10 VARNAME
100 VARNAME
110 IF
120 IF
130 IF
140 IF
150 PLOT
160 NEXT
170 VARNAME
180 VARNAME
190 VARNAME
20 REM use cursor keys to alter direction and speed 
200 VARNAME
210 VARNAME
220 GOTO
30 CURS
40 PALETTE
50 DIM
60 VARNAME
70 FOR
80 FOR
90 PLOT