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=-0.8 required=5.0 tests=BAYES_00,INVALID_DATE autolearn=no autolearn_force=no version=3.4.4 Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!elroy.jpl.nasa.gov!lll-winken!unixhub!stanford.edu!msi.umn.edu!src.honeywell.com!klemmer!vestal From: vestal@SRC.Honeywell.COM (Steve Vestal) Newsgroups: comp.lang.ada Subject: Re: Critique of SEI's Ada DARK project Message-ID: <1991May22.143229.24667@src.honeywell.com> Date: 22 May 91 14:32:29 GMT References: Sender: news@src.honeywell.com (News interface) Distribution: comp.lang.ada Organization: Honeywell Systems & Research Center In-Reply-To: spray@convex.com's message of 21 May 91 20:33:31 GMT Nntp-Posting-Host: klemmer.src.honeywell.com List-Id: In article spray@convex.com (Rob Spray) writes: Rob> One concern I have always had about DARK is how it got funded Rob> targetted to a processor that is not available in a Rob> radiation-hardened configuration. Several embedded systems Rob> I am familiar with are required to use full MIL-SPEC processors. Does mil-spec mean that a processor must be radiation hardened, or just that it be class B, certain temperature range, certain packaging, etc.? "Radiation hardened" isn't a yes/no thing; there are several parameters and several degrees to radiation hardening. For example, of the two processors cited, I am aware that there is a very rad-hard version of the 1750A. As far as I know, there are versions of the i80x86 family that are perhaps less sensitive to radiation in some ways than commercial parts (e.g. maybe tolerate somewhat greater total dose) but may or may not have significantly better numbers in all respects (e.g. sensitivity to single event upset). My speculation would be that radiation hardening requirements for communication sattelites in high orbit, shuttle or space station in low orbit, and aircraft, all vary. Also, this is a systems issue, since one can trade shielding against the radiation insensitivity of the circuitry used. There are Ada development environments and executives for rad-hard computer systems, but I don't think a high degree of radiation insensitivity is a universal requirement on all military systems. Steve Vestal Mail: Honeywell S&RC MN65-2100, 3660 Technology Drive, Minneapolis MN 55418 Phone: (612) 782-7049 Internet: vestal@src.honeywell.com