Yuku free message boards

Recently I've been trying to make a basic typical 2D side scroller game (like mario) using tilemap. The problem I've been having is speed. I have the program set so at every move the entire screen is redrawn. This is done for uniformity of speed for whenever or not the screen is scrolling. Drawing the Screen doesn't slow down the program too much, it's tilemap's DrawPlane function which is used to render the virtual screen according (x,y) coordinates into a pointer variable for memcpy or FastCopyScreen. The slowdown is not bad for moving my character left/right, but it is bad for my gravity effect. The effect just makes the character move downward at an accelerating speed until he collides with tiles on the map. Before incorporating functions for scrolling the tilemap, I just saved and refreshed the screen and the gravity worked fine. But now the DrawPlane function limits the speed my character can move at, so it can't really accelerate downwards. It's simply too slow for falling. Any suggestions?