ADVANCED COMPUTER TECHNOLOGY, LTD.

T486SX-20/T486DX-25/T486DX-33

Processor

80486SX/80487SX/80486DX

Processor Speed

20/25/33MHz

Chip Set

ACT

Max. Onboard DRAM

32MB

Cache

None

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & Keylock

JP22

Speaker

JP28

Reset switch

JP24

Turbo switch

JP30

External battery

JP25

Turbo LED

JP31

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

RAM speed select fast (40 to 70ns)

JP4 & JP5

pins 1 & 2 closed

 

RAM speed select slow (80 to 120ns)

JP4 & JP5

pins 2 & 3 closed

»

Video BIOS cacheable

JP7

pins 1 & 2 closed

 

Video BIOS non-cacheable

JP7

pins 2 & 3 closed

»

Factory configured - do not alter

JP11

N/A

»

Monitor type select color

JP23

pins 2 & 3 closed

 

Monitor type select monochrome

JP23

pins 1 & 2 closed

»

Battery select internal

JP26

pins 1 & 2 closed

 

Battery select external

JP26

pins 2 & 3 closed

»

Power good signal detect from power supply

JP27

pins 1 & 2 closed

 

Power good signal detect from board

JP27

pins 2 & 3 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

32MB

(4) 4M x 9

(4) 4M x 9

DRAM JUMPER CONFIGURATION

Size

JP8

JP9

JP10

1MB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

2MB

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

4MB

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

8MB

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

16MB

pins 2 & 3 closed

pins 2 & 3 closed

pins 1 & 2 closed

32MB

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

CPU TYPE CONFIGURATION

Type

JP2

JP3

JP6

JP12

80486SX - 20MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

80486SX - 33MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

80487SX - 20MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

80486DX - 25/33 MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed