Motherboard Jumper Settings (Pentium 1)
This document provides technical information about using the jumper blocks on the motherboard.
NOTE: This document contains procedures that are highly technical. The person performing these procedures should have extensive computer experience working with both hardware and software.
Configuration jumpers (J1F1)
NOTE: For more information about using the jumpers listed in this table, see the appropriate section below.
|Password clear||J1F1-A||1-2 Password enabled (default) |
2-3 Password clear/disabled
|CMOS clear||J1F1-A||4-5 Keep (default) |
|CMOS Setup Access||J1F1-B||1-2 Access allowed (default) |
2-3 Access denied
|Processor voltage||J1F1-B||4-5 Standard voltage (default) |
5-6 VRE enabled
|CPU speed ratio||J1F1-C||See the "CPU Configuration (J1F1-C, D)" section below.|
|Host bus speed||J1F1-D||See the "CPU Configuration (J1F1-C, D)" section below.|
Password clear (J1F1-A, Pins 1-3)
You should use this jumper only if the user password has been forgotten.
This jumper clears the system password. With the computer off, move the jumper from pins 1-2 to pins 2-3 and then turn the computer on. After five seconds, turn off the computer, and then return the jumper to the 1-2 position to restore normal operation.
The password function is always disabled if this jumper is in the 2-3 position.
CMOS clear (J1F1-A, Pins 4-6)
You should use this jumper whenever the system BIOS is updated.
This jumper allows CMOS settings to be reset to default values. Moving the jumper from the pins 4-5 to pins 5-6 and turning the system on enables this function. When the system reports that "NVRAM cleared by jumper," the system can be turned off, and the jumper should be returned to the 4-5 position to restore normal operation.
CMOS Setup access (J1F1-B, Pins 1-3)
Move this jumper from the 1-2 position to the 2-3 position to disable access to CMOS Setup utility.
CPU voltage (J1F1-B, Pins 4-6)
This jumper should not be changed unless changing to a new processor type.
This jumper block changes the output of the onboard voltage regulator. Pins 4-5 should be jumpered for processors that require standard voltage regulation. Pins 5-6 should be jumpered for processors that require the VRE specification.
NOTE: Some upgraded processors require a different setting. Check the processor documentation for the correct setting (Standard = 3.135-3.63V, VR= 3.3-3.465V, VRE = 3.465-3.63V).
CPU configuration (J1F1-C, D)
These jumper blocks allow motherboard switching between different speeds of the Pentium (R) processor. These jumpers also affect the PCI and ISA clock speeds, according to the following table:
|CPU Freq.(MHz)||Host Bus Freq.(MHz)||Host Bus |
|Host Bus |
|200||66||1-2 and 5-6||1-2 and 5-6||6/2||33|
|180||60||2-3 and 4-5||1-2 and 5-6||6/2||30|
|166||66||1-2 and 5-6||2-3 and 5-6||5/2||33|
|150||60||2-3 and 4-5||2-3 and 5-6||5/2||30|
|133||66||1-2 and 5-6||2-3 and 4-5||4/2||33|
|120||60||2-3 and 4-5||2-3 and 4-5||4/2||30|
|100||66||1-2 and 5-6||1-2 and 4-5||3/2||33|
|90||60||2-3 and 4-5||1-2 and 4-5||3/2||30|
|75||50||2-3 and 5-6||1-2 and 4-5||3/2||25|
|reserved||-||1-2 and 4-5||-||-||-|