UNIDENTIFIED

486SX-DX MAINBOARD

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

33/40/50/66(internal)MHz

Chip Set

Unidentifed

Max. Onboard DRAM

32MB

Cache

None

BIOS

Award

Dimensions

254mm x 220mm

I/O Options

Floppy drive interface, IDE interface, parallel port, PS/2 mouse port, serial ports (2), VGA port

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

VGA port

CN1

Power LED & keylock

J1

Parallel port

CN2

Turbo switch

J2 pins 1 & 2

Serial port 1

CN3

Turbo LED

J2 pins 4 & 5

Serial port 2

CN4

Speaker

J3

PS/2 mouse port

CN5

Reset switch

J4

IDE interface

CN6

IDE interface LED

J5

Floppy drive interface

CN7

Riser Card

SL1

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Video mode select interlaced

JP7

Closed

 

Video mode select non-interlaced

JP7

Open

»

Monitor type select monochrome

JP10

Closed

 

Monitor type select color

JP10

Open

»

CPU OSC select 66MHz

jp11

pins 2 & 3 closed

 

CPU OSC select 50MHz

jp11

pins 1 & 2 closed

»

On board VGA enabled

JP12

pins 2 & 3 closed

 

On board VGA disabled

JP12

pins 1 & 2 closed

»

Monitor type select VESA

JP14

pins 2 & 3 closed

 

Monitor type select VGA

JP14

pins 1 & 2 closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

1MB

(4) 256K x 9

NONE

2MB

(4) 256K x 9

(4) 256K x 9

4MB

(4) 1M x 9

NONE

5MB

(4) 256K x 9

(4) 1M x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

32MB

(4) 4M x 9

(4) 4M x 9

CPU TYPE CONFIGURATION

Type

JP4

JP5

80486SX

Open

pins 1 & 2 closed

80487SX

pins 1 & 2 closed

pins 2 & 3 closed

80486DX

pins 2 & 3 closed

pins 2 & 3 closed

80486DX2

pins 2 & 3 closed

pins 2 & 3 closed

CPU SPEED CONFIGURATION

Speed

JP3

JP6

33MHz

pins 2 & 3 closed

pins 2 & 3 closed

40MHz

pins 2 & 3 closed

pins 1 & 2 closed

50MHz

pins 1 & 2 closed

pins 2 & 3 closed

66iMHz

pins 1 & 2 closed

pins 1 & 2 closed