
SOYO COMPUTER CO., LTD.

486 VESA MAINBOARD

Processor   CX486S/80486SX/CX486S2/80487SX/CX486DX/80486DX/CX486DX2/
            80486DX2/Pentium Overdrive
Processor   25/33/40/50(internal)/50/66(internal)MHz
Speed
Chip Set    ALI
Max. Onboard128MB
DRAM
Cache       64/128/256KB
BIOS        AMI
Dimensions  254mm x 220mm
I/O Options 32-bit VESA local bus slots (2)
NPU Options None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  Power LED & keylock         J17       Turbo switch              J21

  Speaker                     J18       Turbo LED                 J22

  Reset switch                J19       32-bit VESA local      SL1 & SL2
                                        bus slots

  External battery            J20

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Monitor type select monochrome          JP3              Open

      Monitor type select color               JP3             Closed

     CMOS memory normal operation            JP5           pins 1 & 2
                                                              closed

      CMOS memory clear                       JP5           pins 2 & 3
                                                              closed

     Factory configured - do not             JP18             Open
      alter

     Factory configured - do not             JP19             Open
      alter

     Battery type select internal            JP20          pins 1 & 2
                                                              closed

      Battery type select external            JP20          pins 2 & 3
                                                              closed

     CPU type select PGA                     JP30            Closed

      CPU type select PQFP                    JP30             Open

              DRAM CONFIGURATION

      Size          Bank 0          Bank 1

      1MB         (4) 256K x 9       NONE

      2MB         (4) 256K x 9   (4) 256K x 9

      4MB         (4) 1M x 9         NONE

      5MB         (4) 256K x 9    (4) 1M x 9

      8MB         (4) 1M x 9      (4) 1M x 9

      16MB        (4) 4M x 9         NONE

      17MB        (4) 256K x 9    (4) 4M x 9

      20MB        (4) 1M x 9      (4) 4M x 9

      32MB        (4) 4M x 9      (4) 4M x 9

      64MB        (4) 16M x 9        NONE

      68MB        (4) 1M x 9     (4) 16M x 9

      80MB        (4) 4M x 9     (4) 16M x 9

     128MB        (4) 16M x 9    (4) 16M x 9

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

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

     128KB      (4) 32K x 8        NONE       (1) 8K x 8

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

                        CACHE JUMPER CONFIGURATION

      Size              JP16               JP22               JP23

      64KB               N/A               N/A                 N/A

      128KB              N/A               N/A                 N/A

      256KB           pins 1 & 2        pins 2 & 3      pins 2 & 3 closed
                       closed             closed

  Note: The jumper settings for 64KB & 128KB are unavailable from
  manufacturer.

                          CPU TYPE CONFIGURATION

       Type         JP1     JP6      JP7      JP8      JP9        JP10

      CX486S       1 & 2    2 & 3   2 & 3    1 & 2     Open       Open

     80486SX       1 & 2    1 & 2   Open     1 & 2    Closed     Closed

     CX486S2       1 & 2    2 & 3   2 & 3    1 & 2     Open       Open

     80487SX       1 & 2    1 & 2   Open     2 & 3    Closed     Closed

     CX486DX       1 & 2    1 & 2   Open     2 & 3    Closed     Closed

     CX486DX2      1 & 2    1 & 2   Open     2 & 3    Closed     Closed

   80486DX/DX2     1 & 2    1 & 2   Open     2 & 3    Closed     Closed

      Pentium      2 & 3    2 & 3   1 & 2    2 & 3    Closed     Closed
    Overdrive

  Note: Pins designated should be in the closed position.

                      CPU TYPE CONFIGURATION (CONT)

      Type          JP11     JP12     JP13     JP14     JP17      JP31

     CX486S        3 & 4    2 & 3    1 & 2    2 & 3     2 & 3     Open

     80486SX        Open    1 & 2    1 & 2    1 & 2     1 & 2     Open

     CX486S2       3 & 4    2 & 3    1 & 2    2 & 3     2 & 3    Closed

     80487SX       1 & 2    1 & 2    1 & 2    1 & 2     1 & 2     Open

     CX486DX       2 & 3    1 & 2    1 & 2    2 & 3     1 & 2     Open

    CX486DX2       2 & 3    1 & 2    1 & 2    2 & 3     1 & 2    Closed

   80486DX/DX2     2 & 3    1 & 2    1 & 2    1 & 2     1 & 2     Open

     Pentium       1 & 2    1 & 2    2 & 3    1 & 2     1 & 2     Open
    Overdrive

  Note: Pins designated should be in the closed position.

             CPU SPEED CONFIGURATION

  Speed      JP24      JP25      JP26      JP27

  25MHz      Open      Open     Closed     Open

  33MHz     Closed     Open     Closed    Closed

  40MHz      Open     Closed     Open      Open

  50iMHz     Open      Open     Closed     Open

  50MHz      Open      Open     Closed     Open

  66iMHz    Closed     Open     Closed    Closed

                       CPU CLOCK SPEED CONFIGURATION

      Speed              JP15              JP21               JP33

      25MHz           pins 1 & 2         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      33MHz           pins 1 & 2         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      40MHz           pins 2 & 3         pins 2 & 3         pins 2 & 3
                        closed            closed             closed

      50iMHz          pins 1 & 2         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      50MHz           pins 2 & 3         pins 2 & 3         pins 2 & 3
                        closed            closed             closed

      66iMHz          pins 1 & 2         pins 1 & 2         pins 1 & 2
                        closed            closed             closed

      VESA WAIT STATE CONFIGURATION

     Wait states             JP28

    0 wait states     pins 1 & 2 closed

    1 wait state      pins 2 & 3 closed

         BUS SPEED CONFIGURATION

      CPU speed              JP29

      <= 33MHz        pins 1 & 2 closed

       > 33MHz        pins 2 & 3 closed

