Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!wuarchive!udel!ee.udel.edu From: new@ee.udel.edu (Darren New) Newsgroups: comp.lang.misc Subject: Re: CHALLENGE: typing and reusability (was: Re: blip) Message-ID: <49588@nigel.ee.udel.edu> Date: 2 Apr 91 21:20:35 GMT References: <49194@nigel.ee.udel.edu> <8ACALA5@xds13.ferranti.com> Sender: usenet@ee.udel.edu Organization: University of Delaware Lines: 36 Nntp-Posting-Host: snow-white.ee.udel.edu In article <8ACALA5@xds13.ferranti.com> peter@ficc.ferranti.com (Peter da Silva) writes: >In article <49194@nigel.ee.udel.edu> new@ee.udel.edu (Darren New) writes: >> Actually, I was under the impression that the space shuttle was programmed >> in FORTH. >No, but a number of embedded systems on sattelites *are* programmed >in Forth. The choices available, given the hardware constraints, were >Forth and raw assembly. The code for systems like this is generally >desk-checked to the Nth degree. Yes. I've read that for the Voyagers, the output of the compiler was hand checked to make sure that there were no code-generation errors in the compiler. However, I thought the NOVA chip is a FORTH chip (i.e., FORTH as its machine language) that was to replace the old machines in the shuttle. >> I'm also under the impression that the software has never been the >> cause of a serious (for some N) problem on the shuttle. >Well, substantially delaying the first launch could be considered a >serious problem... Hmmm... I hadn't heard this one. I have heard that by the time the software got to the shuttle simulator, if it (the software) crashed, somebody lost their job (at least). I can't imagine the *software* holding up the launch, but I can imagine hardware causing the software to hold up the launch (i.e., software aborting the launch because redundant processors/sensors/actuators/etc failing). I'll try to find the references. -- Darren -- --- Darren New --- Grad Student --- CIS --- Univ. of Delaware --- ----- Network Protocols, Graphics, Programming Languages, FDTs ----- +=+=+ My time is very valuable, but unfortunately only to me +=+=+ + When you drive screws with a hammer, screwdrivers are unrecognisable +