
UNIDENTIFIED

A486DX4/SIS III

Processor     AM486SX/80486SX/CX486DX/AM486DX/80486DX/AM486DX2/
              80486DX2/AM486DX4/80486DX4
Processor     20/25/33/40/50(internal)/50/66(internal)/75(internal)/
Speed         100(internal)MHz
Chip Set      SIS
Video Chip    None
Set
Maximum       64MB
Onboard
Memory
Maximum Video None
Memory
Cache         32/64/128/256/512KB
BIOS          AMI
Dimensions    254mm x 218mm
I/O Options   32-bit VESA local bus slots (3)
NPU Options   None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  Power LED & keylock         J1        Power LED                 LED1

  Speaker                     J2        Turbo switch               S1

  Turbo LED                   J4        32-bit VESA local      SL1 - SL3
                                        bus slots

  Reset switch                J5

                        USER CONFIGURABLE SETTINGS

                Function                     Label          Position

     Factory configured - do not alter       J7          Unidentified

     Factory configured - do not alter       J9             Closed

     Factory configured - do not alter       J11             Open

     Factory configured - do not alter       J12             Open

     Factory configured - do not alter      JP17       Pins 1 & 2 closed

      RC pin used for break switch           JP20       Pins 1 & 2 closed

      RC pin used for RC                     JP20       Pins 2 & 3 closed

      CPU type select any CPU type           JP27             Open

      CPU type select CX486S2 only           JP27            Closed

      Monitor type select CGA                JP38            Closed

      Monitor type select                    JP38             Open
      monochrome/EGA/VGA

     CMOS memory normal operation           JP39       Pins 1 & 2 closed

      CMOS memory clear                      JP39       Pins 2 & 3 closed

     Factory configured - do not alter      JP43       Pins 2 & 3 closed

     Factory configured - do not alter      JP71             Open

      Flash BIOS not installed               JP73       Pins 1 & 2 closed

      Flash BIOS installed                   JP73       Pins 2 & 3 closed

     Factory configured - do not alter      JP74         Unidentified

     Factory configured - do not alter      JP75         Unidentified

     Factory configured - do not alter      JP78       Pins 1 & 2 closed

     Factory configured - do not alter      JP79       Pins 2 & 3 closed

      Turbo disabled                         TBSW       Pins 1 & 2 closed

      Turbo enabled                          TBSW       Pins 2 & 3 closed

      Turbo enabled through S1               TBSW       Pins 4 & 5 closed

      DRAM CONFIGURATION 1

      Size          Bank 0

      1MB        (4) 256K x 9

      4MB         (4) 1M x 9

      16MB        (4) 4M x 9

      64MB        (4) 16M x 9

               DRAM CONFIGURATION 2

      Size            Bank 1           Bank 2

       1MB        (1) 256K x 36         None

       2MB        (1) 512K x 36         None

       4MB         (1) 1M x 36          None

       4MB        (1) 512K x 36    (1) 512K x 36

       8MB         (1) 2M x 36          None

       8MB         (1) 1M x 36      (1) 1M x 36

      16MB         (1) 4M x 36          None

        DRAM CONFIGURATION 2 (CONT)

