help again

Ah hi everyone!
Dumbo question time again, about to rig up these gecko 201's and the
white paper says to use 5 volt from the pulse generator(computer) so
do i get this from one of the pins from the db25 cable and if so
which one? and do I need three seperate ones ,one for each drive? or
can I loop just one to each drive? I know not to do that with power
supply for the motors!
thanking you all in advance
kindest regards
Mark