Format of Video Save Pointer Table [EGA/VGA/MCGA only]

Offset  Size    Description
 00h   DWORD   ptr to Video Parameter Table
 04h   DWORD   ptr to Parameter Dynamic Save Area, else 0 [EGA/VGA only]
 08h   DWORD   ptr to Alphanumeric Character Set Override, else 0
 0Ch   DWORD   ptr to Graphics Character Set Override, else 0
 10h   DWORD   [VGA only] ptr to Secondary Save Pointer Table, must be valid
 14h   DWORD   reserved, zero
 18h   DWORD   reserved, zero

Note: table initially in ROM, copy to RAM to alter, then update 40h:A8h.