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       # GIGA-BYTE TECHNOLOGY CO., LTD.
       
          GA-486TA
       
          Processor   80486SX/80486DX/80486DX2/Pentium Overdrive         
          Processor   25/33/40(internal)/50(internal)/50/66(internal)MHz 
          Speed       
          Chip Set    OPTI                                               
          Max.        128MB                                              
          Onboard     
          DRAM        
          Cache       64/128/256/512KB                                   
          BIOS        AMI                                                
          Dimensions  330mm x 218mm                                      
          I/O Options 32-bit VESA local bus slots (2)                    
          NPU Options None                                               
       
   IMG IMG 1
          
       
          +------------------------------------------------------------+
          |                        CONNECTIONS                         |
          |------------------------------------------------------------|
          | Purpose      | Location | Purpose               | Location |
          |--------------+----------+-----------------------+----------|
          | Power LED &  |    J1    | Turbo switch          |    J4    |
          | keylock      |          |                       |          |
          |--------------+----------+-----------------------+----------|
          | Reset switch |    J2    | Turbo LED             |    J5    |
          |--------------+----------+-----------------------+----------|
          | Speaker      |    J3    | 32-bit VESA Local bus |  SL1 &   |
          |              |          | slots                 |   SL2    |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 USER CONFIGURABLE SETTINGS                 |
          |------------------------------------------------------------|
          |               Function               | Jumper |  Position  |
          |--------------------------------------+--------+------------|
          | » | CPU type select 80486DX/P24T     |   J6   | pins 1 & 2 |
          |   |                                  |        |   closed   |
          |---+----------------------------------+--------+------------|
          |   | CPU type select 80486SX          |   J6   | pins 2 & 3 |
          |   |                                  |        |   closed   |
          |---+----------------------------------+--------+------------|
          | » | Monitor type select color        |  J14   |   Closed   |
          |---+----------------------------------+--------+------------|
          |   | Monitor type select monochrome   |  J14   |    Open    |
          |---+----------------------------------+--------+------------|
          | » | CMOS memory normal operation     |  J17   |    Open    |
          |---+----------------------------------+--------+------------|
          |   | CMOS memory clear                |  J17   |   Closed   |
          |---+----------------------------------+--------+------------|
          | » | Factory configured - do not      |  J18   | pins 2 & 3 |
          |   | alter                            |        |   closed   |
          |---+----------------------------------+--------+------------|
          | » | Factory configured - do not      |  J23   | 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        |
          |------------------+--------------------+--------------------|
          |       32MB       |     (4) 4M x 9     |     (4) 4M x 9     |
          |------------------+--------------------+--------------------|
          |       64MB       |    (4) 16M x 9     |        NONE        |
          |------------------+--------------------+--------------------|
          |      128MB       |    (4) 16M x 9     |    (4) 16M 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) 32K x 8  |
          |------------+---------------+---------------+---------------|
          |   256KB    |  (4) 32K x 8  |  (4) 32K x 8  |  (1) 32K x 8  |
          |------------+---------------+---------------+---------------|
          |   512KB    | (1) 128K x 8  |     NONE      |  (1) 32K x 8  |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                 CACHE JUMPER CONFIGURATION                 |
          |------------------------------------------------------------|
          |  Size   |    J8    |   J9    |   J10   |        J11        |
          |---------+----------+---------+---------+-------------------|
          |  64KB   |   Open   |  Open   |  Open   |        N/A        |
          |---------+----------+---------+---------+-------------------|
          |  128KB  |   Open   | Closed  |  Open   | pins 1 & 2 closed |
          |---------+----------+---------+---------+-------------------|
          |  256KB  |   Open   | Closed  | Closed  | pins 2 & 3 closed |
          |---------+----------+---------+---------+-------------------|
          |  512KB  |  Closed  | Closed  | Closed  | pins 1 & 2 closed |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |                  CPU SPEED CONFIGURATION                   |
          |------------------------------------------------------------|
          | Speed  |       JC0       |      JC1       |      JC2       |
          |--------+-----------------+----------------+----------------|
          | 25MHz  |   pins 2 & 3    |   pins 1 & 2   |   pins 1 & 2   |
          |        |     closed      |     closed     |     closed     |
          |--------+-----------------+----------------+----------------|
          | 33MHz  |   pins 2 & 3    |   pins 2 & 3   |   pins 2 & 3   |
          |        |     closed      |     closed     |     closed     |
          |--------+-----------------+----------------+----------------|
          | 40MHz  |   pins 2 & 3    |   pins 2 & 3   |   pins 1 & 2   |
          |        |     closed      |     closed     |     closed     |
          |--------+-----------------+----------------+----------------|
          | 50iMHz |   pins 2 & 3    |   pins 1 & 2   |   pins 1 & 2   |
          |        |     closed      |     closed     |     closed     |
          |--------+-----------------+----------------+----------------|
          | 50MHz  |   pins 1 & 2    |   pins 1 & 2   |   pins 2 & 3   |
          |        |     closed      |     closed     |     closed     |
          |--------+-----------------+----------------+----------------|
          | 66iMHz |   pins 2 & 3    |   pins 2 & 3   |   pins 2 & 3   |
          |        |     closed      |     closed     |     closed     |
          +------------------------------------------------------------+
       
          +------------------------------------------------------------+
          |           VESA WAIT STATE/BUS SPEEDCONFIGURATION           |
          |------------------------------------------------------------|
          |   CPU speed   |  Wait states  |     J31      |     J32     |
          |---------------+---------------+--------------+-------------|
          |    £ 33MHz    | 0 wait states |     Open     |    Open     |
          |---------------+---------------+--------------+-------------|
          |    > 33MHz    | 1 wait state  |    Closed    |   Closed    |
          +------------------------------------------------------------+