
CHAINTECH COMPUTER COMPANY, LTD.

VESA MAINBOARD SIS 486 (REV. 2)

Processor        80486SX/CX486M7/80486DX/80486DX2/Pentium Overdrive
Processor Speed  25/33/40/50(internal)/50/66(internal)MHz
Chip Set         SIS
Max. Onboard DRAM128MB
Cache            128/256/512KB
BIOS             AMI/Award
Dimensions       330mm x 218mm
I/O Options      32-bit VESA local bus slots (3), green PC connector
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                 Location    Purpose                   Location

  External battery           J1       Reset switch                 J6

  Turbo switch               J3       Power LED & keylock          J7

  Turbo LED                  J4       Green PC connector          JP26

  Speaker                    J5       32-bit VESA local bus    SL1 - SL3
                                      slots

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     SMOUT type select normal mode            J2             Closed

      SMOUT type select standby mode           J2              Open

     CMOS memory normal operation            JP16          pins 1 & 2
                                                              closed

      CMOS memory clear                       JP16          pins 2 & 3
                                                              closed

     Factory configured - do not             JP18             Open
      alter

              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

      65MB        (4) 256K x 9   (4) 16M x 9

      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

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

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

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

                        CACHE JUMPER CONFIGURATION

   Size          JP1            JP2             JP3              JP4

   128KB      pins 1 & 2     pins 1 & 2     pins 1 & 2, 3     pins 1 & 2
                closed         closed        & 4 closed        closed

   256KB      pins 2 & 3     pins 2 & 3     pins 2 & 3, 4     pins 1 & 2
                closed         closed        & 5 closed        closed

   512KB      pins 1 & 2     pins 2 & 3     pins 1 & 2, 3     pins 2 & 3
                closed         closed        & 4 closed        closed

                          CPU TYPE CONFIGURATION

     Type        JP8     JP9      JP10     JP11    JP12     JP13    JP14

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

    CX486M7      1 &    Closed    2 & 3    2 & 3   2 & 3    Open    1 & 2
                  2

  80486DX/DX2    1 &    Closed    2 & 3    2 & 3   3 & 4    1 & 2   2 & 3
                  2

     P23S        2 &     Open     2 & 3    Open    3 & 4    1 & 2   2 & 3
                  3

     P24D        1 &    Closed    1 & 2    2 & 3   1 & 2    2 & 3   2 & 3
                  2

     P24S        1 &    Closed    2 & 3    2 & 3   3 & 4    1 & 2   2 & 3
                  2

     P24T        1 &    Closed    1 & 2    1 & 2   3 & 4    Open    1 & 2
                  2

  Note: Pins designated should be in the closed position.

                      CPU TYPE CONFIGURATION (CONT)

     Type        JP15      JP21      JP22      JP24     JP25       JP30

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

    CX486M7      2 & 3     1 & 2    2 & 3     2 & 3     2 & 3      Open

  80486DX/DX2    4 & 5     2 & 3    1 & 2      Open     Open       Open

     P23S        4 & 5     2 & 3    1 & 2      Open     Open       Open

     P24D        4 & 5     2 & 3    1 & 2      Open     1 & 2     Closed

     P24S        4 & 5     2 & 3    1 & 2      Open     Open       Open

     P24T        1 & 2     1 & 2    1 & 2     1 & 2     1 & 2      Open

  Note: Pins designated should be in the closed position.

         CPU SPEED CONFIGURATION

  Speed      JP5        JP6       JP7

  25MHz      Open     Closed     Open

  33MHz     Closed    Closed    Closed

  40MHz      Open     Closed    Closed

  50iMHz     Open     Closed     Open

  50MHz     Closed     Open      Open

  66iMHz    Closed    Closed    Closed

        CPU CLOCK DELAY CONFIGURATION

         Delay                  JP20

        0 delay          pins 1 & 2 closed

  1 gate buffer delay    pins 2 & 3 closed

    CPU INPUT FREQUENCY CONFIGURATION

        input                JP23

    Single input      pins 1 & 2 closed

    Double input      pins 2 & 3 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

