IBM xSeries 150 User Reference Manual page 28

Boot block
jumper (J37)
System board jumper blocks
Any jumper blocks on the system board that are not shown in the illustration are
reserved. For normal operation of the system, no jumpers should be installed on any
of the jumper blocks. See "Recovering BIOS" on page 94 for information about the
boot block jumper.
System board switch block
The switch block contains microswitches 1-8. As pictured in this illustration, switch 8
is at the top of the switch block and switch 1 is at the bottom. The Off position for each
switch is the side nearer the diagnostics panel.
The following table describes the function for each switch.
Table 2. Switches 1-8
16
IBM® xSeries 150 : User's Reference
Switch Switch
number description
8 Bypass power-on password. The default setting is Off.
When toggled to the On position and back to Off, clears the power-on
password, if one is set.
7 Reserved. The default setting is Off.
6 Clock frequency selection. The default setting is Off.
When On, sets the host bus speed to 100 MHz. When Off, the host bus
speed is 133 MHz.
System board
switch block (SW1)
Diagnostics
panel