C++ has no inherent concept of blinking characters (or even a display, or a keyboard). This is dependent on your hardware and on the libraries available on your system.
int x=0;
while (x<100)
{
std::cout << std::endl;
++x;
}
It's ugly and clumsy, but portable. I recommend you don't do it, though - if you want fine control over the display, stop using the console and move to graphics.