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





AH4/AH4T (REV. 1.2)

ABIT COMPUTER CORPORATION

AH4/AH4T (REV. 1.2)

Processor

80486SX/SL80486SX/CX486M7/80486DX/SL80486DX/CX486DX2/AM486DX2/80486DX2/SL80486DX2/AM486DX4/80486DX4

Processor Speed

20/25/33/40/50(internal)/66(internal)/75(internal)/100(internal)MHz

Chip Set

Unidentifed

Max. Onboard DRAM

128MB

Cache

128/256/512KB

BIOS

Award

Dimensions

330mm x 218mm

I/O Options

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

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Reset switch

JW3

Green PC connector

JP45 pins 7 - 8

Turbo LED

JW4

Power LED & keylock

JW1

Turbo switch

JW5

Speaker

JW2

32-bit VESA local bus slots

SL1 - SL3

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CMOS memory normal operation

JP16

pins 1 & 2 closed

 

CMOS memory clear

JP16

pins 2 & 3 closed

»

Factory configured - do not alter

JP17

N/A

»

Factory configured - do not alter

JP19

pins 1 & 2 closed

»

Factory configured - do not alter

JP23

pins 1 & 2 closed

»

Factory configured - do not alter

JP26

Open

»

Factory configured - do not alter

JP30

N/A

»

Factory configured - do not alter

JP31

N/A

»

Factory configured - do not alter

JP42

Closed

Note: The locations of JP19, JP23 & JP42 are unidentified.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(1) 256K x 36

NONE

NONE

NONE

2MB

(1) 256K x 36

(1) 256K x 36

NONE

NONE

2MB

(1) 512K x 36

NONE

NONE

NONE

4MB

(1) 512K x 36

(1) 512K x 36

NONE

NONE

4MB

(1) 1M x 36

NONE

NONE

NONE

4MB

(1) 256K x 36

(1) 256K x 36

(1) 512K x 36

NONE

5MB

(1) 256K x 36

(1) 1M x 36

NONE

NONE

6MB

(1) 256K x 36

(1) 256K x 36

(1) 1M x 36

NONE

6MB

(1) 512K x 36

(1) 1M x 36

NONE

NONE

8MB

(1) 256K x 36

(1) 256K x 36

(1) 512K x 36

(1) 1M x 36

8MB

(1) 512K x 36

(1) 512K x 36

(1) 1M x 36

NONE

8MB

(1) 1M x 36

(1) 1M x 36

NONE

NONE

8MB

(1) 2M x 36

NONE

NONE

NONE

10MB

(1) 256K x 36

(1) 256K x 36

(1) 1M x 36

(1) 1M x 36

12MB

(1) 512K x 36

(1) 512K x 36

(1) 1M x 36

(1) 1M x 36

12MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

NONE

16MB

(1) 2M x 36

(1) 2M x 36

NONE

NONE

16MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

16MB

(1) 4M x 36

NONE

NONE

NONE

17MB

(1) 256K x 36

(1) 4M x 36

NONE

NONE

18MB

(1) 256K x 36

(1) 256K x 36

(1) 4M x 36

NONE

20MB

(1) 512K x 36

(1) 512K x 36

(1) 4M x 36

NONE

20MB

(1) 1M x 36

(1) 4M x 36

NONE

NONE

24MB

(1) 2M x 36

(1) 2M x 36

(1) 2M x 36

NONE

24MB

(1) 512K x 36

(1) 512K x 36

(1) 1M x 36

(1) 4M x 36

24MB

(1) 1M x 36

(1) 1M x 36

(1) 4M 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

(1) 8M x 36

NONE

NONE

NONE

36MB

(1) 512K x 36

(1) 512K x 36

(1) 4M x 36

(1) 4M x 36

36MB

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

NONE

DRAM CONFIGURATION (CON’T)

