3System Board (P/Ns D3657-63001 and D3661-63001) Principal Components and Features

 

 

 

Default

 

 

Switch Functions

Setting

Switch

Setting

 

 

 

 

 

 

1 - 4

-

Selects system board speed settings, refer to “Bus Frequencies” on page 72.

 

 

 

 

 

5

Open

Enables User and Administrator passwords.

Open

 

 

 

Closed

Clears User and Administrator passwords.

 

 

 

 

 

 

 

6

Open

CMOS memory acts as a non-volatile store for the Setup program..

Open

 

 

 

Closed

Clears the Setup configuration data in the CMOS memory.

 

 

 

 

 

 

 

7

 

Selects system board speed settings, refer to “Bus Frequencies” on page 72.

 

 

 

 

 

 

Open

Disables secure mode.

Open

8

 

 

 

Closed

Sets the security mode. Sets the switch to the closed position to prevent the

 

 

 

 

 

BIOS from being upgraded and to disable writing to disks.

 

 

 

 

 

9

Open

Disables space-bar power-on. This setting overrides the setting in the Setup

Open

 

program.

 

 

 

 

 

 

 

 

 

Closed

Enables space-bar power-on. If you want to enable this feature, set this switch

 

 

 

to Closed. This setting overrides the setting in the Setup program.

 

 

 

 

 

10

 

Not used.

 

 

 

 

 

Processor Socket

The microprocessor is packaged in a pin-grid-array (PGA), which is seated on the system board in a Zero-Insertion-Force (ZIF) socket.

VRM Socket

P54CS (133 150 and 200 MHz) Pentium processors require a 3.3V supply. Since the PC has a regulated 3.3 V output, a shorting block is used to connect the output directly to the processor.

The P54C 166 MHz Pentium processor requires slightly more than 3.3 V and therefore needs an active VRE voltage regulator module (VRM), in which the voltage is derived from both the 3.3 V and 5 V outlets of the power supply.

Main Memory Sockets

There are six main memory module sockets, arranged in three banks (A to C), allowing installation of up to 128 MB DRAM.

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