Weird Microwave problem - trips breaker when you shut the door!

"Paul" bravely wrote to "All" (12 Jul 05 16:17:47) --- on the heady topic of "Re: Weird Microwave problem - trips breaker when you shut the door!"

Pa> From: "Paul" Pa> Xref: aeinews sci.electronics.repair:53019

Pa> Note that the Therac25 was developed from an earlier machine which had Pa> mechanical interlocks and when you pressed the same combination of Pa> back spaces did blow a fuse, possibly 100's of people where over Pa> exposed from what I remember and several fatally or damaged for life. Pa> Do you remember in the 80's or 90's when people where installing there Pa> own mobile phones in cars and where being warned it could mess up the Pa> ABS and engine management causing accidents. Pa> Then there was the F*rd Probe car which had a problem with the ECU Pa> which meant interference from the ignition system could cause it to Pa> accelerate out of control, a man was killed when his car flew off an Pa> off ramp at over a 120 miles and hour into trees. Pa> As for the $20,000,000 planes don't they have more than one computer Pa> for all the main systems with the software written by different Pa> companies, and the computers keep a check on each other to make sure Pa> they are both working.

Paul,

They do but they still manage to rip rudders off airplanes when the pilot only moves the pedals 1-1/2 inches, like happened in New York about a month after 9/11/2001. Just because software is in charge doesn't mean it isn't safe. The problem is always GIGO and unless inputs are properly validated then all hell will and does break loose. Why don't software engineers get it already?

A*s*i*m*o*v

... Bald spot? It's a solar panel for a sex machine.

you

Remenber the Airbus A320? that crashed at its maiden airshow appearance? That wsa a software bug.

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"If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization".

-- Weinberg's Second Law

N

"Sam Goldwasser" bravely wrote to "All" (12 Jul 05 20:05:45) --- on the heady topic of "Re: Weird Microwave problem - trips breaker when you = shut the door!"

SG> From: Sam Goldwasser SG> Xref: ae > Why don't software engineers get it already?

SG> Remenber the Airbus A320? that crashed at its maiden airshow SG> appearance? That wsa a software bug.

Sure do. The program kicked in the thrust reversers because it thought it had already landed. Faulty input or bad coding? Take your pick but the problem was the inputs weren't properly validated and the program jumped into a state that was obviously, to a human at least, wrong to be in. A program should never be able to jump into wrong states out of sequence like that. Just stupid!

A*s*i*m*o*v

... First Church of Binary Science (The Digitarians)

"NSM" bravely wrote to "All" (13 Jul 05 00:29:45) --- on the heady topic of "Re: Weird Microwave problem - trips breaker when you shut the door!"

NS> "If builders built buildings the way programmers wrote programs, then NS> the first woodpecker that came along would destroy civilization".

NS> -- Weinberg's Second Law

Love that quote!

A*s*i*m*o*v

... Programmer(n): One who makes the Salesman's lies reality

I would tend to blame the hardware there. Traffic signal controllers have conflict monitors which are separate devices which monitor the outputs to the lights and in the event of greens in multiple directions will trip the system offline and put it in 4 way flash.