LEADING TECHNOLOGY

386SX 25/33

Processor

80386SX

Processor Speed

25/33MHz

Chip Set

Unidentified

Max. Onboard DRAM

4MB

Cache

None

BIOS

Unidentified

Dimensions

330mm x 218mm

I/O Options

Floppy drive interface, game port, IDE interface, parallel port, serial ports (2)

NPU Options

80387SX

CONNECTIONS

Purpose

Location

Purpose

Location

Serial port 1

CN1

Reset switch

J2 pin 5

Serial port 2

CN2

Ground

J2 pin 8

Game port

CN3

Speaker

J8

Parallel port

CN4

External battery

J9

IDE interface LED

J1

IDE interface

J10

Power LED & keylock

J2 pin 3

Floppy drive interface

J12

Turbo switch

J2 pin 4

Riser Card

SL1

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

NPU disabled

JP1

pins 1 & 2 closed

 

NPU enabled

JP1

pins 2 & 3 closed

»

External battery installed

JP6

pins 1 & 2 closed

 

External battery not installed

JP6

pins 2 & 3 closed

»

Parity disabled (3 SIMM motherboard)

JP15

Open

 

Parity enabled (4 SIMM motherboard)

JP15

Closed

»

Parallel port IRQ select IRQ7

JP34

pins 1 & 2 closed

 

Parallel port IRQ select IRQ5

JP34

pins 2 & 3 closed

»

IDE interface enabled

JP35

pins 2 & 3 closed

 

IDE interface disabled

JP35

pins 1 & 2 closed

»

Game port installed

JP42

pins 1 & 2 closed

 

Game port not installed

JP42

pins 2 & 3 closed

DRAM CONFIGURATION (WITH BANK 0A FACTORY INSTALLED)

Size

Bank 0a

Bank 1

Bank 2

Bank 3

1MB

(2) 1M x 4

NONE

NONE

NONE

2MB

(2) 1M x 4

(1) 1M x 9

NONE

NONE

4MB

(2) 1M x 4

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

Note: This configuration is applicable only with Bank O factory installed. The mainboard is manufactured with either 4 SIMM banks or 3 SIMM banks and 2 DRAM banks. The 2 DRAM banks are factory installed and are not configurable.

DRAM JUMPER CONFIGURATION (WITH BANK 0 FACTORY INSTALLED)

Size

JP11-12, JP16, JP19-27

1MB

pins 2 & 3 closed

2MB

pins 2 & 3 closed

4MB

pins 2 & 3 closed

Note: This configuration is applicable only with Bank O factory installed.

DRAM CONFIGURATION (WITH BANK 0 USER INSTALLED)

Size

Bank 0

Bank 1

Bank 2

Bank 3

2MB

(1) 1M x 9

(1) 1M x 9

NONE

NONE

4MB

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

Note: This configuration is applicable only with Bank O user installed.

DRAM CONFIGURATION (WITH BANK 0 USER INSTALLED)

Size

JP11-12, JP16, JP19-27

2MB

pins 2 & 3 closed

4MB

pins 2 & 3 closed

Note: This configuration is applicable only with Bank O user installed.

PARALLEL PORT CONFIGURATION

Parallel port

JP30

JP31

LPT1 (0378h)

pins 2 & 3 closed

pins 1 & 2 closed

LPT1 (02BCh)

pins 2 & 3 closed

pins 2 & 3 closed

LPT2 (0278h)

pins 1 & 2 closed

pins 2 & 3 closed

SERIAL PORT 1 CONFIGURATION

Port 1

JP28

JP40

»

COM 1

pins 2 & 3 closed

pins 1 & 2 closed

 

COM 3

pins 1 & 2 closed

pins 2 & 3 closed

 

COM 4

pins 2 & 3 closed

pins 2 & 3 closed

 

Disabled

pins 1 & 2 closed

pins 1 & 2 closed

SERIAL PORT 1 INTERRUPT CONFIGURATION

IRQ

JP32

JP39

»

IRQ4

pins 1 & 2 closed

N/A

 

IRQ3

pins 1 & 2 closed

pins 1 & 2 closed

SERIAL PORT 2 CONFIGURATION

Port 2

JP29

JP41

»

COM 2

pins 2 & 3 closed

pins 1 & 2 closed

 

COM 3

pins 2 & 3 closed

pins 2 & 3 closed

 

COM 4

pins 1 & 2 closed

pins 2 & 3 closed

 

Disabled

pins 1 & 2 closed

pins 1 & 2 closed

SERIAL PORT 2 INTERRUPT CONFIGURATION

IRQ

JP32

JP39

»

IRQ3

N/A

pins 1 & 2 closed

 

IRQ4

pins 2 & 3 closed

pins 2 & 3 closed

FLOPPY DRIVE CONFIGURATION

Type

JP37

JP44

A = 3.5" & B = 5.25"

pins 2 & 3 closed

pins 2 & 3 closed

A = 5.25" & B = 3.5"

pins 2 & 3 closed

pins 1 & 2 closed

PAGE INTERLEAVE CONFIGURATION

Mode

JP14

JP18

Disabled

pins 1 & 2 closed

pins 2 & 3 closed

Enabled ( requires 4 SIMM configuration)

pins 2 & 3 closed

pins 2 & 3 closed