...because we can't all be on the bleeding edge...





AN4

ABIT COMPUTER CORPORATION

AN4

Processor

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

Processor Speed

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

Chip Set

SIS

Max. Onboard DRAM

64MB

Cache

128/256/512KB

BIOS

AMI/Award

Dimensions

260mm x 220mm

I/O Options

32-bit VESA local bus slots (3), green PC feature

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Reset switch

JW3

Green PC monitor AC connector

JP8

Turbo switch

JW4

Power LED & keylock

JW1

Turbo LED

JW5

Speaker

JW2

32-bit VESA Local bus slots

SL1 - SL3

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Factory configured - do not alter

JP9

Closed

»

CMOS memory normal operation

JP10

pins 1 & 2 closed

 

CMOS memory clear

JP10

pins 2 & 3 closed

»

Green PC enabled

JP13

Closed

 

Green PC disabled

JP13

Open

»

Factory configured - do not alter

JP19

Open

»

Factory configured - do not alter

JP36

Closed

Note: The location of the factory configured jumpers is unidentified.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(4) 256K x 9

NONE

NONE

NONE

1MB

(1) 256K x 36

NONE

NONE

NONE

2MB

(4) 256K x 9

(4) 256K x 9

NONE

NONE

2MB

(1) 256K x 36

(1) 256K x 36

NONE

NONE

4MB

(4) 1M x 9

NONE

NONE

NONE

4MB

(1) 1M x 36

NONE

NONE

NONE

6MB

(1) 256K x 36

(1) 256K x 36

(4) 1M x 9

NONE

6MB

(4) 1M x 9

(1) 256K x 36

(1) 256K x 36

NONE

8MB

(1) 2M x 36

NONE

NONE

NONE

8MB

(4) 1M x 9

(4) 1M x 9

NONE

NONE

10MB

(4) 256K x 9

(4) 256K x 9

(1) 1M x 36

(1) 1M x 36

10MB

(1) 1M x 36

(1) 1M x 36

(4) 256K x 9

(4) 256K x 9

12MB

(4) 1M x 9

(1) 1M x 36

(1) 1M x 36

NONE

16MB

(4) 1M x 9

(4) 1M x 9

(1) 1M x 36

(1) 1M x 36

16MB

(1) 2M x 36

(1) 2M x 36

NONE

NONE

16MB

(1) 4M x 36

NONE

NONE

NONE

16MB

(4) 4M x 9

NONE

NONE

NONE

18MB

(4) 256K x 9

(4) 256K x 9

(1) 4M x 36

NONE

20MB

(1) 1M x 36

(1) 4M x 36

NONE

NONE

24MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

NONE

24MB

(4) 1M x 9

(4) 1M x 9

(1) 4M x 36

NONE

24MB

(1) 2M x 36

(1) 2M x 36

(1) 2M x 36

NONE

32MB

(1) 2M x 36

(1) 2M x 36

(1) 2M x 36

(1) 2M x 36

32MB

(1) 4M x 36

(1) 4M x 36

NONE

NONE

32MB

(4) 4M x 9

(4) 4M x 9

NONE

NONE

36MB

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

NONE

36MB

(4) 4M x 9

(4) 4M x 9

(1) 1M x 36

NONE

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

40MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

40MB

(4) 4M x 9

(4) 4M x 9

(1) 2M x 36

NONE

48MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

NONE

48MB

(4) 4M x 9

(4) 4M x 9

(1) 4M x 36

NONE

64MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

DRAM JUMPER CONFIGURATION

Bank 0

Bank 1

Bank 2

Bank 3

JP39

JP40

JP41

SIMM 1 - 4

SIMM 5 - 8

SIMM 9 (S)

SIMM 10 (S)

1 & 2

1 & 2

Open

SIMM 1 - 4

SIMM 5 - 8

SIMM 9 (D)

SIMM 10 (D)

1 & 2

1 & 2

Open

SIMM 9 (S)

SIMM 10 (S)

