Smoking clover
[ITS] A
display hack originally due to Bill Gosper.
Many convergent lines are drawn on a colour monitor in
AOS mode (so that every pixel struck has its colour incremented).
The lines all have one endpoint in the middle of the screen; the other endpoints are spaced one pixel apart around the perimeter of a large square.
The colour map is then repeatedly rotated.
This results in a striking, rainbow-hued, shimmering four-leaf clover.
Gosper joked about keeping it hidden from the FDA (the US's Food and Drug Administration) lest its hallucinogenic properties cause it to be banned.