     Size          Bank 1        Bank 2

     16MB        (1) 2M x 36   (1) 2M x 36

     32MB        (1) 8M x 36      None

     32MB        (1) 4M x 36   (1) 4M x 36

     64MB        (1) 8M x 36   (1) 8M x 36

                  DRAM JUMPER CONFIGURATION

    Configuration            JP45                 JP46

          1            Pins 2 & 3 closed         Closed

          2            Pins 1 & 2 closed          Open

                      CACHE CONFIGURATION

      Size          Bank 0          Bank 1           TAG

      32KB        (4) 8K x 8         None         (1) 8K x 8

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

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

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

   256KB (B)      (4) 64K x 8        None        (1) 32K x 8

     512KB       (4) 128K x 8        None        (1) 32K x 8

                        CACHE JUMPER CONFIGURATION

   Size     JP30      JP31     JP32     JP34     JP35     JP36      JP81

   32KB     1 & 2    1 & 2    1 & 2     Open     1 & 2    1 & 2    2 & 3

   64KB     2 & 3    1 & 2    1 & 2     1 & 2    2 & 3    1 & 2    2 & 3

  128KB     2 & 3    2 & 3    1 & 2     2 & 3,   1 & 2    2 & 3    2 & 3
                                        4 & 5

   256KB    2 & 3    2 & 3    2 & 3     1 & 2,   2 & 3    2 & 3    2 & 3
   (A)                                  3 & 4

   256KB    2 & 3    2 & 3    2 & 3     2 & 3,   1 & 2    2 & 3    2 & 3
   (B)                                  4 & 5

  512KB     2 & 3    2 & 3    2 & 3     2 & 3,   1 & 2    2 & 3    1 & 2
                                        4 & 5

  Note: Pins designated should be in the closed position.

            CPU SPEED SELECTION

   Speed      JP5        JP6        JP7

   20MHz     Closed      Open     Closed

   25MHz     Closed     Closed     Open

   33MHz      Open      Closed    Closed

   40MHz     Closed      Open      Open

  50iMHz     Closed     Closed     Open

   50MHz      Open       Open     Closed

  66iMHz      Open      Closed    Closed

  75iMHz     Closed     Closed     Open

  100iMHz     Open      Closed    Closed

                         CPU TYPE SELECTION

    Type        J13        JP8        JP10        JP12       JP13

  AM486SX     Closed      2 & 3       2 & 3       Open       Open

  80486SX     Closed      2 & 3       2 & 3       Open       Open

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

  AM486DX     Closed      2 & 3       2 & 3       Open       Open

  80486DX     Closed      2 & 3       2 & 3       Open       Open

  AM486DX2    Closed      2 & 3       2 & 3       Open       Open

  80486DX2    Closed      2 & 3       2 & 3       Open       Open

  AM486DX4    Closed      2 & 3       Open        Open       Open

  80486DX4    Closed      2 & 3       Open        Open       Open

  Note: Pins designated should be in the closed position.

                        CPU TYPE SELECTION (CONT)

      Type         JP18        JP19       JP24        JP25        JP28

    AM486SX        1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    80486SX        1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    CX486DX        2 & 3      1 & 2       2 & 3      1 & 2, 3     Open
                                                       & 4

    AM486DX        1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    80486DX        1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    AM486DX2       1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    80486DX2       1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    AM486DX4       1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

    80486DX4       1 & 2      2 & 3       4 & 5       2 & 3       1 & 2

  Note: Pins designated should be in the closed position.

                        CPU TYPE SELECTION (CONT)

       Type            JP29          JP33          JP37          JP40

     AM486SX          3 & 4         2 & 3          Open        1 & 2 or 2
                                                                  & 3

     80486SX          3 & 4         2 & 3          Open        1 & 2 or 2
                                                                  & 3

     CX486DX          2 & 3         1 & 2         3 & 4          1 & 2

     AM486DX          3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

     80486DX          3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

     AM486DX2         3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

     80486DX2         3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

     AM486DX4         3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

     80486DX4         3 & 4       1 & 2, 3 &      3 & 4        1 & 2 or 2
                                      4                           & 3

  Note: Pins designated should be in the closed position.

         CPU MULTIPLIER SELECTION

     Multiplier              JP44

         2x           Pins 1 & 2 closed

        2.5x          Pins 2 & 3 closed

         3x                  Open

                   CPU VOLTAGE SELECTION

      Voltage             Setting              JP80

       3.45v           UMB on board         Auto detect

         5v            UMB on board         Auto detect

       3.45v          UMB not on board      No support

         5v           UMB not on board        Closed

       VL BUS WAIT STATE SELECTION

       Setting               JP4

          0           Pins 1 & 2 closed

          1           Pins 2 & 3 closed

          VL BUS SPEED SELECTION

        Speed                JP3

      <= 33MHz        Pins 1 & 2 closed

       >33 MHz        Pins 2 & 3 closed

