Have two BR units in this one I'm posting with, one is a CD/DVD/BR burner (LG M-disc), the other a more standard CD/DVD burner unit (Also LG) but it too can read BR.
Have several out at the shack including an Asus CD/DVD "Lightscribe" IDE and a few others for good measure I've accumilated over the years.
I don't know much about ATA/IDE but I think IDE devices are supposed to be chained. You may have bought some former bootlegger's old rig (you know the guy who was always burning copies of pirated stuff for family, friends and acquaintances). Of course, it could have been a legit operation as well technically but I don't know who would be burning so much homemade, licensed or legally purchased content but not have a duplicator.
You're referring to "Master" and Slave" drives on the same IDE ribbon cable.
You can have two IDE devices on the same cable and you have a jumper on these drives to set them as such according to how you have them plugged into the cable, this goes for both, disc drives and HDD's.
Yes, you can have one of each on the same cable as long as you have the jumpers set correctly. There is a little diagram on the end of the drive that tells you how to set these jumpers.
For an HDD, alot of the time it's on the drive's label but for disc drives it's always stamped into the metal at the end where the jumper is.
For those that don't know, It goes like this:
Each IDE cable have three plugs total, what I call the "Long" and "Short" ends of the cable
is based on how close to the middle plug each end is.
The board end plug is the "Long" end of the cable and is on one end of it, that always goes to the board itself and is further away from the middle plug.
The drive plugs are always towards the "Short" end of the cable.
The master drive plug on it is
always at the very end of the ribbon cable too like the board end is and the master end is
always closer to the middle (Slave) plug than the board end is.
Once you look at an IDE cable, you can lay it out and easily see this layout for yourself.
Usually there are labels saying what each plug is for is but that's how you can tell if there are no labels for these plugs on the cable.