Processor

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

Processor Speed

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

Chip Set

Micronics

Max. Onboard DRAM

64MB

Cache

64/128/256/512KB

BIOS

Phoenix

Dimensions

355mm x 304mm

I/O Options

parallel port, serial ports (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

Hard drive LED

CN1

Parallel port

J30

External battery

J3

Floppy drive interface

J31

Turbo switch

J4

IDE interface

J32

Turbo LED

J5

Serial port 1

J33

Power LED & keylock

J8

Serial port 2

J34

Speaker

J10

32-bit VESA Local bus slot

S1

Reset switch

J11

32-bit VESA Local bus slot

S2

External keyboard connector

J13

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Factory configured - do not alter

W1

pins 1 & 2 closed

»

Monitor type select color

W7

Closed

Monitor type select monochrome

W7

Open

»

AT style keyboard

W16

Open

PS/2 style keyboard

W16

Closed

»

CMOS memory normal operation

W17

pins 1 & 2 closed

CMOS memory clear

W17

pins 2 & 3 closed

»

Real Time Clock memory normal operation

W18

Open

Real Time Clock memory clear

W18

Closed

Note: W18 may not appear on the system mainboard, depending upon the clock chip installed. If W18 is present, use it instead of W17. The location of W18 is unknown.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

4MB

(1) 1M x 36

NONE

NONE

NONE

8MB

(1) 1M x 36

(1) 1M x 36

NONE

NONE

12MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

NONE

16MB

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

(1) 1M x 36

16MB

(1) 4M x 36

NONE

NONE

NONE

20MB

(1) 1M x 36

(1) 4M x 36

NONE

NONE

24MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

NONE

32MB

(1) 4M x 36

(1) 4M x 36

NONE

NONE

36MB

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

NONE

40MB

(1) 1M x 36

(1) 1M x 36

(1) 4M x 36

(1) 4M x 36

48MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

NONE

64MB

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

(1) 4M x 36

CACHE CONFIGURATION

Size

Bank 0

Bank 1

TAG/U42

TAG/U43

TAG/U44

TAG/U45

64KB

(4) 8K x 8

(4) 8K x 8

NONE

NONE

(1) 64K x 8

(1) 8K x 8

128KB

(4) 32K x 8

NONE

NONE

NONE

(1) 64K x 8

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 16K x1

(1) 16K x1

(1) 64K x 8

NONE

512KB

(4) 128K x 8

NONE

NONE

NONE

(1) 64K x 8

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

W8

W9

W10

W11

W12

W13

W14

W15

64KB

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

1 & 2

3 & 4

2 & 3

128KB

2 & 3

1 & 2

1 & 2

2 & 3

1 & 2

1 & 2

4 & 5

1 & 2

256KB

2 & 3

2 & 3

1 & 2

2 & 3

2 & 3

1 & 2

1 & 2

1 & 2

512KB

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

2 & 3

4 & 5

1 & 2

Note:Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

U1

U2

W2

W5

W6

None

80486SX (PQFP)

pins 1 & 2

pins 1 & 2

None

80486SX

None

pins 1 & 2

pins 2 & 3

pins 2 & 3

80487SX

80486SX (PQFP)

pins 1 & 2

pins 2 & 3

pins 1 & 2, 3 & 4

80487SX

None

pins 1 & 2

pins 2 & 3

pins 1 & 2, 3 & 4

80486DX

80486SX (PQFP)

pins 2 & 3

pins 1 & 2

pins 1 & 2, 3 & 4

80486DX

None

pins 2 & 3

pins 1 & 2

pins 1 & 2, 3 & 4

80486DX2

80486SX (PQFP)

pins 1 & 2

pins 2 & 3

pins 1 & 2, 3 & 4

80486DX2

None

pins 1 & 2

pins 1 & 2

pins 1 & 2, 3 & 4

Pentium Overdrive

None

pins 2 & 3

pins 2 & 3

pins 1 & 2, 3 & 4

Note:Pins designated should be in the closed position.

CPU SPEED CONFIGURATION

CPU

Speed

W3

80486SX/80486DX

25MHz

On

80486SX/80486DX

33MHz

Off

80486DX2

50i MHz

On

80486DX2

66i MHz

Off