CHAINTECH COMPUTER COMPANY, LTD.

420SXB/425SXB/433SCB/450SCB

Processor

80486SX/80487SX/80486DX/ODP486SX/80486DX2

Processor Speed

16/20/25/33/50(internal)/50/66(internal)MHz

Chip Set

SIS

Max. Onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

None

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Speaker

J4

Turbo LED

J2

Power LED & keylock

J5

Turbo switch

J3

Reset switch

J6

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Turbo enabled

J3

Closed

 

Turbo disabled

J3

Open

»

Monitor type select monochrome

J7

Open

 

Monitor type select color

J7

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

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

Bank 1

TAG

64KB

(4) 8K x 8

(4) 8K x 8

(1) 8K x 8

128KB

(4) 32K x 8

NONE

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

RN12

RN15

RN16

RN17

RN18

RN19

64KB

Installed

Installed

Not installed

Not installed

Not installed

Not installed

128KB

Not installed

Not installed

Not installed

Installed

Installed

Not installed

256KB

Not installed

Not installed

Installed

Not installed

Not installed

Installed

CPU TYPE CONFIGURATION

Type

JP7

80486SX

pins 2 & 3 closed

ODP486SX

pins 2 & 3 closed

80487SX

pins 2 & 3 closed

80486DX

pins 1 & 2 closed

80486DX2

pins 1 & 2 closed

CPU SPEED CONFIGURATION

Speed

JP1

16MHz

pins 2 & 3 closed

20MHz

pins 2 & 3 closed

> 25MHz

pins 1 & 2 closed

MISCELLANEOUS TECHNICAL NOTE

Note:If a Weitek coprocessor is desired, the optional daughter board must be installed in CPU socket.