AMERICAN MEGATRENDS, INC.

ENTERPRISE-IV EISA VLB

Processor

80486SX/80487SX/80486DX/ODP486SX/80486DX2/Pentium Overdrive

Processor Speed

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

Chip Set

AMI

Max. Onboard DRAM

256MB

Cache

256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (2), floppy drive interface,

IDE interface, parallel port, serial ports (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Serial port 1

J2

Power LED & keylock

J34

Serial port 2

J3

Turbo switch

J39

Parallel port

J4

Speaker

J40

IDE interface LED

J5

Reset switch

J41

Floppy drive interface

J6

Turbo LED

J42

IDE interface

J9

32-bit VESA Local bus slot

S1

PS/2 mouse

J11

32-bit VESA Local bus slot

S2

USER CONFIGURABLE SETTINGS

Function

Jumper/Switch

Position

»

Factory configured - do not alter

J10

N/A

»

Factory configured - do not alter

J21

N/A

»

CPU low priority

J31

pins 1 & 2 closed

 

CPU high priority

J31

pins 2 & 3 closed

»

Factory configured - do not alter

J38

N/A

»

Factory configured - do not alter

SW1/switch 1

Off

»

Monitor type select monochrome

SW1/switch 2

Off

 

Monitor type select color

SW1/switch 2

On

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

4MB

(1) 1M x 36

None

None

None

6MB

(1) 256K x 36

(1) 256K x 36

(1) 1M x 36

None

8MB

(1) 1M x 36

(1) 1M x 36

None

None

10MB

(1) 256K x 36

(1) 256K 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) 1M x 36

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

16MB

(1) 4M x 36

None

None

None

18MB

(1) 256K x 36

(1) 256K x 36

(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

32MB

(1) 4M x 36

(1) 4M x 36

None

None

36MB

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

None

40MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

48MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

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

128MB

(1) 16M x 36

(1) 16M x 36

None

None

192MB

(1) 16M x 36

(1) 16M x 36

(1) 16M x 36

None

256MB

(1) 16M x 36

(1) 16M x 36

(1) 16M x 36

(1) 16M x 36

CPU SPEED CONFIGURATION

Speed

J12

J13

J14

25MHz

Open

Open

Open

33MHz

Open

Closed

Open

50i MHz

Open

Open

Open

50MHz

Closed

Open

Closed

66i MHz

Open

Closed

Open

CPU TYPE CONFIGURATION

PGA CPU

PQFP CPU

J15

J16

J43

None

80486SX,80486DX

N/A

N/A

Open

ODP486SX, 80487SX, ODP586SX

80486SX,80486DX

1&2, 3&4

pins 2 & 3

Closed

ODP486SX, 80487SX, ODP586SX

None

1&2, 3&4

pins 2 & 3

N/A

80486DX, 80486DX2

None

1&2, 3&4

pins 1 & 2

N/A

80486DX, 80486DX2

80486SX,80486DX

1&2, 3&4

pins 1 & 2

Closed

80486SX

None

pins 2 & 3

N/A

N/A

80486SX

80486SX,80486DX

pins 2 & 3

N/A

Closed

Note:Pins designated should be in the closed position.

SERIAL PORT INTERRUPT SELECTION

Port 1 (J2)

Port 2 (J3)

J22

J23

»

IRQ4

IRQ3

pins 2 & 3 closed

pins 1 & 2 closed

 

IRQ3

IRQ4

pins 1 & 2 closed

pins 2 & 3 closed