The logic of the system presented in this report is divided into six parts for computer processing and manipulation. They are: (1) processing of Library of Congress copy, (2) editing of input into standard format, (3) processing of information into and out from the authority files, (4) creation of the catalog records, (5) production of the catalogs, and (6) printing out the required listings and records. 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 following information is provided in this volume about the computer operation of the cataloging system: (1) the flowchart of the computer runs and the associated input and output, (2) a narrative description of the functioning of the system, (3) the file content and record derivation specifications for every data file, (4) the record content sheets for each record format used by the system giving the data fields in each format, (5) the derivation of the output fields from the proper input fields, (6) the special codes and their values, (7) a summary of the error conditions, (8) the controls necessary for proper functioning of the system, (9) programming notes, and (10) two sets of parameters which define options available to the user and options available within the system for each run. (CM)