Abstract: An automated library circulation control system includes a plurality of remote book processing terminals and a computer controlling the terminals and processing data between the terminals and the computer to maintain a current inventory of the circulation status of the library books. The system provides for automatic charging of library materials by patrons, record keeping of all library transactions, modification and interrogation of computer data files, intercommunication between the computer and a remote data processor and detection of unauthorized removal of books from the library. Each terminal has a card reader for patron identification, an optical reader for book identification, an electromagnetic activator for magnetizing and demagnetizing a magnetic strip in each book, a printer for printing charge-out information, and a display screen and keyboard for communications between patron and computer.