Well Most emulators and Back-up systems are legal
On October 28, 2003, the Librarian of Congress, on the recommendation of the Register of Copyrights, announced the classes of works subject to the exemption from the prohibition against circumvention of technological measures that control access to copyrighted works. The four classes of works exempted are:
(3) Computer programs and video games distributed in formats that have become obsolete and which require the original media or hardware as a condition of access. A format shall be considered obsolete if the machine or system necessary to render perceptible a work stored in that format is no longer manufactured or is no longer reasonably available in the commercial marketplace.
Definitions. (1) “Internet locations” are defined to include domains, uniform resource locators (URLs), numeric IP addresses or any combination thereof.
(2) “Obsolete” shall mean “no longer manufactured or reasonably available in the commercial marketplace.”
(3) “Specialized format,” “digital text” and “authorized entities” shall have the same meaning as in 17 U.S.C. §121.