
UNIDENTIFIED

SIS 486

Processor        CX486SX/80486SX/80487SX/CX486DX/80486DX/80486DX2
Processor Speed  25/33/40/50(internal)/50/66(internal)MHz
Chip Set         SIS
Max. Onboard DRAM64MB
Cache            128/256KB
BIOS             AMI
Dimensions       254mm x 220mm
I/O Options      32-bit VESA local bus slots (3)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                 Location      Purpose               Location

  Auxiliary keyboard        CN1         Turbo switch       JP22 pins 15 -
  connector                                                      17

  External battery          CN3         Reset switch       JP22 pins 19 -
                                                                 20

  Power LED & keylock   JP22 pins 1 -   Bus mouse port     JP22 pins 19 -
                             5                                   20

  Speaker               JP22 pins 6 -   32-bit VESA          SL1 - SL3
                             10         local bus slots

  Turbo LED             JP22 pins 12
                            - 13

                        USER CONFIGURABLE SETTINGS

                Function                      Jumper         Position

     Battery type select internal             CN3           pins 2 & 3
                                                              closed

      Battery type select external             CN3            Closed

     Factory configured - do not alter        JGPC             N/A

     Monitor type select monochrome           JP1             Open

      Monitor type select color                JP1            Closed

     PQFP CPU disabled                        JP5            Closed

      PQFP CPU enabled                         JP5             Open

     CPU speed select 50MHz (Cyrix            JP6           pins 1 & 2
      only)                                                   closed

      CPU speed select <50MHz (Cyrix           JP6           pins 2 & 3
      only)                                                   closed

     CPU type select all                      JP16          pins 2 & 3
                                                              closed

      CPU type select 80486DX-40/50            JP16          pins 1 & 2
      only                                                    closed

     VESA card select normal                  JP23            Open

      VESA card select Genoa                   JP23           Closed

                        DRAM CONFIGURATION

      Size            Bank 0           Bank 1          Bank 2

       4MB         (4) 256K x 9    (1) 256K x 36    (1) 512K x 36

       4MB             NONE        (1) 512K x 36    (1) 512K x 36

       8MB          (4) 1M x 9     (1) 512K x 36    (1) 512K x 36

      20MB          (4) 4M x 9     (1) 512K x 36    (1) 512K x 36

       4MB          (4) 1M x 9          NONE            NONE

       8MB             NONE         (1) 1M x 36      (1) 1M x 36

       8MB          (4) 1M x 9      (1) 1M x 36         NONE

      12MB          (4) 1M x 9      (1) 1M x 36      (1) 1M x 36

      16MB             NONE         (1) 4M x 36         NONE

      16MB          (4) 4M x 9          NONE            NONE

      32MB             NONE         (1) 4M x 36      (1) 4M x 36

      64MB          (4) 4M x 9      (1) 4M x 36      (1) 4M x 36

                            DRAM CONFIGURATION

      Size              JPA                JPB                 JPC

      4MB            pins 1 & 2         pins 4 & 5      pins 1 & 2 closed
                      closed              closed

      4MB            pins 2 & 3            Open               Open
                      closed

      8MB            pins 2 & 3         pins 2 & 3      pins 1 & 2 closed
                      closed              closed

      20MB           pins 2 & 3         pins 2 & 3      pins 1 & 2 closed
                      closed              closed

      4MB              Open                Open         pins 2 & 3 closed

      8MB            pins 2 & 3            Open               Open
                      closed

      8MB              Open             pins 4 & 5      pins 1 & 2 closed
                                          closed

      12MB           pins 1 & 2         pins 4 & 5      pins 1 & 2 closed
                      closed              closed

      16MB             Open                Open               Open

      16MB             Open                Open         pins 2 & 3 closed

      32MB           pins 2 & 3            Open               Open
                      closed

      64MB           pins 1 & 2         pins 1 & 2      pins 1 & 2 closed
                      closed              closed

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

     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               JP2               JP3                 JP4

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

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

                          CPU TYPE CONFIGURATION

       Type               JP12               JP13              JP15

      80486SX             Open            pins 2 & 3           Open
                                            closed

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

      80486DX           pins 1 & 2        pins 1 & 2          Closed
                         closed             closed

     80486DX2           pins 1 & 2        pins 1 & 2          Closed
                         closed             closed

                          CPU SPEED CONFIGURATION

      Speed              JS0                JS1                JS2

      25MHz              Open              Open              Closed

      33MHz             Closed             Open               Open

      40MHz             Closed            Closed              Open

      50iMHz             Open              Open              Closed

      50MHz              Open             Closed        pins 1 & 2 closed

      66iMHz            Closed             Open               Open

      VESA WAIT STATE CONFIGURATION

     Wait states             JP8

    0 wait states     pins 1 & 2 closed

    1 wait state      pins 2 & 3 closed

         BUS SPEED CONFIGURATION

      CPU speed              JP9

      <= 33MHz        pins 1 & 2 closed

       > 33MHz        pins 2 & 3 closed

