UNIDENTIFIED

80486 MOTHERBOARD

Processor

CX486S/80486SX/80487SX/80486DX/80486DX2/80486DX4

Processor Speed

25/33/40/50/50i/66i/75i/100iMHz

Chip Set

Unidentified

Max. Onboard DRAM

64MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

250mm x 220mm

I/O Options

32-bit VESA local bus slots (3)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

CPU power board

J10

Turbo LED

JP18

External battery

JP1

Reset switch

JP19

Power LED & Keylock

JP16

Turbo switch

JP20

Speaker

JP17

32-bit VESA local bus slots

SL1-SL3

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

VL-bus card select general

JP2

pins 1 & 2 closed

 

VL-bus card select Power 9000

JP2

pins 2 & 3 closed

»

Factory configured - do not alter

JP3

N/A

»

80486DX4 power board voltage select 3.45

JP4

Open

 

80486DX4 power board voltage select 5

JP4

Closed

»

80486DX4 clock speed select tripled

JP28

Closed

 

80486DX4 clock speed select doubled

JP28

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) 1M x 9

256K

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

20MB

(4) 4M x 9

(4) 1M x 9

32MB

(4) 4M x 9

(4) 4M x 9

64MB

(4) 16M x 9

NONE

CACHE CONFIGURATION

Size

Bank 0

Bank 1

Tag (U28)

Tag (U29)

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

NONE

128KB

(4) 32K x 8

NONE

(1) 8K x 8

NONE

256KB

(4) 32K x 8

(4) 32K x 8

(1) 8K x 8 or (1) 32K x 8

(1) 8K x 8 or NONE

CACHE JUMPER CONFIGURATION

Size

JP9

JP10

JP11

JP12

64KB

pins 1 & 2 closed

Open

Open

Open

128KB

pins 2 & 3 closed

pins 2 & 3 closed

Closed

Open

256KB

pins 1 & 2 closed

pins 1 & 2 closed

Closed

Closed

CPU CLOCK SPEED CONFIGURATION (MX8310)

Speed

JP13

JP14

JP15

25MHz

Closed

Open

Open

33MHz

Closed

Closed

Closed

40MHz

Closed

Closed

Open

50MHz

Open

Open

Closed

50i MHz

Closed

Open

Open

66i MHz

Closed

Closed

Closed

75i MHz

Closed

Open

Open

100i MHz

Open

Open

Closed

CPU CLOCK SPEED CONFIGURATION (KTS0802C/PLL52C05)

Speed

JP13

JP14

JP15

25MHz

Closed

Closed

Open

33MHz

Open

Closed

Open

40MHz

Closed

Open

Closed

50MHz

Closed

Open

Open

50i MHz

Closed

Closed

Open

66i MHz

Open

Closed

Open

75i MHz

Closed

Closed

Open

100i MHz

Closed

Open

Open

CPU TYPE SELECT

Type

JP5-JP8

JP22

JP23

CX 486S

Closed

pins 2 & 3 closed

Open

80486SX

Closed

pins 2 & 3 closed

Open

80487SX

Closed

pins 1 & 2,3 & 4 closed

pins 2 & 3 closed

486DX/DX2

Closed

pins 1 & 2,3 & 4 closed

pins 1 & 2 closed

80486DX4

Open

pins 1 & 2,3 & 4 closed

pins 1 & 2 closed

Note: Using 80486DX4, CPU power board (optional) must be in J10.

VESA BUS SPEED CONFIGURATION

Speed

JP21

25MHz

Open

33MHz

Open

40MHz

Open

50MHz

Closed

50i MHz

Open

66i MHz

Open

75i MHz

Open

100i MHz

Closed