
J-MARK COMPUTER CORPORATION

J-656B

Processor            Pentium
Processor Speed      75/90/100/120/133/150/180/200MHz
Chip Set             Intel
Video Chip Set       None
Maximum Onboard      128MB (EDO supported)
Memory
Maximum Video Memory None
Cache                256/512KB
BIOS                 Award
Dimensions           330mm x 218mm
I/O Options          32-bit PCI slots (4), floppy drive interface, IDE
                     interfaces (2), parallel port, PS/2 mouse interface,
                     serial ports (2), VRM connector. IR connector
NPU Options          None

[Image]

                                CONNECTIONS

  Purpose                  Location    Purpose                  Location

  Serial port 2              CN1       Speaker                     J4

  Serial port 1              CN2       Power LED & keylock         J5

  Parallel port              CN3       Turbo LED                   J6

  Floppy drive interface     CN4       Turbo switch                J7

  IDE interface 2            CN5       IR connector               JP8

  IDE interface 1            CN6       PS/2 mouse interface       MS1

  Reset switch                J2       32-bit PCI slots         PC1  PC4

  IDE interface LED           J3       VRM connector              VRM

                        USER CONFIGURABLE SETTINGS

               Function                    Label           Position

     Factory configured - do not           J8           Unidentified
      alter

     Factory configured - do not           J9           Unidentified
      alter

     PCI CLK select CLK/4                  JP3        Pins 2 & 3 closed

      PCI CLK select CLK/3                  JP3        Pins 1 & 2 closed

     I/O address select 250 HEX            JP4        Pins 2 & 3 closed

      I/O address select 3F0 HEX            JP4        Pins 1 & 2 closed

     IDE interface 1 IRQ select            JP5        Pins 1 & 2 closed
      IRQ14

      IDE interface 1 IRQ select            JP5        Pins 2 & 3 closed
      MIRQ1

     IDE interface 2 IRQ select            JP6        Pins 1 & 2 closed
      IRQ15

      IDE interface 2 IRQ select            JP6        Pins 2 & 3 closed
      MIRQ0

     Factory configured - do not           JP9          Unidentified
      alter

     Green PC disabled                    JP10              Open

      Green PC enabled                     JP10             Closed

     Factory configured - do not          JP13          Unidentified
      alter

     Factory configured - do not          JP15          Unidentified
      alter

     Factory configured - do not          JP16          Unidentified
      alter

     CMOS memory normal operation         JP17              Open

      CMOS memory clear                    JP17             Closed

     CPU type select write back           JP18              Open

      CPU type select write through        JP18             Closed

     CPU pipeline enabled                 JP19             Closed

      CPU pipeline disabled                JP19              Open

     Factory configured - do not          JP20          Unidentified
      alter

     Factory configured - do not          JP24          Unidentified
      alter

     Factory configured - do not          JP32          Unidentified
      alter

             DRAM CONFIGURATION

     Size          Bank 0        Bank 1

      8MB        (2) 1M x 36      None

     16MB        (2) 2M x 36      None

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

     24MB        (2) 2M x 36   (2) 1M x 36

                        DRAM CONFIGURATION (CONT)

          Size                    Bank 0                   Bank 1

          32MB                 (2) 4M x 36                  None

          32MB                 (2) 2M x 36              (2) 2M x 36

          40MB                 (2) 4M x 36              (2) 1M x 36

          48MB                 (2) 4M x 36              (2) 2M x 36

          64MB                 (2) 8M x 36                  None

          64MB                 (2) 4M x 36              (2) 4M x 36

          72MB                 (2) 8M x 36              (2) 1M x 36

          80MB                 (2) 8M x 36              (2) 2M x 36

          96MB                 (2) 8M x 36              (2) 4M x 36

          128MB                (2) 8M x 36              (2) 8M x 36

  Note: Board accepts EDO memory. Board also accepts x 32 SIMMs. Banks
  are interchangeable.

                            CACHE CONFIGURATION

       Size              Bank 0            Bank 1              TAG

     256KB (A)        (2) 32K x 32          None            (1) 8K x 8

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

     512KB (A)        (2) 64K x 32          None         (1) 16K/32K x 8

     512KB (B)            None           (8) 64K x 8     (1) 16K/32K x 8

        CACHE JUMPER CONFIGURATION

        Size                 JP14

      256KB (A)       Pins 1 & 2 closed

      256KB (B)       Pins 1 & 2 closed

      512KB (A)       Pins 2 & 3 closed

      512KB (B)       Pins 2 & 3 closed

                        CACHE VOLTAGE CONFIGURATION

           Voltage                    JP1                    JP2

       3v synchronous                 Open           Pins 1 & 2, 3 & 4, 5
                                                          & 6 closed

       3v asynchronous                Open           Pins 1 & 2, 3 & 4, 5
                                                          & 6 closed

    5v mixed asynchronous      Pins 1 & 2, 3 & 4,            Open
                                  5 & 6 closed

                            CPU SPEED SELECTION

    CPU      Clock    Multiplier     JP11      JP12      JP26      JP27
  speed     speed

  75MHz     50MHz        1.5x        Open      Open      Open      Open

  90MHz     60MHz        1.5x        Open     Closed     Open      Open

  100MHz    66MHz        1.5x       Closed    Closed     Open      Open

  120MHz    60MHz         2x         Open     Closed     Open     Closed

  133MHz    66MHz         2x        Closed    Closed     Open     Closed

  150MHz    60MHz        2.5x        Open     Closed    Closed    Closed

  180MHz    60MHz         3x         Open     Closed    Closed     Open

  200MHz    66MHz         3x        Closed    Closed    Closed     Open

           CPU VOLTAGE SELECTION

  Voltage     JP28       JP29      JP30

   3.3v      Closed      Open      Open

   3.45v      Open      Closed     Open

   3.6v       Open       Open     Closed

                              BIOS SELECTION

          Setting                    JP21                   JP31

             EPROM            Pins 1 & 2 closed       Pins 2 & 3 closed

          12v flash          Pins 2 & 3 closed       Pins 1 & 2 closed

            5v flash          Pins 2 & 3 closed       Pins 2 & 3 closed

