VEXTREC TECHNOLOGY, INC.

GMB-486UN (VER. 3.00)

Device Type

Mainboard

Processor

80486SX/80486DX/80486DX2

Processor Speed

25/33/50/66MHz

Chip Set

Unidentified

Maximum Onboard Memory

32MB DRAM

Cache

32/64/128/256KB

BIOS

Acer

I/O Options

None

CONNECTIONS

External battery

JP1

Turbo LED

JP16

Reset switch

JP14

Speaker

JP17

Turbo switch

JP15

Power LED & keylock

JP18

USER CONFIGURABLE SETTINGS

Function

Label

Position

»

CMOS memory normal operation

JP2

Pins 1 & 2 closed

 

CMOS memory clear

JP2

Pins 2 & 3 closed

»

Hardware emulate KBGA20

JP10

Pins 1 & 2 closed

 

Keyboard controller 8042

JP10

Pins 2 & 3 closed

»

Color display enabled

JP12

Closed

 

Monochrome display enabled

JP12

Open

DRAM CONFIGURATION

Size

Bank 0

Bank 1

1MB

(4) 256KB x 9

None

2MB

(4) 256KB x 9

(4) 256KB x 9

4MB

(4) 1MB x 9

None

5MB

(4) 1MB x 9

(4) 256KB x 9

8MB

(4) 1MB x 9

(4) 1MB x 9

16MB

(4) 4MB x 9

None

17MB

(4) 4MB x 9

(4) 256KB x 9

20MB

(4) 4MB x 9

(4) 1KB x 9

32MB

(4) 4MB x 9

(4) 4MB x 9

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

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP22

JP23

JP25

JP26

32KB

Pins 2 & 3 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

64KB

Pins 2 & 3 closed

Pins 2 & 3 closed

Pins 2 & 3 closed

Pins 1 & 2 closed

128KB

Pins 2 & 3 closed

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 2 & 3 closed

256KB

Pins 1 & 2 closed

Pins 2 & 3 closed

Pins 2 & 3 closed

Pins 2 & 3 closed

CACHE JUMPER CONFIGURATION (CONT.)

Size

JP27

JP28

JP29

JP30

32KB

Closed

Open

Open

Open

64KB

Open

Closed

Open

Open

128KB

Open

Open

Closed

Open

256KB

Open

Open

Open

Closed

CPU SPEED SELECTION

Speed

JP3

JP7

JP9

JP13

25MHz

2 & 3

Open

2 & 3

2 & 3

33MHz

1 & 2

1 & 2

1 & 2, 3 & 4

1 & 2

50MHz (DX)

2 & 3

1 & 2

1 & 2, 3 & 4

1 & 2

50MHz (DX2)

1 & 2

1 & 2

1 & 2, 3 & 4

1 & 2

66MHz

1 & 2

1 & 2

1 & 2, 3 & 4

1 & 2