"The Turbo switch must be turned OFF to preserve
the hardware."
 The computer teacher really did believe that using the Turbo button
 would cause the computers to wear down faster. 
This is not *totally* wrong.  Running faster generally means running
hotter, which shortens lifespan.  (Now, whether this effect was
significant compared to all the other things also affecting lifespan,
that's another story. :-)
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