UNIDENTIFIED

STC-SIS486C-DX/SX

Processor

80486SX/80487SX/80486DX

Processor Speed

20/25/33/50MHz

Chip Set

SIS

Max. onboard DRAM

32MB

Cache

32/64/128/256KB

BIOS

AMI

Dimensions

218mm x 218mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Turbo LED

J6

Power LED & keylock

J3

Turbo switch

J7

Speaker

J4

Reset switch

J8

Unknown

J5

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CMOS memory normal operation (internal battery)

J1

pins 2 & 3 closed

 

CMOS memory normal operation (external battery)

J1

pins 1 & 4 closed

 

CMOS memory clear

J1

Open

»

Monitor type select color

J2

Closed

 

Monitor type select monochrome

J2

Open

»

CPU speed select iOSC/1

J9

pins 1 & 2 closed

 

CPU speed select iOSC/2

J9

pins 2 & 3 closed

»

Turbo switch enabled

J10

Closed

 

Turbo switch disabled

J10

Open

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

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

20MB

(4) 1M x 9

(4) 4M x 9

32MB

(4) 4M x 9

(4) 4M x 9

CACHE CONFIGURATION

Size

Bank 0 (U26 - 29)

Bank 1 (U22 - U25)

Tag

Dirty Bit

32KB

(4) 8K x 8

NONE

8K x 8

16K x 4

64KB

(4) 8K x 8

(4) 8K x 8

8K x 8

16K x 4

128KB

(4) 32K x 8

NONE

32K x 8

16K x 4

256KB

(4) 32K x 8

(4) 32K x 8

32K x 8

16K x 4

CACHE JUMPER CONFIGURATION

Size

J11

J12

J13

J14

J15

J16

J17

J18

J19

32KB

1 & 2

Open

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

64KB

2 & 3

Open

1 & 2

2 & 3

1 & 2

1 & 2

2 & 3

1 & 2

1 & 2

128KB

1 & 2

1 & 2

2 & 3

2 & 3

2 & 3

1 & 2

2 & 3

2 & 3

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

J20

J21

J22

80486SX

Closed

pins 1 & 2 closed

pins 1 & 2 closed

80487SX

Closed

pins 1 & 2 closed

pins 2 & 3 closed

80486DX

Open

pins 2 & 3 closed

Open