
AST RESEARCH, INC.

PREMIUM II 386SX/20 (MH ver. 2)

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)
SRAM 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)

[Image]

                                CONNECTIONS

  Purpose                    Location   Purpose                  Location

  SVGA port                    CN1      Front panel switches       P5
                                        & LEDs

  Bus mouse port               CN2      Speaker                    P6

  Serial port 1 (COM1)         CN3      External battery           P8

  Parallel port                CN4      IDE interface              P11

  Serial port 2 (COM2)         J15      Fan power                 P101

  VGA pass-through             J18      16-bit external            S1
                                        CPU/Memory module

  Floppy drive interface       P3       16-bit external            S2
                                        Memory module slot

  Third floppy drive           P4       16-bit external            S3
  interface                             Memory module slot

                        USER CONFIGURABLE SETTINGS

                 Function                    Switch SW1       Position

     VGA port enabled                        switch 1         closed

      VGA port disabled                       switch 1          open

     Password check enabled                  switch 2          open

      Password check disabled                 switch 2         closed

     Factory configured - do not alter       switch 3          open

     Factory configured - do not alter       switch 4          open

     Factory configured - do not alter       switch 5         closed

     Factory configured - do not alter       switch 6         closed

     Monitor type select PS/2 style          switch 7         closed

      Monitor type select AT style            switch 7          open

     Monitor type select VGA or              switch 8          open
      fixed-frequency

      Monitor type select multi-frequency     switch 8         closed

[Image]

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Parity check enabled                     E1             closed

      Parity check disabled                    E1              open

  Note:AST CPU/Memory module part number is 202438-001 or 202438-002.

                            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 are 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.

