Mitsubishi Electric Apricot XEN pentium Owner's Handbook Manual page 131

Jumper J3 - Flash ROM program
This jumper is used to enable programming of the
motherboard flash ROM to upgrade the BIOS. During normal
operation the flash ROM is write protected and the jumper
clip should be in the position marked WP on the motherboard.
Note
Upgrading the BIOS should only be carried out by your supplier or
an authorized maintainer.
In order to reprogram the flash ROM chip; with the system
powered down, move the jumper clip to the position marked
EN. Once you have upgraded the BIOS power the system
down and return the jumper to the WP position.
Jumper J4 - BIOS recover
This jumper is provided to allow recovery from a failed attempt
to upgrade the BIOS. During normal operation the jumper clip
should be in the position marked NOR on the motherboard.
If an attempt to reprogram the flash ROM chip with an updated
BIOS fails and the system will not boot; with the system
powered down, move the jumper clip to the position marked
REC.
With the jumper in the REC position the system uses a minimal
bootable BIOS in a small area of the ROM that is always write
protected. Once you have recovered from the problem,
power the system down and return the jumper to the NOR
position.
Inside your computer
XEN OWNER'S HANDBOOK A/15