10 REM Mandelbrot set
20 CLS
30 FOR I=0 TO 95
40 LET X=(I-78)/48
50 REM ** When X<>0
60 FOR J=1 TO 22
70 LET Y=(22-J)/30
80 LET XA=0:X2=0
90 LET YA=0:Y2=0
100 LET ITER=0
110 LET XTEMP=X2-Y2+X
120 LET YA=2*XA*YA+Y:Y2=YA*YA
130 LET XA=XTEMP:X2=XA*XA
140 LET ITER=ITER+1
150 IF X2+Y2<=4 AND ITER<200 THEN 110
160 IF ITER=200 THEN SET(I,J):SET(I,44-J)
170 NEXT J
180 REM ** When X=0
190 LET XA=0:X2=0
200 LET ITER=0
210 LET XA=X2+X:X2=XA*XA
220 LET ITER=ITER+1
230 IF X2<=4 AND ITER<200 THEN 210
240 IF ITER=200 THEN SET(I,22)
250 NEXT I
290 REM ** Set up machine code INKEY$ command
300 IF PEEK(1)<>0 THEN RESTORE 510
310 DOKE 4100,3328:FOR A=3328 TO 3342 STEP 2
320 READ B:DOKE A,B:NEXT A
400 SCREEN 1,15
410 PRINT "Hit any key to exit.";
420 A=USR(0):IF A<0 THEN 420
430 CLS
440 END
490 REM ** Data for machine code INKEY$
500 DATA 25055,1080,-53,536,-20665,3370,-5664,0
510 DATA 27085,14336,-13564,6399,18178,10927
520 DATA -8179,233