'Plot cosine
10 cls
20 input p:if p<1 goto 20
30 u=50*100:v=0:c=0
40 for x=0 to 159
50 y=68-u/100
60 poke y*256+x,c
70 u=u+v:v=v-u/p
80 next x
90 c=c+23:goto 40