JOINT FILING AGREEMENT ---------------------- The undersigned hereby agree to jointly file a statement on Schedule 13D, together with any amendments thereto (collectively, the "Schedule 13Ds"), with the Securities and Exchange Commission pursuant to...

 
                                                                       EXHIBIT 1

                            JOINT FILING AGREEMENT
                            ----------------------
                                        
          The undersigned hereby agree to jointly file a statement on Schedule
13D, together with any amendments thereto (collectively, the "Schedule 13Ds"),
with the Securities and Exchange Commission pursuant to the requirements of Rule
13d-1(f) under the Securities Exchange Act of 1934, as amended.

          This Joint Filing Agreement may be signed in counterpart copies.


                           (Signature Page Follows)

 
Date:  May 1, 1998                          GENERAL MOTORS CORPORATION
 
 
 
                                            By:  /s/ Xxxxxx X. Xxxxxxx
                                                --------------------------------
                                            Name:  Xxxxxx X. Xxxxxxx
                                            Title: Assistant Secretary
 


Date:  May 1, 1998                          XXXXXX COMMUNICATIONS, INC.
 
 
 
                                            By:  /s/ Xxxxxxx X. Xxxxx
                                                --------------------------------
                                            Name:  Xxxxxxx X. Xxxxx
                                            Title: Senior Vice President