70 MODE2 80 VDU19,0,4,0,0,0 90 REPEAT 100 PROCinput 110 PROCinitialise 120 PROCplot 130 PRINT"press a key "; 140 A$=GET$:IF A$="D":*GDUMP 150 UNTIL A$="E" 160 END 170 : 180 DEFPROCinitialise 190 step=0.02 200 IF a>15 OR b>15 THEN step=0.002 210 m=0.1E-30 220 FOR z=0 TO 2*PI STEP 0.1 230 r=ABS(FNequation) 240 IF m7 THEN GOTO 290 390 INPUT"A = "a 400 INPUT"B = "b 410 ENDPROC 420 : 430 DEFPROCplot 440 CLS 450 FOR z=0 TO 2*PI+step STEP step 460 r=FNequation 470 X%=640+512*COS(a*z)*r/m 480 Y%=512+512*SIN(b*z)*r/m 490 IF z=0 THEN MOVE X%,Y% 495 GCOL0,RND(7) 500 DRAW X%,Y% 510 NEXT z 520 ENDPROC 530 : 540 DEFFNequation 550 IF n=1 =1 560 IF n=2 =SIN(z) 570 IF n=3 =SIN(5*z) 580 IF n=4 =2*COS(z) 590 IF n=5 =1+COS(z) 600 IF n=6 =1+SIN(2*z) 610 =1+2*COS(2*z)