Despite recent research and development in the field of library automation, libraries have been unable to reap the benefits promised by technology due to the high cost of building and maintaining their own computer-based systems. Time-sharing and disc mass storage devices will bring automation costs, if spread over a number of users, within the range of economic feasibility. Now, the distribution of the Machine Readable Cataloging Code (MARC) II tapes by the Library of Congress is dramatically cutting the costs for data conversion. The combination of these advances is about to open up the automated library services market for serious business. (Author/MF)