India Broadband Forum

India Broadband Forum

Jumpers are usually found on PATA (Parallel ATA) or IDE (Integrated Drive Electronics) disc drives. As we all know, the number of such drives in use are dwindling because they have been largely replaced by the more advanced and higher performance SATA (Serial ATA) interface. However, PATA drives still do exist and people are ever more confused about jumper settings found on such drives. A jumper is a short length of conductor on an electronic device used to short out or bypass a certain ciruit. The jumper is shorted with a small conductor encased in plastic, known as a jumper shunt.

The PATA interface supports two devices per IDE port on a computer motherboard connected with a single cable. Hence, there comes a need for the computer to differentiate between the two devices and identify each as separate. To achieve this, one device on a single IDE port is identified as ‘Master’ and the other one as ‘Slave’, and this is where the jumper pins come into play. Each PATA hard drive or DVD drive has about 4 sets of jumper pins (or higher). Each device assumes a different identity as soon as a particular jumper pin is shorted out with a shunt.

A hard drive typically has the following jumper settings, master, slave, cable select, limit capacity to 32 GB. The master and slave options are self explanatory and the user simply has to short out a jumper pin according to the configuration that is wanted. However, no two devices on the same cable can assume the same Master or Slave setting, one device has to be Master, the other has to be Slave. The cable select option takes the decision of configuring a device as Master or Slave in its own hands and the user can just set both the devices to cable select. The ‘limit capacity to 32 GB’ option is for older motherboards which did not recognize higher capacity drives, and hence the hard drive capacity is limited to 32GB if this jumper pin is shorted.