
CHICONY, INC.

CH-491E

Processor    CX486S/80486SDX/CX487S/80487SX/CX486DX/AM486DX/80486DX/
             CX486DX2/AM486DX2/80486DX2/Pentium Overdrive
Processor    20/25/33/40/50(internal)/50/66(internal)MHz
Speed
Chip Set     Advanced
Max. Onboard 64MB
DRAM
Cache        32/64/128/256KB
BIOS         AMI
Dimensions   220mm x 250mm
I/O Options  32-bit VESA local bus slots (3)
NPU Options  None

[Image]

                                CONNECTIONS

  Purpose                  Location    Purpose                  Location

  External battery            J3       Speaker                     J7

  Reset switch                J4       Power LED & keylock         J8

  Turbo switch                J5       32-bit VESA local bus   SL1 - SL3
                                       slots

  Turbo LED                   J6

                        USER CONFIGURABLE SETTINGS

                Function                    Jumper           Position

     CMOS memory normal operation            JP1              Open

      CMOS memory clear                       JP1             Closed

      Address strobe delay disabled           JP7           pins 1 & 2
                                                              closed

      Address strobe delay enabled            JP7           pins 2 & 3
                                                              closed

     PQFP CPU enabled                       JP12              Open

      PQFP CPU disabled                      JP12             Closed

     VGA card select normal card            JP19           pins 1 & 2
      installed                                               closed

      VGA card select Weitek Power           JP19           pins 2 & 3
      9000 card installed                                     closed

              DRAM CONFIGURATION

      Size          Bank 0          Bank 1

      1MB         (4) 256K x 9       NONE

      1MB            NONE        (4) 256K x 9

      2MB         (4) 256K x 9   (4) 256K x 9

      4MB         (4) 1M x 9         NONE

      4MB            NONE         (4) 1M x 9

      5MB         (4) 1M x 9     (4) 256K x 9

      5MB         (4) 256K x 9    (4) 1M x 9

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

      16MB        (4) 4M x 9         NONE

      16MB           NONE         (4) 4M x 9

      17MB        (4) 4M x 9     (4) 256K x 9

      17MB        (4) 256K x 9    (4) 4M x 9

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

                            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          (4) 32K x 8       (4) 32K x 8       (1) 16K x 8 or
                                                           (1) 32K x 8

                   CACHE JUMPER CONFIGURATION

   Size        JP2        JP3        JP4        JP5       JP6

   32KB       2 & 3      2 & 3      Open       Open       Open

   64KB       1 & 2      1 & 2      Open       Open      Closed

   128KB      2 & 3      2 & 3      Open      Closed     Closed

   256KB      1 & 2      1 & 2     Closed     Closed     Closed

  Note: Pins designated should be in the closed position.

                          CPU TYPE CONFIGURATION

      Type         JP15       JP16         JP17        JP18       JP20

     CX486S        2 & 3      Open         Open       2 & 3       2 & 3

    80486SX        2 & 3      Open         Open       2 & 3       2 & 3

     CX487S       1 & 2, 3    1 & 2        Open       1 & 2       1 & 2
                    & 4

    80487SX       1 & 2, 3    2 & 3        Open       2 & 3       2 & 3
                    & 4

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

   AM80486DX      1 & 2, 3    1 & 2        Open       2 & 3       2 & 3
                    & 4

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

    CX486DX2      1 & 2, 3    1 & 2       Closed      2 & 3       2 & 3
                    & 4

    AM486DX2      1 & 2, 3    1 & 2        Open       2 & 3       2 & 3
                    & 4

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

      P24T        1 & 2, 3    1 & 2        Open       2 & 3       2 & 3
                    & 4

  Note: Pins designated should be in the closed position.

             CPU SPEED CONFIGURATION

  Speed      JP8       JP9       JP10      JP11

  20Mhz     Closed    Closed    Closed    Closed

  25MHz      Open      Open     Closed    Closed

  33MHz      Open      Open     Closed     Open

  40MHz      Open      Open      Open     Closed

  50iMHz     Open      Open     Closed    Closed

  50MHz      Open      Open      Open      Open

  66iMHz     Open      Open     Closed     Open

  VL BUS WAIT STATE CONFIGURATION

   Wait states           JP13

  0 wait states          Open

   1 wait state         Closed

  VL BUS SPEED CONFIGURATION

   CPU speed         JP14

   <= 33MHz          Open

    > 33MHz         Closed

