'Simulate pulsar signal
'in Joy Division style
10 poke42,0:poke43,63:cls
20 at0,112:print
30 v=rnd(30)-80:p=5:q=128
40 y=2000+rnd(700)
50 for x=0 to 30
60 w=10+y/q:if w>0 w=0
65 if peek(6)<128 w=w+1
70 line 5,w-z:z=w
80 y=y+p*v:v=v-y/q
90 next x:goto 20