Two different protocols can be used for jumpering EIDE devices, including disk drives. One is the master-slave relationship. With this protocol, one device is jumpered as master and the other is jumpered as slave. The second protocol is cable select. With this protocol, both devices are jumpered as cable select and their position on the cable dictates which device is the master and which device is the slave. The end device is master while the device on the middle of the cable is slave. You can use either of these protocols but you cannot mix them on the same data cable. Both methods refer to having multiple devices attached to the same IDE cable and have options for single drive installations (only 1 drive installed on the system). For Western Digtial 3.5" EIDE hard drives: