MIKE ROSS wrote in a message to Greg Mayman:

 MR> I was thinking about relays the other day while waiting for the 
 MR> elevator. As the elevator door opened I noticed both the up and
 MR> down arrows lit up together but it was going down. The elevator
 MR> beside it was going up and both its lights were off. Luckily the
 MR> 3rd elevator door didn't open to an empty shaft...!!! Today the
 MR> elevator repairman was busy working on the elevators. In the 19'th
 MR> century all the elevator logic was controlled by relays and they
 MR> got stuck quite regularly. Now why do modern computers without any
 MR> moving parts in their ALU's get stuck logic just like the relays in
 MR> the early days of elevators? Bizzare!

Yes it is...

And I'll bet there are still lots of those setups with relays out there, 
in some places.

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