Santanu,

To summarize:

1. Make sure your display routine is not being
interrupted.

2. Increase the display refresh rate if you can in
your C program.

3. If you cannot increase the refresh rate in C, then
you must consider writing the display routine in
assembly to gain some speed.
4. A trick you might want to use is to refresh the
display multiple times during the Main execution
thread of the program.

example:

Main:
Update Display
some code
more code
Update Display
some code
more code
Update Display
Jmp Back to Main

Jacob