BIOSTAR MICROTECH INTERNATIONAL CORPORATION

MB-1425/33/40/50UCV-B/C/D/E

Processor

CX486S/80486SX/80487SX/80486DX/ODP486SX/80486DX2/80486DX4/ Pentium Overdrive

Processor Speed

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

Chip Set

Unidentified

Max. Onboard DRAM

64MB

Cache

32/64/128/256KB

BIOS

AMI

Dimensions

254mm x 218mm

I/O Options

32-bit VESA local bus slots (3), green PC connector

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Daughter board connector

BC20

Turbo LED

JP15 pins 10 - 11

External battery

JP8

Reset switch

JP15 pins 12 - 13

Green PC connector (Ver. D & E)

JP14

Turbo switch

JP15 pins 14 - 16

Speaker

JP15 pins 1 - 4

+5v ground

JP15 pins 17 - 18

Power LED & keylock

JP15 pins 5 - 9

32-bit VESA local bus slots

SL1 - SL3

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Password normal operation

JP3

Open

 

Password memory clear

JP3

Closed

»

CMOS memory normal operation

JP8

pins 2 & 3 closed

 

CMOS memory clear

JP8

pins 3 & 4 closed

 

Battery type select external

JP8

Closed

»

Power good signal detect from power supply

JP11

pins 1 & 2 closed

 

Power good signal detect from board

JP11

pins 2 & 3 closed

»

CPU type select PQFP or PGA

JP12

pins 1 & 2 closed

 

CPU type select PGA enabled & PQFP disabled

JP12

pins 2 & 3 closed

»

Monitor type select color (Ver. B & C only)

JP14

pins 2 & 3 closed

 

Monitor type select monochrome (Ver. B & C only)

JP14

pins 1 & 2 closed

»

VGA card select normal card

JP28

pins 1 & 2 closed

 

VGA card select Weitek Power 9000 VGA card only

JP28

pins 2 & 3 closed

»

Cyrix CPU type select CX486DX

JP34

Open

 

Cyrix CPU type select CX486DX2

JP34

Closed

»

Factory configured - do not alter

JP36

Open

»

Mouse COM port select COM2

JP39

pins 1 & 2 closed

 

Mouse COM port select COM1

JP39

pins 2 & 3 closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

1MB

(4) 256K x 9

NONE

NONE

2MB

(4) 256K x 9

(1) 256K x 36

NONE

3MB

(4) 256K x 9

(1) 256K x 36

(1) 256K x 36

4MB

(4) 256K x 9

(1) 256K x 36

(1) 512K x 36

5MB

(4) 256K x 9

(1) 1M x 36

NONE

6MB

(4) 256K x 9

(1) 1M x 36

(1) 256K x 36

8MB

(4) 1M x 9

(1) 1M x 36

NONE

10MB

(4) 1M x 9

(1) 1M x 36

(1) 512K x 36

12MB

(4) 1M x 9

(1) 1M x 36

(1) 1M x 36

16MB

(4) 1M x 9

(1) 1M x 36

(1) 2M x 36

20MB

(4) 4M x 9

(1) 1M x 36

NONE

24MB

(4) 4M x 9

(1) 1M x 36

(1) 1M x 36

32MB

(4) 4M x 9

(1) 4M x 36

NONE

36MB

(4) 4M x 9

(1) 1M x 36

(1) 4M x 36

48MB

(4) 4M x 9

(1) 4M x 36

(1) 4M x 36

64MB

(4) 16M x 9

NONE

NONE

Note: If this board uses 30-pin and 72-pin modules, use this table.

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

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

17MB

(4) 4M x 9

(4) 256K x 9

20MB

(4) 4M x 9

(4) 1M x 9

32MB

(4) 4M x 9

(4) 4M x 9

64MB

(4) 16M x 9

NONE

Note: If this board does not use 72-pin sockets, use this table. Depending on board revision, it will have either this setup or the above setup.

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) 16K x 8

256KB (B)

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP5

JP6

JP7

JP9

JP10

32KB

2 & 3

Open

Open

Open

Open

64KB

1 & 2

Open

Open

Closed

Open

128KB

2 & 3

2 & 3

Closed

Closed

Open

256KB (A)

1 & 2

1 & 2

Closed

Closed

2 & 3

256KB (B)

1 & 2

1 & 2

Closed

Closed

1 & 2

Note: Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

Type

JP16

JP17

CX486S

Open

pins 2 & 3 closed

80486SX

Open

pins 2 & 3 closed

ODP486SX

pins 2 & 3 closed

pins 1 & 2, 3 & 4 closed

80487SX

pins 2 & 3 closed

pins 1 & 2, 3 & 4 closed

80486DX

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

80486DX2

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

80486DX4

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

Pentium Overdrive

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

CPU SPEED CONFIGURATION

Speed

JP21

JP22

JP23

JP27

25MHz

Closed

Open

Closed

Open

33MHz

Closed

Closed

Open

Open

40MHz

Open

Open

Closed

Closed

50iMHz

Closed

Open

Closed

Open

50MHz

Open

Closed

Open

Closed

66iMHz

Closed

Closed

Open

Open

75iMHz

Closed

Open

Closed

Open

100iMHz

Closed

Closed

Open

Open

CPU SPEED CONFIGURATION (80486DX4 ONLY)

Speed

JP41

2x

pins 2 & 3 closed

3x

pins 1 & 2 closed

CPU VOLTAGE CONFIGURATION

Voltage

JP42

JP44

3.3v

Open

Open

5v

pins 3 & 5, 4 & 6 closed

pins 1 & 2, 3 & 4 closed

VESA BUS CLOCK CONFIGURATION (SLOT 1)

Setting

JP26

Synchronous

pins 1 & 2 closed

Asynchronous

pins 2 & 3 closed

VESA BUS CLOCK CONFIGURATION (SLOT 2)

Setting

JP25

Synchronous

pins 1 & 2 closed

Asynchronous

pins 2 & 3 closed

VESA BUS CLOCK CONFIGURATION (SLOT 3)

Setting

JP29

Synchronous

pins 1 & 2 closed

Asynchronous

pins 2 & 3 closed

VGA CARD CONFIGURATION (CIRRUS LOGIC VER. AB)

CPU speed

JP19

JP20

25MHz

pins 2 & 3 closed

pins 1 & 2 closed

33MHz

pins 2 & 3 closed

pins 1 & 2 closed

40MHz

pins 1 & 2 closed

pins 1 & 2 closed

50MHz

pins 1 & 2 closed

pins 1 & 2 closed

VGA CARD CONFIGURATION (CIRRUS LOGIC VER. AC)

CPU speed

JP19

JP20

25MHz

pins 2 & 3 closed

pins 1 & 2 closed

33MHz

pins 2 & 3 closed

pins 1 & 2 closed

40MHz

pins 1 & 2 closed

pins 2 & 3 closed

50MHz

pins 1 & 2 closed

pins 2 & 3 closed