[comp.sys.mac] Novice Mac hardware question

pavel@dgp.toronto.edu (Pavel Rozalski) (05/20/89)

How do I detect the vertical position of the video beam? The problem is
that I am drawing an image to the screen often and noticed that when
it is at the top of the screen there is anoying flicker but lower down
there isn't any at all. This is in monochrome and in color but the
monochrome is better (flickers only very close to the top). I am using
CopyBits. What I had in mind was to wait till the video beam was below
where I wanted to put the image and then start to draw.

Any advice?

Pavel Rozalski

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