Size

Bank 0

Bank 1

Bank 2

Bank 3

36MB

(1) 1M x 36

(1) 8M x 36

NONE

NONE

40MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

40MB

(1) 1M x 36

(1) 1M x 36

(1) 8M x 36

NONE

48MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

NONE

48MB

(1) 4M x 36

(1) 8M x 36

NONE

NONE

64MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

64MB

(1) 16M x 36

NONE

NONE

NONE

64MB

(1) 4M x 36

(1) 4M x 36

(1) 8M x 36

NONE

64MB

(1) 8M x 36

(1) 8M x 36

NONE

NONE

65MB

(1) 256K x 36

(1) 16M x 36

NONE

NONE

68MB

(1) 1M x 36

(1) 16M x 36

NONE

NONE

68MB

(1) 1M x 36

(1) 8M x 36

(1) 8M x 36

NONE

72MB

(1) 1M x 36

(1) 1M x 36

(1) 16M x 36

NONE

72MB

(1) 1M x 36

(1) 1M x 36

(1) 8M x 36

(1) 8M x 36

80MB

(1) 4M x 36

(1) 16M x 36

NONE

NONE

80MB

(1) 4M x 36

(1) 8M x 36

(1) 8M x 36

NONE

96MB

(1) 4M x 36

(1) 4M x 36

(1) 16M x 36

NONE

96MB

(1) 4M x 36

(1) 4M x 36

(1) 8M x 36

(1) 8M x 36

96MB

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

NONE

128MB

(1) 16M x 36

(1) 16M x 36

NONE

NONE

128MB

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

(1) 8M x 36

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

256KB

(4) 64K x 8

NONE

(1) 32K x 8

512KB

(4) 64K x 8

(4) 64K x 8

(1) 32K x 8

512KB

(4) 128K x 8

NONE

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP1

JP2

JP4

JP40

JP41

128KB

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

256KB

2 & 3

2 & 3

1 & 2

2 & 3

2 & 3

256KB

1 & 2

2 & 3

1 & 2

1 & 2

1 & 2

512KB

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

512KB

1 & 2

2 & 3

2 & 3

1 & 2

1 & 2

Note: Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

Type

JP8

JP9

JP11

JP12

JP14

80486SX

2 & 3

Open

Open

3 & 4

2 & 3

SL80486SX

2 & 3

Open

Open

3 & 4

2 & 3

CX486M7

1 & 2

Closed

2 & 3

2 & 3

1 & 2, 3 & 4

80486DX

1 & 2

Closed

2 & 3

3 & 4

2 & 3

SL80486DX

1 & 2

Closed

2 & 3

3 & 4

2 & 3

CX486DX2

1 & 2

Closed

2 & 3

2 & 3

1 & 2, 3 & 4

AM486DX2

1 & 2

Closed

2 & 3

3 & 4

2 & 3

80486DX2

1 & 2

Closed

2 & 3

3 & 4

2 & 3

SL80486DX2

1 & 2

Closed

2 & 3

3 & 4

2 & 3

AM486DX4

1 & 2

Closed

2 & 3

3 & 4

2 & 3

80486DX4

1 & 2

Closed

2 & 3

3 & 4

2 & 3

Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard

CPU TYPE CONFIGURATION

Type

JP15

JP21

JP22

JP24

JP25

80486SX

4 & 5

2 & 3

1 & 2

Open

Open

SL80486SX

4 & 5

2 & 3

1 & 2

Open

Open

CX486M7

2 & 3

1 & 2

2 & 3

2 & 3

2 & 3

80486DX

4 & 5

2 & 3

1 & 2

Open

Open

SL80486DX

4 & 5

2 & 3

1 & 2

Open

Open

CX486DX2

2 & 3

1 & 2

2 & 3

2 & 3

2 & 3

AM486DX2

4 & 5

2 & 3

1 & 2

Open

Open

80486DX2

4 & 5

2 & 3

1 & 2

Open

Open

SL80486DX2

4 & 5

2 & 3

1 & 2

Open

Open

AM486DX4

4 & 5

2 & 3

1 & 2

Open

Open

80486DX4

4 & 5

2 & 3

1 & 2

Open

Open

Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard

CPU TYPE CONFIGURATION

Type

JP32

JP46

JP48

JP49

JP50

JP62

80486SX

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

SL80486SX

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

CX486M7

1 & 2

1 & 2

2 & 3

Open

2 & 3

Open

80486DX

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

SL80486DX

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

CX486DX2

1 & 2

1 & 2

1 & 2

Open

1 & 2

Open

AM486DX2

1 & 2

2 & 3

1 & 2

Open

1 & 2

Open

80486DX2

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

SL80486DX2

1 & 2

2 & 3

2 & 3

Open

2 & 3

Open

AM486DX4

1 & 2

2 & 3

1 & 2

1 & 2

1 & 2

Closed

80486DX4

Open

2 & 3

1 & 2

1 & 2

1 & 2

Open

Note: Pins designated should be in the closed position. SL80486DX/DX2 is only available on the AH4T mainboard

CPU SPEED CONFIGURATION

Speed

JP5

JP6

JP7

20MHz

Closed

Open

Closed

25MHz

Closed

Closed

Open

33MHz

Open

Closed

Closed

40MHz

Closed

Open

Open

50iMHz

Closed

Closed

Open

66iMHz

Open

Closed

Closed

75iMHz

Closed

Closed

Open

100iMHz

Open

Closed

Closed

CPU VOLTAGE CONFIGURATION

Voltage

JP53

JP54

JP55

JP56

3.3v

Closed

Open

Open

Open

3.45v

Open

Closed

Open

Open

3.6v

Open

Open

Closed

Open

4v

Open

Open

Open

Closed

BUS SPEED CONFIGURATION

CPU speed

JP29

<= 33MHz

pins 1 & 2 closed

> 33MHz

pins 2 & 3 closed