SUPER MICRO Computer Super PIIIDM4 user manual Jumper Settings, Explanation of Jumpers, CMOS Clear

Chapter 2: Installation

2-7 Jumper Settings

Explanation of

Jumpers

To modify the operation of the moth- erboard, jumpers can be used to choose between optional settings. Jumpers create shorts between two pins to change the function of the connector. Pin 1 is identified with a square solder pad on the printed cir- cuit board. See the motherboard layout pages for jumper locations.

CMOS Clear

Refer to Table 2-24 for the jumper settings to clear CMOS. Always remove the AC power cord from the system before clearing CMOS.

NOTE: For an ATX power supply, you must completely shut down the system, remove the AC power cord and then use JBT1 to clear CMOS. Replace JBT1 back to the pin 1-2 posi- tion before powering up the system again. Do not use the PW_ON connector to clear CMOS.

C o n n e c t o r		3	2	1
Pins
J u m p e r
C a p
		3	2	1
Setting
	Pin 1-2 short
Table 2-24
CMOS Clear Jumper Settings
(JBT1)
Jumper
Position	Definition
1-2	Normal
2-3	CMOS Clear
Position	Position
1-2	2-3
r m a l	C l e a r
N o	O S
	C M

Installation

Front Side Bus Speed

Use JP3 to change the FSB speed. You can also change the CPU speed with the "CPU Speed at FSB" setting in BIOS. This setting will show you the actual CPU speed for each FSB speed option selected . See Table 2 - 25 for jumper settings. Note: If the sys- tem does not reboot after chang- ing the CPU speed, clear CMOS, reboot and then set the correct CPU speed in BIOS.

Table 2-25

Front Side Bus Speed

Jumper Settings (JP3)

Jumper
Position	Definition
1-2	Auto
2-3	133	MHz
O F F	100	MHz

*Note: The Auto setting allows the CPU to set the speed.

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