Configure a hard drive by changing its jumper plugs.
A programming jumper plug is a small electromechanical part that lets you change settings and features for computers, radios and other kinds of equipment. The jumper plug fits onto a pair of wire pins, forming an electrical connection. When you turn the equipment on, it detects the jumper settings and configures its operating software accordingly.
Description
A jumper plug has a tiny rectangular plastic body that holds a spring-loaded metal connector. Holes in the bottom of the plug admit pins that fit into the connector, forming a secure electrical connection. The overall size of the plug varies slightly, though the spacing between the holes is a standard 2.54mm or one-tenth of an inch. Plugs have a maximum current capacity of 3 amps.
Plug, Pins and Block
The jumper plug fits on a pair of stiff metal pins; to use a jumper, the equipment needs a minimum of two pins, though some devices have dozens of pins organized in blocks of two rows each. Though each pair of pins can accommodate a jumper, the number of jumpers used at a given time depends on the equipment. Sealed devices such as hard drives locate the block on the case exterior; for equipment having a case that opens, the main circuit board or motherboard situates the pins in an easily accessible location.
Programming
To program a piece of equipment using its jumpers, the user turns the unit off and, if necessary, opens the case to reveal the jumper block. Using a pair of long-nose pliers, he slips the jumper onto a pin pair or pulls it from its pins according to the manufacturer's directions. The owner's manual includes a list of pin locations along with the features that the jumpers enable or disable. The device changes its features when the user turns it on.
Benefits
Jumper plugs allow an equipment maker to design devices with extra features the user can configure himself. The jumpers are inexpensive, secure and last the lifetime of the equipment. Jumper settings are unaffected power outages, temperature changes and most types of shock and vibration. The owner can change jumper settings in a few minutes with standard hand tools.
Drawbacks
Changing jumpers takes some dexterity and technical skill; the user must study the equipment manual before making any changes. If dropped, the tiny plugs are easily lost. Programming becomes cumbersome for more than a handful of features; jumpers are not suitable for coding larger amounts of data such as dates, serial numbers or phone numbers.
Tags: jumper plug, electrical connection, jumper plug fits, jumper settings, onto pair, plug fits, user turns