J-MARK COMPUTER CORPORATION

JET-486

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

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

Chip Set

OPTI

Max. Onboard DRAM

32MB

Cache

64/128/256KB

BIOS

AMI/Award

Dimensions

220mm x 220mm

I/O Options

None

NPU Options

None

CONNECTIONS

Purpose

Location

Purpose

Location

External battery

J1

Turbo LED

JP11

Speaker

J17

Reset switch

SW1

Power LED & keylock

J18

Turbo switch

SW2

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

CMOS memory normal operation

JP1

pins 2 & 3 closed

 

CMOS memory clear

JP1

pins 1 & 2 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) 1M x 9

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

17MB

(4) 4M x 9

(4) 256K x 9

20MB

(4) 4M x 9

(4) 1M 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

(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

CACHE JUMPER CONFIGURATION

Size

JP3

JP4

JP6

JP7

64KB

pins 2 & 3 closed

Open

Open

Open

128KB

pins 1 & 2 closed

Closed

Closed

Open

256KB

pins 2 & 3 closed

Closed

Closed

Closed

CPU TYPE CONFIGURATION

Type

JP8

JP9

JP10

80486SX

pins 2 & 3 closed

Open

Open

80487SX

pins 1 & 2 closed

Closed

pins 1 & 2 closed

80486DX

pins 1 & 2 closed

Closed

pins 2 & 3 closed

80486DX2

pins 1 & 2 closed

Closed

pins 2 & 3 closed