This makes the microcontroller very application dependent,
but may save use some headaches.
The idea is to write a program to produce the code to show a
complex drawing.
sufficiently handles the back/front porch without disrupting the sync
signal
todo improvement: compute a sensible amount of cycles to waste during
the porch
not the whole screen, but vertically locked
actually it has some issues, there is a single dot (at the
end/beginning of a cycle) that messes up the horizontal sync and moves
all the picture... must be fixed
giomba