anchor.diff:            n:= Ord(Buffer[i]);
   
             //If control chars present, then non-text
  -          if (n < 32) and not (byte(n) in cAllowedControlChars) then
  +          if IsAsciiControlChar(n) then
             begin
               Result:= False;
               Break
  
positive.code:   TableSize: Integer;
    Str: TFileStream;
    SSign: string;
    IsOEM, IsLE: boolean;
  begin
    Result:= False;
    IsOEM:= False;
    Str:= nil;
    Buffer:= nil;
  
  
negative.code: type
    TFreqTable = array[$80 .. $FF] of Integer;
  
  function IsAsciiControlChar(n: integer): boolean; inline;
  const
    cAllowedControlChars: set of byte = [
      7, //Bell
      9,
      10,
      13,
      12, //FormFeed
      26 //EOF
      ];
  begin
    Result:= (n < 32) and not (byte(n) in cAllowedControlChars);
  end;
  
  function IsFileContentText(const fn: string; BufSizeKb: integer;
    BufSizeWords: integer;
  