A little experiment I made using the "Oscar64" C compiler for the C64: a classic "Starfield" effect, where the stars move outward from the center of the screen, just like in old space shooters.
Here's the link:
pastebin.com/KNc2U97w
@IlGuiscardo@INGVterremoti Il boom di un caccia non lo fa solo quando passa “il muro del suono” ma continuamente: quando è supersonico un aereo genera costantemente un’onda d’urto e quando questa raggiunge un osservatore questo sente il caratteristico boom.
@DaveRVW Thanx... It's worth trying but you almost certainly won't have the same effect with a color darker than yellow, because the contrast between the two rectangles and the background would be similar to each other.
I emulated "the stepping feet illusion" on C64. It seems that the two rectangles are moving jerkily, taking steps, but instead they both move at the same constant speed. If you remove the black & white stripes behind, the illusion vanishes.