We all know there are two ide channels, primary & secondary.  What we all DON'T know is the PIO, or in out speed are diff from primary to secondary, & slave + master are diff also. To answer your ? yes you probably can burn from cdrom to burner on the same secondary channel especially since your burner has "burnproof"!  However, the speed of your burner will be slowed somewhat while the drives "wait" for each other to complete their "talk" to the cpu on the same channel.  Remember only one drive can have control @ one time on a single ide channel & the speed is as fast as the slowest device, in your case the cdrom as slave on secondary channel.........Rancher