ACER, INC.

ISA486GXi MODEL I433A

Processor

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

Processor Speed

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

Chip Set

ALI

Max. Onboard DRAM

32MB

SRAM Cache

64/256KB

BIOS

Acer

Dimensions

220mm x 240mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

JP5

Turbo LED

JP16/12 & 13

Power LED & keylock

JP16/1 - 5

Turbo switch

JP16/15 - 17

Speaker

JP16/7 - 10

Reset switch

JP16/19 & 20

SRAM CONFIGURATION

Size

Cache

TAG

(U36)

JP10

JP11

JP12

64KB

(8) 8K x 8

(1) 8K x 8

(1) 16K x 4

open

pins 2 & 3

pins 1 & 2

64KB

(8) 8K x 8

(1) 8K x 8

NONE

open

pins 1 & 2

pins 2 & 3

256KB

(8) 32K x 8

(1) 32K x 8

(1) 16K x 4

closed

pins 2 & 3

pins 1 & 2

256KB

(8) 32K x 8

(1) 32K x 8

NONE

closed

pins 1 & 2

pins 2 & 3

Note:Pins designated should be in the closed position.

JP10 is closed by shorting pins 1 & 2, 3 & 4, and 5 & 6.

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CMOS memory normal operation

JP6

open

 

CMOS memory clear

JP6

closed

 

System automatically detects CPU type installed

JP7

closed

 

System detects only 486SX/DX CPUs

JP7

open

»

Factory configured - do not alter

JP8

pins 1 & 2 closed

»

Factory configured - do not alter

JP13

pins 1 & 2 closed

»

Factory configured - do not alter

JP17

open

DRAM CONFIGURATION

Size

Bank 0

Bank 1

1MB

(4) 256K x 9

NONE

2MB

(4) 256K x 9

(4) 256K x 9

2MB

(4) 512K x 9

NONE

4MB

(4) 512K x 9

(4) 512K x 9

4MB

(4) 1M x 9

NONE

5MB

(4) 1M x 9

(4) 256K x 9

6MB

(4) 512K x 9

(4) 1M x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

17MB

(4) 256K x 9

(4) 4M x 9

18MB

(4) 512K x 9

(4) 4M x 9

20MB

(4) 1M x 9

(4) 4M x 9

32MB

(4) 4M x 9

(4) 4M x 9

CPU SPEED CONFIGURATION FOR CH9001 SYSTEM CLOCK CHIP

CPU Speed

JP1

JP9

20MHz

pins 1 & 2 closed

pins 2 & 3 closed

25MHz

open

pins 2 & 3 closed

33MHz

pins 3 & 4 closed

pins 2 & 3 closed

40MHz

pins 1 & 2 and 5 & 6 closed

pins 1 & 2 closed

50MHz

pins 5 & 6 closed

pins 1 & 2 closed

CPU SPEED CONFIGURATION FOR IMISC425 SYSTEM CLOCK CHIP

CPU Speed

JP1

JP9

20MHz

pins 1 & 2 and 3 & 4 closed

pins 2 & 3 closed

25MHz

pins 3 & 4 closed

pins 2 & 3 closed

33MHz

pins 1 & 2 closed

pins 2 & 3 closed

40MHz

pins 1 & 2, 3 & 4, and 5 & 6 closed

pins 1 & 2 closed

50MHz

pins 5 & 6 closed

pins 1 & 2 closed