fileStream

procedure TForm1.Button1Click(Sender: TObject);
var
   f1:TFileStream;
      filename:String;
begin
   OpenDialog1.Execute ;
   filename:=OpenDialog1.FileName ;
   f1:=TfileStream.Create (filename,fmopenread);
   try
      RichEdit1.Lines.LoadFromStream(f1);
      f1.Position:=0;
      Memo1.Lines.LoadFromStream(f1);
   finally
      f1.free;
   end;

end;

procedure TForm1.Button2Click(Sender: TObject);
var f1:TFileStream;
   filename:string;
begin
   savedialog1.Execute ;
   filename:=saveDialog1.FileName ;
   f1:=TFilestream.Create (filename,FmCreate);
   try
      RichEdit1.Lines.SaveToStream (f1);

   finally
      f1.Free ;
   end;
end;