
MECER CORPORATION

B860/B860 (REV. A)

Processor        CX486SX/80486SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  25/33/40/50(internal)/50/66(internal)MHz
Chip Set         Unidentified
Max. Onboard DRAM32/128MB (depends on board revision)
Cache            128/256KB
BIOS             AMI
Dimensions       330mm x 218mm
I/O Options      32-bit VESA local bus slots (2)
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose               Location      Purpose                 Location

  Power LED &         JP6 pins 1 -    Reset switch          JP6 pins 19 -
  keylock                  5                                     20

  Speaker             JP6 pins 6 -    External battery          JP17
                           9

  Turbo LED           JP6 pins 11 -   Auxiliary keyboard        JP35
                           12         connector

  Turbo switch        JP6 pins 16 -   32-bit VESA local      SL1 & SL2
                           17         bus slots

                        USER CONFIGURABLE SETTINGS

                Function                    Jumper           Position

     PQFP CPU disabled                       JP1             Closed

      PQFP CPU enabled                        JP1              Open

     CMOS memory normal operation           JP16           pins 1 & 2
                                                              closed

      CMOS memory clear                      JP16           pins 2 & 3
                                                              closed

     Battery type select 4.5v               JP34             Closed

      Battery type select 6.0v               JP34              Open

     CPU speed select 20/25MHz              JP72             Closed

      CPU speed select => 33MHz              JP72              Open

     VESA card select normal                JP89             Closed

      VESA card select Weitek VESA           JP89              Open
      card only

          DRAM CONFIGURATION (REV. 0)

      Size          Bank 0          Bank 1

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

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

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

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

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

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

          DRAM CONFIGURATION (REV. A)

      Size          Bank 0          Bank 1

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

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

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

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

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

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

      65MB        (4) 256K x 9   (4) 16M x 9

      68MB        (4) 1M x 9     (4) 16M x 9

      80MB        (4) 4M x 9     (4) 16M x 9

     128MB        (4) 16M x 9    (4) 16M x 9

                         DRAM JUMPER CONFIGURATION

  Revision     JP76      JP77      JP90       JP91       JP92      JP93

   Rev. 0      1 & 2    2 & 3      Open       Open       Open      2 & 3

   Rev. A      2 & 3    1 & 2     Closed     Closed     Closed     1 & 2,
                                                                   3 & 4

  Note: Pins designated should be in the closed position.

                    CACHE CONFIGURATION

     Size          Bank 0         Bank 1          TAG

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

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

                  CACHE JUMPER CONFIGURATION

        Size                 JP7                  JP8

        128KB          pins 1 & 2 closed   pins 2 & 3 closed

        256KB          pins 1 & 2 closed   pins 1 & 2 closed

                          CPU TYPE CONFIGURATION

       Type           JP2        JP3         JP4         JP5       JP9

     CX486SX         2 & 3       Open        Open       2 & 4     2 & 3

  80486SX (PQFP)     Open        Open        Open       3 & 5     2 & 3

  80486SX (PGA)      2 & 3       Open        Open       2 & 3     2 & 3

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

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

      Pentium       1 & 2, 3    1 & 2       Closed      2 & 3     2 & 3
    Overdrive         & 4

  Note: Pins designated should be in the closed position.

                          CPU SPEED CONFIGURATION

         Speed                    JP33                     JP36

         25MHz              pins 2 & 3 closed        pins 2 & 6, 4 & 8
                                                          closed

         33MHz              pins 2 & 3 closed        pins 3 & 7, 4 & 8
                                                          closed

         40MHz              pins 2 & 3 closed        pins 2 & 6 closed

         50iMHz             pins 2 & 3 closed        pins 2 & 6, 4 & 8
                                                          closed

         50MHz              pins 1 & 2 closed        pins 3 & 7 closed

         66iMHz             pins 2 & 3 closed        pins 3 & 7, 4 & 8
                                                          closed

  VESA WAIT STATE CONFIGURATION

   Wait states          ID2

  0 wait states        Open

  1 wait state        Closed

  BUS SPEED CONFIGURATION

  CPU speed        ID3

   <= 33MHz        Open

   > 33MHz        Closed

                      PAL JUMPER CONFIGURATION

  Revision     JP96        TP1         TP2         TP3        TP4

   Rev. 0      Open       2 & 3       2 & 3       2 & 3      2 & 3

   Rev. A     Closed      1 & 2       1 & 2       1 & 2      1 & 2

  Note: Pins designated should be in the closed position.

                    BOARD REVISION JUMPER CONFIGURATION

    Revision         JP78          JP79           JP97           JP98

     Rev. 0       pins 1 & 2     pins 1 & 2    pins 1 & 2     pins 1 & 2
                    closed        closed         closed         closed

     Rev. A       pins 2 & 3     pins 2 & 3    pins 2 & 3     pins 2 & 3
                    closed        closed         closed         closed

  Note: These jumpers configure the board revision.

