This program is for the CDC6500 at the Living Computer Museum. 
It provides an ascii version of the barnsley fern. In order
for this program to run, you must put the system in ascii mode
by issuing the "ASCII" command prior to issuing the "BASIC"
command. It uses VT100 escape sequences.

10 PRINT CHR$(27);"[2J" 
20 Q=800
30 X=0
40 Y=0
50 FOR N=1 TO Q 
60 P=RND(-1)*80 
70 IF P<=1 THEN GOTO 210
80 IF P<=8 THEN GOTO 240
90 IF P<=15 THEN GOTO 270 
100 V=0.85*X+0.04*Y 
110 W=-0.04*X+0.85*Y+1.6
120 X=V 
130 Y=W 
140 C=INT(X*8)+34 
150 L=INT(Y*3.8)
160 T$=SUBSTR(STR$(L),1,2)
170 U$=SUBSTR(STR$(C),1,2)
180 M$=CHR$(27)+"["+T$+";"+U$+"H" 
190 PRINT M$;"."
200 NEXT N
201 GOTO 300
210 V=0 
220 W=0.16*Y
230 GOTO 120
240 V=0.2*X-0.26*Y
250 W=0.23*X+0.22*Y+1.6 
260 GOTO 120
270 V=-0.15*X+0.28*Y
280 W=0.26*X+0.24*Y+0.44
290 GOTO 120
300 END