the visiting Americans nodded appreciatively....[..] and the Yanks left with a newfound respect for Australian wildlife. Simulator supervisors report that pilots from that point onward have strictly avoided kangaroos, just as they were meant to." This demonstration in front of foreign officials is alleged to be the untrue noise making the reports inaccurate. A URL I had in July 2000 with a statement from a staff member at the department concerned pointed out that one would expect reporters to actually ring them up to confirm that the story is true. The URL pointed to a subdirectory of ~glen on HTTP://WWW.QNX.com but Glen seems to have left and it is not up there now. Colin Paul In article , Ted Dennison wrote: ">In article <4ZmA6.1693$Ak1.181271@newsread2.prod.itd.earthlink.net>, Phaedrus >says... >> >>I'm reminded of another famous software failure, that may or >>may not be an urban legend: >>According to the story, when programming a helicopter simulation >>for the Australian military, someone noticed that they didn't have >>any kangaroos. Rather than write a whole bunch of new code to >>simulate them, they just derived a new subclass from the class that >>they used to simulate the ground troops. I forgot about this part. The OO mumbo-jumbo that got thrown in here was just made up. They were interfacing their virtual sim to another simulation capable of generating and controlling other entities (perhaps MODSAF). When this is done, each entity MODSAF is controlling needs to be mapped on the virtual sim to an entity that the virtual sim's image generator knows how to render. Its fairly common in such a setup to map one entity to another similar one that MODSAF (or whatever they are using) doesn't have. I've been on two different projects that did this. There's nothing particularly OO about it. But the story has slowly mutated itself into some kind of unspecified object lesson on the dangers of OO programming. Go figure. To put my previous post in perspective, they weren't expecting SAMs to come out of MODSAF, so they didn't set up a mapping for them. That meant they got the default mapping, which happened to be multicolored beach balls. :-) BTW: I've personally seen a (simulated) marine helocopter fly in close formation with a heap of rubble for over thirty minutes due to a similar issue. We had them keep flying that long so we could monitor the network traffic and try to figure out where the bug was. The pilots entertained themselves during this time by pretending that the squarish rubble heap was a Borg ship. :-)"