EXHIBIT 10 (bb)




                       AMENDMENT NO. 3 TO LETTER OF CREDIT
                           AND REIMBURSEMENT AGREEMENT

           THIS AMENDMENT NO. 3 TO LETTER OF CREDIT AND  REIMBURSEMENT   
AGREEMENT (this "Agreement") is made and entered into as of this 11th day of 
December, 1996 among:

           DATA  GENERAL  CORPORATION,   a  Delaware  corporation  ("Borrower"),
NATIONSBANK OF TEXAS, NATIONAL ASSOCIATION, a national banking association,  THE
BANK OF NEW  YORK and  FLEET  NATIONAL  BANK,  formerly  known as Fleet  Bank of
Massachusetts,  N.A.  (each  individually,  a  "Lender"  and  collectively,  the
"Lenders"); and

           NATIONSBANK  OF  TEXAS,  NATIONAL  ASSOCIATION,  a  national  banking
association,  in its  capacity as agent for the Lenders (in such  capacity,  the
"Agent");

                              W I T N E S S E T H:
                              --------------------

           WHEREAS, the Borrower,  the Lenders and the Agent have entered into a
Letter of Credit and  Reimbursement  Agreement dated as of December 21, 1994, as
amended by Amendment No. 1 to Letter of Credit and Reimbursement Agreement dated
as of October 5, 1995, as further amended by Amendment No. 2 to Letter of Credit
and  Reimbursement  Agreement  dated as of December 10, 1995 among the Borrower,
the  Lenders  and the Agent and as  hereby  amended  (as  amended,  the  "Credit
Agreement"),  pursuant to which the Lenders  agreed to issue certain  letters of
credit on behalf of the Borrower; and

           WHEREAS,  the Borrower  has  requested  that the Credit  Agreement be
amended in the manner set forth herein and the Agent and the Lenders are willing
to agree to such amendment;

           NOW,  THEREFORE,  in  consideration  of the mutual  covenants and the
fulfillment  of the  conditions  set forth herein,  the parties hereto do hereby
agree as follows:

     1.  Definitions. Any capitalized terms used herein without definition shall
have the meaning set forth in the Credit Agreement.

     2.  Amendment.  Subject to the terms and conditions  set forth herein,  the
Credit Agreement is hereby amended as follows:

                    (a) The definitions of "Commitment  Termination  Date" shall
 be amended and restated in its entirety to read as follows:

                               "Commitment  Termination Date" means the earliest
                     to occur of (i)  December  17,  1997  (364  days  after the
                     Commitment   Termination  Date   established   pursuant  to
                     Amendment  No. 2 to  Letter  of  Credit  and  Reimbursement
                     Agreement  dated as of December  10, 1995 among all parties
                     hereto),  or (ii)  the  date  of  termination  of  Lenders'
                     obligations  pursuant  to  Section  8.01  hereof  upon  the
                     occurrence  of an Event of  Default,  or (iii) such date as
                     the Borrower may voluntarily and permanently  terminate the
                     Letter of Credit Facility by causing all Obligations of the
                     Borrower  to  NationsBank  and  the  Lenders  to  be  Fully
                     Satisfied and  terminating  all  obligations of NationsBank
                     and the  Lenders  with  respect  to  Letters  of Credit and
                     Participations;

     3.  Amendment  Fee.  The  Borrower  shall pay to the Agent for the pro rata
benefit of the Lenders based on their Applicable Commitment  Percentages,  a fee
(the  "Facility  Fee")  equal to the  product  of the  Total  Letter  of  Credit
Commitment multiplied by 1/8 of 1% (.125%).

     4.  Effectiveness.  This  Agreement  shall become  effective as of the date
hereof  upon  receipt by the Agent of (a) seven  fully  executed  copies of this
Agreement (which may be signed in  counterparts)  and (b) payment in full of the
Facility Fee to be held by the Agent for the pro rata benefit of the Lenders.

