unit
  convert;
interface
  function HexToDec (Hexadecimal: string): cardinal;
implementation
uses
  SysUtils;
function HexToDec (Hexadecimal: string): cardinal;
var
  I: cardinal;
  Koef: Integer;
  Hex: string [8];
const
  HexaChars = '123456789ABCDEF';
begin
  Hex:=UpperCase (Hexadecimal);
  Koef:=1;
  HexToDec:=0;
  for I:=1 to Length (Hex) do
  begin
    Inc (HexToDec,Koef  Pos(Hex[Length(Hex)-I+1],HexaChars));
    Koef:=Koef 16;
  end;
end;
end.

procedure TForm1.FormCreate(Sender: TObject);
begin
  caption := inttostr(strtoint('$AA'));
end;

dibaris Inc (HexToDec,Koef * Pos(Hex[Length(Hex)-I+1],HexaChars)); keluar error message not enough actual parameter

function HexToDec (Hexadecimal: string): cardinal;
  var
    I, hit: cardinal;
    Koef: Integer;
    Hex: string [8];
  const
    HexaChars = '123456789ABCDEF';
  begin
    Hex:=UpperCase (Hexadecimal);
    Koef:=1;
    Hit:=0;
    for I:=1 to Length (Hex) do
    begin
      Inc(Hit,Koef  Pos(Hex[Length(Hex)-I+1],HexaChars));
      Koef:=Koef 16;
    end;
    result := hit;
  end;