20 lines, that's just right for a newb like me

. I've been experimenting a bit with mathemetically creating backdrops, and was surprised myself what some of the outcomes were. Well, here are a few of them.
sync on : sync rate 0
for i=1 to 8
for h=0 to 479
for w=0 to 639
select i
case 1 : dot w,h,rgb(0,0,h*w) : endcase
case 2 : dot w,h,rgb(0,0,h*h-w*w) : endcase
case 3 : dot w,h,rgb(0,0,w*w+h*h) : endcase
case 4 : dot w,h,rgb(0,0,h*h/w+w*w/h) : endcase
case 5 : dot w,h,rgb(0,0,h*sin(h*cos(w))) : endcase
case 6 : dot w,h,rgb(0,0,h*sin(w*w*w)/(h*sin(h))) : endcase
case 7 : dot w,h,rgb(0,0,h*(h/w)+w*(w/h)) : endcase
case 8 : dot w,h,rgb(0,0,sqrt(w*w*w+h*h*h)) : endcase
endselect
next w
next h
sync
suspend for key
if escapekey()=1 then exit
next i