Processor

80486SX/80486DX/80486DX2/Pentium Overdrive

Processor Speed

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

Chip Set

OPTI

Max. Onboard DRAM

128MB

Cache

64/128/256/512KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Power LED & keylock

J1

Turbo switch

J4

Reset switch

J2

Turbo LED

J5

Speaker

J3

32-bit VESA Local bus slots

SL1 & SL2

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CPU type select 80486DX/P24T

J6

pins 1 & 2 closed

CPU type select 80486SX

J6

pins 2 & 3 closed

»

Monitor type select color

J14

Closed

Monitor type select monochrome

J14

Open

»

CMOS memory normal operation

J17

Open

CMOS memory clear

J17

Closed

»

Factory configured - do not alter

J18

pins 2 & 3 closed

»

Factory configured - do not alter

J23

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

64MB

(4) 16M x 9

NONE

128MB

(4) 16M x 9

(4) 16M 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) 32K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

512KB

(1) 128K x 8

NONE

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

J8

J9

J10

J11

64KB

Open

Open

Open

N/A

128KB

Open

Closed

Open

pins 1 & 2 closed

256KB

Open

Closed

Closed

pins 2 & 3 closed

512KB

Closed

Closed

Closed

pins 1 & 2 closed

CPU SPEED CONFIGURATION

Speed

JC0

JC1

JC2

25MHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

33MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

40MHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 1 & 2 closed

50iMHz

pins 2 & 3 closed

pins 1 & 2 closed

pins 1 & 2 closed

50MHz

pins 1 & 2 closed

pins 1 & 2 closed

pins 2 & 3 closed

66iMHz

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed

VESA WAIT STATE/BUS SPEEDCONFIGURATION

CPU speed

Wait states

J31

J32

£ 33MHz

0 wait states

Open

Open

> 33MHz

1 wait state

Closed

Closed