Method and apparatus for increasing pixel interpretations by implementing a transparent overlay without requiring window identifier support

A method in a data processing system for displaying pixels, the method comprising:

• setting first display information for a single pixel interpretation to display pixels in an overlay frame buffer, wherein a window identifier is unnecessary for accessing the information in the overlay window attribute table;
• responsive to receiving a window identifier, retrieving second display information in a color window attribute table using the set of window identifiers;
• retrieving the first display information without requiring the window identifier;
• and
• displaying pixels on a display screen using the second display information retrieved from the color window attribute table and the first information.

A display apparatus comprising:

• a first frame buffer for storing a first set of pixels;
• a second frame buffer for storing a second set of pixels;
• a color window attribute table storing display information;
• an overlay window attribute table storing display information, wherein all entries in the overlay window attribute table are identical;
• a window identifier buffer connected to the color window attribute table and the overlay window attribute table, wherein the window identifier buffer stores window identifiers used to identify display information for the first set of pixels and for the second set of pixels;
• a random access memory digital to analog converter unit connected to the first frame buffer, the second frame buffer, the color window attribute table, and the overlay window attribute table and having a connection configured for connection to a display device, wherein the random access memory digital to analog converter unit receives pixels for display from the first frame buffer and the second frame buffer and displays the pixels using display information from the color window attribute table and the overlay window attribute table;
• and
• a processing unit, wherein the processing unit identifies display information for pixels from a first window attribute table and a second window attribute table in which the second window attribute table has identical display information for selected information in the second window attribute table such that a window identifier for the second window attribute table is unnecessary to obtain display information from the first window attribute table and displays a pixel in a first frame buffer in response to a transparency value being set for a corresponding pixel in a second frame buffer.

A data processing system for displaying data, the data processing system comprising:

• setting means for setting each entry in a plurality of entries for an overlay window attribute table with identical information, wherein a window identifier is unnecessary for accessing the information in the overlay window attribute table;
• first retrieving means, responsive to receiving a set of window identifiers, for retrieving information in a color window attribute table using the set of window identifiers;
• second retrieving means for retrieving the information in the overlay window attribute table without requiring the window identifier;
• and
• displaying means for displaying pixels on a display screen using the information retrieved from the color window attribute table and the information retrieved from the overlay window attribute table.

A computer program product in a computer readable medium for displaying data, the computer program product comprising:

• first instructions for setting each entry in a plurality of entries for an overlay window attribute table with identical information, wherein a window identifier is unnecessary for accessing the information in the overlay window attribute table;
• second instructions, responsive to receiving a set of window identifiers, for retrieving information in a color window attribute table using the set of window identifiers;
• third instructions for retrieving the information in the overlay window attribute table without requiring the window identifier;
• and
• fourth instructions for displaying pixels on a display screen using the information retrieved from the color window attribute table and the information retrieved from the overlay window attribute table.