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=-1.3 required=5.0 tests=BAYES_00,INVALID_MSGID autolearn=no autolearn_force=no version=3.4.4 X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: fac41,a48e5b99425d742a X-Google-Attributes: gidfac41,public X-Google-Thread: 103376,a48e5b99425d742a X-Google-Attributes: gid103376,public X-Google-Thread: f43e6,a48e5b99425d742a X-Google-Attributes: gidf43e6,public X-Google-Thread: 107d55,a48e5b99425d742a X-Google-Attributes: gid107d55,public X-Google-Thread: 1108a1,5da92b52f6784b63 X-Google-Attributes: gid1108a1,public X-Google-Thread: ffc1e,a48e5b99425d742a X-Google-Attributes: gidffc1e,public From: john@assen.demon.co.uk (John McCabe) Subject: Re: Papers on the Ariane-5 crash and Design by Contract Date: 1997/03/23 Message-ID: <333503fe.6977287@news.demon.co.uk>#1/1 X-Deja-AN: 227676278 X-NNTP-Posting-Host: assen.demon.co.uk References: <332B5495.167EB0E7@eiffel.com> <332d95c9.1004852@news.demon.co.uk> <5h019d$g7r@access5.digex.net> Newsgroups: comp.lang.eiffel,comp.object,comp.software-eng,comp.programming.threads,comp.lang.ada,comp.lang.java.tech Date: 1997-03-23T00:00:00+00:00 List-Id: nigel@access5.digex.net (Nigel Tzeng) wrote: >In article <332d95c9.1004852@news.demon.co.uk>, >John McCabe wrote: >>nouser@nohost.nodomain (Thomas) wrote: >> >>>In article <332B5495.167EB0E7@eiffel.com> Bertrand Meyer writes: >> >><..snip..> >> >>The most commonly used device in the european space industry at the >>moment is the GPS MA31750 (probably), a MIL-STD-1750 implementation >>that runs at 10MHz and gives a performance of 1.3 MIPS. It is, >>however, available radiation hardened. 200MHz Pentium Pros are not. > >No, but rad hard 386s are available (flown on SAMPEX and later SMEX >missions). R3000s have also been flight qual'd although the floating >point performance isn't as good as the 386. I think one flew on >Clementine. Who supplies the Rad-Hard 386? Is it SEI? If so, although specified to 100kRads total dose I believe, (which is technically Rad-Tolerant) the Rad-Pak doesn't really enhance the SEE (Single Event Effect) performance. I am aware of the R3000, Harris build it don't they? I was interested in using this before, but we came up with too many reasons not to. Possibly cost, power, radiation performance (again I believe it's built on a Rad Tolerant rather than Rad-Hard process). >Why folks still baseline on the 1750A is something of a mystery to >this software person. I suppose there is a base of 1750A test suites >and simulators that 386 users wouldn't have. Possibly, but I think from the point of view of the space industry, they can go to GPS and buy a 300kRad total dose Silicon On Sapphire (SOS) device and be pretty sure it's not going to fail. SOS and SOI (I think) are really the only way you can avoid the effects of radiaition on processor. Bulk-CMOS is good, but you're still taking a bit of a risk. Also, the 1750A has a built in FPU, the 386 hasn't. Best Regards John McCabe