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486U

AUSTIN COMPUTER SYSTEMS

486U

Processor

80486SX/80487SX/80486DX/80486DX2

Processor Speed

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

Chip Set

OPTI

Max. Onboard DRAM

32MB

Cache

64/256KB

BIOS

Mylex

Dimensions

330mm x 218mm

I/O Options

Floppy drive interface, IDE interface, parallel port, serial ports (2)

NPU Options

4167

CONNECTIONS

Purpose

Location

Purpose

Location

Parallel port

J1

Turbo LED

JP3

Serial port COM 2

J2

Reset switch

JP4

Serial port COM 1

J3

Speaker

JP5

Floppy controller

J4

IDE interface LED

JP6

IDE interface

J5

External battery

JP22

Power LED & keylock

JP2

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

Monitor type select monochrome

JP1

open

 

Monitor type select color

JP1

closed

Parallel port IRQ select IRQ7

JP19

pins 2 & 3 closed

 

Parallel port IRQ select IRQ5

JP19

pins 1 & 2 closed

CMOS memory normal operation

JP21

pins 2 & 3 closed

 

CMOS memory clear

JP21

pins 1 & 2 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

5MB

(4) 1M x 9

(4) 256K x 9

8MB

(4) 1M x 9

(4) 1M x 9

16MB

(4) 4M x 9

NONE

32MB

(4) 4M x 9

(4) 4M x 9

CACHE CONFIGURATION

Size

Bank 0

TAG (U1)

TAG (U2)

64KB

(8) 8K x 8

(1) 64K x 1

(1) 8K x 8

256KB

(8) 32K x 8

(1) 64K x 1

(1) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP7

JP11

JP12

JP13

64KB

Open

Open

Open

Open

256KB

Closed

Closed

Open

Closed

CPU TYPE CONFIGURATION

Type

JP8

JP9

JP10

80486SX

Open

pins 2 & 3 closed

Open

80487SX

pins 2 & 3 closed

pins 1 & 2 closed

Closed

80486DX

pins 1 & 2 closed

pins 1 & 2 closed

Closed

80486DX2

pins 1 & 2 closed

pins 1 & 2 closed

Closed

CPU SPEED CONFIGURATION

Speed

JP14

JP15

JP16

JP17

JP18

20MHz

2 & 3

1 & 2

2 & 3

1 & 2

Open

25MHz

2 & 3

2 & 3

1 & 2

2 & 3

Open

33MHz

2 & 3

1 & 2

1 & 2

2 & 3

Open

50MHz

1 & 2

2 & 3

1 & 2

2 & 3

Closed

50iMHz

2 & 3

2 & 3

1 & 2

2 & 3

Open

66iMHz

2 & 3

1 & 2

1 & 2

2 & 3

Open

Note: Pins designated should be in the closed position.

ON BOARD I/O CONFIGURATION

Setting

JP20

Serial port 1, serial port 2, parallel port, floppy drive interface enabled

pins 1 & 2 closed

Serial port 1, serial port 2, parallel port, floppy drive interface disabled

pins 2 & 3 closed