AST RESEARCH, INC.

PREMIUM II 386SX/20 (MH Version 1)

MODELS 202373-001 & 202373-002

Processor

80386SX(on external CPU/Memory module)

Processor Speed

20MHz

Chip Set

AST

Max. Onboard DRAM

None (16MB on external CPU/Memory module)

Cache

None (16KB on external CPU/Memory module)

BIOS

AST

Dimensions

344mm x 250mm

I/O Options

16-bit external CPU/Memory module slot

16-bit external Memory module slot (2)

bus mouse port, floppy drive interface

IDE interface, parallel port, serial port (2), SVGA port

NPU Options

80387SX(on external CPU/Memory module)

CONNECTIONS

Purpose

Location

Purpose

Location

SVGA port

CN1

Front panel switches & LEDs

P5

Bus mouse port

CN2

Speaker

P6

Serial port 1

CN3

External battery

P8

Parallel port

CN4

IDE interface

P11

Serial port 2

J15

Fan power

P101

VGA pass-through

J18

16-bit external CPU/Memory module

S1

Floppy drive interface

P3

16-bit external Memory module slot

S2

Third floppy drive interface

P4

16-bit external Memory module slot

S3

USER CONFIGURABLE SETTINGS

Function

Switch

Position

»

VGA port enabled

SW1/switch 1

Closed

 

VGA port disabled

SW1/switch 1

Open

»

Password check enabled

SW1/switch 2

Open

 

Password check disabled

SW1/switch 2

Closed

»

Factory configured - do not alter

SW1/switch 3

Open

»

Factory configured - do not alter

SW1/switch 4

open

»

Factory configured - do not alter

SW1/switch 5

Closed

»

Factory configured - do not alter

SW1/switch 6

Closed

»

Monitor type select PS/2 style

SW1/switch 7

Closed

 

Monitor type select AT style

SW1/switch 7

Open

»

Monitor type select VGA or fixed-frequency

SW1/switch 8

Open

 

Monitor type select multi-frequency

SW1/switch 8

Closed

USER CONFIGURABLE SETTINGS

Function

Jumper

Position

»

Parity check enabled

E1

Closed

 

Parity check disabled

E1

Open

Note: AST CPU/Memory module part number is 202337-001 or 202337-002.

DRAM CONFIGURATION

Size

Bank 0

Bank 1

Bank 2

Bank 3

1MB

(1) 1M x 9

NONE

NONE

NONE

2MB

(1) 1M x 9

(1) 1M x 9

NONE

NONE

3MB

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

NONE

4MB

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

4MB

(1) 4M x 9

NONE

NONE

NONE

5MB

(1) 1M x 9

(1) 4M x 9

NONE

NONE

6MB

(1) 1M x 9

(1) 1M x 9

(1) 4M x 9

NONE

7MB

(1) 1M x 9

(1) 1M x 9

(1) 1M x 9

(1) 4M x 9

8MB

(1) 4M x 9

(1) 4M x 9

NONE

NONE

9MB

(1) 1M x 9

(1) 4M x 9

(1) 4M x 9

NONE

10MB

(1) 1M x 9

(1) 1M x 9

(1) 4M x 9

(1) 4M x 9

12MB

(1) 4M x 9

(1) 4M x 9

(1) 4M x 9

NONE

13MB

(1) 1M x 9

(1) 4M x 9

(1) 4M x 9

(1) 4M x 9

16MB

(1) 4M x 9

(1) 4M x 9

(1) 4M x 9

(1) 4M x 9

Notes: 16KB of SRAM Cache is on the CPU/Memory module.

128KB of DRAM is reserved for System and VGA BIOS shadowing and cannot be disabled.

Up to two of the following memory boards may be installed in addition to the CPU/Memory module: AST part numbers 202275-004, 202275-006, 202387-001, or 202387-005.