Program testz; uses Classes,zstream; Var F : TFileStream; C : TCompressionStream; D : TDeCompressionStream; I,J : longint; begin Writeln ('Start Writing'); F:=TFileStream.Create('ztest.dat',FMCreate); Writeln ('Created filestream'); C:=TCompressionStream.Create(cldefault,F); Writeln ('Created Compressionstream. Writing'); For I:=1 to 100000 do C.Write(I,SizeOf(I)); writeln ('End of write'); C.Free; writeln ('freed CompressionStream'); F.Free; writeln ('freed FileStream'); Writeln ('Start Reading'); F:=TFileStream.Create('ztest.dat',FMOpenRead); Writeln ('Created filestream'); D:=TDeCompressionStream.Create(F); Writeln ('Created Decompressionstream. Reading...'); For I:=1 to 100000 do begin D.Read(J,SizeOf(J)); If J<>I then Writeln ('Oh-Oh',J,'doesn''t match',i); end; writeln ('End of Read'); D.Free; writeln ('freed CompressionStream'); F.Free; writeln ('freed FileStream'); end.