UNIDENTIFIED

MS-4125 VERSION 2.1

Processor

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

Processor Speed

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

Chip Set

Contaq

Max. Onboard DRAM

32MB

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

Auxiliary keyboard connector

J2

Turbo LED

J5 pins 12 - 13

External battery

J4

Turbo switch

J5 pins 15 - 17

Power LED & keylock

J5 pins 1 - 5

Reset switch

J5 pins 19 - 20

Speaker

J5 pins 6 - 10

32-bit VESA local bus slots

SL1 & SL2

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Battery type select internal

J4

pins 2 & 3 closed

 

Battery type select external

J4

Closed

»

Monitor type select monochrome

JP17

Open

 

Monitor type select color

JP17

Closed

»

Factory configured - do not alter

JP23

pins 1 & 2 closed

»

Factory configured - do not alter

JP26

pins 1 & 2 closed

»

Factory configured - do not alter

JP37

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) 256K x 9

(4) 1M x 9

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

17MB

(4) 256K x 9

(4) 4M x 9

20MB

(4) 1M x 9

(4) 4M x 9

20MB

(4) 4M x 9

(4) 1M x 9

32MB

(4) 4M x 9

(4) 4M 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

JP1

JP6

JP7

64KB

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

128KB

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

256KB

pins 4 & 5 closed

pins 1 & 2 closed

pins 1 & 2 closed

CPU TYPE CONFIGURATION

Type

JP31

JP32

JP33

80486SX (PQFP)

Open

Open

pins 1 & 2 closed

80486SX (PGA)

pins 3 & 4 closed

Open

pins 2 & 3, 4 & 5 closed

ODP486SX

pins 2 & 3, 4 & 5 closed

pins 1 & 2 closed

pins 2 & 3, 4 & 5 closed

80487SX

pins 2 & 3, 4 & 5 closed

pins 1 & 2 closed

pins 2 & 3, 4 & 5 closed

80486DX (PQFP)

pins 1 & 2 closed

pins 4 & 5 closed

pins 1 & 2 closed

80486DX (PGA)

pins 2 & 3, 4 & 5 closed

pins 2 & 3 closed

pins 2 & 3, 4 & 5 closed

80486DX2

pins 2 & 3, 4 & 5 closed

pins 2 & 3 closed

pins 2 & 3, 4 & 5 closed

Pentium Overdrive

pins 2 & 3, 4 & 5 closed

pins 1 & 2 closed

pins 2 & 3, 4 & 5 closed

Note: Depending on board revision, it will have either a PGA or PQFP socket.

CPU SPEED CONFIGURATION

Speed

JP8

JP12

JP13

JP14

25MHz

pins 2 & 3 closed

Open

Open

Closed

33MHz

pins 1 & 2 closed

Closed

Open

Open

40MHz

pins 1 & 2 closed

Closed

Closed

Open

50iMHz

pins 2 & 3 closed

Open

Open

Closed

50MHz

pins 1 & 2 closed

Open

Closed

Open

66iMHz

pins 1 & 2 closed

Closed

Open

Open

VESA WAIT STATE CONFIGURATION

Wait states

JP19

0 wait states

Open

1 wait state

Closed

BUS SPEED CONFIGURATION

CPU speed

JP20

<= 33MHz

Open

> 33MHz

Closed

VESA CARD TYPE CONFIGURATION

Card type

JP18

JP22

Normal

Closed

pins 1 & 2 closed

Weitek P9000

Open

pins 2 & 3 closed