SILICON STAR INTERNATIONAL, INC.
================================

   AT420/AT425/AT433/AT450

   Processor          80486SX/80486DX                             
   Processor Speed    20/25/33/50MHz                              
   Chip Set           SIS                                         
   Max. Onboard DRAM  32MB                                        
   Cache              32/64/128/256/512/1024KB                    
   BIOS               AMI                                         
   Dimensions         330mm x 218mm                               
   I/O Options        None                                        
   NPU Options        4167                                        

<gopher://bitreich.org/I/th99/m/A-B/30702-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   | Purpose             | Location | Purpose        | Location |
   |---------------------+----------+----------------+----------|
   | Speaker             |   CN1    | Turbo switch   |   JP1    |
   |---------------------+----------+----------------+----------|
   | Power LED & keylock |   CN2    | Turbo LED      |   JP2    |
   |---------------------+----------+----------------+----------|
   | External battery    |   CN3    | Reset switch   |   SW1    |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 USER CONFIGURABLE SETTINGS                 |
   |------------------------------------------------------------|
   |               Function               | Jumper |  Position  |
   |--------------------------------------+--------+------------|
   |>> | CMOS memory normal operation     |  JP5   | pins 1 & 2 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |   | CMOS memory clear                |  JP5   | pins 2 & 3 |
   |   |                                  |        |   closed   |
   |---+----------------------------------+--------+------------|
   |>> | Monitor type select monochrome   |  JP7   |    Open    |
   |---+----------------------------------+--------+------------|
   |   | Monitor type select color        |  JP7   |   Closed   |
   |---+----------------------------------+--------+------------|
   |>> | Factory configured - do not      |  JP8   |    Open    |
   |   | alter                            |        |            |
   |------------------------------------------------------------|
   | Note:Jumper JPX3 is closed using an 8-pin terminating      |
   | resistor.                                                  |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     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        |
   |------------------+--------------------+--------------------|
   |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                    CACHE CONFIGURATION                     |
   |------------------------------------------------------------|
   |  Size  |   Bank 0    |   Bank 1    |    TAG     | Location |
   |--------+-------------+-------------+------------+----------|
   |  32KB  | (4) 8K x 8  |    NONE     | (1) 8K x 8 |   T-1    |
   |--------+-------------+-------------+------------+----------|
   |  32KB  | (4) 8K x 8  | (4) 8K x 8  | (2) 16K x  |   T-2    |
   |        |             |             |     4      |          |
   |--------+-------------+-------------+------------+----------|
   |  64KB  | (4) 8K x 8  | (4) 8K x 8  | (1) 8K x 8 |   T-1    |
   |--------+-------------+-------------+------------+----------|
   |  64KB  | (4) 8K x 8  | (4) 8K x 8  | (2) 16K x  |   T-2    |
   |        |             |             |     4      |          |
   |--------+-------------+-------------+------------+----------|
   | 128KB  | (4) 32K x 8 |    NONE     | (1) 8K x 8 |   T-1    |
   |--------+-------------+-------------+------------+----------|
   | 128KB  | (4) 32K x 8 |    NONE     | (2) 16K x  |   T-2    |
   |        |             |             |     4      |          |
   |--------+-------------+-------------+------------+----------|
   | 256KB  | (4) 32K x 8 | (4) 32K x 8 | (2) 16K x  |   T-2    |
   |        |             |             |     4      |          |
   |--------+-------------+-------------+------------+----------|
   | 512KB  | (4) 128K x  |    NONE     | (1) 32K x  |   T-1    |
   |        |      8      |             |     8      |          |
   |--------+-------------+-------------+------------+----------|
   | 512KB  | (4) 128K x  |    NONE     | (2) 64K x  |   T-2    |
   |        |      8      |             |     4      |          |
   |--------+-------------+-------------+------------+----------|
   | 1024KB | (4) 128K x  | (4) 128K x  | (1) 128K x |   T-1    |
   |        |      8      |      8      |     8      |          |
   |--------+-------------+-------------+------------+----------|
   | 1024KB | (4) 128K x  | (4) 128K x  | (2) 64K x  |   T-2    |
   |        |      8      |      8      |     4      |          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   |  Size   |   JP3   |   JP4   |      JPX4      |    JPX5     |
   |---------+---------+---------+----------------+-------------|
   |  32KB   |  Open   |  Open   |   pins 1 - 8   | pins 1 - 8  |
   |         |         |         |     closed     |   closed    |
   |---------+---------+---------+----------------+-------------|
   |  64KB   |  Open   |  Open   |  pins 9 - 16   | pins 3 - 10 |
   |         |         |         |     closed     |   closed    |
   |---------+---------+---------+----------------+-------------|
   |  128KB  |  Open   | Closed  |   pins 1 - 8   | pins 5 - 12 |
   |         |         |         |     closed     |   closed    |
   |---------+---------+---------+----------------+-------------|
   |  256KB  |  Open   | Closed  |  pins 9 - 16   | pins 7 - 14 |
   |         |         |         |     closed     |   closed    |
   |---------+---------+---------+----------------+-------------|
   |  512KB  |  Open   | Closed  |   pins 1 - 8   | pins 9 - 16 |
   |         |         |         |     closed     |   closed    |
   |---------+---------+---------+----------------+-------------|
   | 1024KB  | Closed  | Closed  |  pins 9 - 16   | pins 9 - 16 |
   |         |         |         |     closed     |   closed    |
   |------------------------------------------------------------|
   | Note:Jumpers JPX4 & JPX5 are closed using 8-pin            |
   | terminating resistors.                                     |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 CACHE JUMPER CONFIGURATION                 |
   |------------------------------------------------------------|
   |        Type        |        JP6        |       JPX3        |
   |--------------------+-------------------+-------------------|
   |      80486SX       |      Closed       |       Open        |
   |--------------------+-------------------+-------------------|
   |      80486DX       |       Open        |      Closed       |
   +------------------------------------------------------------+