
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


