BALLOTS (Bibliographic Automation of Large Library Operations using a Time-sharing System) is an on-line interactive library automation system that supports the acquisition and cataloging functions of the Stanford University Libraries' technical processing operations. The BALLOTS system is being implemented in a series of 11 modules. This paper describes the first module, BALLOTS-MARC, or simply the MARC module, and various aspects of system hardware and software as they pertain to this module. The MARC module supports the production of purchase orders, catalog card sets, spine labels, and several types of file slips and management reports. An on-line MARC file stored on disk is updated from the weekly Library of Congress MARC tapes. Several indexes are maintained in the file in order to support extensive on-line interactive file searching. One way of describing BALLOTS is to explain how the system looks to the user and how it is used in normal day-to-day library operations. A typical book cycle will be traced in the examples that follow. (Other documents on BALLOTS are available as ED 038 153, 044 049, 049 786, and 060 883.) (Author)