Rather than WAIT, use VSYNC instead. Place "VSYNC 1" at the beginning of the loop, before the CLS. The VSYNC 1 command basically waits until 1 frame is complete before continuing. This is good as it prevents flickering and also allows better control of the game on a 60 FPS basis. (The loop will complete 60 times a second, assuming it isnt so complicated it takes longer than one frame to process.)