MICRO EXPRESS, INC.

FOREX 486 VESA (Rev. VL 421A/422)

Processor

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

Processor Speed

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

Chip Set

FOREX

Max. Onboard DRAM

32MB

SRAM Cache

64/128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA card slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

JP2

Turbo switch

JP15

Reset switch

JP3

Turbo LED

JP16

Power LED & keylock

JP9

32-bit VESA local bus slots

S1 & S2

Speaker

JP10

 

 

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Battery select internal

JP2

pins 1 & 2 closed

 

Battery select external

JP2

connected

»

Factory configured - do not alter

JP5

closed

»

CMOS memory normal operation

JP6

open

 

CMOS memory clear

JP6

closed

 

VESA bus select zero wait states £ 33MHz

JP102

pins 1 & 2 closed

 

VESA bus select one wait state > 33MHz

JP102

pins 2 & 3 closed

 

VESA bus speed select £ 33MHz

JP103

pins 1 & 2 closed

 

VESA bus speed select > 33MHz

JP103

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

5MB

(4) 256K x 9

(4) 1M x 9

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

CPU SPEED CONFIGURATION

CPU speed

JP7A

JP7B

JP7C

50MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

33MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

25MHz

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

20MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

CPU TYPE CONFIGURATION

CPU Type

JP12

JP13

JP29

JP30

80486DX2

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

ODP486SX

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

80486DX

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

80487SX

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

pins 2 & 3 closed

80486SX

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

SRAM CONFIGURATION

Size

Cache SRAM

Location

TAG

JP8A & D

JP8B & E

64KB

(8) 8K x 8

Banks 0 & 1

(1) 8K x 8

pins 2 & 3

pins 2 & 3

128KB

(4) 32K x 8

Bank 0

(1) 8K x 8

pins 1 & 2

pins 1 & 2

256KB

(8) 32K x 8

Banks 0 & 1

(1) 32K x 8

pins 2 & 3

pins 1 & 2

Note: Pins designated should be in the closed position.