Remote Control 4th paragraph #0005

BACKGROUND OF THE INVENTION 4th paragraph

Often, a change of the image is limited to a small section of the screen (e.g. moving the mouse pointer, pulling down a menu, highlighting an object) and only the changed data need to be refreshed.
The controller system can use the screen data previously received and just refresh the modified part of the screen.
By cutting out redundant screen refresh data, a remote control program can improve the response time.
Cache memories speed the performance of hard drives and memory chips, and can also be useful for remote control programs.
The idea behind a cache is to keep recently used data in a temporary storage area that is quickly accessible.
If the data are soon needed again, it is much quicker to access them from a fast-access temporary storage area than to retrieve from the original source.
According to this technique, elements of a recently displayed screen are saved as a cache in extended memory.
The entire page redraws from the controller PC screen cache, eliminating the need to transfer large amounts of information over the modem from the target to the controller PC.
Screen elements that are often redrawn from a screen cache include bit maps, text and fonts.
To be continued  #0006
- Anfossi, et al. Screen remote control. U.S.Patent 6,141,022. October 31, 2000.