
ATC/UNITRON COMPUTERS & COMPUTER PARTS

U6931/G/E/C

Processor  CX486M6/80486SX/80487SX/CX486M7/80486DX/80486DX2/80486DX4/
           P24D/P24T
Processor  25/33/40/50(internal)/50/66(internal)/75(internal/100(internal)MHz
Speed
Chip Set   OPTI
Max.       128MB
Onboard
DRAM
Cache      64/128/256/512KB
BIOS       Award
Dimensions 250mm x 220mm
I/O        32-bit VESA local bus slots (3), green PC connector
Options
NPU        None
Options

[Image]

                                CONNECTIONS

  Purpose                 Location    Purpose                   Location

  External battery           J2       Speaker                     JP38

  Power LED & keylock       JP22      Green PC connector          JP39

  Turbo LED                 JP34      Reset switch                 S1

  Turbo switch              JP36      32-bit VESA local bus    SL1 - SL3
                                      slots

                        USER CONFIGURABLE SETTINGS

                 Function                      Jumper         Position

      Monitor type select                       JP1             Open
      monochrome/EGA/VGA

      Monitor type select color/CGA             JP1            Closed

     CMOS memory normal operation              JP2          Pins 2 & 3
                                                               closed

      CMOS memory clear                         JP2          Pins 1 & 2
                                                               closed

     Factory configured - do not alter         JP6             Open

     Factory configured - do not alter         JP7            Closed

      P24D write back enabled                   JP19         Pins 1 & 2
                                                               closed

      P24D write through enabled                JP19         Pins 2 & 3
                                                               closed

      CPU type select any CPU except            JP22            Open
      CX486M7 2x

      CPU type select CX486M7 2x only           JP22           Closed

     Factory configured - do not alter         JP31         Pins 2 & 3
                                                               closed

     Factory configured - do not alter         JP41            N/A

                            DRAM CONFIGURATION

     Size          Bank 0         Bank 1         Bank 2         Bank 3

      2MB        (4) 256K x 9    (1) 256K x       None           None
                                    36

      2MB           None         (1) 512K x       None           None
                                    36

      4MB        (4) 1M x 9        None           None           None

      4MB           None        (1) 1M x 36       None           None

      8MB        (4) 1M x 9     (1) 1M x 36       None           None

      8MB           None        (1) 2M x 36       None           None

     16MB        (4) 4M x 9        None           None           None

     16MB           None        (1) 4M x 36       None           None

     16MB        (4) 1M x 9     (1) 1M x 36    (1) 1M x 36   (1) 1M x 36

     16MB           None        (1) 2M x 36    (1) 2M x 36       None

     32MB        (4) 4M x 9     (1) 4M x 36       None           None

     32MB           None        (1) 4M x 36    (1) 4M x 36       None

     64MB           None        (1) 16M x 36      None           None

     64MB        (4) 4M x 9     (1) 4M x 36    (1) 4M x 36   (1) 4M x 36

     128MB          None        (1) 16M x 36    (1) 16M x        None
                                                   36

            DRAM JUMPER CONFIGURATION

         Setting                   JP5

  30-pin SIMM as Bank 0     Pins 2 & 3 closed

  72-pin SIMM as Bank 0     Pins 1 & 2 closed

                      CACHE CONFIGURATION

      Size          Bank 0          Bank 1           TAG

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

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

   256KB (A)      (4) 32K x 8     (4) 32K x 8    (1) 16K x 8

   256KB (B)      (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         JP8         JP27         JP28         JP43        JP44

    64KB        2 & 3        Open         Open         Open       1 & 2

    128KB       1 & 2       Closed        Open         Open       1 & 2

  256KB (A)     2 & 3       Closed       Closed        Open       2 & 3

  256KB (B)     2 & 3       Closed       Closed        Open       1 & 2

    512KB       1 & 2       Closed       Closed       Closed      1 & 2

  Note: Pins designated should be in the closed position.

                          CPU TYPE CONFIGURATION

    Type        JP9     JP11     JP12    JP13     JP15     JP23     JP32

  CX486M6     Closed    2 & 3    2 & 3   Open     Open     2 & 3   1 & 2

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

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

  CX486M7     Closed    2 & 3    2 & 3   1 & 2    Open      1 &     Open
                                                            2, 3
                                                            & 4

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

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

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

  80486DX4      N/A     1 & 2    1 & 2   1 & 2     N/A      1 &     Open
                                                            2, 3
                                                            & 4

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

  Note: Pins designated should be in the closed position. See also JP19 &
  JP22 in User Configurable.

                          CPU TYPE CONFIGURATION

       Type             JP10          JP12          JP20         JP21

  Non SL-enhanced       Open          Open          Open         Open

    SL-enhanced        Closed      Pins 1 & 2      Closed       Closed
                                     closed

          CPU SPEED CONFIGURATION

   Speed      JP16       JP17      JP18

   25MHz      Open       Open      Open

   33MHz      Open      Closed    Closed

   40MHz      Open      Closed     Open

  50iMHz      Open       Open      Open

   50MHz      Open       Open     Closed

  66iMHz      Open      Closed    Closed

  75iMHz      Open       Open      Open

  100iMHz     Open      Closed    Closed

  CPU SPEED CONFIGURATION (80486DX4 ONLY)

        Speed                  JP30

          2x            Pins 1 & 2 closed

         2.5x           Pins 2 & 3 closed

          3x                   Open

               CPU VOLTAGE CONFIGURATION

          Voltage                      JP29

           3.45v             Pins 3 & 5, 4 & 6 closed

             5v              Pins 1 & 3, 2 & 4 closed

  VL BUS WAIT STATE CONFIGURATION

   Wait states           JP35

  0 wait states          Open

   1 wait state         Closed

                  VL BUS SPEED CONFIGURATION

      CPU speed              JP33                 JP37

      <= 33MHz         Pins 2 & 3 closed          Open

       > 33MHz         Pins 1 & 2 closed         Closed

