Updated: Thursday, March 27, 1997

Contents

• Jumper Locations and Definitions
• CPU Configuration
• Other Jumpers

Jumper Locations and Definitions

Function		Jumper Block		Configuration
        

Password clear		J10C1-A		1-2 Password enabled (Default)
	                     		2-3 Password clear/disabled

CMOS clear		J10C1-A		4-5 Keep (Default)
	                     		5-6 Clear

Setup Access		J10C1-B		1-2 Access allowed (Default)
	                      		2-3 Access denied

Microprocessor		J10C1-C		See CPU Configuration
speed ratio

Host bus speed		J10C1-D		See CPU Configuration
(Note:  These jumpers also set the PCI and ISA clock speeds.)

Processor voltage 	J5K1		1-2 VRE enabled
					2-3 Standard voltage (Default)

BIOS recovery	  	J9A1		1-2 Normal operation (Default)
                        		2-3 Recovery mode

CPU Configuration - Jumper Block J4L1 (C&D)
These allow the motherboard to be switched between different speeds of the Pentium processor. These jumpers also affect the PCI and ISA clock speeds according to the following table:

Microprocessor Freq.(MHz)	Host Bus Freq.(MHz)	Setting for J10C1-C	Setting for J10C1-D	PCI Freq.(MHz)	Clock Ratio	ISA freq. (MHz)
200	66	1-2 and 5-6	1-2 and 5-6	33	6/2	8.33
180	60	2-3 and 4-5	1-2 and 5-6	30	6/2	7.5
166	66	1-2 and 5-6	2-3 and 5-6	33	5/2	8.33
150	60	2-3 and 4-5	2-3 and 5-6	30	5/2	7.5
133	66	1-2 and 5-6	2-3 and 4-5	33	4/2	8.33
120	60	2-3 and 4-5	2-3 and 4-5	30	4/2	7.5
100	66	1-2 and 5-6	1-2 and 4-5	33	3/2	8.33
90	60	2-3 and 4-5	1-2 and 4-5	30	3/2	7.5
75	50	2-3 and 5-6	1-2 and 4-5	25	3/2	8.33
Reserved	--	1-2 and 4-5	--	--	--	--

Note:
There are no separate or additional jumpering requirements for Pentium processors with MMX™ technology

Other Jumpers

Password clear (J10C1-A, Pins 1, 2, and 3)
Allows both passwords to be cleared by moving the jumper from pins 1-2 to pins 2-3 and turning the computer on. The computer should then be turned off and the jumper should be returned to the 1-2 position to restore normal operation. This procedure should only be done if the user or administrative password has been forgotten. The password function is effectively disabled if this jumper is in the 2-3 position. Default is for the password to be enabled (1-2 position).

Clear CMOS (J10C1-A, Pins 4, 5, and 6)
Allows CMOS settings to be reset to default values by moving the jumper from pins 4-5 to pins 5 6 and turning the computer on. When the computer reports that "NVRAM cleared by jumper", the computer can be turned off, and the jumper should be returned to the 4-5 position to restore normal operation. Default is for this jumper to be on pins 4-5.

Setup Access (J10C1-B, Pins 1, 2, and 3)
Allows access to Setup program to be disabled by moving this jumper from the 1-2 position to the 2-3 position. Default is for access to Setup to be enabled (1-2 position).

Microprocessor Voltage (J5K1)
This jumper block changes the output of the on-board voltage regulator. Pins 1-2 should be jumpered for processors that require the VRE specification. Pins 2-3 should be jumpered for processors that require standard voltage regulation. This jumper should not be changed by the user unless changing to a new processor type. Some upgrade processors may require a different setting. Check the processor's documentation for the correct setting. (Standard = 3.135-3.63V, VR = 3.3 3.465V, VRE = 3.465-3.63V).

Note: Technical Product Specification 281820-001 incorrectly has the processor voltage jumper settings reversed. See the Motherboard Specification Update for details.