Okay, here ya go in an easier than
"David confusing you" 
version;
(sorry David, I couldn't help picking on you, it's in my charachter)
Front bottom = drive 1 = drive slot 0 = 10000
(Primary Master or C/S)
Front top = drive 2 = drive slot 1 = 10008
(Primary Slave or C/S)
Rear bottom = drive 3 = drive slot 2 = 10010
(Secondary Master or C/S)
Rear top = drive 4 = drive slot 3 = 10018
(Secondary Slave or C/S)
Now, with that said, that is how it is
SUPPOSED to be.
BUT,
Revision 1 and revision 2 use Master/Slave settings rather than C/S like the revision 3 and revision 4. In the revision 1 and 2 units, the bottom drives are supposed to be the Masters and the top drives are supposed to be Slaves. However, sometimes you will find where they have been reversed (Masters on top and Slaves on the bottom), or even where only one pair has been reversed. So keep that in mind.
Everyone clear? Good...