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=2.1 required=5.0 tests=BAYES_40,INVALID_MSGID, REPLYTO_WITHOUT_TO_CC autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 103376,5ecb5248e650e812 X-Google-Attributes: gid103376,public From: Alan Brain Subject: Re: Ada and robots Date: 1997/06/25 Message-ID: <33B1DC6E.4364@dynamite.com.au>#1/1 X-Deja-AN: 252439760 References: <9706242128.AA09652@stealth.ctron.com> Organization: @Home Reply-To: aebrain@dynamite.com.au Newsgroups: comp.lang.ada Date: 1997-06-25T00:00:00+00:00 List-Id: Huy Vo wrote: > Cool; Ada is not as safe as I thought it was; so, when I board a Boeing > I should think twice. By the way, aren't there components on a Boeing > that are based on 8 bit processors that can't take C let alone Ada. > So what is the justification of insisting on building supposedly > safe systems (the Boeing) with a mix of safe components (Ada) and > unsafe ones (C and assembly)? OK, here's a facetious reply: Good idea. Rip out all safety belts from cars, ban airbags, take away headlights (headlights don't prevent ALL car crashes at night, therefore there's no reason to have them, right?), remove the brakes (brakes won't save you from being hit from the side, therefore remove them as un-neccessary). There is one heck of a difference between having 4-5 lines per million which are as (un)safe as C casts, are confined to known locations, and where one can write explicit safety code around, rather than having 4-5 of these per 100 lines. As regards 8-bit components on the Boeings, you may well be right. I have no idea what controllers are on the microwave ovens, for example. But the safety-critical avionics aren't 8-bit. Neither in the cockpit controls, nor the navigation system, nor the engines. Never mind, I assume this was a "rattle their cage" troll, so I'll leave it go. Unless you can adduce some logical argument, further dielectic would be futile. -- aebrain@dynamite.com.au <> <> How doth the little Crocodile | Alan & Carmel Brain| xxxxx Improve his shining tail? | Canberra Australia | xxxxxHxHxxxxxx _MMMMMMMMM_MMMMMMMMM 100026.2014 compuserve o OO*O^^^^O*OO o oo oo oo oo By pulling MAERKLIN Wagons, in 1/220 Scale See http://www.z-world.com/graphics/z/master/8856.gif for picture