Ah, TBytes is just 'array of byte'. Solved.BTW, this place in SysUtils has rather strange IFDEFs. Why first int consttant is not ok?Code: Pascal [Select][+][-] PByteArray = ^TByteArray; TByteArray = Array[0..{$ifdef CPU16}32766{$else}32767{$endif}] of Byte; PWordarray = ^TWordArray; TWordArray = array[0..{$ifdef CPU16}16382{$else}16383{$endif}] of Word;