10 rem ** 320x200x32col fractal(?) 20 rem ** 30 rem ** this is a little demonstration how to do a formula-based 40 rem ** computer graphic using the screen instructions of the c65 50 rem ** calculation will last about 20 minutes on a real c65, 60 rem ** but will be much faster on hi65 70 rem ** http://devilmaster.altervista.org/hi65.html 80 rem ** 90 rem ** contact me: devilmaster (a snail) email (a period) com 100 rem 110 trap 330 120 graphic clr 130 screen def 1,0,0,5 140 screen open 1 150 for i=1 to 31 160 read a,b,c 170 palette 1,i,a,b,c 180 next i 190 screen set 1,1 200 scnclr 0 210 border 0 220 pen 0,15 230 char 14,2,2,2,2,"devil master" 240 char 15,20,1,1,2,"calculating 20 minutes" 250 for x=0 to 319 260 for y=0 to 189 261 ca=x*x 262 cb=y*y 263 cb=cb*x 265 cc=ca+cb 279 a=cc/600 280 pen 0,a 290 line x,y,x,y 300 next y 310 next x 320 get a$ : if a$ = "" then goto 320 330 screen close 1 340 palette restore 350 border 6 360 end 370 data 1,1,0,3,3,0,5,5,0,7,7,0,9,9,0,11,11,0,13,13,0,15,15,0 380 data 15,13,0,15,11,0,15,9,0,15,7,0,15,5,0,15,3,0,15,1,0 390 data 13,3,0,11,5,0,9,7,0,7,9,0,5,11,0,3,13,0,1,15,0,0,13,0 400 data 0,11,0,0,9,0,0,7,0,0,5,0,0,3,0,0,1,0,0,0,0,0,0,0