
BIOSTAR MICROTECH INTERNATIONAL CORPORATION

MB-1420/1425/1433V

Processor        80486SX/80487SX/80486DX/80486DX2/Pentium Overdrive
Processor Speed  20/25/33/50(internal)/50/66(internal)MHz
Chip Set         VLSI
Max. Onboard DRAM32MB
Cache            None
BIOS             Award
Dimensions       230mm x 218mm
I/O Options      None
NPU Options      None

[Image]

                                CONNECTIONS

  Purpose                   Location   Purpose                   Location

  Speaker                     J1       Turbo switch                J5

  Power LED & keylock         J2       5v DC ground                J6

  Turbo LED                   J3       External battery            CN2

  Reset switch                J4

                        USER CONFIGURABLE SETTINGS

                Function                     Jumper          Position

     Keyboard type select BTC keyboard        JP1            Closed

      Normal operation                         JP1             Open

     AT bus clock mode select                 JP2           pins 1 & 2
      asynchronous                                            closed

      AT bus clock mode select                 JP2           pins 2 & 3
      synchronous                                             closed

     Monitor type select monochrome           JP3             Open

      Monitor type select color                JP3            Closed

     8042 turbo control pin select pin        JP4           pins 1 & 2
      30 closed                                               closed

      8042 turbo control pin select pin        JP4           pins 2 & 3
      23 closed                                               closed

     CMOS memory normal operation             JP5           pins 1 & 2
                                                              closed

      CMOS memory clear                        JP5           pins 3 & 4
                                                              closed

     On board keyboard fuse enabled           JP9             Open

      On board keyboard fuse disabled          JP9            Closed

              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

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

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

      16MB        (4) 4M x 9         NONE

      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

                CPU TYPE CONFIGURATION (PQFP CPU INSTALLED)

           Type                JP7         JP8        JP14        JP15

      80486SX (PQFP) &        1 & 2       2 & 3      1 & 2        1 & 2
     upgrade to DX/DX2

      80486SX (PQFP) &        open        1 & 2      2 & 3        2 & 3
   upgrade to Overdrive

  Note: Pins designated should be in the closed position.

              CPU TYPE CONFIGURATION (PGA ONLY CPU INSTALLED)

       Type             JP7            JP8           JP14         JP15

      80487SX        pins 1 & 2     pins 2 & 3     pins 2 & 3     Open
                       closed        closed         closed

    80486DX/DX2      pins 1 & 2     pins 2 & 3     pins 1 & 2     Open
                       closed        closed         closed

  Note: The PQFP CPU is optional and may not be present. If there is no
  PQFP, use the above settings.

