EXHIBIT A



                              AMENDMENT NO. 2
                                     TO
                              RIGHTS AGREEMENT


                    This AMENDMENT NO. 2 TO RIGHTS AGREEMENT (the
               "Amendment") is entered into as of the 20th day of August,
               1997 between Boston Technology, Inc., a Delaware corporation
               (the "Company"), and State Street Bank & Trust Company, a
               national banking association (the "Rights Agent").
               Capitalized terms not otherwise defined herein shall have
               the meanings given them in the Rights Agreement by and
               between the parties hereto.


                                  RECITALS

          WHEREAS, the Board of Directors has determined that it is in the
best interests of the Company to amend the Rights Agreement as set forth
herein prior to and in connection with the execution of that certain
Agreement and Plan of Merger dated as of August 20, 1997, as the same may
be amended from time to time (the "Merger Agreement"), between Comverse
Technology, Inc., a New York corporation ("Comverse"), and the Company
(pursuant to which Merger Agreement, among other things, the Company shall
merge with and into Comverse (the "Merger")).

          WHEREAS, the Company has requested that the Rights Agreement be
amended in accordance with Section 26 of the Rights Agreement, as set forth
herein, and the Rights Agent is willing to amend the Rights Agreement as
set forth herein.


                                 AGREEMENT

          NOW, THEREFORE, the parties, intending to be legally bound,
hereby agree as follows:

          1. Section 7(a) of the Rights Agreement is hereby amended to read
in its entirety as follows:

          "(a) Subject to Section 7(e) hereof, the registered holder of any
     Rights Certificate may exercise the Rights evidenced thereby (except
     as otherwise provided herein including, without limitation, the
     restrictions on exercisability set forth in Section 9(c), Section
     11(a)(iii) and Section 23(a) hereof) in whole or in part at any time
     after the Distribution Date upon surrender of the Rights Certificate,
     with the form of election to purchase and the certificate on the
     reverse side thereof duly executed, to the Rights Agent at the office
     of the Rights Agent designated for such purpose, together with payment
     of the aggregate Purchase Price with respect to the total number of
     Units (or other securities, cash or other assets, as the case may be)
     as to which such surrendered Rights are then exercisable, at or prior
     to the earlier of (i) the Final Expiration Date, (ii) the time at
     which the Rights are redeemed as provided in Section 23 hereof, or
     (iii) immediately prior to the Effective Time, as defined in the
     Agreement and Plan of Merger dated as of August 20, 1997, as the same
     may be amended from time to time, between Comverse Technology, Inc., a
     New





     York corporation ("Comverse"), and the Company (the "Merger
     Agreement"), pursuant to which Merger Agreement, among other things,
     the Company shall merge with and into Comverse (the "Merger") (the
     earlier of (i), (ii) and (iii) being herein referred to as the
     "Expiration Date")."

          2. Section 34 of the Rights Agreement is hereby added as follows:

          "Section 34. Comverse Transaction. Notwithstanding any provision
     of this Rights Agreement to the contrary, no Distribution Date, Stock
     Acquisition Date or Triggering Event shall be deemed to have occurred,
     neither Comverse nor any Affiliate or Associate of Comverse shall be
     deemed to have become an Acquiring Person and no holder of Rights
     shall be entitled to exercise such Rights under or be entitled to any
     rights pursuant to Section 7(a), 11(a) or 13(a) of this Rights
     Agreement by reason of (x) the approval, execution, delivery or
     effectiveness of the Merger Agreement or (y) the consummation of the
     transactions contemplated under the Merger Agreement in accordance
     with the terms thereof, (including, without limitation, the
     consummation of the Merger)."

          3. Except as amended hereby, the Rights Agreement shall remain
unchanged and shall remain in full force and effect.

          4. This Amendment may be executed in any number of counterparts,
each of which shall be an original, but all of which together shall
constitute one instrument.


          IN WITNESS WHEREOF, the parties have caused this Amendment to be
executed by their respective duly authorized representatives as of the date
first above written.


                                       BOSTON TECHNOLOGY, INC.


                                         by
                                           ------------------------------
                                           Name:
                                           Title:


                                        STATE STREET BANK & TRUST
                                        COMPANY


                                          by
                                            ------------------------------
                                            Name:
                                            Title: