10 REM MANDELBROT SET 20 PRINT CHR$(147):X1=39:Y1=22 30 C=30:M=4:K=32+C+1 40 I1=-1.0:I2=1.0:R1=-2.0:R2=1.0 50 S1=(R2-R1)/X1:S2=(I2-I1)/Y1 60 FOR Y=0 TO Y1 70 I3=I1+S2*Y 80 FOR X=0 TO X1 90 R3=R1+S1*X:Z1=R3:Z2=I3 100 FOR N=0 TO C 110 A=Z1*Z1:B=Z2*Z2 120 IF A+B>M GOTO 150 130 Z2=2*Z1*Z2+I3:Z1=A-B+R3 140 NEXT N 150 PRINT CHR$(K-N); 160 NEXT X 170 NEXT Y 180 GET K$:IF K$="" GOTO 180 190 END