
J-MARK COMPUTER CORPORATION

J-656C

Processor          CX M1/Pentium
Processor Speed    75/90/100/120/133/150/166/180/200MHz
Chip Set           Intel
Video Chip Set     None
Maximum Onboard    128MB (EDO supported)
Memory
Maximum Video      None
Memory
Cache              256/512KB
BIOS               Award
Dimensions         255mm x 220mm
I/O Options        32-bit PCI slots (4), floppy drive interface, green PC
                   connector, IDE interfaces (2), parallel port, PS/2
                   mouse port, serial ports (2), cache slot
NPU Options        None

[Image]

                                CONNECTIONS

  Purpose                Location      Purpose                Location

  IDE interface 2           J1         IDE interface LED    JP6 pins 14 &
                                                                 15

  IDE interface 1           J2         Turbo switch         JP6 pins 18 &
                                                                 19

  Serial port 2             J7         Reset switch         JP6 pins 22 &
                                                                 23

  Serial port 1             J8         Turbo LED            JP6 pins 25 &
                                                                 26

  Floppy drive              J9         Parallel port            JP15
  interface

  Power LED &          JP6 pins 1 -    32-bit PCI slots       PC1  PC4
  keylock                   5

  Green PC connector   JP6 pins 7 &    PS/2 mouse                PS2
                            8          interface

  Speaker              JP6 pins 10 -   Cache slot                SL1
                            13

                        USER CONFIGURABLE SETTINGS

               Function                    Label           Position

     Factory configured - do not           J5           Unidentified
      alter

     CMOS memory normal operation          JP3              Open

      CMOS memory clear                     JP3             Closed

      Flash BIOS voltage select 12v         JP5        Pins 1 & 2 closed

      Flash BIOS voltage select 5v          JP5        Pins 2 & 3 closed

     ISA clock select PCI CLK/4            JP8        Pins 2 & 3 closed

      ISA clock select PCI CLK/3            JP8        Pins 1 & 2 closed

     Factory configured - do not          JP13          Unidentified
      alter

     Factory configured - do not           JV1          Unidentified
      alter

     Factory configured - do not           JW1          Unidentified
      alter

     Factory configured - do not           JW2          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

         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 at 64MB and above.

                            CACHE CONFIGURATION

       Size            Bank 0               SL1                 TAG

    256KB (A)       (2) 32K x 32       Not installed        (1) 32K x 8

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

    512KB (A)       (2) 32K x 32        256KB module        (1) 32K x 8
                                         installed

    512KB (B)           None            512KB module        (1) 32K x 8
                                         installed

                        CACHE JUMPER CONFIGURATION

    Size           JC1            JC2            JT2             JX2

  256KB (A)     Pins 1 & 2     Pins 1 & 2     Pins 1 & 2      Pins 1 & 2
                 closed          closed         closed         closed

  256KB (B)        N/A            N/A            N/A             N/A

  512KB (A)     Pins 2 & 3     Pins 1 & 2     Pins 2 & 3      Pins 1 & 2
                 closed          closed         closed         closed

  512KB (B)        N/A            N/A            N/A             N/A

    CACHE TYPE CONFIGURATION

      Type           JP101

  Asynchronous      Closed

  Synchronous        Open

                        CPU SPEED SELECTION (CYRIX)

  CPU speed      Clock      Multiplier      JF1         J1          J3
                speed

   120MHz       50MHz           2x         3 & 4      Closed       Open

   150MHz       60MHz           2x         1 & 2      Closed       Open

   166MHz       66MHz           2x         Open       Closed       Open

  Note: Pins designated should be in the closed position.

                        CPU SPEED SELECTION (INTEL)

  CPU speed     Clock      Multiplier      JF1         J1          J3
                speed

   75MHz        50MHz         1.5x        3 & 4       Open        Open

   90MHz        60MHz         1.5x        1 & 2       Open        Open

   100MHz       66MHz         1.5x        Open        Open        Open

   120MHz       60MHz          2x         1 & 2      Closed       Open

   133MHz       66MHz          2x         Open       Closed       Open

   150MHz       60MHz         2.5x        1 & 2      Closed      Closed

   166MHz       66MHz         2.5x        Open       Closed      Closed

   180MHz       60MHz          3x         1 & 2       Open       Closed

   200MHz       66MHz          3x         Open        Open       Closed

  Note: Pins designated should be in the closed position.

                           CPU VOLTAGE SELECTION

                Voltage                                JV2

                   3.3v                         Pins 1 & 2 closed

                  3.45v                        Pins 3 & 4 closed

                   3.6v                         Pins 5 & 6 closed

                       CPU CLOCK TOLERANCE SELECTION

              Tolerance                                JP7

                   3.3v                         Pins 2 & 3 closed

                   5v                          Pins 1 & 2 closed

