EXHIBIT 21.1


                         SUBSIDIARIES OF THE REGISTRANT


         Zentropic Computing, LLC, a Virginia limited liability company

         United System Engineers, Inc., a Japanese corporation

         Fireplug Computers Inc., a Vancouver, B.C. corporation

         INUP S.A., a societe anonyme French corporation

         Moreton Bay Ventures Pty Ltd, an Australian corporation

         RT-Control, Inc., a Toronto, Ontario corporation