FastGraphics 
 Format 
fastgraphics
 Description 
Turns fastgraphics mode on, until the program is halted. Fastgraphics mode means that the graphics display is not updated until a REFRESH command is issued. It can be used to significantly speed up complex animations and eliminate flicker.
 Note 
When doing animation, it's recommended to do all of your drawing commands in subroutines and use a single REFRESH command after all drawing has been done for that frame.
 See Also 
Refresh