This revised fifth edition closely follows the format of previous editions, but provides 25% more listings, bringing the total number to over 4,000. Producers and distributors of software are listed alphabetically by firm, as are manufacturers and distributors of hardware. In both sections, the information given for each firm includes address, telephone number, names of key personnel, professional organization affiliations, available catalogs, and other services offered. Separate indexes classify the software suppliers by subject and by media. Another index identifies the manufacturers and distributors of hardware by product lines. National AV organizations, educational organizations with special AV committees, and allied groups are provided in the directory. A calendar of AV exhibitions and conferences scheduled for 1974-75, a state-by-state listing of educational radio and television stations, an annotated bibliography of important reference works and publications in the AV field, and a list of publications that review AV hardware and/or software are also included. A separate Service Section gives information on firms offering specialized AV assistance such as cataloging, production, laboratory services and companies that rent equipment or facilities. (WCM)