Jumper
Jumpers allow the computer to close an electrical circuit, allowing the electricity to flow throughout certain sections of the circuit board. Jumpers consist of a set of small pins that can be covered with a small plastic box, as shown in the illustration to the right. Below the illustration, is a picture of what the jumpers may look like
on your motherboard. In this example, the jumpers have a small tab on top of them allowing them to be easily removed.
Jumpers are used to configure the settings for computer peripherals such as the motherboard, hard drives, modems, sound cards, and various other components. For example, if your motherboard supported intrusion detection, a jumper can be set to enable and disable this feature.
In the past, before Plug and play, jumpers and dip switches were commonly used to adjust device resources, such as changing what IRQ the device is using. However, today most users will not need to adjust any jumpers on their motherboard or expansion cards. Usually most will only encounter jumpers when installing a new drive, such as a hard disk drive. As can be seen in the below picture, ATA (IDE) hard disk drives have jumpers with three sets of two pins. Moving a jumper between each two pins will change the drive from master drive, slave drive, or cable select.
Some
documentation may refer to setting the jumpers to on, off, closed, or open.
When a jumper is on or covering two pins it is a closed jumper, when
a jumper is off or only covering one pin it is an open jumper.
When changing the jumpers on any device, the device and your computer should be turned off. In addition, whenever
working in a computer or with any electronic device be aware of ESD.
Also see: Dip switch, Electronic definitions, Jump