SOYO COMPUTER CO., LTD.

486 VESA MAINBOARD

Processor

CX486S/80486SX/CX486S2/80487SX/CX486DX/80486DX/CX486DX2/ 80486DX2/Pentium Overdrive

Processor Speed

25/33/40/50(internal)/50/66(internal)MHz

Chip Set

ALI

Max. Onboard DRAM

128MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

254mm x 220mm

I/O Options

32-bit VESA local bus slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

J17

Turbo switch

J21

Speaker

J18

Turbo LED

J22

Reset switch

J19

32-bit VESA local bus slots

SL1 & SL2

External battery

J20

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select monochrome

JP3

Open

 

Monitor type select color

JP3

Closed

»

CMOS memory normal operation

JP5

pins 1 & 2 closed

 

CMOS memory clear

JP5

pins 2 & 3 closed

»

Factory configured - do not alter

JP18

Open

»

Factory configured - do not alter

JP19

Open

»

Battery type select internal

JP20

pins 1 & 2 closed

 

Battery type select external

JP20

pins 2 & 3 closed

»

CPU type select PGA

JP30

Closed

 

CPU type select PQFP

JP30

Open

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

17MB

(4) 256K x 9

(4) 4M x 9

20MB

(4) 1M x 9

(4) 4M x 9

32MB

(4) 4M x 9

(4) 4M x 9

64MB

(4) 16M x 9

NONE

68MB

(4) 1M x 9

(4) 16M x 9

80MB

(4) 4M x 9

(4) 16M x 9

128MB

(4) 16M x 9

(4) 16M x 9

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

128KB

(4) 32K x 8

NONE

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP16

JP22

JP23

64KB

N/A

N/A

N/A

128KB

N/A

N/A

N/A

256KB

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

Note: The jumper settings for 64KB & 128KB are unavailable from manufacturer.

CPU TYPE CONFIGURATION

Type

JP1

JP6

JP7

JP8

JP9

JP10

CX486S

1 & 2

2 & 3

2 & 3

1 & 2

Open

Open

80486SX

1 & 2

1 & 2

Open

1 & 2

Closed

Closed

CX486S2

1 & 2

2 & 3

2 & 3

1 & 2

Open

Open

80487SX

1 & 2

1 & 2

Open

2 & 3

Closed

Closed

CX486DX

1 & 2

1 & 2

Open

2 & 3

Closed

Closed

CX486DX2

1 & 2

1 & 2

Open

2 & 3

Closed

Closed

80486DX/DX2

1 & 2

1 & 2

Open

2 & 3

Closed

Closed

Pentium Overdrive

2 & 3

2 & 3

1 & 2

2 & 3

Closed

Closed

Note: Pins designated should be in the closed position.

CPU TYPE CONFIGURATION (CON’T)

Type

JP11

JP12

JP13

JP14

JP17

JP31

CX486S

3 & 4

2 & 3

1 & 2

2 & 3

2 & 3

Open

80486SX

Open

1 & 2

1 & 2

1 & 2

1 & 2

Open

CX486S2

3 & 4

2 & 3

1 & 2

2 & 3

2 & 3

Closed

80487SX

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

Open

CX486DX

2 & 3

1 & 2

1 & 2

2 & 3

1 & 2

Open

CX486DX2

2 & 3

1 & 2

1 & 2

2 & 3

1 & 2

Closed

80486DX/DX2

2 & 3

1 & 2

1 & 2

1 & 2

1 & 2

Open

Pentium Overdrive

1 & 2

1 & 2

2 & 3

1 & 2

1 & 2

Open

Note: Pins designated should be in the closed position.

CPU SPEED CONFIGURATION

Speed

JP24

JP25

JP26

JP27

25MHz

Open

Open

Closed

Open

33MHz

Closed

Open

Closed

Closed

40MHz

Open

Closed

Open

Open

50iMHz

Open

Open

Closed

Open

50MHz

Open

Open

Closed

Open

66iMHz

Closed

Open

Closed

Closed

CPU CLOCK SPEED CONFIGURATION

Speed

JP15

JP21

JP33

25MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

33MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

40MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

50iMHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

50MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

66iMHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

VESA WAIT STATE CONFIGURATION

Wait states

JP28

0 wait states

pins 1 & 2 closed

1 wait state

pins 2 & 3 closed

BUS SPEED CONFIGURATION

CPU speed

JP29

<= 33MHz

pins 1 & 2 closed

> 33MHz

pins 2 & 3 closed