     5.  Representations  and  Warranties.  In order to induce the Agent and the
Lender to enter into this Agreement, the Borrower represents and warrants to the
Agent and the Lenders as follows:

                     (a) The  representations and warranties made by Borrower in
           Article V of the Credit  Agreement  are true and correct on and as of
           the date hereof,  except to the extent that such  representations and
           warranties  expressly  relate to an earlier  date and except that the
           financial  statements referred to in Section 5.01(e)(i) of the Credit
           Agreement  shall be  deemed  to be those  financial  statements  most
           recently  delivered to the Agent and the Lenders  pursuant to Section
           6.01 of the Credit Agreement;

                     (b)  There  has  been no  material  adverse  change  in the
           condition,   financial  or   otherwise,   of  the  Borrower  and  its
           Subsidiaries,  taken as a whole,  since  the date of the most  recent
           financial  reports  of the  Borrower  received  by the  Agent and the
           Lenders under  Section  6.01(a) of the Credit  Agreement,  other than
           changes in the ordinary course of business;

                     (c) The  business  and  properties  of the Borrower and its
           Subsidiaries,  taken as a whole,  are not,  and since the date of the
           most recent  financial  report of the Borrower  and its  Subsidiaries
           received by the Agent and the Lenders  under  Section  6.01(a) of the
           Credit  Agreement,   have  not  been,   adversely   affected  in  any
           substantial  way as the  result of any fire,  explosion,  earthquake,
           accident,  strike,  lockout,  combination of workers, flood, embargo,
           riot,  activities of armed  forces,  war or acts of God or the public
           enemy, or cancellation or loss of any major contracts; and

                     (d)  No  event  has  occurred  and  is   continuing   which
           constitutes,  and no condition  exists which upon the consummation of
           the transaction contemplated hereby would constitute, a Default or an
           Event  of  Default  on the  part of the  Borrower  under  the  Credit
           Agreement, either immediately or with the lapse of time or the giving
           of notice, or both.

     6. Entire Agreement. This Agreement sets forth the entire understanding and
agreement  of the parties  hereto in relation to the subject  matter  hereof and
supersedes any prior  negotiations  and agreements among the parties relative to
such subject matter.

     7.  Full  Force  and  Effect of  Agreement.  Except as hereby  specifically
amended, modified or supplemented,  the Credit Agreement and all other Letter of
Credit  Documents  are hereby  confirmed  and ratified in all respects and shall
remain in full force and effect according to their respective terms.

     8.  Counterparts.   This  Agreement  may  be  executed  in  any  number  of
counterparts,  each of which  shall be deemed an  original  as against any party
whose signature appears thereon,  and all of which shall together constitute one
and the same instrument.

     9. Governing  Law. This Agreement  shall in all respects be governed by the
laws and judicial decisions of the State of New York.

     10.  Enforceability.  Should  any  one or more  of the  provisions  of this
Agreement be determined to be illegal or  unenforceable as to one or more of the
parties hereto,  all other  provisions  nevertheless  shall remain effective and
binding on the parties hereto.

     11.  Credit  Agreement.  All  references  in any of the  Letter  of  Credit
Documents  to the Credit  Agreement  shall mean the Credit  Agreement as amended
hereby.

                            [Signature page follows.]


<PAGE>



 IN WITNESS  WHEREOF,  the parties  hereto have caused this Agreement to be duly
executed  by their duly  authorized  officers,  all as of the day and year first
above written.

                                      BORROWER:

                                      DATA GENERAL CORPORATION

                                      By:
                                      Name:
                                      Title:


                                      LENDERS:

                                      NATIONSBANK OF TEXAS, NATIONAL
                                      ASSOCIATION

                                      By:
                                      Name:
                                      Title:


                                      THE BANK OF NEW YORK

                                      By:
                                      Name:
                                      Title:


                                      FLEET NATIONAL BANK

                                      By:
                                      Name:
                                      Title:


                                      AGENT:

                                      NATIONSBANK OF TEXAS, NATIONAL ASSOCIATION
                                      as Agent for the Lenders

                                      By:
                                      Name:
                                      Title: