Changes
/* TODO : old screen effect (called also sometimes scanline) */
Scanline is also a simple visual effect to enable/disable, making games looking like old CRT monitors.
Let's recall that here "old screen effect" (looking at VGA like if it was an CRT, with triangular pixels)
[http://www.cpcwiki.eu/forum/games/everything-looks-better-in-scanlines!/msg119154/#msg119154 Everything looks better in scanlines!]
=== DONE : Monochrome option ===
