VIA Technologies VT82C686A User Manual page 18

Mainboard User's Manual
Jumper JP18: BIOS Write Protection Selector
Use this jumper to enable or disable the BIOS write protection that
make the BIOS read-only on the mainboard. You should disable
this jumper when you want to flash the BIOS.
Function
Disable
Enable (read only)
14
Jumper Setting
Short Pins 1-2
Short Pins 2-3