ABIT COMPUTER CORPORATION

486 VESA/486 ISA

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

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

Chip Set

UNI

Max. Onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI/Award

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (2)

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

JW1

Reset switch

JW5

Speaker

JW2

External battery

JP16

Turbo LED

JW3

32-bit VESA local bus slots

S1 & S2

Turbo switch

JW4

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Factory configured - do not alter

JP1

Closed

»

Factory configured - do not alter

JP2

Closed

»

Factory configured - do not alter

JP3

pins 1 & 2 closed

»

Factory configured - do not alter

JP9

Closed

»

Factory configured - do not alter

JP10

Closed

»

Monitor type select monochrome

JP11

pins 1 & 2 closed

 

Monitor type select color

JP11

pins 2 & 3 closed

»

Factory configured - do not alter

JP12

Closed

»

Factory configured - do not alter

JP14

Closed

»

CMOS memory normal operation

JP15

pins 2 & 3 closed

 

CMOS memory clear

JP15

pins 1 & 2 closed

»

Factory configured - do not alter

JP17

Closed

»

Factory configured - do not alter

JP18

Closed

»

Factory configured - do not alter

JP19

Closed

»

Factory configured - do not alter

JP20

Closed

»

Factory configured - do not alter

JP21

Closed

»

Factory configured - do not alter

JP22

Closed

»

Factory configured - do not alter

JP23

Closed

»

Factory configured - do not alter

JP24

Closed

»

Factory configured - do not alter

JPX4

Closed

»

Factory configured - do not alter

JPX5

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

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

Max Cachable

Bank 0

Bank 1

TAG

64KB

8MB

(4) 8K x 8

(4) 8K x 8

8K x 8

128KB

16MB

(4) 32K x 8

NONE

8K x 8

256KB

32MB

(4) 32K x 8

(4) 32K x 8

32K x 8

CACHE JUMPER CONFIGURATION

Size

JPX10

JPX20

JPX30

64KB

Closed

Open

Open

128KB

Open

Closed

Open

256KB

Open

Open

Closed

CPU SPEED CONFIGURATION

Speed

JP4

JP28

JP29

JP31

JP32

JP33

25MHz

1 & 2

1 & 2

1 & 2

Closed

Open

Closed

33MHz

1 & 2

1 & 2

1 & 2

Closed

Closed

Open

40MHz

2 & 3

2 & 3

2 & 3

Open

Closed

Closed

50iMHz

1 & 2

1 & 2

1 & 2

Closed

Open

Closed

50MHz

2 & 3

2 & 3

2 & 3

Closed

Open

Closed

66iMHz

1 & 2

1 & 2

1 & 2

Closed

Closed

Open

NotePins designated should be in the closed position.

CPU TYPE CONFIGURATION

CPU Type

JP5-JP8, JP25

JPX1

JPX2

JPX3

80486SX

pins 1 & 2 closed

Open

Closed

Closed

80487SX

pins 1 & 2 closed

Open

Open

Closed

80486DX, DX2

pins 1 & 2 closed

Closed

Open

Open

VESA WAIT STATE/BUS SPEED CONFIGURATION

CPU speed

Wait States

JP26

JP27

< 33MHz

O wait states

pins 1 & 2 closed

pins 1 & 2 closed

> 33MHz

1 wait state

pins 2 & 3 closed

pins 2 & 3 closed