>Actually I need to detect vertical sync when overlay in progress. >Leo. While I'm afraid that I don't have an answer for you, what you are looking for is a timing signal as to when field one occurs (beginning of the frame). Just wanted to clarify this question for those who might have the answer. MB -- e-mail: vidiot@xxxxxxxxxx /~\ The ASCII \ / Ribbon Campaign [So it's true, scythe matters. Willow 5/12/03] X Against Visit - URL: http://vidiot.com/ / \ HTML Email