If the BIOS has become damaged, such as from a power failure during a flashupdate, you can recover the BIOS using the boot block jumper and a BIOS flashdiskette. See “Recovering BIOS code” on page 16 for information about the bootblock jumper.System board switch blockThe switch block contains microswitches 1-8. As shown in this illustration, switch 8is at the top of the switch block and switch 1 is at the bottom.The following table describes each switch.Table 2. Switches 1-8Switch number Description1- 4 Reserved5 Clock frequency selection.When On, the host bus speed is 100 Mhz. When Off, the host bus speed is 133 Mhz. Thedefault setting is off. Set this to Off to optimize the system performance.6 Password override. (Toggling this switch allows one opportunity to enter the Setup Utility tochange or delete the power-on password.)See “Setting the password override switch” on page 28 for more information.7 Reserved. The default setting is Off.8 Power-on override.When On, overrides the power-on switch and forces power-on mode. The system will alwaysstart without the use of the power-on switch. the default setting is Off (disabled).Note: The speed settings shown below apply only to unlocked processors. If theprocessors are production level they are locked and there is no need tochange the speed settings.Installing options 39
