Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

20/25/33/50(internal)/50/66(internal)MHz

Chip Set

OPTI

Max. Onboard DRAM

128MB

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

32-bit local bus card

COM1

Turbo switch

J11

32-bit local bus card

COM2

Speaker

J12

Reset switch

J9

Power LED & keylock

J13

Turbo LED

J10

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select monochrome

JP1

Open

Monitor type select color

JP1

Closed

»

Factory configured - do not alter

JP2

pins 2 & 3 closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

4MB

(4) 1M x 9

NONE

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

20MB

(4) 1M x 9

(4) 4M x 9

20MB

(4) 4M x 9

(4) 1M x 9

32MB

(4) 4M x 9

(4) 4M x 9

64MB

(4) 16M x 9

NONE

128MB

(4) 16M x 9

(4) 16M x 9

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG (U39)

TAG(U42)

Dirty Bit(U43)

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

(1) 16K x 4

(1) 16K x 4

128KB

(4) 32K x 8

NONE

(1) 8K x 8

(1) 16K x 4

(1) 16K x 4

256KB

(4) 32K x 8

(4) 32K x 8

(1) 8K x 8

(1) 16K x 4

(1) 16K x 4

Note:256KB configuration requires the addition of (1) 8K x 8 tag chip at (U38).

CACHE JUMPER CONFIGURATION

Size

JP4

JP5

JP6

JP7

JP8

64KB

Open

Open

Open

Open

pins 2 & 3 closed

128KB

Open

Closed

Open

Closed

pins 1 & 2 closed

256KB

Closed

Closed

Closed

Closed

pins 2 & 3 closed

CPU TYPE CONFIGURATION

Type

JP15

JP17

80486SX

pins 1 & 2 closed

pins 1 & 2, 3 & 4 closed

80487SX

pins 2 & 3 closed

pins 1 & 2, 3 & 4 closed

80486DX

Open

pins 2 & 3 closed

80486DX2

Open

pins 2 & 3 closed

CPU SPEED CONFIGURATION

Speed

JP9

JP12

JP11

JP13

JP14

JP16

80486SX-20

2 & 3

2 & 3

1 & 2

2 & 3

Open

Open

80486SX-25

1 & 2

1 & 2

1 & 2

2 & 3

Open

Open

80486DX-25

1 & 2

1 & 2

1 & 2

2 & 3

Open

Open

80486DX-33

1 & 2

1 & 2

2 & 3

2 & 3

Open

Closed

80486DX-50

1 & 2

1 & 2

1 & 2

1 & 2

Closed

Closed

80486DX2-50

1 & 2

1 & 2

1 & 2

2 & 3

Open

Open

Note: Oscillator speed remains synchronous with the CPU, except when using an 80486DX2-50, the oscillator should be 25MHz. Pins designated should be in the closed position.