On the IDE cable that you have your first CD Drive on, look further down
the cable. There should be a second connector. Connect that to your
second CDRW drive and hook up a power cable to the second CDRW drive.
Note: You may need to set jumpers on the back of the drives. The first
needs to be either Master or CS (Cable Select) and the second must be
either Slave or CS.
Nathan McNulty