Hardware settings are made using mini
jumper connectors on the motherboard. Jumpers are devices that
bridge pins on circuit boards. Closing or opening the circuits
establishes logic levels to select functions for the operation of the
board. Data generally does not travel through these circuits. Most of the jumpers will correlate to
the CPU.
Typically, motherboard jumpers are configured by using a jumper
to bridge a pair of pins that are to be connected together (to
complete a circuit) on the board. Removing or inserting jumpers on
a set of pins will enable or clear a given option, as specified in
the motherboard manual. For all settings, it is recommended that
the instructions found in the motherboard manual be followed
closely. Table
shows an example of how this information is presented in the
manual. Remember that the jumper specifications for any board are
provided by its manufacturer; they are not necessarily the same as
those found in this table.
Caution: Do not move any of the jumpers with the power
on. Always turn off the power and unplug the power cord from the
computer before changing jumpers.
Other Jumpers 
Several other jumper settings may have to be set along with the
general motherboard configurations. These are
summarized as follows:
- BIOS recovery – This jumper is for recovering BIOS data
from a diskette in the event of a catastrophic failure. Leave this
to the default (normal operation) values. Check the technical
product specifications for details.
- Clear CMOS – This jumper, when provided, is used to
reset the CMOS settings to the default values. This procedure must
be done each time the BIOS is updated.
- Password clear – Use this jumper, if provided, to clear
the password if the password is forgotten. The default setting is
usually password enabled.
- BIOS setup access – This jumper enables or disables
access to the Setup program. The default setting is access
enabled.
- Processor voltage – This jumper (or jumpers), when
provided, sets the output of the onboard voltage regulator. The
two choices are usually standard voltage or VRE.
Caution: When installing a processor in the motherboard
for the first time or upgrading to a new processor, check the
processor documentation for the correct voltage setting. Operating the processor at the wrong voltage can cause unreliable
performance or damage.