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486SX/DX VERSION II

J-MARK COMPUTER CORPORATION

486SX/DX VERSION II

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

16/20/25/33/50(internal)/50/66(internal) MHz

Chip Set

OPTI

Max. onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI

Dimensions

240mm x 220mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Speaker

J17

Turbo switch

JP9

Power LED & keylock

J18

Turbo LED

JP10

Reset switch

SW1

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

CMOS memory normal operation

JP1

pins 1 & 2 closed

 

CMOS memory clear

JP1

pins 2 & 3 closed

Monitor type select color

JP2

Closed

 

Monitor type select monochrome

JP2

Open

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 (U39)

TAG (U40)

64KB

(4) 8K x 8

NONE

(1) 8K x 8

NONE

128KB

(4) 32K x 8

NONE

(1) 8K x 8

NONE

256KB

(4) 32K x 8

(4) 32K x 8

(1) 8K x 8

(1) 8K x 8

256KB

(4) 32K x 8

(4) 32K x 8

(1) 32K x 8

NONE

CACHE JUMPER CONFIGURATION

Size

JP5

JP6

JP7

JP8

JP15

JP16

64KB

Open

Open

Open

pins 2 & 3

Open

Open

128KB

Closed

Open

Closed

pins 1 & 2

Open

Closed

256KB

Closed

Closed

Closed

pins 2 & 3

closed

closed

Note:Pins designated should be in the closed postion.

CPU TYPE CONFIGURATION

CPU type

JP17

JP18

JP19

JP20

80486SX PQFP

Open

Open

Closed

pins 2 & 3 closed

80486SX PGA

Closed

Open

Closed

pins 2 & 3 closed

80487SX

Closed

pins 2 & 3 closed

Closed

pins 1 & 2 closed

80486DX/DX2

Closed

pins 1 & 2 closed

Closed

pins 1 & 2 closed

CPU SPEED CONFIGURATION

Speed

JP11

JP12

JP13

JP14

16MHz

Closed

Closed

Closed

Closed

20MHz

Open

Closed

Closed

Open

25MHz

Open

Closed

Open

Closed

33MHz

Open

Open

Closed

Open

50i MHz

Open

Closed

Open

Closed

50MHz

Open

Open

Closed

Open

66i MHz

Open

Open

Closed

Open