Changing Frames per Second

Is there a way using Screen to control how many frames are played per
second?

I am creating something similar to DriftDemo except the grating is
full screen. I have gotten this far, but now I need to be able to
control the frames per second in order to control the frequency of the
sinusoid on the screen.

In the end, this full screen sinusoid would flow at the same frequency
as a TTL. Since I need these to be in sync, if I can control the FPS I
hope to be able to start the TTL and the movie at the same time. Do
you think I will need Simulink to create this in real time? I have no
experience with Simulink or using Real Time components of MatLab and
would love to do this without that hassle! :)

Thanks for any help,
Mike