Hello! OK! Here is a part of the code RD_ENCDR.SRC chk_encoder mov new, encoder and new, #00000011b mov temp, new xor temp, old jz :return clc rl old xor old, new jb old.1, :up :down dec counter skip :up inc counter and counter, #00001111b mov old, new :return ret My question are : What language is this? Regards =C5keN -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.