EFA CORPORATION

4M50HL2S

Processor

80486SX/80486DX/80486DX2/Pentium Overdrive

Processor Speed

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

Chip Set

UMC

Max. Onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

330mm x 218mm

I/O Options

32-bit VESA local bus slots (2)

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Reset switch

J10

Turbo LED

J7

32-bit VESA Local bus slot

S1

Speaker

J8

32-bit VESA Local bus slot

S2

Power LED & keylock

J9

 

 

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Factory configured - do not alter

J3

N/A

»

Speed set Turbo

J11

Open

 

Speed normal

J11

Closed

»

CPU type package PGA

J12

pins 2 & 3 closed

 

CPU type package PQFP

J12

pins 1 & 2 closed

»

Factory configured - do not alter

J13

pins 2 & 3 closed

»

Western Digital HDD WDAC2340 installed

J17

pins 2 & 3 closed

 

Western Digital HDD WDAC2340 not installed

J17

pins 1 & 2 closed

»

CMOS memory normal operation

W1

pins 1 & 2 closed

 

CMOS memory clear

W1

pins 2 & 3 closed

»

On board battery enabled

W2

Closed

 

On board battery disabled

W2

Open

Note:The exact location of W2 is unknown.

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

8K x 8

128KB

(4) 32K x 8

NONE

8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

32K x 8

CACHE JUMPER CONFIGURATION

Size

W4

W5

W6

W7

W8

W9

W10

W11

64KB

1 & 2

1 & 2

1 & 2

Open

Open

Open

Open

Open

128KB

2 & 3

1 & 2

2 & 3

1 & 2

Open

Closed

Open

Closed

256KB

2 & 3

2 & 3

1 & 2

2 & 3

Closed

Closed

Closed

Closed

Note:Pins designated should be in the closed position.

CPU TYPE CONFIGURATION

Type

SW3/1

SW3/2

SW3/3

SW3/4

SW3/5

SW3/6

80486SX/20

Off

Off

Off

On

On

Off

80486SX/25

Off

Off

Off

Off

On

Off

80486SX/33

Off

Off

Off

Off

On

Off

80486DX

Off

On

On

Off

Off

Off

Pentium Overdrive

Off

On

On

Off

Off

Off

CPU TYPE CONFIGURATION

Type

J6

J13

J14

J15

JP1

JP3

80486SX

pins 2 & 3

pins 2 & 3

pins 1 & 2

pins 2 & 3

pins 1 & 2

pins 2 & 3

80486DX

pins 2 & 3

pins 2 & 3

pins 1 & 2

pins 2 & 3

pins 1 & 2

pins 2 & 3

80486DX2

pins 2 & 3

pins 2 & 3

pins 1 & 2

pins 2 & 3

pins 1 & 2

pins 2 & 3

ODP486SX

pins 2 & 3

pins 2 & 3

pins 1 & 2

pins 2 & 3

pins 1 & 2

pins 2 & 3

Note:Pins designated should be in the closed position.

CPU SPEED CONFIGURATION

Speed

SW1/1

SW1/2

SW1/3

SW1/4

20MHz

Off

Off

On

Off

25MHz

On

On

Off

On

33MHz

On

Off

On

On

40MHz

Off

Off

On

Off

50i MHz

On

On

Off

On

50MHz

Off

Off

Off

Off

66i MHz

On

Off

On

On

VESA WAIT STATE/BUS SPEED CONFIGURATION

CPU speed

Wait states

J4

J5

J16

£ 33MHz

0 wait states

pins 1 & 2 closed

pins 1 & 2 closed

pins 1 & 2 closed

> 33MHz

1 wait state

pins 2 & 3 closed

pins 2 & 3 closed

pins 2 & 3 closed