lNT3R.NET

Mandelbrot Basic Demo

Generic, Port to your system

10 FOR Y=-12 to 12
20 FOR X=-39 TO 39
30 CA=X*.0458
40 CB=Y*.08333
50 A=CA
60 B=CB
70 FOR I = 0 TO 15
80 T=A*A-B*B+CA
90 B=2*A*B+CB
100 A=T
110 IF(A*A+B*B)>4 GOTO 200
120 NEXT I
130 PRINT " ";
140 GOTO 210
200 IF I>9 THEN I=I+7
205 PRINT CHR$(48+I);
210 NEXT X
220 PRINT
230 NEXT Y

For VAX VMS Basic

10  ! ASCII Mandelbrot Set for VAX BASIC with Timer
15  CALL LIB$INIT_TIMER()
20  FOR Y = -12 TO 12
30      FOR X = -39 TO 39
40          CA = X * 0.04584
50          CB = Y * 0.08333
60          A = CA
70          B = CB
80          FOR I = 0 TO 15
90              T = A * A - B * B + CA
100             B = 2 * A * B + CB
110             A = T
120             IF (A * A + B * B) > 4.0 THEN GOTO 160
130         NEXT I
140         PRINT " ";
150         GOTO 180
160         IF I > 9 THEN I = I + 7
170         PRINT CHR$(48 + I);
180     NEXT X
190     PRINT
200 NEXT Y
205 CALL LIB$SHOW_TIMER()
210 END