SOYO COMPUTER CO., LTD.
      486 VESA GREEN MAINBOARD

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



                                   CONNECTIONS
       Purpose                  Location Purpose                  Location
       Green PC connector         J4     Turbo switch              J21
       Power LED & keylock        J17    Turbo LED                 J22
       Speaker                    J18    Green PC connector        JP28
       Reset switch               J19    Green PC connector        JP34
       External battery           J20    32-bit VESA slots        SL1 & SL2


                              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
         CMOS memory clear                           JP5      pins 2 & 3
        *CPU type select PGA                        JP18         Closed
         CPU type select PQFP                       JP18         Open
        *Factory configured - do not alter          JP23         Open
        *Factory configured - do not alter          JP31         Open
        *Factory configured - do not alter          JP32         Open
        *Factory configured - do not alter          JP35         Open
        *Factory configured - do not alter          JP36         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           JP24            JP25            JP26
              64KB            Open          1 & 2             Open
             128KB          1 & 2           2 & 3            2 & 3 
             256KB          2 & 3           2 & 3            1 & 2 


                                CPU TYPE CONFIGURATION
            Type        JP1        JP4        JP6       JP8        JP9
           CX486SX      1 & 2     2 & 3      Open       Open      2 & 3
           80486SX      2 & 3     1 & 2      Closed     Open      2 & 3
           CX486DX      1 & 2     2 & 3      Open      Closed     1 & 2
           80486DX      2 & 3     1 & 2      Closed    Closed     1 & 2
          80486DX2      2 & 3     1 & 2      Closed    Closed     1 & 2
Pentium Overdrive       1 & 2     1 & 2      Open      Closed     1 & 2


                             CPU TYPE CONFIGURATION (CON'T)
            Type         JP10         JP11          JP12         JP13
           CX486SX       2 & 3        2 & 3         2 & 3        Open
           80486SX       4 & 5         Open         Open         Open
           80486DX       4 & 5         Open         Open         Open
           CX486DX       2 & 3        2 & 3         2 & 3        2 & 3
          80486DX2       4 & 5         Open         Open         Open
Pentium Overdrive        1 & 2        1 & 2         1 & 2        1 & 2


                             CPU TYPE CONFIGURATION (CON'T)
            Type         JP16         JP17          JP29         JP33
           CX486SX     1&2,3&4      1&2,3&4         2 & 3        2 & 3
           80486SX       2 & 3        2 & 3         1 & 2        2 & 3
           CX486DX     1&2,3&4      1&2,3&4         1 & 2        2 & 3
           80486DX       2 & 3        2 & 3         1 & 2        2 & 3
          80486DX2       2 & 3        2 & 3         1 & 2        2 & 3
Pentium Overdrive        2 & 3        2 & 3         1 & 2        1 & 2


                               CPU SPEED CONFIGURATION
               Speed              JP20           JP21           JP22
               25MHz              Closed         Open           Closed
               33MHz              Open           Closed         Closed
               40MHz              Closed         Open           Open
               50MHz              Open           Closed         Open
50MHz (Pentium Overdrive only)    Closed         Open           Closed
               50iMHz             Closed         Open           Closed
               66iMHz             Open           Closed         Closed