TI-92+s have a serial number. Other than that, no other calculator does. Except maybe the 89. ------ STL137@aol.com ===> Website: http://members.aol.com/stl137/ PGP keys: ~~~pgp.html Quotes: ~~~quotes.html "I have sworn upon the altar of God eternal hostility against every form of tyranny over the mind of man" - Thomas Jefferson