What is a jumper and do I need one?
The jumper tells the computer how to configure the hard drive. The most common jumper setting used is to configure the drive as the Master ATA device on the bus. It should be installed if your drive is to be the main boot device on the primary ATA bus, or if it is to be the master device on the secondary ATA bus of an enhanced ATA controller. A jumper can also used to tell the master drive that a slave drive is present on the cable. There is also Cable Select, this is an option where the position of the drive on the cable determines if the drive is a Master or Slave drive. In these situations both the master and slave drive will have their jumper settings set to CS. This setting requires Ultra ATA cables to be installed in your system.
