SOYO COMPUTER CO., LTD.

486 VESA

Processor        80486SX/80487SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  25/33/40/50(internal)/50/66(internal)MHz
Chip Set         SIS
Max. Onboard DRAM32MB
Cache            64/128/256KB
BIOS             AMI
Dimensions       230mm x 218mm
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/EGA/VGA         JP3            Closed

  »   CMOS memory normal operation              JP5          pins 1 & 2
                                                               closed

      CMOS memory clear                         JP5          pins 2 & 3
                                                               closed

  »   Factory configured - do not alter         JP6          pins 2 & 3
                                                               closed

              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

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

      16MB        (4) 4M x 9         NONE

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

      32MB        (4) 4M x 9      (4) 4M 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              JP14               JP15               JP21

      64KB            pins 1 & 2           Open         pins 2 & 3 closed
                       closed

      128KB           pins 2 & 3        pins 1 & 2      pins 2 & 3 closed
                       closed             closed

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

                           CPU TYPE CONFIGURATION

       Type             JP8          JP9          JP12           JP13

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

   80486SX (PGA)       Open        Closed         Open        pins 2 & 3
                                                                closed

      80487SX         Closed       Closed      pins 2 & 3     pins 1 & 2
                                                 closed         closed

    80846DX/DX2       Closed       Closed      pins 1 & 2     pins 1 & 2
                                                 closed         closed

     Overdrive        Closed       Closed      pins 2 & 3     pins 1 & 2
                                                 closed         closed

         CPU SPEED CONFIGURATION

  Speed      JP16      JP17      JP18

  25MHz     Closed     Open     Closed

  33MHz      Open     Closed    Closed

  40MHz     Closed     Open      Open

  50iMHz    Closed     Open     Closed

  50MHz      Open     Closed     Open

  66iMHz     Open     Closed    Closed

                  VESA WAIT STATE/BUS SPEED CONFIGURATION

     CPU speed        Wait states           JP19               JP20

      £ 33MHz        0 wait states       pins 1 & 2         pins 1 & 2
                                           closed             closed

      > 33MHz        1 wait state        pins 2 & 3         pins 2 & 3
                                           closed             closed