On Tue, 23 Jan 2001 08:26:41 -0800 James Paul > w= rote: > John, >=20 > Whatever methods of making, storing and burning hydrogen you choose, > I'd triple up on the processors so as to provide redunduncy because > hydrogen is very unforgiving when ignited. It burn, very rapidly. > Without some sort of fail safe, I believe you're just asking for > trouble. I'm not saying you're not capable, but just be very very > careful, and make ALL your control systems redundunt. You don't > want your house to burn down or be blown up due to some non behaving > hydrogen. >=20 > Regards, >=20 > Jim Just on this issue of redundancy, "tripling" the processors does NOTHING.= =20 The general issue is we need to get a bunch of processors to reach concensus about an event (ie "open the valve"). If we wish to allow "k" failures in the system and have the system still work safely, the number of processors we need is 3k+1. This is a "you-can't-dodge-it" result from information theory. The best exposition of this is in an IEEE computer issue from the early 1990's - can't locate it right now, old age has that effect :-). The interested reader is encouraged to think about the NASA Space Shuttle, which is supposed to be fail-safe, fail-safe, fail-operational. That is, k=3D3. They have 5 processors. OOPS. Cheers /Kevin -- Kevin J. Maciunas Net: kevin@cs.adelaide.edu.au Dept. of Computer Science Ph : +61 8 8303 5845 University of Adelaide Fax: +61 8 8303 4366 Adelaide 5005 SOUTH AUSTRALIA Web: http://www.cs.adelaide.edu.au/~kevin -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics