MYLEX CORPORATION

MSI/MDI486 System Board

Processor

80486SX/80487SX/80486DX

Processor Speed

20/25/33MHz

Chip Set

OPTI

Max. Onboard DRAM

32MB

Cache

64/256KB

BIOS

Mylex

Dimensions

330mm x 218mm

I/O Options

Floppy drive interface, IDE interface, parallel port, serial ports (2)

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

BAT

Turbo LED

JP3

Serial port 2

COM2

Reset switch

JP4

Serial port 1

COM1

Speaker

JP5

Floppy drive interface

FDD

IDE interface LED

JP6

IDE interface

IDE

Parallel port

LPT

Power LED & keylock

JP2

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select color

JP1

Closed

 

Monitor type select monochrome

JP1

Open

»

Parallel port select LPT1 interrupt IRQ7

JP19

pins 2 & 3 closed

 

Parallel port select LPT2 interrupt IRQ5

JP19

pins 1 & 2 closed

»

On-board interface ports enabled

JP20

pins 1 & 2 closed

 

On-board interface ports disabled

JP20

pins 2 & 3 closed

»

Battery type select internal

JP21

pins 2 & 3 closed

 

Battery type select external

JP21

Open

 

CMOS memory clear

JP21

pins 1 & 2 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

5MB

(4) 1M x 9

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

17MB

(4) 4M x 9

(4) 256K x 9

20MB

(4) 4M x 9

(4) 1M x 9

32MB

(4) 4M x 9

(4) 4M x 9

CACHE CONFIGURATION

Size

Bank 0

TAG (U19)

TAG (U20)

64KB

(8) 8K x 8

(1) 8K x 8

(1) 64K x 1

256KB

(8) 32K x 8

(1) 32K x 8

(1) 64K x 1

CACHE JUMPER CONFIGURATION

Size

JP7

JP11

JP12

JP13

64KB

Open

Open

Open

Open

256KB

Closed

Closed

Open

Closed

CPU TYPE CONFIGURATION

Type

JP8

JP9

JP10

80486SX

Open

pins 2 & 3 closed

Open

80487SX

pins 2 & 3 closed

pins 1 & 2 closed

Closed

80486DX

pins 1 & 2 closed

pins 1 & 2 closed

Closed

CPU SPEED CONFIGURATION

Speed

JP14

JP15

JP16

JP17

20MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

25MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

33MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed