UNIDENTIFIED

5/486 MOTHERBOARD

Processor

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

Processor Speed

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

Chip Set

Unknown

Max. Onboard DRAM

128MB

Cache

128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (3)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J2

Power LED & keylock

JP123

Reset switch

JP119

32-bit memory expansion slot

S1

Turbo switch

JP120

32-bit memory expansion slot

S2

Turbo LED

JP121

32-bit memory expansion slot

S3

Speaker

JP122

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select color

JP31

Closed

 

Monitor type select monochrome

JP31

Open

»

CMOS memory normal operation

JP33

pins 1 & 2 closed

 

CMOS memory clear

JP33

pins 2 & 3 closed

»

VESA clock normal

JP118

pins 1 & 2 closed

 

VESA clock adjusted

JP118

pins 2 & 3 closed

CPU SPEED

Speed

JP34

JP35

JP36

25MHz

Closed

Open

Closed

33MHz

Closed

Closed

Open

40MHz

Open

Open

Closed

50iMHz

Closed

Open

Closed

50MHz

Open

Closed

Open

66iMHz

Closed

Closed

Open

CPU TYPE CONFIGURATION

Type

JP30

80486SX

pins 5 & 6 closed

80487SX

pins 1 & 2, 4 & 5, 6 & 7 closed

80486DX

pins 2 & 3, 4 & 5, 6 & 7 closed

80486DX2

pins 2 & 3, 4 & 5, 6 & 7 closed

Pentium Overdrive

pins 1 & 2, 4 & 5, 6 & 7 closed

CACHE CONFIGURATION

Size

U51, U52, U53, U54

U55, U56, U57, U58

TAG

JP58

128KB

(4) 32K x 8

NONE

(1) 8K x 8

Pins 1 & 2 closed

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

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) 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

65MB

(4) 16M x 9

(4) 256K x 9

68MB

(4) 16M x 9

(4) 1M x 9

80MB

(4) 16M x 9

(4) 4M x 9

128MB

(4) 16M x 9

(4) 16M x 9