Instruction: Given a question and the related document, and generate the answer to the question based on the information provided in the document.

Input:
Question: I have 2 drives on the ribbon, a working DVD ROM and a non working CD-RW.  Replaced the CD-RW and not recognized.  Where are master/slave settings?
Document: Initial testing... it's working. Replaced broken old DVD with this and the ASUS DVD writer. Have not written to it yet, but reads both CD/DVD fine. I didn't need it (my HD is on a separate channel/cable), but glad I picked up this converter with the Master/Slave jumper incase I need it later. It defaulted to Master as I needed.
Started up the computer, played a music CD fine, burned a DVD video fine, played the freshly burned DVD fine. It seems to operate perfectly. Just for reference, the adapter chip is a JMicron JM20330.I noticed that someone asked "Where are master/slave settings?".
I was excited about this product as I needed to replace a bad CD-RW drive with a DVD-RW and had an IDE connector. This seemed like an inexpensive and simple solution to enable me to use an SATA drive. Most reviews rated it as plug and play. Well, maybe if you just have one drive and are replacing it, but I had 2 drives. My old computer with XP just would not recognize the drive.
this works to adapt a sata dvd drive to IDE ribbon connector. if you use 2 dvd/cd drives NOTICE ! that little plug on one end is the master/slave plug!! will not show your 2 drives at all if both plugs are on the adapters. just remove one. and both drives will be shown in My Computer. one will be master one slave. your original plug setting was on your old dvd/cd drive now it is on your adapter.
You probably just move the jumper onto 1 pin for Slave, (to save the jumper in case you later want to switch it back to Master). I haven't had it in a 2 drive situation though, so I haven't played with that.The only problem I had was after testing the adapter and SATA drive, the IDE ribbon cable connector fit so tightly in the adapter connector that I was afraid to pull hard enough on the adapter to remove it.
Not yet having moved up to the newer SATA 3 or SATA 6 motherboards, my computers still have ribbon cables for the optical drives. I bought 2 SATA DVD burner drives a while back, and I've been looking for a good way to make use of them. I tried a more expensive Koutech IDE to SATA II adapter, but the burners didn't work with it.
I switched the jumpers on the other drive from S to M to C and nothing helped. Both drives were originally set to C (cable select) so I switched the other drive back to C.  The SATA drive had no jumpers or settings so what to do? Finally I noticed a single jumper on the adapter below the power supply plug. I pulled it off and everything seems to be working now.
I read a lot of Negative reviews about this item, but works OK for me. It must be run as a Master---top of Serial Strap, and your slave Optic drive---PULL THE PIN... Both will drives will work, howsoever, If your using two of these I'm not sure if they will work in Tandem?
A lesson in futility. I was trying to install it as a second drive. It doesn't have a &#34;cable select&#34; but can be set to slave or master. I changed my 1st drive to be the master and the new one the slave but whenever it was connected both drives were not found. Put everything back the way it was - the orginanal drive that can't read a dvd anymore.
I bought this converter to use SATA optical drives in my DELL Dimension desktop with IDE/PATA connector. Price is reasonable with quick delivery. The converter works well with easy installation. If two optical drives are used, the user should be aware of master/slave configuration, it cannot be done through BIOS or software. It is done simply by configuring a pin device on the converter board.Only suggestion I have is that the supplier should include installation instruction, especially mention function of the pin device on the board.
Answer: There is a jumper on each drive (near the power & signal cables). Set one to MASTER the other to SLAVE. Usually the jumpers are labeled, but if not, need to confirm with the manufacturer or user guide.Also see: http://www.dummies.com/how-to/content/how-to-set-jumpers-for-your-computers-ide-drive.html, http://www.kitchentablecomputers.com/hdrive3.php, http://en.wikipedia.org/wiki/Advanced_Technology_Attachment#Master_and_slave_clarification.Hope this helps.