bug

1 May 2000

      Hi, all.

I've been fighting a bug for a while, and when I stripped it down to its
basics, I was surprised.  My test program is appended.

The issue involves arrays of size > 255.  When I use Ymax = Zmax = 250,
the program runs fine.  When I use Ymax = Zmax = 260, the portion of the
program that runs in Main works fine, but the procedure stops at y = 7,
z = 260 - the program hangs, with ^C ineffective.

I'm running a pentium 400 under Win98.  I've had no trouble with this in
small arrays, but 256 seems to be a divide of some sort.

Any suggestions appreciated.
Toby

Toby Ewing
Soil Scientist, Iowa State University

-------------------------------------------------------------------

Program TestLgArray;

Const
  Xmax       = 25 ;                    {physical space - grid units}
  Ymax       = 260;                    {physical space - grid units}
  Zmax       = 260;

Type
  Compary     = array[1..Ymax, 1..Zmax] of integer;

var
  Comp        : Compary;
  x, y, z     : integer;

{________________________________________________
}
Procedure Zero;

var
  Comp        : Compary;
  x, y, z     : integer;

begin
  writeln('Procedure:');
  readln;
  for y := 1 to Ymax do begin                    {zero the comp array}
    for z := 1 to Zmax do Comp[y,z] := 0;
    writeln('y=', y:3, '  z=', z:1);
  end;
end;
{________________________________________________
}

begin                                            {Main Program}
  writeln('Main:');
  readln;
  for y := 1 to Ymax do begin                    {zero the comp array}
    for z := 1 to Zmax do Comp[y,z] := 0;
    writeln('y=', y:3, '  z=', z:1);
  end;
  Zero;
  write(' done');
end.