BIOSTAR MICROTECH INTERNATIONAL CORPORATION
===========================================

   MB-1425/33/40/50UCV-A

   Processor    CX486S/80486SX/80487SX/80486DX/ODP486SX/80486DX2/ 
                                                                  
                Pentium Overdrive                                 
   Processor    25/33/40/50(internal)/50/66(internal)MHz          
   Speed        
   Chip Set     Biostar                                           
   Max. Onboard 64MB                                              
   DRAM         
   Cache        32/64/128/256KB                                   
   BIOS         AMI                                               
   Dimensions   330mm x 218mm                                     
   I/O Options  32-bit VESA local bus slots (3)                   
   NPU Options  None                                              

<gopher://bitreich.org/I/th99/m/A-B/31866-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose          | Location | Purpose           | Location |
   |------------------+----------+-------------------+----------|
   | External battery |   JP8    | Power LED &       |  JP15E   |
   |                  |          | keylock           |          |
   |------------------+----------+-------------------+----------|
   | 5V ground        |  JP15A   | Speaker           |  JP15F   |
   |------------------+----------+-------------------+----------|
   | Turbo switch     |  JP15B   | 32-bit VESA Local |    V1    |
   |                  |          | bus slot          |          |
   |------------------+----------+-------------------+----------|
   | Reset switch     |  JP15C   | 32-bit VESA Local |    V2    |
   |                  |          | bus slot          |          |
   |------------------+----------+-------------------+----------|
   | Turbo LED        |  JP15D   | 32-bit VESA Local |    V3    |
   |                  |          | bus slot          |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |               Function               | Jumper |  Position  |
   |--------------------------------------+--------+------------|
   |>> | CMOS memory normal operation     |  JP8   | pins 2 & 3 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | CMOS memory clear                |  JP8   | pins 3 & 4 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Power good signal detect from    |  JP11  | pins 1 & 2 |
   |   | power supply                     |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Power good signal detect from    |  JP11  | pins 2 & 3 |
   |   | board                            |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | One CPU (PQFP or PGA) on board   |  JP12  | pins 1 & 2 |
   |   | installed                        |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Two CPUs (enabled PGA and        |  JP12  | pins 2 & 3 |
   |   | disabled PQFP) on board          |        |   closed   |
   |   | installed                        |        |            |
   |---+----------------------------------+--------+------------|
   |>> | Monitor type select color        |  JP14  | pins 2 & 3 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Monitor type select monochrome   |  JP14  | pins 1 & 2 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Add on card select normal        |  JP28  | pins 1 & 2 |
   |   | operation                        |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Add on card select Weitek 9000   |  JP28  | pins 2 & 3 |
   |   | VGA card installed               |        |   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) 1M x 9     |    (4) 256K x 9    |
   |------------------+--------------------+--------------------|
   |       8MB        |     (4) 1M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       16MB       |     (4) 4M x 9     |     (4) 4M x 9     |
   |------------------+--------------------+--------------------|
   |       17MB       |     (4) 4M x 9     |    (4) 256K x 9    |
   |------------------+--------------------+--------------------|
   |       20MB       |     (4) 4M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
   |------------------+--------------------+--------------------|
   |       64MB       |    (4) 16M x 9     |        NONE        |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    CACHE CONFIGURATION                     |
   |------------------------------------------------------------|
   | Size  |     Max     |   Bank 0   |   Bank 1   |    TAG     |
   |       |  Cachable   |            |            |            |
   |-------+-------------+------------+------------+------------|
   | 32KB  |     8MB     | (4) 8K x 8 |    NONE    | (1) 8K x 8 |
   |-------+-------------+------------+------------+------------|
   | 64KB  |    16MB     | (4) 8K x 8 | (4) 8K x 8 | (1) 8K x 8 |
   |-------+-------------+------------+------------+------------|
   | 128KB |    32MB     | (4) 32K x  |    NONE    | (1) 8K x 8 |
   |       |             |     8      |            |            |
   |-------+-------------+------------+------------+------------|
   | 256KB |    64MB     | (4) 32K x  | (4) 32K x  | (1) 16K x  |
