POSITIVE CORPORATION

PERSONAL COMPUTER SYTEMS SYSTEM BOARD

Processor

80386SX/80486SX/80487SX (depends on CPU board installed)

Processor Speed

20/33MHz

Chip Set

Unidentified

Max. Onboard DRAM

32MB

Cache

32/128KB (depends on CPU board installed)

BIOS

Unidentified

Dimensions

254mm x 218mm

I/O Options

Parallel port, serial ports (2), VGA port, VGA feature connector, floppy drive interface, IDE interface, riser slot, CPU slot

NPU Options

80387SX

CONNECTIONS

Purpose

Location

Purpose

Location

VGA port

J2

External battery

J17

Serial port 1

J3

Turbo LED

J25

Serial port 2

J4

IDE interface LED

J26

Parallel port

J5

Auxiliary speaker

J27

VGA feature connector

J7

Reset switch

S1

Floppy drive interface

J11

Riser Card

SL1

IDE interface

J12

CPU slot

SL2

Speaker

J16

   

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

256KB - 640KB memory enabled

J6

pins 1 & 2 closed

 

256KB - 640KB memory disabled

J6

pins 1 & 2 open

»

512KB - 640KB memory enabled

J6

pins 3 & 4 closed

 

512KB - 640KB memory disabled

J6

pins 3 & 4 open

»

Security disabled

J6

pins 5 & 6 closed

 

Security enabled

J6

pins 5 & 6 open

»

VGA mode select PS/2

J10

pins 5 & 6 closed

 

VGA mode select AT

J10

pins 5 & 6 open

»

Monitor timing select any monitor timing

J10

pins 7 & 8 open

 

Monitor timing select Multi Sync 1 timing

J10

pins 7 & 8 closed

»

Factory configured - do not alter

J13

N/A

»

Factory configured - do not alter

J28

N/A

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

512KB

(2) 256K x 9

NONE

NONE

NONE

1MB

(2) 256K x 9

(2) 256K x 9

NONE

NONE

1.5MB

(2) 256K x 9

(2) 256K x 9

(2) 256K x 9

NONE

2MB

(2) 256K x 9

(2) 256K x 9

(2) 256K x 9

(2) 256K x 9

2MB

(2) 1M x 9

NONE

NONE

NONE

2.5MB

(2) 1M x 9

(2) 256K x 9

NONE

NONE

3MB

(2) 256K x 9

(2) 256K x 9

(2) 1M x 9

NONE

3.5MB

(2) 256K x 9

(2) 256K x 9

(2) 1M x 9

(2) 256K x 9

4MB

(2) 1M x 9

(2) 1M x 9

NONE

NONE

4.5MB

(2) 1M x 9

(2) 1M x 9

(2) 256K x 9

NONE

5MB

(2) 1M x 9

(2) 1M x 9

(2) 256K x 9

(2) 256K x 9

6MB

(2) 1M x 9

(2) 1M x 9

(2) 1M x 9

NONE

6.5MB

(2) 1M x 9

(2) 1M x 9

(2) 1M x 9

(2) 256K x 9

8MB

(2) 1M x 9

(2) 1M x 9

(2) 1M x 9

(2) 1M x 9

8MB

(2) 4M x 9

NONE

NONE

NONE

8.5MB

(2) 4M x 9

(2) 256K x 9

NONE

NONE

9MB

(2) 256K x 9

(2) 256K x 9

(2) 4M x 9

NONE

10MB

(2) 4M x 9

(2) 1M x 9

NONE

NONE

DRAM CONFIGURATION (CON’T)

Size

Bank 0

Bank 1

Bank 2

Bank 3

12MB

(2) 4M x 9

(2) 1M x 9

(2) 1M x 9

NONE

14MB

(2) 1M x 9

(2) 1M x 9

(2) 4M x 9

(2) 1M x 9

16MB

(2) 4M x 9

(2) 4M x 9

NONE

NONE

16.5MB

(2) 4M x 9

(2) 4M x 9

(2) 256K x 9

NONE

17MB

(2) 4M x 9

(2) 4M x 9

(2) 256K x 9

(2) 256K x 9

18MB

(2) 4M x 9

(2) 4M x 9

(2) 1M x 9

NONE

20MB

(2) 4M x 9

(2) 4M x 9

(2) 1M x 9

(2) 1M x 9

24MB

(2) 4M x 9

(2) 4M x 9

(2) 4M x 9

NONE

32MB

(2) 4M x 9

(2) 4M x 9

(2) 4M x 9

(2) 4M x 9

VRAM CONFIGURATION

Size

Bank 0

Bank 1

512KB

512KB

NONE

1MB

512KB

512KB

CACHE CONFIGURATION

Size

Bank 0

Bank 1

32KB

(2) 8K x 8

(2) 8K x 8

128KB

(2) 32K x 8

(2) 32K x 8

CACHE JUMPER CONFIGURATION

Size

JP1

32KB

pins 1 & 2 closed

128KB

pins 3 & 4 closed

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Factory configured - do not alter

JP1

N/A

CPU TYPE CONFIGURATION

Type

JP1

JP2

80486SX-20

Open

Closed

80486SX-33

Closed

Open

80487SX-20

Closed

Open