SOYO COMPUTER CO., LTD.
=======================

   486 VESA

   Processor    80486SX/80487SX/80486DX/80486DX2/Pentium          
                Overdrive                                         
   Processor    25/33/40/50(internal)/50/66(internal)MHz          
   Speed        
   Chip Set     SIS                                               
   Max. Onboard 32MB                                              
   DRAM         
   Cache        64/128/256KB                                      
   BIOS         AMI                                               
   Dimensions   230mm x 218mm                                     
   I/O Options  32-bit VESA local bus slots (2)                   
   NPU Options  None                                              

<gopher://bitreich.org/I/th99/m/S-T/32009-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose          | Location | Purpose           | Location |
   |------------------+----------+-------------------+----------|
   | Power LED &      |   J17    | Turbo switch      |   J21    |
   | keylock          |          |                   |          |
   |------------------+----------+-------------------+----------|
   | Speaker          |   J18    | Turbo LED         |   J22    |
   |------------------+----------+-------------------+----------|
   | Reset switch     |   J19    | 32-bit VESA Local |  SL1 &   |
   |                  |          | bus slots         |   SL2    |
   |------------------+----------+-------------------+----------|
   | External battery |   J20    |                   |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |               Function               | Jumper |  Position  |
   |--------------------------------------+--------+------------|
   |>> | Monitor type select monochrome   |  JP3   |    Open    |
   |---+----------------------------------+--------+------------|
   |   | Monitor type select              |  JP3   |   Closed   |
   |   | color/EGA/VGA                    |        |            |
   |---+----------------------------------+--------+------------|
   |>> | CMOS memory normal operation     |  JP5   | pins 1 & 2 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | CMOS memory clear                |  JP5   | pins 2 & 3 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Factory configured - do not      |  JP6   | pins 2 & 3 |
   |   | alter                            |        |   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        |
   |------------------+--------------------+--------------------|
   |       8MB        |     (4) 1M x 9     |     (4) 1M x 9     |
   |------------------+--------------------+--------------------|
   |       16MB       |     (4) 4M x 9     |        NONE        |
   |------------------+--------------------+--------------------|
   |       20MB       |     (4) 1M x 9     |     (4) 4M x 9     |
   |------------------+--------------------+--------------------|
   |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    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    |  (4) 32K x 8  |  (4) 32K x 8  |  (1) 32K x 8  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   | Size  |      JP14       |      JP15       |      JP21      |
   |-------+-----------------+-----------------+----------------|
   | 64KB  |   pins 1 & 2    |      Open       |   pins 2 & 3   |
   |       |     closed      |                 |     closed     |
   |-------+-----------------+-----------------+----------------|
   | 128KB |   pins 2 & 3    |   pins 1 & 2    |   pins 2 & 3   |
   |       |     closed      |     closed      |     closed     |
   |-------+-----------------+-----------------+----------------|
   | 256KB |   pins 2 & 3    |   pins 2 & 3    |   pins 1 & 2   |
   |       |     closed      |     closed      |     closed     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   CPU TYPE CONFIGURATION                   |
   |------------------------------------------------------------|
   |    Type     |  JP8   |  JP9   |     JP12      |    JP13    |
   |-------------+--------+--------+---------------+------------|
   |   80486SX   |  Open  |  Open  |     Open      | pins 2 & 3 |
   |   (PQFP)    |        |        |               |   closed   |
   |-------------+--------+--------+---------------+------------|
   |   80486SX   |  Open  | Closed |     Open      | pins 2 & 3 |
   |    (PGA)    |        |        |               |   closed   |
   |-------------+--------+--------+---------------+------------|
   |   80487SX   | Closed | Closed |  pins 2 & 3   | pins 1 & 2 |
   |             |        |        |    closed     |   closed   |
   |-------------+--------+--------+---------------+------------|
   | 80846DX/DX2 | Closed | Closed |  pins 1 & 2   | pins 1 & 2 |
   |             |        |        |    closed     |   closed   |
   |-------------+--------+--------+---------------+------------|
   |  Overdrive  | Closed | Closed |  pins 2 & 3   | pins 1 & 2 |
   |             |        |        |    closed     |   closed   |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  CPU SPEED CONFIGURATION                   |
   |------------------------------------------------------------|
   |     Speed     |     JP16     |     JP17     |     JP18     |
   |---------------+--------------+--------------+--------------|
   |     25MHz     |    Closed    |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     33MHz     |     Open     |    Closed    |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     40MHz     |    Closed    |     Open     |     Open     |
   |---------------+--------------+--------------+--------------|
   |    50iMHz     |    Closed    |     Open     |    Closed    |
   |---------------+--------------+--------------+--------------|
   |     50MHz     |     Open     |    Closed    |     Open     |
   |---------------+--------------+--------------+--------------|
   |    66iMHz     |     Open     |    Closed    |    Closed    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |          VESA WAIT STATE/BUS SPEED CONFIGURATION           |
   |------------------------------------------------------------|
   | CPU speed |  Wait states  |       JP19        |    JP20    |
   |-----------+---------------+-------------------+------------|
   |  GBP 33MHz  | 0 wait states | pins 1 & 2 closed | pins 1 & 2 |
   |           |               |                   |   closed   |
   |-----------+---------------+-------------------+------------|
   |  > 33MHz  | 1 wait state  | pins 2 & 3 closed | pins 2 & 3 |
   |           |               |                   |   closed   |
   +------------------------------------------------------------+