Changing the Jumper Settings

The jumpers on the main system board control certain functions and are preset at the factory to default positions; however, you can use the information in the following tables to change their settings, if necessary. (The jumpers listed in the tables are the only ones you may need to change; others are for service purposes only.)

Miscellaneous jumper settings

jumper

Jumper

Function

number

setting

JA

1-2*

Enables LPT (parallel port)

 

2-3

Disables LPT (parallel port)

JB**

1-2*

Enables HDC (lDE hard disk drive controler)

 

2-3

Disables HDC ODE hard disk drive controler)

JC

1- 2*

Enables COMA (serial port1)

 

2-3

Disables COMA (serial part 1)

JD

1-2*

Enables COMB (serial port 2)

 

2-3

Disables COMB (serial-port 2)

JE**

1-2*

Enables HDC (lDE hard disk drive controller)

 

2-3

Dlsablss HDC (IDE hard disk drive controller)

J4

1-2

Enables game port (J1)

 

2-3*

Disables game port (J1)

 

 

 

J5

1-2*

Assigns the parallel port as LPTl (378h-37Fh)

 

2-3

Assigns the parallel port as LPT2 (278h-27Fh)

J6

1-2*

Assigns serial port 1 as COM1 (3F8h-3FFh)

 

2-3

Assigns serial port 1 as COM3 (3E8h-3EFh)

J7

1 - 2 *

Assigns serial port 2 as COM2 (2F8h-2FFh)

 

2-3

Assigns serlal port 2 as COM4 (2E8h-2EFh)

J8

1-2*

Enables the diskette drive controlIer

 

2-3

Disables the diskette drive controller

 

 

 

J10

O n *

Enables VGA interrupt

 

Off

Disables VGA interrupt

J17***

1 - 2

Microprocessor installed runs at 33 MM or 66 MM or a

 

 

multiple of these (486SX/33. 486DX/33, 486DX2/66, DX4/100

 

3-4

and Pentium)

 

Microprocessor installed is a 486DX/50

 

1-2, 3-4

Microprocssor installed is a DX/40

 

5-6

Microprocessor installed at 25 MHz or 50 MHz or a

 

 

multIpIe of these (486SX/25, 486DX2/50. DX4/75. and SX2/50)

 

 

 

3-6 Installing and Removing Options