IBM Netfinity 4500R, Hardware Maintenance Manual

Page: 51 / 192

Installing options
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System board switch block (SW1)
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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 16 for information about the
boot block jumper.
System board switch block
The switch block contains microswitches 1-8. As shown in this illustration, switch 8 is
at the top of the switch block and switch 1 is at the bottom.
The following table describes each switch.
Table 7. Switches 1-8.
Switch
number
Description
1- 4 Microprocessor speed setting. See Table 8 on page 44.
5 Power-on override.
When On, overrides the power-on switch and forces power-on mode. The
system will always boot without the use of the power-on switch. The default
setting is Off (disabled).
6 Clock frequency selection.
When On, sets the host bus speed to 100 MHz. When Off, the host bus speed
is 133 MHz. The default setting is Off.
7 Reserved. The default setting is Off.