FOREX COMPUTER CORPORATION

FOREX 486 REV. VL2

Processor

80486SX/80487SX/80486DX/80486DX2/Pentium Overdrive

Processor Speed

20/25/33/40/50(internal)/50/66(internal)MHz

Chip Set

Forex

Max. Onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

254mm x 220mm

I/O Options

32-bit VESA local bus slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Turbo LED

J5

Reset switch

J9

Speaker

J6

External battery

JP1

Turbo switch

J7

32-bit local bus slots

SL1 & SL2

Power LED & keylock

J8

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CMOS memory normal operation

JP6

Open

 

CMOS memory clear

JP6

Closed

»

Factory configured - do not alter

JP9

Open

»

CPU type select 80486

JP12

pins 1 & 2 closed

 

CPU type select Pentium Overdrive

JP12

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

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) 16K/32K x 8

CACHE JUMPER CONFIGURATION

Size

JP8A

JP8B

JP8C

64KB

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

128KB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

256KB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

CPU TYPE CONFIGURATION

Type

JP2

JP3

JP4

JP5

80486SX

pins 2 & 3 closed

Open

Open

pins 2 & 3 closed

80486SX/DX PQFP

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

80487SX

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

80486DX/DX2

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

Pentium Overdrive

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

CPU SPEED CONFIGURATION

Speed

JP7A

JP7B

JP7C

20MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

25MHz

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

33MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

40MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 1 & 2 closed

50iMHz

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

50MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

66iMHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

VESA WAIT STATE CONFIGURATION

Wait states

JP10

0 wait states

pins 1 & 2 closed

1 wait state

pins 2 & 3 closed

BUS SPEED CONFIGURATION

CPU speed

JP11

<= 33MHz

pins 1 & 2 closed

> 33MHz

pins 2 & 3 closed