I'm trying to move a circular target at approx 1hz horizontally back and fore across the screen.

I've drawn the target in a hidden window and simply copy it to the new (visible) coordinates after a waitforverticalblank call.

My problem is that the ball is leaving a visible ghost trail of about 5-10mm behind it. Is there any way to stop this happening?

The target is about 10mm wide and my LCD monitor is running at 75hz.

Thanks in advance for any feedback,

J

...I'm an immortal...so far...