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).

                                                                          
  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)

                                                                          
  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)


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