100 SCREEN 3 : COLOR ,,,,2 : CLS 3 110 ' 120 T=0 : X=320 : Y=200 130 FOR I=0 TO 400 STEP 10 140 LINE (I+120,0)-(I+120,400),13 150 LINE (120,I)-(520,I),13 160 NEXT 170 ' 200 FOR I=1 TO 4 210 FOR J=1 TO 3 220 CALL *前進(5) 230 CALL *方向(120) 240 NEXT J 250 CALL *前進(10) 260 CALL *方向(90) 270 NEXT I 280 ' 990 CIRCLE (320,200),2,2 : END 1000 ' 1010 SUB *方向(P) 1020 SHARED T 1030 T=T+P 1040 END SUB 1050 ' 1060 SUB *前進(D) 1070 SHARED T,X,Y 1080 XD=COS(T/360*3.1416#*2)*D*10 1090 YD=SIN(T/360*3.1416#*2)*D*10 1100 LINE (X,Y)-(X+XD,Y-YD) 1110 X=X+XD :Y=Y-YD 1120 END SUB