Processor

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

Processor Speed

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

Chip Set

FOREX

Max. Onboard DRAM

64MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

230mm x 218mm

I/O Options

32-bit VESA local bus slots (3)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Turbo LED

J6

Reset switch

J10

Speaker

J7

External battery

JP1

Turbo switch

J8

32-bit VESA Local bus slots

SL1

Power LED & keylock

J9

32-bit VESA Local bus slots

SL2 & SL3

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CPU type select - 486DX/DX2/P24T (PGA)

JP2

pins 1 & 2 closed

CPU type select - 486SX/DX (PQFP) & 487SX/P23T (PGA)

JP2

pins 2 & 3 closed

»

CPU type select -PGA

JP3 & JP4

pins 1 & 2 closed

CPU type select -PQFP

JP3 & JP4

pins 2 & 3 closed

»

PFPQ disabled

JP5

Closed

PFPQ enabled

JP5

Open

»

CMOS memory normal operation

JP6

Open

CMOS memory clear

JP6

Closed

»

Factory configured - do not alter

JP9

Open

»

CPU type select - 486CPU

JP12

pins 1 & 2 closed

CPU type select - P24T CPU

JP12

pins 2 & 3 closed

»

Factory configured - do not alter

JP13

Open

»

Factory configured - do not alter

JP14

Open

»

Factory configured - do not alter

JP15

Open

»

Factory configured - do not alter

JP16

Open

»

Cyrix CPU type select - CX486DX

JP20

Open

Cyrix CPU type select - CX486DX2

JP20

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

64MB

(4) 16M x 9

NONE

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

Note: Bank 0 = U31, U32, U33, U34 Bank 1 = U27, U28, U29, U30

CACHE JUMPER CONFIGURATION

Size

JP8A

JP8B

JP8C

64KB

pins 2 & 3 closed

pins 1 & 2 closed

pins 2 & 3 closed

128KB

pins 1 & 2 closed

pins 2 & 3 closed

pins 1 & 2 closed

256KB

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

CLOCK SPEED CONFIGURATION

Speed

JP7A

JP7B

JP7C

20MHz

Open

Closed

Closed

25MHz

Closed

Open

Open

33MHz

Open

Open

Open

40MHz

Closed

Closed

Open

50MHz

Open

Closed

Open

50iMHz

Closed

Open

Open

66iMHz

Open

Open

Open

VESA WAIT STATE/BUS SPEED CONFIGURATION

CPU speed

Wait states

JP10

JP11

< 33MHz

0 wait states

pins 1 & 2 closed

pins 1 & 2 closed

> 33MHz

1 wait state

pins 2 & 3 closed

pins 2 & 3 closed