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0:4A8h                   Double-Word Pointer to Video Parameters for the EGA

 Length: 4 bytes

    This double-word pointer points to a list of pointers that contain
    various parameters and overrides for the Enhanced Graphics Adapter
    (EGA).

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  Table Pointed to by Double-Word at 0:4A8h

     Offset  Size (bytes)  Description
      00h         4        Video Parameter Table Pointer
      04h         4        Dynamic Save Area Pointer
      08h         4        Alpha Mode Auxiliary Character Generator Pointer
      0Ch         4        Graphics Mode Auxiliary Character Generator Pointer
      10h         4        Reserved (always 00:00h)
      14h         4        Reserved (always 00:00h)
      18h         4        Reserved (always 00:00h)

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  Video Parameter Table Pointer (Double-Word)

    This double-word pointer is initialized to point to the BIOS video
    parameter table.

  --------------------------------------------------------------------------
  Dynamic Save Area Pointer (Double-Word)

    This double-word pointer is optional, hence it is initialized to
    00:00h. When used, this pointer points to a RAM table where specific
    dynamic values are saved. Currently the values are defined as follows:

          Offset      Size (bytes)      Description
            00h           16            16 EGA palette register values
            10h            1            Overscan value
            11h          239            Reserved

  --------------------------------------------------------------------------
  Alpha Mode Auxiliary Character Generator Pointer (Double-Word)

    This double-word pointer is optional; hence it is initialized to
    00:00h. When used, this pointer points to a table as defined below:

          Offset      Size (bytes)      Description
            00h            1            Bytes per character
            01h            1            Block to load (0=normal operation)
            02h            2            Count to store (256=normal operation)
            04h            2            Character offset (0=normal operation)
            06h            4            Double-word pointer to Font Table
            0Ah            1            Maximum displayable rows (If FFh,
                                        maximum rows calculated)
            0Bh            n            'n' bytes consisting of different
                                        mode values for this font.
                                        (0FFh is terminator)

  --------------------------------------------------------------------------
  Graphics Mode Auxiliary Character Generator Pointer (double-word)

    This double-word pointer is optional; hence it is initialized to
    00:00h. When used, this pointer points to a table as defined below:

          Offset      Size (bytes)      Description
            00h            1            Displayable rows
            01h            2            Bytes per character
            03h            4            Double-word pointer to Font Table
            07h            n            'n' bytes consisting of different
                                        mode values for this font.
                                        (0FFh is terminator)