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                                               

<gopher://bitreich.org/I/th99/m/E-H/32006-1.png>
   

   +------------------------------------------------------------+
   |                        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     |
   |---------------+---------------+--------------+-------------|
   |    GBP 33MHz    | 0 wait states |     Open     |    Open     |
   |---------------+---------------+--------------+-------------|
   |    > 33MHz    | 1 wait state  |    Closed    |   Closed    |
   +------------------------------------------------------------+