SIMM 1 - 4

SIMM 5 - 8

2 & 3

2 & 3

Open

SIMM 9 (D)

SIMM 10 (D)

SIMM 1 - 4

SIMM 5 - 8

2 & 3

2 & 3

Open

SIMM 9 (D)

SIMM 9 (D)

SIMM 10 (D)

SIMM 10 (D)

2 & 3

2 & 3

Closed

SIMM 9 (S)

SIMM 5 - 8

SIMM 1 - 4

NONE

2 & 3

1 & 2

Open

SIMM 1 - 4

SIMM 10 (S)

SIMM 9 (S)

NONE

1 & 2

Open

Open

SIMM 1 - 4

SIMM 10 (S)

SIMM 9 (D)

SIMM 9 (D)

1 & 2

Open

Open

SIMM 9 (D)

SIMM 9 (D)

SIMM 10 (S)

SIMM 5 - 8

Open

2 & 3

Closed

Note: Pins designated should be in the closed position.

DRAM JUMPER CONFIGURATION (CON’T)

Bank 0

Bank 1

Bank 2

Bank 3

JP42

JP43

JP44

SIMM 1 - 4

SIMM 5 - 8

SIMM 9 (S)

SIMM 10 (S)

1 & 2

1 & 2

1 & 2

SIMM 1 - 4

SIMM 5 - 8

SIMM 9 (D)

SIMM 10 (D)

1 & 2

1 & 2

1 & 2

SIMM 9 (S)

SIMM 10 (S)

SIMM 1 - 4

SIMM 5 - 8

2 & 3

1 & 2

2 & 3

SIMM 9 (D)

SIMM 10 (D)

SIMM 1 - 4

SIMM 5 - 8

2 & 3

2 & 3

1 & 2

SIMM 9 (D)

SIMM 9 (D)

SIMM 10 (D)

SIMM 10 (D)

2 & 3

2 & 3

Open

SIMM 9 (S)

SIMM 5 - 8

SIMM 1 - 4

NONE

2 & 3

Open

Open

SIMM 1 - 4

SIMM 10 (S)

SIMM 9 (S)

NONE

1 & 2

1 & 2

2 & 3

SIMM 1 - 4

SIMM 10 (S)

SIMM 9 (D)

SIMM 9 (D)

1 & 2

1 & 2

2 & 3

SIMM 9 (D)

SIMM 9 (D)

SIMM 10 (S)

SIMM 5 - 8

2 & 3

2 & 3

Open

Note: Pins designated should be in the closed position.

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG

128KB

(4) 32K x 8

NONE

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

512KB

(4) 128K x 8

NONE

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP1

JP2

JP3`

JP20

JP21

JP38

128KB

1 & 2

1 & 2

2 & 3

1 & 2

2 & 3

1 & 2

256KB

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

1 & 2

512KB

1 & 2

1 & 2

2 & 3

2 & 3

2 & 3

2 & 3

Note: Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

Type

JP15

JP16

JP18

80486SX

pins 2 & 3 closed

Open

Open

80487SX

pins 1 & 2 closed

pins 2 & 3 closed

Closed

80486DX/DX2

pins 1 & 2 closed

pins 1 & 2 closed

Closed

CPU SPEED CONFIGURATION

Speed

JP11

JP12

JP14

25MHz

Open

Closed

Closed

33MHz

Closed

Closed

Open

40MHz

Open

Open

Closed

50iMHz

Open

Closed

Closed

50MHz

Closed

Open

Open

66iMHz

Closed

Closed

Open

VESA WAIT STATE CONFIGURATION

Wait states

JP4

0 wait states

pins 1 & 2 closed

1 wait state

pins 2 & 3 closed

VESA BUS SPEED CONFIGURATION

CPU speed

JP5

< = 33MHz

pins 1 & 2 closed

> 33MHz

pins 2 & 3 closed

GREEN PC CONFIGURATION

Description

JP8

Signal

pin 1

Ground

pin 2