Creating the program "Flasher": I need help

[LAWise520]

I've recently been looking into things such as binaural beats and the program that was known as "Flasher." It was originally created using DOS and is supposed to flash at different hertz (anywhere between 1 and 50 or so) to recreate specific brain "wave" frequencies. If anyone knows about this...or how to create a program that will simply flash alternating black and white screens at high speeds, that would be great.

Thanks.