UNIDENTIFIED

MS-4123 VERSION 3.0

Processor

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

Processor Speed

20/25/33/40/50(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

JP1

Open

 

Monitor type select color

JP1

Closed

»

Factory configured - do not alter

JP8

pins 2 & 3 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) 256K x 9

(4) 4M x 9

17MB

(4) 4M x 9

(4) 256K 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

JP2

64KB

pins 1 & 2, 4 & 5, 7 & 8, 10 & 11 closed

128KB

pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 closed

256KB

pins 2 & 3, 5 & 6, 8 & 9, 11 & 12 closed

CPU TYPE CONFIGURATION

Type

JP6

80486SX

pins 2 & 5, 3 & 6, 8 & 11, 9 & 12 closed

80487SX

pins 1 & 2, 4 & 5, 7 & 8, 10 & 11 closed

80486DX

pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 closed

80486DX2

pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 closed

Pentium Overdrive

pins 1 & 2, 4 & 5, 8 & 9, 11 & 12 closed

CPU SPEED CONFIGURATION

Speed

JP3

JP5

JP7

20MHz

pins 2 & 3 closed

pins 1 & 2, 5 & 6 closed

pins 2 & 3 closed

25MHz

pins 2 & 3 closed

pins 5 & 6 closed

pins 2 & 3 closed

33MHz

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

pins 2 & 3 closed

40MHz

pins 1 & 2 closed

pins 1 & 2, 5 & 6 closed

pins 1 & 2 closed

50iMHz

pins 2 & 3 closed

pins 5 & 6 closed

pins 2 & 3 closed

50MHz

pins 1 & 2 closed

pins 5 & 6 closed

pins 1 & 2 closed

66iMHz

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

pins 2 & 3 closed

BUS SPEED CONFIGURATION

CPU speed

JP13

<= 33MHz

Open

> 33MHz

Closed