Exhibit 2


                       AMENDMENT NO. 1 TO RIGHTS AGREEMENT


This AMENDMENT NO. 1, dated as of August 6, 1999 (this "Amendment"),  is between
Data General Corporation,  a Delaware  corporation (the "Corporation"),  and The
Bank of New York, as Rights Agent (the "Rights Agent").


                                    Recitals


WHEREAS, the Corporation and the Rights Agent are parties to a Rights Agreement,
dated  as  of  October  3,  1986   (Renewed and Restated as of October 19, 1996)
(the "Rights Agreement"); and


WHEREAS,  EMC  Corporation,   a  Massachusetts   corporation  ("EMC"),  and  the
Corporation  propose to enter into an Agreement  and Plan of Merger (the "Merger
Agreement")  pursuant to which the  Corporation  will merge with Emerald  Merger
Corporation,  a Delaware corporation and subsidiary of EMC (the "Merger"), and a
related Stock Option  Agreement by and between the Corporation,  as issuer,  and
EMC,  as  grantee  (the  "Option  Agreement").  The  Board of  Directors  of the
Corporation  has  approved  the  Merger  Agreement,  the  Merger  and the Option
Agreement; and


WHEREAS,  pursuant to Section 26 of the Rights Agreement, the Board of Directors
of the Corporation  has determined that an amendment to the Rights  Agreement as
set forth herein is necessary and desirable in connection with the foregoing and
the  Corporation  and the Rights  Agent  desire to evidence  such  amendment  in
writing;


NOW, THEREFORE,  in consideration of the foregoing and the mutual agreements set
forth herein, the parties hereto agree as follows:


(a) Amendment of Section 1(a).  Section 1(a) of the Rights  Agreement is amended
to add the following sentence at the end thereof:


         Notwithstanding  anything in this Rights Agreement to the contrary, EMC
         shall  not be  deemed  to be an  Acquiring  Person by virtue of (i) the
         consummation  of the Merger,  (ii) the  execution  and  delivery of the
         Merger Agreement and the Option Agreement, or (iii) the consummation of
         any of the other transactions  contemplated in the Merger Agreement and
         the Option Agreement.


(b)  Amendment  of  Section   3(a).  Section 3 (a)  of  the  Rights Agreement is
amended to add the following sentence at the end thereof:


         Notwithstanding  anything in this Rights  Agreement to the contrary,  a
         Distribution Date shall not be deemed to have occurred as the result of
         (i) the  consummation  of the Merger,  (ii) the execution of the Merger
         Agreement and the Option Agreement, or (iii) the consummation of any of
         the other  transactions  contemplated  in the Merger  Agreement and the
         Option Agreement.


(c) Amendment of Section 1(k).  Section 1(k) of the Rights  Agreement is amended
and restated to read as follows:


                  (i)   "Final Expiration Date" shall mean October 19, 2001.


                  (ii)  "Merger"  shall have the meaning set forth in the Merger
                        Agreement.


                  (iii) "Merger Agreement" shall mean that certain Agreement and
                        Plan of Merger, dated as of August 6, 1999, by and among
                        EMC, Emerald Merger Corporation and the Corporation,  as
                        amended from time to time.


                  (iv)  "Option  Agreement" shall mean that certain Stock Option
                        Agreement,  dated as of August 6, 1999,  by and  between
                        EMC,  as grantee,  and the  Corporation,  as issuer,  as
                        amended from time to time.


                  (v)  "EMC"  shall  mean  EMC   Corporation,   a  Massachusetts
                       corporation.


(d)  Amendment of Section 7(a).  Section 7(a) of the Rights  Agreement is hereby
amended and restated to state in its entirety as follows:


         Subject to Section  7(e)  hereof,  the  registered  holder of any Right
         Certificate  may  exercise  the  Rights  evidenced  thereby  (except as
         otherwise  provided  herein)  in whole or in part at any time after the
         Distribution  Date upon  surrender of the Right  Certificate,  with the
         form of election to purchase on the reverse side thereof duly executed,
         to the Rights Agent at the principal  office of the Rights Agent as set
         forth in Section 25 hereof, together with payment of the Purchase Price
         with respect to each one one-hundredth of a share of Preferred Stock as
         to which the Rights are exercised, at or prior to the Close of business
         on the earlier of (i) the Final Expiration Date, (ii) the date on which
         the Rights are redeemed as provided in Section 23 hereof,  or (iii) the
         consummation  of the Merger (such earlier date being herein referred to
         as the "Expiration Date").


(e)  Amendment of Section 12.  Section 12 of  the Rights Agreement is amended to
add the following sentence at the end thereof:


         Notwithstanding anything in this Rights Agreement to the contrary, none
         of (i) the consummation of the Merger, (ii) the execution of the Merger
         Agreement and the Option  Agreement,  and (iii) the consummation of any
         of the other transactions  contemplated in the Merger Agreement and the
         Option  Agreement shall be deemed to be events of the type described in
         the first  sentence of this  Section 12, and shall not cause the Rights
         to be adjusted or exercisable  in accordance  with, or any other action
         to be taken or obligation to arise pursuant to, this Section 12.


(f) Effectiveness. This Amendment shall be deemed effective as of the date first
written above, as if executed on such date. Except as amended hereby, the Rights
Agreement  shall  remain  in full  force  and  effect  and  shall  be  otherwise
unaffected hereby.


(g)  Miscellaneous.  This Amendment  shall be deemed to be a contract made under
the laws of the State of Delaware and for all purposes  shall be governed by and
construed in accordance  with the laws of such state  applicable to contracts to
be made and performed  entirely  within such state,  except as to the duties and
liabilities  of the Rights  Agent which shall be  governed by and  construed  in
accordance  with  the laws of the  State  of New  York.  This  Amendment  may be
executed in any number of counterparts,  each of such counterparts shall for all
purposes be deemed to be an original,  and all such counterparts  shall together
constitute but one and the same instrument. If any term, provision,  covenant or
restriction  of this Amendment is held by a court of competent  jurisdiction  or
other  authority  to be invalid,  void or  unenforceable,  the  remainder of the
terms, provisions,  covenants and restrictions of this Amendment shall remain in
full force and effect and shall in no way be affected,  impaired or invalidated.
It is the intent of the parties  hereto to enforce the  remainder  of the terms,
provisions, covenants and restrictions to the maximum extent permitted by law.




                  IN  WITNESS  WHEREOF,  the  parties hereto  have  caused  this
Amendment No. 1 to  be  duly executed,  all as of  the date and year first above
written.





Attest:                                                 DATA GENERAL CORPORATION

By:      /s/ James K. Jacobs                      By:      /s/ Robert C. McBride
   -------------------------                         ---------------------------
Name:    James K. Jacobs                          Name:    Robert C. McBride
Title:   Assistant Secretary                      Title:   Chief Administrative
                                                  Officer, Treasurer  and  Vice
                                                  President


Attest:                                                 THE BANK OF NEW YORK,
                                                        AS RIGHTS AGENT

By:      /s/ Ralph Chianese                       By:      /s/ Eon A. Canzius
   -------------------------                         ---------------------------
Name:    Ralph Chianese                           Name:    Eon A. Canzius
Title:   Vice President                           Title:   Assistant Treasurer