unit Unit1;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    Edit1: TEdit;
    Label1: TLabel;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

procedure TForm1.Button1Click(Sender: TObject);
var USERNAME:String;
    LEN,SERIAL:Integer;
begin
  USERNAME:=Edit1.Text;
  LEN:=length(USERNAME);
     ASM
        MOV ECX,EAX
        XOR EAX,EAX                  //Put TMP to 0
        XOR EBX,EBX                  //GET EBX to 00000000
        MOV ESI,USERNAME             //Load nick in string
        MOV ECX,LEN

      @keygen:
        MOVZX EAX,BYTE PTR DS:[ESI]   //Get char
        ADD EBX,EAX                  //Current tmp number to sum
        INC ESI                      //remove 1st letter from left of string
        LOOP @keygen                 //Loop it
        MOV SERIAL,EBX               //ebx=code
     end;
   //showmessage(format('%0.1X',[SERIAL]));
   Edit.Text:='Serial '+ inttostr(SERIAL);
end;

end.