Configuration Jumpers

	Overview

	Installation and Configuration Notes (FAQ)

	BIOS Updates

	Driver Updates

	User-Installable Upgrades

	Configuration Jumpers

	Connectors

	Product Documentation

Advanced/EV Jumper Settings

Updated: Tuesday, August 6, 1996

Contents

Jumper Locations and Definitions
Microprocessor Configuration
Setup Disable
Clear CMOS
Password Clear
VR/VRE
ISA Bus Clock
Recovery Boot Enable/Bus Frequency

Jumper Locations and Definitions

Microprocessor Configuration
External/Internal CPU Clock Speed (Switches 6, 7, & 8)
Switches 6, 7 & 8 are used to set the CPU's external operating frequency at 50, 60, or 66 Mhz. Default setting depends on the specific product code, see table for specific Pentium processor configuration information.

The following table gives the position of Switches 6, 7 and 8 and Jumper J1N1:

External Bus Speed	Bus Clock Multiplier	Processor Speed	Switch 6	Switch 7	Switch 8	J1N1
50	1.5	75	off	on	off	4/5
60	1.5	90	off	off	off	4/5
66	1.5	100	off	on	on	4/5
60	2	120	on	off	off	4/5
66	2	133	on	on	on	4/5
60	5/2	150	on	off	off	5/6
66	5/2	166	on	on	on	5/6
66	3	200	off	on	on	5/6

Setup Disable (Switch 5)
Allows access to CMOS Setup Utility to be disabled by setting switch 5 to the ON position. Default is for access to setup to be enabled (switch 5 = OFF)

Clear CMOS (Switch 4)
Allows CMOS settings to be reset to default values by moving switch 4 to the ON position and turning the system on. The system should then be turned off and switch 4 should be returned to the OFF position to restore normal operation. This procedure should be done whenever the system BIOS is updated.

Password Clear (Switch 3)
Allows system password to be cleared by moving switch 3 to the ON position and turning the system on. The system should then be turned off and switch 3 should be returned to the OFF position to restore normal operation. This procedure should only be done if the user password has been forgotten.

VR/VRE (Switch 2)
Changes the output of the on-board voltage regulator. OFF = standard VR, ON = VRE specification. This switch 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. (VR = 3.3-3.465V, VRE = 3.465-3.63V)

ISA Bus Clock (Switch 1)
This switch changes the clock frequency of the ISA bus. The effect of this switch on the ISA clock depends upon the setting of the CPU clock speed switches. The default setting for this switch is OFF. In general, this switch should only be set to ON if higher ISA performance is required, and the ISA expansion cards can handle the faster bus clock.

Bus Freq.	Switch 1	ISA Bus Speed
50 MHz	ON/OFF	8.33 MHz
60 MHz	OFF ON	7.5 MHz 10 MHz
66 MHz	OFF ON	8.25 MHz 11 MHz

Recovery Boot Enable/Bus Frequency (JumperJ1N1)
Jumper J1N1 performs dual function. Recovery Boot Enable allows the system to boot in the event the system BIOS has been corrupted by moving the jumper from the default position of 1-2 to the 2-3 position. The procedure for recovery boot is described in detail in Appendix M. Along with switches 6, 7, and 8, J1N1 is used to set the CPU's external operating frequency. See table B-1 for settings.