Hi All, I am trying to figure out why Nehe''s lesson 38 would be slow when running fullscreen. When running in the default windowed mode, the images fall at an acceptable speed. I thought it might be because of the pixelformat?? but I have recompiled with "bits" set to 8,16,24, and 32 and this does not seem to help. I am using a Dell notebook with an ATI M1 graphics chip and 8 Meg of video memory (I know, this is not new technology, but it runs Unreal Tournament at a decent rate so 50 butterflies should not be a problem!!!) Any help would be appreciated, jpummill