COMBAT: Video Programming 1

Writing Directly to the Video RAM

Problem 1 (minor):

• You might write the memory cell that is currently read by the video card -> somtimes weird effects
• Solution: write only during vertical blank (may be to short)

Problem 2 (major):

• Usually, there are some moving objects
• To update the position of such an object you erase it at the old position and and redraw it at the new position.
• Now, if those two operations happen to occur during different frames The object will be invisible for one frame -> flickering.
• Solution: Double Buffering