The logic of the system presented in this report is divided into five parts for computer processing and manipulation. They are: (1) incorporating publication information and Library of Congress catalog copy into the system, (2) processing of authority files and assignment of supplier, (3) preparing data for cataloging and acquisitions, (4) ordering, invoicing, and library billings and payment, and (5) producing reports, worksheets, orders, bills, and statements and checks. None of these parts are independent of the other; successive parts feed back recycling information to earlier logical units. Having only one input point and one output point in the system provides an advantage in minimizing operations complexity. The system is designed to make extensive use of bibliographic information received in machine readable form. The following information is provided in this volume about the computer operation of the cataloging system: (1) the flow chart of the computer runs and the associated input and output, (2) a narrative description of the functioning ofthe system, (3) the file content and record derivation specification for every data file, (4) the record content sheets for each record format used by the system, (5) the derivation of the output fields from the proper input fields, and (6) two sets of parameters which define options available to the user and options available within the system for each run. (CM)