UNIDENTIFIED

A486DX4/SIS III

Processor

AM486SX/80486SX/CX486DX/AM486DX/80486DX/AM486DX2/ 80486DX2/AM486DX4/80486DX4

Processor Speed

20/25/33/40/50(internal)/50/66(internal)/75(internal)/ 100(internal)MHz

Chip Set

SIS

Video Chip Set

None

Maximum Onboard Memory

64MB

Maximum Video Memory

None

Cache

32/64/128/256/512KB

BIOS

AMI

Dimensions

254mm x 218mm

I/O Options

32-bit VESA local bus slots (3)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

J1

Power LED

LED1

Speaker

J2

Turbo switch

S1

Turbo LED

J4

32-bit VESA local bus slots

SL1 - SL3

Reset switch

J5

   

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

Factory configured - do not alter

J7

Unidentified

»

Factory configured - do not alter

J9

Closed

»

Factory configured - do not alter

J11

Open

»

Factory configured - do not alter

J12

Open

»

Factory configured - do not alter

JP17

Pins 1 & 2 closed

 

RC pin used for break switch

JP20

Pins 1 & 2 closed

 

RC pin used for RC

JP20

Pins 2 & 3 closed

 

CPU type select any CPU type

JP27

Open

 

CPU type select CX486S2 only

JP27

Closed

 

Monitor type select CGA

JP38

Closed

 

Monitor type select monochrome/EGA/VGA

JP38

Open

»

CMOS memory normal operation

JP39

Pins 1 & 2 closed

 

CMOS memory clear

JP39

Pins 2 & 3 closed

»

Factory configured - do not alter

JP43

Pins 2 & 3 closed

»

Factory configured - do not alter

JP71

Open

 

Flash BIOS not installed

JP73

Pins 1 & 2 closed

 

Flash BIOS installed

JP73

Pins 2 & 3 closed

»

Factory configured - do not alter

JP74

Unidentified

»

Factory configured - do not alter

JP75

Unidentified

»

Factory configured - do not alter

JP78

Pins 1 & 2 closed

»

Factory configured - do not alter

JP79

Pins 2 & 3 closed

 

Turbo disabled

TBSW

Pins 1 & 2 closed

 

Turbo enabled

TBSW

Pins 2 & 3 closed

 

Turbo enabled through S1

TBSW

Pins 4 & 5 closed

DRAM CONFIGURATION 1

Size

Bank 0

1MB

(4) 256K x 9

4MB

(4) 1M x 9

16MB

(4) 4M x 9

64MB

(4) 16M x 9

DRAM CONFIGURATION 2

Size

Bank 1

Bank 2

1MB

(1) 256K x 36

None

2MB

(1) 512K x 36

None

4MB

(1) 1M x 36

None

4MB

(1) 512K x 36

(1) 512K x 36

8MB

(1) 2M x 36

None

8MB

(1) 1M x 36

(1) 1M x 36

16MB

(1) 4M x 36

None

DRAM CONFIGURATION 2 (CON’T)

Size

Bank 1

Bank 2

16MB

(1) 2M x 36

(1) 2M x 36

32MB

(1) 8M x 36

None

32MB

(1) 4M x 36

(1) 4M x 36

64MB

(1) 8M x 36

(1) 8M x 36

DRAM JUMPER CONFIGURATION

Configuration

JP45

JP46

1

Pins 2 & 3 closed

Closed

2

Pins 1 & 2 closed

Open

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

32KB

(4) 8K x 8

None

(1) 8K x 8

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

128KB

(4) 32K x 8

None

(1) 8K x 8

256KB (A)

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

256KB (B)

(4) 64K x 8

None

(1) 32K x 8

512KB

(4) 128K x 8

None

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP30

JP31

JP32

JP34

JP35

JP36

JP81

32KB

1 & 2

1 & 2

1 & 2

Open

1 & 2

1 & 2

2 & 3

64KB

2 & 3

1 & 2

1 & 2

1 & 2

2 & 3

1 & 2

2 & 3

128KB

2 & 3

2 & 3

1 & 2

2 & 3, 4 & 5

1 & 2

2 & 3

2 & 3

256KB (A)

2 & 3

2 & 3

2 & 3

1 & 2, 3 & 4

2 & 3

2 & 3

2 & 3

256KB (B)

2 & 3

2 & 3

2 & 3

2 & 3, 4 & 5

1 & 2

2 & 3

2 & 3

512KB

2 & 3

2 & 3

2 & 3

2 & 3, 4 & 5

1 & 2

2 & 3

1 & 2

Note: Pins designated should be in the closed position.

CPU SPEED SELECTION

Speed

JP5

JP6

JP7

20MHz

Closed

Open

Closed

25MHz

Closed

Closed

Open

33MHz

Open

Closed

Closed

40MHz

Closed

Open

Open

50iMHz

Closed

Closed

Open

50MHz

Open

Open

Closed

66iMHz

Open

Closed

Closed

75iMHz

Closed

Closed

Open

100iMHz

Open

Closed

Closed

CPU TYPE SELECTION

Type

J13

JP8

JP10

JP12

JP13

AM486SX

Closed

2 & 3

2 & 3

Open

Open

80486SX

Closed

2 & 3

2 & 3

Open

Open

CX486DX

Open

2 & 3

2 & 3

2 & 3

2 & 3

AM486DX

Closed

2 & 3

2 & 3

Open

Open

80486DX

Closed

2 & 3

2 & 3

Open

Open

AM486DX2

Closed

2 & 3

2 & 3

Open

Open

80486DX2

Closed

2 & 3

2 & 3

Open

Open

AM486DX4

Closed

2 & 3

Open

Open

Open

80486DX4

Closed

2 & 3

Open

Open

Open

Note: Pins designated should be in the closed position.

CPU TYPE SELECTION (CON’T)

Type

JP18

JP19

JP24

JP25

JP28

AM486SX

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

80486SX

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

CX486DX

2 & 3

1 & 2

2 & 3

1 & 2, 3 & 4

Open

AM486DX

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

80486DX

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

AM486DX2

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

80486DX2

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

AM486DX4

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

80486DX4

1 & 2

2 & 3

4 & 5

2 & 3

1 & 2

Note: Pins designated should be in the closed position.

CPU TYPE SELECTION (CON’T)

Type

JP29

JP33

JP37

JP40

AM486SX

3 & 4

2 & 3

Open

1 & 2 or 2 & 3

80486SX

3 & 4

2 & 3

Open

1 & 2 or 2 & 3

CX486DX

2 & 3

1 & 2

3 & 4

1 & 2

AM486DX

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

80486DX

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

AM486DX2

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

80486DX2

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

AM486DX4

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

80486DX4

3 & 4

1 & 2, 3 & 4

3 & 4

1 & 2 or 2 & 3

Note: Pins designated should be in the closed position.

CPU MULTIPLIER SELECTION

Multiplier

JP44

2x

Pins 1 & 2 closed

2.5x

Pins 2 & 3 closed

3x

Open

CPU VOLTAGE SELECTION

Voltage

Setting

JP80

3.45v

UMB on board

Auto detect

5v

UMB on board

Auto detect

3.45v

UMB not on board

No support

5v

UMB not on board

Closed

VL BUS WAIT STATE SELECTION

Setting

JP4

0

Pins 1 & 2 closed

1

Pins 2 & 3 closed

VL BUS SPEED SELECTION

Speed

JP3

<= 33MHz

Pins 1 & 2 closed

>33 MHz

Pins 2 & 3 closed