EXHIBIT (21) Subsidiaries of the Registrant The Registrant had the following subsidiaries at May 31, 1994, each of which was wholly-owned by the Registrant, except as noted below: Jurisdiction of Name Incorporation National Billing Systems, Inc. Georgia National Data Payment Systems, Inc. New York Modular Data, Inc. Delaware Connection Technologies, Inc. Georgia NDC Federal Systems, Inc. Delaware NDC Advanced Network Services, Inc. Georgia Technology Sales & Leasing Co., Inc. Georgia NDC International, Inc. Georgia National Data Realty, Inc. Georgia National Data Corporation of Canada, Ltd. Canada Nationcall, Inc. Georgia NDC/Yes Check, Inc. (See Note 1) Georgia Note 1: NDC/Yes Check, Inc. is 80% owned by the Registrant.