SOYO COMPUTER CO., LTD.

486SX/DX Board (VER. 2)

Processor         80486SX/80486DX
Processor Speed   20/25/33/50MHz
Chip Set          ETEQ
Max. Onboard DRAM 32MB
Cache             64/256KB
BIOS              AMI/Award
Dimensions        330mm x 218mm
I/O Options       32-bit external memory card slot
NPU Options       None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  32-bit external             CN1       External battery          J20
  memory card

  Power LED & keylock         J17       Turbo switch              J21

  Speaker                     J18       Turbo LED                 J22

  Reset switch                J19

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

  »   Factory configured - do not alter        JP2            Closed

  »   Monitor type select monochrome           JP3           pins 2 & 3
                                                              closed

      Monitor type select color                JP3           pins 1 & 2
                                                              closed

  »   CMOS memory normal operation             JP5           pins 1 & 2
                                                              closed

      CMOS memory clear                        JP5           pins 2 & 3
                                                              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) 1M x 9    (4) 256K 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

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

     10MB       (4) 256K x 9  (4) 256K x 9    (4) 1M x 9     (4) 1M x 9

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

     13MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9    (4) 256K x 9

     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

     20MB       (4) 1M x 9     (4) 4M x 9        NONE           NONE

     24MB       (4) 1M x 9     (4) 1M x 9     (4) 4M x 9        NONE

     28MB       (4) 1M x 9     (4) 1M x 9     (4) 1M x 9     (4) 4M x 9

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

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

     37MB       (4) 256K x 9   (4) 1M x 9     (4) 4M x 9     (4) 4M x 9

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

     48MB       (4) 4M x 9     (4) 4M x 9     (4) 4M x 9        NONE

     49MB       (4) 256K x 9   (4) 4M x 9     (4) 4M x 9     (4) 4M x 9

     52MB       (4) 1M x 9     (4) 4M x 9     (4) 4M x 9     (4) 4M x 9

     64MB       (4) 4M x 9     (4) 4M x 9     (4) 4M x 9     (4) 4M x 9

  Note:Banks 2 and 3 are used when a 32-bit external memory card is
  installed at CN1.

     CACHE CONFIGURATION

     Size          Bank 0

     64KB        (8) 8K x 8

     256KB      (8) 32K x 8

                   CACHE JUMPER CONFIGURATION

   Size       JP15       JP16       JP17       JP18       JP33

   64KB       Open       Open       2 & 3      2 & 3      Open

   256KB     Closed     Closed      1 & 2      1 & 2     Closed

  Note: Pins designated should be in the closed position.

                          CPU TYPE CONFIGURATION

       Type              JP103              JP104             JP106

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

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

                          CPU SPEED CONFIGURATION

   Speed      Oscillator at    Oscillator at       JP13          JP23
                   U18              U22

   20MHz          40MHz            50MHz        pins 1 & 2     pins 1 & 2
                                                  closed        closed

   25MHz          NONE             50MHz        pins 2 & 3     pins 1 & 2
                                                  closed        closed

   33MHz          NONE             66MHz        pins 2 & 3     pins 1 & 2
                                                  closed        closed

   50MHz          NONE             50MHz        pins 2 & 3     pins 2 & 3
                                                  closed        closed