MICRONICS COMPUTERS, INC.

MINI 486 SYSTEM BOARD

Processor

80486SX/80486DX/ODP486SX/80486DX2

Processor Speed

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

Chip Set

Micronics

Max. Onboard DRAM

64MB

Cache

64/128/256KB

BIOS

Phoenix

Dimensions

230mm x 218mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External keyboard connector

J1

Turbo switch

W16

Speaker

J20

Turbo LED

W17

Reset switch

W15

Power LED & keylock

W18

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Monitor type select color

W2

Closed

 

Monitor type select monochrome

W2

Open

»

Real Time Clock enabled

W3

pins 1 & 2 closed

 

External battery enabled

W3

pins 2 & 3 closed

»

Factory configured - do not alter

W43

pins 1 & 2 closed

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 9

(1) 4M x 36

NONE

64MB

(1) 4M x 36

(1) 4M x 9

(1) 4M x 36

(1) 4M x 36

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG/U41

TAG/U42

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

N/A

128KB

(4) 32K x 8

NONE

(1) 32K x 8

N/A

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

N/A

Note:Tag/U42 is not currently in use.

CACHE JUMPER CONFIGURATION

Size

W5

W6

W7

W8

W9

W10

W11

W12

W13

64KB

2 & 3

1 & 2

1 & 2

2 & 3

1 & 2

1 & 2

1 & 2

2 & 3

2 & 3

128KB

2 & 3

2 & 3

1 & 2

2 & 3

2 & 3

1 & 2

2 & 3

1 & 2

1 & 2

256KB

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

Note:Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

Type

W14

W19

80486SX

N/A

pins 1 & 2 closed

80486DX

pins 2 & 3 closed

pins 2 & 3 closed

ODP486SX

pins 1 & 2 closed

pins 2 & 3 closed

80486DX2

pins 2 & 3 closed

pins 2 & 3 closed

CPU SPEED CONFIGURATION

Speed

W21

W22

25MHz

pins 2 & 3 closed

pins 2 & 3 closed

33MHz

pins 1 & 2 closed

pins 2 & 3 closed

50i MHz

pins 2 & 3 closed

pins 2 & 3 closed

50MHz

pins 1 & 2 closed

pins 1 & 2 closed

66i MHz

pins 1 & 2 closed

pins 2 & 3 closed