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

   SY-020H

                                                                  
   Processor       80486SX/80487SX/80486DX                        
   Processor Speed 16/20/25/33/40/50(internal)/50/66(internal)MHz 
   Chip Set        SIS                                            
   Max. Onboard    32MB                                           
   DRAM            
   Cache           32/64/128/256KB                                
   BIOS            AMI                                            
   Dimensions      245mm x 220mm                                  
   I/O Options     None                                           
   NPU Options     4167                                           
                                                                  

<gopher://bitreich.org/I/th99/m/S-T/31012-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose        | Location  | Purpose           | Location  |
   |----------------+-----------+-------------------+-----------|
   | Power LED &    |    J17    | External battery  |    J20    |
   | keylock        |           |                   |           |
   |----------------+-----------+-------------------+-----------|
   | Speaker        |    J18    | Turbo switch      |    J21    |
   |----------------+-----------+-------------------+-----------|
   | Reset switch   |    J19    | Turbo LED         |    J22    |
   |------------------------------------------------------------|
   | Note:The oscillator at OSC1 must match the external speed  |
   | of the CPU installed.                                      |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |               Function               | Jumper |  Position  |
   |--------------------------------------+--------+------------|
   |>> | Monitor type select monochrome   |  JP3   |    Open    |
   |---+----------------------------------+--------+------------|
   |   | Monitor type select color        |  JP3   |   Closed   |
   |---+----------------------------------+--------+------------|
   |>> | CMOS memory normal operation     |  JP5   | pins 1 & 2 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | CMOS memory clear                |  JP5   | pins 2 & 3 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Power good signal detect from    |  JP7   | pins 1 & 2 |
   |   | board                            |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Power good signal detect from    |  JP7   | pins 2 & 3 |
   |   | power supply                     |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Keyboard BIOS clock source       |  JP18  | pins 1 & 2 |
   |   | select programmable timer        |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | Keyboard BIOS clock source       |  JP18  | pins 2 & 3 |
   |   | select 7MHz                      |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | CPU speed select 3 to 25MHz      |  JP19  | pins 1 & 2 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | CPU speed select < 25MHz         |  JP19  | pins 2 & 3 |
   |   |                                  |        |   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      |
   |------------+---------------+---------------+---------------|
   |    32KB    |  (4) 8K x 8   |     NONE      |  (2) 4K x 4   |
   |------------+---------------+---------------+---------------|
   |    64KB    |  (4) 8K x 8   |  (4) 8K x 8   |  (2) 4K x 4   |
   |------------+---------------+---------------+---------------|
   |   128KB    |  (4) 32K x 8  |     NONE      |  (2) 16K x 4  |
   |------------+---------------+---------------+---------------|
   |   256KB    |  (4) 32K x 8  |  (4) 32K x 8  |  (2) 16K x 4  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   | Size | JP8 | JP9 |JP10 |JP11 |JP12 |JP13 |JP14 |JP15 |JP16 |
   |------+-----+-----+-----+-----+-----+-----+-----+-----+-----|
   | 32KB |1 & 2|1 & 2|1 & 2|1 & 2|1 & 2|1 & 2|1 & 2|1 & 2|1 & 2|
   |------+-----+-----+-----+-----+-----+-----+-----+-----+-----|
   | 64KB |2 & 3|1 & 2|1 & 2|2 & 3|1 & 2|1 & 2|2 & 3|2 & 3|1 & 2|
   |------+-----+-----+-----+-----+-----+-----+-----+-----+-----|
   |128KB |2 & 3|2 & 3|1 & 2|2 & 3|2 & 3|1 & 2|1 & 2|1 & 2|2 & 3|
   |------+-----+-----+-----+-----+-----+-----+-----+-----+-----|
   |256KB |2 & 3|2 & 3|2 & 3|2 & 3|2 & 3|2 & 3|2 & 3|2 & 3|2 & 3|
   |------------------------------------------------------------|
   |Note: Pins designated should be in the closed position.     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     CPU CONFIGURATION                      |
   |------------------------------------------------------------|
   |   Type   |       JP24        |  JP25   |       JP26        |
   |----------+-------------------+---------+-------------------|
   | 80486SX  | pins 2 & 3 closed |  Open   |       Open        |
   |----------+-------------------+---------+-------------------|
   | 80487SX  | pins 1 & 2 closed | Closed  | pins 2 & 3 closed |
   |----------+-------------------+---------+-------------------|
   | 80486DX  | pins 1 & 2 closed | Closed  | pins 1 & 2 closed |
   +------------------------------------------------------------+