vsync
From ArchaicPixels: HuC and PCEAS Documentation
vsync();
vsync(char nb_frame);
Synchronize your program to the video vertical blanking
signal (VBL), which is 1/60th of a second.
Without parameters this function return as soon as
a VBL signal has been received, else your program will
be synchronized to the number of frame you requested.
So for example to run your game at 20fps, just use
vsync(3) at the end of your game loop.
