
AST RESEARCH, INC.

PREMMIA MS 486

Processor     80486SX/80486DX/ODP486SX/80486DX2/80486DX4/Pentium Overdrive
Processor     25/33/50(internal)/66(internal)MHz
Speed
Chip Set      AST
Max. Onboard  128MB
DRAM
Cache         64/256KB
BIOS          AMI
Dimensions    330mm x 218mm
I/O Options   Floppy drive interface, IDE interfaces (2), parallel port,
              PS/2 mouse port, serial ports (2), VGA port
NPU Options   None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  VGA port                    CN1      External battery            J26

  Parallel port               CN2      Speaker                     J27

  Serial port 2               CN3      Chassis fan power           J28

  Serial port 1               CN4      Front panel connector       J29

  PS/2 mouse port             CN5      Chassis fan power           J32

  IDE interface 2             J22      IDE interface LED           J40

  IDE interface 1             J23      Riser Card                  SL1

  Floppy drive interface      J24

                        USER CONFIGURABLE SETTINGS

              Function                  Jumper/Switch        Position

     Cache type select write back           E1                Open

      Cache type select write                E1               Closed
      through

     Factory configured - do not            E6              pins 1 & 2
      alter                                                   closed

     CMOS memory normal                     E8                Open

      CMOS memory clear                      E8               Closed

     Flash BIOS write protect              SW1/1               Off
      enabled

      Flash BIOS write protect              SW1/1               On
      disabled

     Password enabled                      SW1/2               On

      Password disabled                     SW1/2               Off

     Monitor type select color             SW1/3               On

      Monitor type select                   SW1/3               Off
      monochrome

     System setup enabled                  SW1/4               On

      system setup disabled                 SW1/4               Off

     Factory configured - do not           SW1/5               Off
      alter

     Factory configured - do not           SW1/6               Off
      alter

     Factory configured - do not           SW1/7               Off
      alter

     Factory configured - do not           SW1/8               Off
      alter

                            DRAM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2         Bank 3

     2MB        (1) 256K x     (1) 256K x        NONE           NONE
                    36             36

     3MB        (1) 256K x     (1) 256K x     (1) 256K x        NONE
                    36             36             36

     4MB        (1) 256K x     (1) 256K x     (1) 256K x    (1) 256K x 36
                    36             36             36

     4MB       (1) 1M x 36        NONE           NONE           NONE

     8MB       (1) 1M x 36    (1) 1M x 36        NONE           NONE

     9MB       (1) 1M x 36    (1) 1M x 36     (1) 256K x        NONE
                                                  36

     10MB      (1) 1M x 36    (1) 1M x 36     (1) 256K x    (1) 256K x 36
                                                  36

     12MB      (1) 1M x 36    (1) 1M x 36    (1) 1M x 36        NONE

     16MB      (1) 1M x 36    (1) 1M x 36    (1) 1M x 36     (1) 1M x 36

     16MB      (1) 4M x 36        NONE           NONE           NONE

     32MB      (1) 4M x 36    (1) 4M x 36        NONE           NONE

     33MB      (1) 4M x 36    (1) 4M x 36     (1) 256K x        NONE
                                                  36

     34MB      (1) 4M x 36    (1) 4M x 36     (1) 256K x    (1) 256K x 36
                                                  36

     36MB      (1) 4M x 36    (1) 4M x 36    (1) 1M x 36        NONE

     40MB      (1) 4M x 36    (1) 4M x 36    (1) 1M x 36     (1) 1M x 36

     48MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36        NONE

     49MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36    (1) 256K x 36

     64MB      (1) 4M x 36    (1) 4M x 36    (1) 4M x 36     (1) 4M x 36

     64MB      (1) 8M x 36    (1) 8M x 36        NONE           NONE

     65MB      (1) 8M x 36    (1) 8M x 36     (1) 256K x        NONE
                                                  36

     66MB      (1) 8M x 36    (1) 8M x 36     (1) 256K x    (1) 256K x 36
                                                  36

                       DRAM CONFIGURATION (CONT)

     Size         Bank 0         Bank 1         Bank 2        Bank 3

     68MB       (1) 8M x 36   (1) 8M x 36    (1) 1M x 36       NONE

     72MB       (1) 8M x 36   (1) 8M x 36    (1) 1M x 36    (1) 1M x 36

     96MB       (1) 8M x 36   (1) 8M x 36    (1) 8M x 36       NONE

    128MB       (1) 8M x 36   (1) 8M x 36    (1) 8M x 36    (1) 8M x 36

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

     64KB        (4) 8K x 8     (4) 8K x 8    (1) 8K x 8

     256KB      (4) 32K x 8    (4) 32K x 8    (1) 32K x 8

  CACHE JUMPER CONFIGURATION

     Size             E5

     64KB            Open

     256KB          Closed

                          CPU TYPE CONFIGURATION

        Type             E1           E2             E3            E4

   80486SX (PQFP)       Open       pins 2 & 3     pins 1 & 2      Open
                                    closed         closed

      ODP486SX          Open       pins 2 & 3     pins 1 & 2      Open
                                    closed         closed

   80486DX (write       Open       pins 1 & 2     pins 2 & 3      Open
       back)                        closed         closed

    80486DX/DX2         Open       pins 1 & 2     pins 1 & 2      Open
                                    closed         closed

      80486DX4          Open       pins 1 & 2     pins 1 & 2      Open
                                    closed         closed

  Pentium Overdrive     Open       pins 2 & 3     pins 2 & 3      Open
                                    closed         closed

                   CPU SPEED CONFIGURATION

        Speed                 E7                   E9

        25MHz          pins 1 & 2 closed         Closed

        33MHz          pins 2 & 3 closed          Open

       50iMHz          pins 1 & 2 closed         Closed

       66iMHz          pins 2 & 3 closed          Open

