1 diml(63):a(0)=-40:a(1)=1:a(2)=40:a(3)=-1:?"{clear}":fori=1to60:poke1024+rnd(1)*999,90:next 
2 p=p+a(d):l(u)=p+1524:c=peek(l(u)):on-(c<>32andc<>90)goto3:pokel(u),81:pokel(u-f-3and63),32 
3 f=f-(c=90):?"{home}"f:u=u+1and63:geta$:d=d+(a$="a")-(a$="d")and3:on-(c=32orc=90)goto2 
