UNIDENTIFIED

OPTI486DX-33/50WB, 486SX-20/25WB

Processor         80486SX/80486DX
Processor Speed   20/25/33/50(internal)MHz
Chip Set          OPTI
Max. Onboard DRAM 40MB (8MB on external memory card)
Cache             64/256KB
BIOS              AMI
Dimensions        330mm x 218mm
I/O Options       32-bit external memory card
NPU Options       4167

[Image]

                                CONNECTIONS

  Purpose                 Location     Purpose                  Location

  External battery           J10       32-bit external            SL1
                                       memory card

  Turbo LED                  J12       Reset switch               SW1

  Power LED & keylock        J23       Turbo switch               SW2

  Speaker                    J24

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

  »   Monitor type select monochrome          JP1              Open

      Monitor type select color               JP1             Closed

  »   CMOS memory normal operation            JP2           pins 2 & 3
                                                              closed

      CMOS memory clear                       JP2           pins 1 & 2
                                                              closed

                            DRAM CONFIGURATION

     Size         Bank 0         Bank 1         Bank 2         Bank 3

     1MB        (4) 256K x 9      NONE           NONE           NONE

     2MB        (4) 256K x 9   (4) 256K x 9      NONE           NONE

     3MB        (4) 256K x 9   (4) 256K x 9   (4) 256K x 9      NONE

     4MB        (4) 256K x 9   (4) 256K x 9   (4) 256K x 9  (4) 256K x 9

     4MB        (4) 1M x 9        NONE           NONE           NONE

     5MB        (4) 256K x 9   (4) 1M x 9        NONE           NONE

     6MB        (4) 256K x 9   (4) 256K x 9   (4) 1M x 9        NONE

     7MB        (4) 256K x 9   (4) 256K x 9   (4) 256K x 9   (4) 1M x 9

     8MB        (4) 1M x 9     (4) 1M x 9        NONE           NONE

     12MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9        NONE

     16MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9     (4) 1M x 9

     16MB       (4) 4M x 9        NONE           NONE           NONE

     32MB       (4) 4M x 9     (4) 4M x 9        NONE           NONE

     36MB       (4) 4M x 9     (4) 4M x 9     (4) 1M x 9        NONE

     40MB       (4) 4M x 9     (4) 4M x 9     (4) 1M x 9     (4) 1M x 9

  Note: Banks 2 & 3 are located on the external memory card.

                    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      JP8       JP9      JP10      JP11

   64KB      Open     Open      Open      Open

  256KB     Closed   Closed    Closed    Closed

                          CPU TYPE CONFIGURATION

       Type               JP5                JP6               JP7

      80486SX          pins 1 & 2         pins 2 & 3           Open
                         closed            closed

      80486DX          pins 2 & 3         pins 1 & 2          Closed
                         closed            closed