Sleep mode on a desktop

I have a Dell XPS 710 desktop machine and am operating it from a
Microsoft keyboard with MyComputer, Calculator and Sleep buttons above
the numeric keyboard.  Calculator is programmed to invoke the
calculator on screen but today I accidentally hit the Sleep button and
to my surprise the whole system closed down (suspend mode - possibly
to RAM).  There were messages so it looks like the Mandriva kernel
handles this rather than it being hardwired somehow.  I had no idea
how to recover from this state so pressed keys at random and also the
power-on button on the front panel.  One of these must have worked
because the graphics display suddenly came back, with no intermediate
console messages.  I would rather have the Sleep button disabled or
reprogrammed but how do you obtain the keycode for that button?  I
would normally use xev for that but that would not work would it?  The
other thing is, how does one wake up the machine from the sleep state?
The power button is the prime candidate.  I do not wish to tinker
because there are BOINC project jobs running all the time and I do not
know if the sudden hibernation would damage the computations.


Len