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.