UNITRON COMPUTER, INC.

486SX SYSTEM

Processor

80486SX/80486DX

Processor Speed

25/33MHz

Chip Set

UMC

Max. Onboard DRAM

32MB

SRAM Cache

32/128KB

BIOS

Phoenix

Dimensions

346mm x 218mm

I/O Options

Floppy drive interface, game port, IDE interface, modem interface, parallel port, serial port (2), VGA port

NPU Options

4167 (location unverified)

CONNECTIONS

Purpose

Location

Purpose

Location

Game port

C1

IDE interface

J22

VGA port

C2

Modem interface

J23

Parallel port

C3

Turbo LED

J26

Serial port 2

C4

Power LED

J28

Serial port 1

C5

Floppy drive interface

J31

Fan power

J3

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Serial port 1 (CN5) enabled

J18

pins 1 & 2 closed

 

Serial port 1 (CN5) disabled

J18

pins 2 & 3 closed

»

Serial port 1 (CN5) select COM1 (I/O address 3F8-3FFh)

J19

pins 1 & 2 closed

 

Serial port 1 (CN5) select COM3 (I/O address 3E8-3EFh)

J19

pins 2 & 3 closed

»

Parallel port (C3) select LPT1 interrupt IRQ7 at 378-37F

J20

pins 1 & 2 closed

 

Parallel port (C3) select LPT2 interrupt IRQ5 at 278-27F

J20

pins 2 & 3 closed

»

Parallel port (CN3) enabled

J21

pins 1 & 2 closed

 

Parallel port (CN3) disabled

J21

pins 2 & 3 closed

»

IDE interface (J22) enabled

J25

pins 1 & 2 closed

 

IDE interface (J22) disabled

J25

pins 2 & 3 closed

»

Floppy drive interface (J31) enabled

J27

pins 1 & 2 closed

 

Floppy drive interface (J31) disabled

J27

pins 2 & 3 closed

»

Serial port 2 (CN4) select COM2 (I/O address 2F8-2FFh)

J29

pins 1 & 2 closed

 

Serial port 2 (CN4) select COM4 (I/O address 2E8-2EFh)

J29

pins 2 & 3 closed

»

Serial port 2 (CN4) enabled

J30

pins 1 & 2 closed

 

Serial port 2 (CN4) disabled

J30

pins 2 & 3 closed

DRAM CONFIGURATION

Size

Bank 0

Bank 1

1MB

(1) 256K x 36

NONE

2MB

(1) 256K x 36

(1) 256K x 36

3MB

(1) 512K x 36

(1) 256K x 36

4MB

(1) 1M x 36

NONE

5MB

(1) 256K x 36

(1) 1M x 36

8MB

(1) 1M x 36

(1) 1M x 36

12MB

(1) 2M x 36

(1) 1M x 36

16MB

(1) 2M x 36

(1) 2M x 36

32MB

(1) 4M x 36

(1) 4M x 36

CPU TYPE CONFIGURATION

CPU

JP1

JP2

80486DX

pins 1 & 2 closed

pins 1 & 2 and 3 & 4 closed

80486SX

open

pins 2 & 3 closed

Note:The location of jumpers JP1 and JP2 is unknown.

SRAM JUMPER CONFIGURATION

Size

J7

J10

J11

J13

J14

32KB

open

pins 1 & 2

pins 1 & 2

pins 1 & 2

pins 1 & 2

128KB

closed

pins 2 & 3

pins 2 & 3

pins 2 & 3

pins 2 & 3

Note:Pins designated should be in the closed postion.

SRAM CONFIGURATION

Size

Cache SRAM

Location

TAG

32KB

(4) 8K x 8

CACHE

(1) 8K x 8

128KB

(4) 32K x 8

CACHE

(1) 32K x 8

Note:This configuartion is unverified.

VRAM CONFIGURATION

Size

VRAM

Location

256KB

(2) 44256

Bank 0

512KB

(4) 44256

Banks 0 & 1

1MB

(8) 44256

Banks 0, 1, 2 and 3