PC BRAND

486/25C CACHE MAINBOARD

(MYSTERY MACHINE)

Processor

80486SX

Processor Speed

25MHz

Chip Set

OPTI

Max. Onboard DRAM

16MB

Cache

128KB (on external cache card)

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

External cache card

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Turbo switch

J9

Power LED & keylock

J6

Turbo LED

J10

Speaker

J7

External cache slot

SL1

Reset switch

J8

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Battery type select internal

J1

pins 2 & 3 closed

 

Battery type select external

J1

Closed

»

Monitor type select monochrome

J2

Open

 

Monitor type select color

J2

Closed

»

Factory configured - do not alter

J3

N/A

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(4) 256K x 9

NONE

NONE

NONE

2MB

(4) 256K x 9

(4) 256K x 9

NONE

NONE

3MB

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

NONE

4MB

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

4MB

(4) 1M x 9

NONE

NONE

NONE

5MB

(4) 256K x 9

(4) 1M x 9

NONE

NONE

5MB

(4) 1M x 9

(4) 256K x 9

NONE

NONE

6MB

(4) 256K x 9

(4) 256K x 9

(4) 1M x 9

NONE

6MB

(4) 256K x 9

(4) 1M x 9

(4) 256K x 9

NONE

6MB

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

NONE

7MB

(4) 256K x 9

(4) 256K x 9

(4) 1M x 9

(4) 256K x 9

7MB

(4) 256K x 9

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

7MB

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

NONE

NONE

9MB

(4) 256K x 9

(4) 1M x 9

(4) 1M x 9

NONE

9MB

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

NONE

9MB

(4) 1M x 9

(4) 256K x 9

(4) 1M x 9

NONE

10MB

(4) 256K x 9

(4) 256K x 9

(4) 1M x 9

(4) 1M x 9

10MB

(4) 256K x 9

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

10MB

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

(4) 256K x 9

10MB

(4) 1M x 9

(4) 256K x 9

(4) 1M x 9

(4) 256K x 9

12MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

NONE

13MB

(4) 256K x 9

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

13MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

(4) 256K x 9

13MB

(4) 1M x 9

(4) 256K x 9

(4) 1M x 9

(4) 1M x 9

16MB

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

(4) 1M x 9

CACHE CONFIGURATION

Size

SL1

128KB

Card installed

CACHE JUMPER CONFIGURATION

Setting

J4

J5

Cache mode

pins 1 & 2 closed

pins 1 & 2 closed

Burst mode

pins 2 & 3 closed

pins 2 & 3 closed