   |       |             |     8      |     8      |     8      |
   |-------+-------------+------------+------------+------------|
   | 256KB |    64MB     | (4) 32K x  | (4) 32K x  | (1) 32K x  |
   |       |             |     8      |     8      |     8      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   | Size  |    JP5     |   JP6    |  JP7   |  JP9   |   JP10   |
   |-------+------------+----------+--------+--------+----------|
   | 32KB  | pins 2 & 3 |   Open   |  Open  |  Open  |   Open   |
   |-------+------------+----------+--------+--------+----------|
   | 64KB  | pins 1 & 2 |   Open   |  Open  | Closed |   Open   |
   |-------+------------+----------+--------+--------+----------|
   | 128KB | pins 2 & 3 | pins 2 & | Closed | Closed |   Open   |
   |       |            |    3     |        |        |          |
   |-------+------------+----------+--------+--------+----------|
   | 256KB | pins 1 & 2 | pins 1 & | Closed | Closed | pins 2 & |
   |       |            |    2     |        |        |    3     |
   |-------+------------+----------+--------+--------+----------|
   | 256KB | pins 1 & 2 | pins 1 & | Closed | Closed | pins 1 & |
   |       |            |    2     |        |        |    2     |
   |------------------------------------------------------------|
   | Note:Pins designated should be in the closed position.     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   CPU TYPE CONFIGURATION                   |
   |------------------------------------------------------------|
   |       Type        |       JP16        |        JP17        |
   |-------------------+-------------------+--------------------|
   |      CX486S       |       Open        | pins 2 & 3 closed  |
   |-------------------+-------------------+--------------------|
   |      80486SX      |       Open        | pins 2 & 3 closed  |
   |-------------------+-------------------+--------------------|
   |      80487SX      | pins 2 & 3 closed | pins 1 & 2 and 3 & |
   |                   |                   |      4 closed      |
   |-------------------+-------------------+--------------------|
   |      80486DX      | pins 1 & 2 closed | pins 1 & 2 and 3 & |
   |                   |                   |      4 closed      |
   |-------------------+-------------------+--------------------|
   |     ODP486SX      | pins 2 & 3 closed | pins 1 & 2 and 3 & |
   |                   |                   |      4 closed      |
   |-------------------+-------------------+--------------------|
   |     80486DX2      | pins 1 & 2 closed | pins 1 & 2 and 3 & |
   |                   |                   |      4 closed      |
   |-------------------+-------------------+--------------------|
   | Pentium Overdrive | pins 1 & 2 closed | pins 1 & 2 and 3 & |
   |                   |                   |      4 closed      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CPU SPEED CONFIGURATION                   |
   |------------------------------------------------------------|
   |   Speed    |   JP21    |   JP22    |   JP23    |   JP27    |
   |------------+-----------+-----------+-----------+-----------|
   |   25MHz    |  Closed   |   Open    |  Closed   |   Open    |
   |------------+-----------+-----------+-----------+-----------|
   |   33MHz    |  Closed   |  Closed   |   Open    |   Open    |
   |------------+-----------+-----------+-----------+-----------|
   |   40MHz    |   Open    |   Open    |  Closed   |  Closed   |
   |------------+-----------+-----------+-----------+-----------|
   |  50i MHz   |  Closed   |   Open    |  Closed   |   Open    |
   |------------+-----------+-----------+-----------+-----------|
   |   50MHz    |   Open    |  Closed   |   Open    |  Closed   |
   |------------+-----------+-----------+-----------+-----------|
   |  66i MHz   |  Closed   |  Closed   |   Open    |   Open    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                VESA BUS SPEED CONFIGURATION                |
   |------------------------------------------------------------|
   |     Mode     | JP19  | JP20  | JP25  | JP26  | JP29 | JP30 |
   |              |       |       | (V2)  | (V1)  | (V3) | (V2  |
   |              |       |       |       |       |      |  &   |
   |              |       |       |       |       |      | V3)  |
   |--------------+-------+-------+-------+-------+------+------|
   | Synchronous  | pins  | pins  | pins  | pins  | pins | pins |
   |              | 1 & 2 | 1 & 2 | 1 & 2 | 1 & 2 | 1 &  | 1 &  |
   |              |       |       |       |       |  2   |  2   |
   |--------------+-------+-------+-------+-------+------+------|
   | Asynchronous | pins  | pins  | pins  | pins  | pins | pins |
   |              | 2 & 3 | 2 & 3 | 2 & 3 | 2 & 3 | 2 &  | 2 &  |
   |              |       |       |       |       |  3   |  3   |
   |------------------------------------------------------------|
   | Note:Pins designated should be in the closed position.     |
   |                                                            |
   | When V2 & V3 are used at the same time, JP25 must be left  |
   | open.                                                      |
   +------------------------------------------------------------+