J-BOND COMPUTER SYSTEMS CORPORATION

486 VL450C-1

Processor        80486SX/80486DX/80486DX2
Processor Speed  20/25/33/40(internal)/50(internal)/50/66(internal)MHz
Chip Set         SIS
Max. Onboard DRAM32MB
Cache            64/128/256KB
BIOS             AMI
Dimensions       230mm x 218mm
I/O Options      32-bit VESA local bus slots (2)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                  Location     Purpose                 Location

  External battery            J1        Turbo LED                  J5

  Power LED & keylock         J2        Reset switch               J6

  Speaker                     J3        32-bit VESA Local      SL1 & SL2
                                        bus slots

  Turbo switch                J4

                        USER CONFIGURABLE SETTINGS

                Function                      Jumper         Position

  »   Factory configured - do not alter         J7             Open

  »   A20 type select fast gate                JP2           pins 1 & 2
                                                              closed

      A20 type select keyboard                 JP2           pins 2 & 3
      controller gate                                         closed

  »   CMOS memory normal operation             JP3             Open

      CMOS memory clear                        JP3           pins 2 & 3
                                                              closed

  »   VESA local bus normal operation          JP27          pins 1 & 2
                                                              closed

      VESA local bus compatibility             JP27          pins 2 & 3
      problems (See note below)                               closed

  »   PQFP CPU enabled                         JSX6            Open

      PQFP CPU disabled                        JSX6           Closed

  Note: If compatibility problems arise with nonstandard VESA local bus
  peripherals, jumper pins 2 & 3.

              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

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

      16MB        (4) 4M x 9         NONE

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

      32MB        (4) 4M x 9      (4) 4M x 9

                            CACHE CONFIGURATION

       Size              Bank 0            Bank 1              TAG

       64KB            (4) 8K x 8        (4) 8K x 8        (1) 8K x 8 or
                                                           (1) 32K x 8

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

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

                        CACHE JUMPER CONFIGURATION

    Size          JP4             JP5            JP6             JP7

    64KB          Open           Open            Open           Open

   128KB         Closed        pins 1 & 2        Open          Closed
                                closed

   256KB         Closed        pins 2 & 3       Closed         Closed
                                closed

                          CPU TYPE CONFIGURATION

     Type         JSX1        JSX2        JSX3        JSX4        JSX5

    80486SX       Open        Open        Open       Closed       Open

    80487SX       Open       Closed      Closed       Open       Closed

  80486DX/DX2    Closed       Open       Closed       Open       Closed

   Overdrive      Open       Closed      Closed       Open       Closed

         CPU SPEED CONFIGURATION

  Speed      JP20      JP21      JP22

  20MHz      Open      Open      Open

  25MHz     Closed     Open      Open

  33MHz     Closed    Closed    Closed

  40MHz     Closed    Closed     Open

  50iMHz    Closed     Open      Open

  50MHz      Open      Open     Closed

  66iMHz    Closed    Closed    Closed

                  VESA WAIT STATE/BUS SPEED CONFIGURATION

  CPU speed    Wait states     JP8         JP9        JP10        JP11

   < 33MHz       0 wait       Open        Open        Open        Open
                 states

   > 33MHz       1 wait       Short       Short       Short       Short
                 state