MICROFIELD GRAPHICS, INC.
=========================

   T8C

   Category                     Video                             
   Video Types Supported        CGA/EGA/VGA/XVGA                  
   Video Processor              Trident                           
   Highest Resolution Supported 1280 x 1024                       
   Data Bus Type                16-bit ISA                        
   Memory Type                  VRAM                              
   Maximum Onboard Memory       2048KB                            

<gopher://bitreich.org/I/th99/v/M-O/50308-1.png>
   

   +------------------------------------------------------------+
   |                        CONNECTIONS                         |
   |------------------------------------------------------------|
   |               Purpose                |      Location       |
   |--------------------------------------+---------------------|
   | 15-pin analog video port             |         J1          |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                EMULATION TYPE CONFIGURATION                |
   |------------------------------------------------------------|
   |        Type         |   Address    |    JP1    |   JP1A    |
   |---------------------+--------------+-----------+-----------|
   |>> |  VGA/EGA with   | 3DDh - 3DEh  | Pins 1 &2 | Pins 1 &  |
   |   | High Resolution |              |  closed   | 2 closed  |
   |---+-----------------+--------------+-----------+-----------|
   |   |  CGA with High  | 3DDh - 3DEh  | Pins 2 &  | Pins 2 &  |
   |   |   Resolution    |              | 3 closed  | 3 closed  |
   |---+-----------------+--------------+-----------+-----------|
   |   | High resolution | 3DDh - 3DEh  | Pins 1 &  | Pins 2 &  |
   |   |                 |              | 2 closed  | 3 closed  |
   |---+-----------------+--------------+-----------+-----------|
   |   | High resolution | 30Dh - 30Eh  | Pins 2 &  | Pins 1 &  |
   |   |                 |              | 3 closed  | 2 closed  |
   |------------------------------------------------------------|
   |      Note:Address setting 30Dh - 30Eh requires special     |
   |      device driver software for operation.                 |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                 ALTERNATE I/O PORT ADDRESS                 |
   |------------------------------------------------------------|
   |          Address           |              S6               |
   |----------------------------+-------------------------------|
   |>> |          3xx           |       Pins 1 & 2 closed       |
   |---+------------------------+-------------------------------|
   |   |          1xx           |       Pins 2 & 3 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                      BIOS SIZE SELECT                      |
   |------------------------------------------------------------|
   |            Size            |              J10              |
   |----------------------------+-------------------------------|
   |            16KB            |       Pins 1 & 2 closed       |
   |----------------------------+-------------------------------|
   |            32KB            |       Pins 2 & 3 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  VIDEO FREQUENCY SETTINGS                  |
   |------------------------------------------------------------|
   | Frequency  |      Mode      |    S1    |   S2    |   S7    |
   |------------+----------------+----------+---------+---------|
   |   1280 x   | Non-interlaced | Pins 2 & | Pins 2  |  Open   |
   |    1024    |                | 3 closed |   & 3   |         |
   |            |                |          | closed  |         |
   |------------+----------------+----------+---------+---------|
   |   1280 x   |   Interlaced   | Pins 2 & | Pins 1  |  Open   |
   |    1024    |                | 3 closed |   & 2   |         |
   |            |                |          | closed  |         |
   |------------+----------------+----------+---------+---------|
   |   1280 x   | Non-interlaced | Pins 2 & | Pins 2  | Closed  |
   |    1024    |                | 3 closed |   & 3   |         |
   |            |                |          | closed  |         |
   |------------+----------------+----------+---------+---------|
   | 1024 x 768 | Non-interlaced | Pins 1 & | Pins 1  | Closed  |
   |            |                | 2 closed |   & 2   |         |
   |            |                |          | closed  |         |
   |------------------------------------------------------------|
   | Note: The last two settings require an optional dual       |
   | crystal and 512KB microcode EPROM.                         |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                     DMA CHANNEL SELECT                     |
   |------------------------------------------------------------|
   |   DRQ    |  Dack   |        S5         |        S8         |
   |----------+---------+-------------------+-------------------|
   |>> |  7   |    7    | Pins 1 & 2 closed | Pins 1 & 2 closed |
   |---+------+---------+-------------------+-------------------|
   |   |  6   |    6    | Pins 3 & 4 closed | Pins 3 & 4 closed |
   |---+------+---------+-------------------+-------------------|
   |   |  5   |    5    | Pins 5 & 6 closed | Pins 5 & 6 closed |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                   VIDEO INTERRUPT SELECT                   |
   |------------------------------------------------------------|
   |            IRQ             |              S3               |
   |----------------------------+-------------------------------|
   |>> |         IRQ10          |       Pins 3 & 4 closed       |
   |---+------------------------+-------------------------------|
   |   |          IRQ9          |       Pins 1 & 2 closed       |
   |---+------------------------+-------------------------------|
   |   |         IRQ11          |       Pins 5 & 6 closed       |
   |---+------------------------+-------------------------------|
   |   |         IRQ12          |       Pins 7 & 8 closed       |
   |---+------------------------+-------------------------------|
   |   |        Disabled        |      Pins 9 & 10 closed       |
   +------------------------------------------------------------+

   +------------------------------------------------------------+
   |                  MONITOR CONNECTOR SENSE                   |
   |------------------------------------------------------------|
   |     Connector Sense      |       J8       |       J9       |
   |--------------------------+----------------+----------------|
   |>>       |    Disabled    |   Pins 1 & 2   |   Pins 1 & 2   |
   |         |                |     closed     |     closed     |
   |---------+----------------+----------------+----------------|
   |         |    Enabled     |   Pins 2 & 3   |   Pins 2 & 3   |
   |         |                |     closed     |     closed     |
   |------------------------------------------------------------|
   | Note: An optional microcode EPROM must be installed before |
   | Connector Sense can be enabled.                            |
   +------------------------------------------------------------+