function HexToBin(Hexadecimal:string):string;
const
 BCD: array [0..15] of string =
     ('0000','0001','0010','0011','0100','0101','0110','0111',
      '1000','1001','1010','1011','1100','1101','1110','1111');
var
   i: integer;
begin
   for i := Length(Hexadecimal) downto 2 do
     Result := BCD[StrToInt('$'+Hexadecimal[i])] + Result;
end;
procedure TForm1.BConvertClick(Sender: TObject);
var a,b: string;
    i: integer;
begin
 EBiner.Text:=HexToBin(EAscii.Text);
end;

function HexToDec(Str: string): Integer;
var
  i, M: Integer;
begin
  Result:=0;
  M:=1;
  Str:=AnsiUpperCase(Str);
  for i:=Length(Str) downto 2 do
  begin
    case Str[i] of
      '1'..'9': Result:=Result+(Ord(Str[i])-Ord('0'))M;
      'A'..'F': Result:=Result+(Ord(Str[i])-Ord('A')+10) M;
    end;
    M:=M shl 4;
  end;
end;
procedure TForm1.BConvertClick(Sender: TObject);
begin
EDec.Text:=IntToStr(HexToDec(EAscii.Text));
end;

EHex.Text:=Copy(EAscii.Text,2,Length(EAscii.Text));

// String Heksadesimal ke Bilangan Bulat Desimal
StrToInt('$' + Input); // Jangan lupa pake blok try ... except/finally
// Bilangan Bulat Desimal ke String Heksadesimal
Format('%X', [Input]);

// String Heksadesimal ke Bilangan Bulat Desimal
StrToInt('$' + Input); // Jangan lupa pake blok try ... except/finally
// Bilangan Bulat Desimal ke String Heksadesimal
Format('%X', [Input]);

@daryl_sukma_gumilar: @ Wahyudi : nice Answer .. Saya mau tanya maz .. kalo merubah dari Biner ke ascii (Asciinya 8 bit) Misalnya : 100 1111 - > O 101 0010 - > S Bagaimana ya maz ...