IntToBinary

function IntToBin(i:Int64; bits:Int32=8): String; //bits:8,16,32,64
var c:Int8;
begin
  for c:=bits-1 downto 0 do
    Result += ToStr((i shr c) and 1);
end;

begin
  WriteLn('>> ', IntToBin(13));
  WriteLn('>> ', IntToBin(34));
  WriteLn('>> ', IntToBin(13 or 34));
end.