NB hgr.ill
NB (c)2001 Cat's Eye Technologies.
NB All rights reserved.  All liability disclaimed.
NB See the file COPING for license information.

hgr;
*i=0; *x=0; *y=0; *c=0;
for i = 0 to 100
{
  for x = 0 to 319
  {
    for y = 0 to 199
    {
      hplot x, y, (x+y+i);
    }
  }
};
while c <> 27 in tty c;
text;
FIN