BIOSTAR MICROTECH INTERNATIONAL CORPORATION

MB-1420/1425/1433PB REV. A

MB-1420/1425/1433PV REV. A

Processor

80486SX/80487SX/P23T/80486DX/80486DX2

Processor Speed

20/25/33/50(internal)/50/66(internal)MHz

Chip Set

Unidentified

Max. Onboard DRAM

32MB

Cache

None

BIOS

AMI

Dimensions

254mm x 218mm

I/O Options

None

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

J1

Turbo switch

JP6

Speaker

J2

External battery

JP8

Turbo LED

J3

Reset switch

SW1

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select color

JP5

Closed

 

Monitor type select monochrome

JP5

Open

»

CMOS memory normal operation

JP7

pins 2 & 3 closed

 

CMOS memory clear

JP7

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) 1M x 9

(4) 256K 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

JP9

JP10

JP11

JP12

80486SX (PQFP)

Open

Open

Closed

Open

80486SX (PGA)

Open

Open

2 & 3

Open

80487SX

2 & 3

1 & 2

Closed

Open

80486SX (PQFP) & 80487SX

2 & 3

1 & 2

Closed

1 & 2

80486SX (PQFP) & P23T

2 & 3

1 & 2

Closed

2 & 3

80486SX (PQFP) & 80486DX/DX2

1 & 2

1 & 2

Closed

2 & 3

80486DX

1 & 2

1 & 2

Closed

Open

80486DX2

1 & 2

1 & 2

Closed

Open

Note: Pins designated should be in the closed position.

KEYBOARD BIOS CONFIGURATION

Type

JP1

JP2

JP3

JP4

8042 (23 pins)

Closed

Open

Open

Open

8042 (24 pins)

Open

Closed

Open

Open

8042 (27 pins)

Open

Open

Closed

Open

8042 (30 pins)

Open

Open

Open

Closed