GIGA-BYTE TECHNOLOGY CO., LTD.

GA-486US

Processor

80486SX/80486DX

Processor Speed

16/20/25/33/50MHz

Chip Set

UMC

Max. Onboard DRAM

32MB

SRAM Cache

64/128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit local bus card slots (2)

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & Keylock

J1

External battery

J17

Reset switch

J2

32-bit local bus slots

LB1 & LB2

Speaker

J3

 

LB2

Turbo LED

J5

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

External cache enabled

J4

pins 1 & 2 closed

 

External cache disabled

J4

pins 2 & 3 closed

 

CPU type select 80486DX

J8

pins 1 & 2 closed

 

CPU type select 80486SX

J8

pins 2 & 3 closed

»

CPU speed select iOSC/1

J13

Open

 

CPU speed select iOSC/2

J13

Closed

»

Monitor type select color

J16

Closed

 

Monitor type select monochrome

J16

Open

»

CMOS memory normal operation

J18

Closed

 

CMOS memory clear

J18

Open

Note:If J13 is closed, you must set the Bus speed select to CLKIN/5 in the advanced chipset setup.

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

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

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

(3) 16K x 4

128KB

(4) 32K x 8

NONE

(3) 16K x 4

256KB

(4) 32K x 8

(4) 32K x 8

(3) 16K x 4

CACHE CONFIGURATION

Size

J10

J11

J12

64KB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

128KB

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

256KB

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed