[codefunction CRC32T(Initial: LongWord; Data: array of Byte; DataSize: LongWord): LongWord;
const
 poly = $EDB88320;
var
 j: Integer;
 tmp1, tmp2, crc, i: LongWord;
begin
 crc := Initial;
 i := 0;
 while i < DataSize do
 begin
   tmp1 := 0;
   tmp2 := crc xor Data[i];
   for j := 0 to 7 do
   begin
     if tmp2 and 1 = 1 then
       tmp1 := tmp1 xor poly;
     tmp2 := tmp2 shr 1;
   end;
   crc := (crc shr 8) xor tmp1;
   Inc(i);
 end;
 Result := not crc;
end;