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                                                                   Exhibit 10.23

                          AGREEMENT AND GENERAL RELEASE

CONSULT WITH A LAWYER BEFORE SIGNING THIS AGREEMENT AND RELEASE. BY SIGNING THIS
AGREEMENT, YOU GIVE UP AND WAIVE IMPORTANT LEGAL RIGHTS.

I, George Donahue, of 373 Marlborough Street, Unit 1, Boston, MA 02115,
understand and, of my own free will, enter into this AGREEMENT AND GENERAL
RELEASE ("AGREEMENT" or "Agreement") for the benefit of Unisphere Solutions,
Inc., a Delaware corporation with principal offices at One Executive Drive,
Chelmsford, MA 01824, and its subsidiaries, (hereinafter referred to
individually and collectively as "UNISPHERE"), and in consideration of the
payments and benefits described herein, agree as follows:

1.   My employment with UNISPHERE will be terminated on June 1, 2000 (the
     "Termination Date"). My last day actively at work with UNISPHERE will be
     June 1, 2000. I hereby resign from any corporate office or official
     position which I hold with UNISPHERE or any subsidiary of UNISPHERE
     effective as of the Termination Date.

2.   I hereby acknowledge and agree that, in accordance with the terms of
     UNISPHERE's Stock Incentive Compensation Plan (the "Plan"), all options
     previously awarded to me under that Plan shall be cancelled and forfeited
     by me upon termination of my employment on the Termination Date. In
     consideration of my entering into this Agreement and in further
     consideration of my agreement to forfeit any and all option awards
     previously granted to me, I will be eligible to receive an amended
     non-qualified stock option award under the Plan for a total of 16,666
     shares (on a post-split basis) of common stock of Unisphere Solutions, Inc.
     with immediate vesting of those 16,666 options upon the Effective Date of
     this Agreement (as set forth in Paragraph 13 hereof) and a one (1) year
     period following the Termination Date to exercise the same, at an exercise
     price of $9.30 per share.

3.   I understand that, except as provided in Paragraph 2 of this AGREEMENT,
     after the Termination Date, I will have no further rights to any other
     compensation or benefits from UNISPHERE or any of its subsidiaries,
     including, but not

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     limited to, any rights to or under any salary, bonus, compensation,
     milestone, incentive, retention or stock option plans of UNISPHERE or its
     subsidiaries, or vacation, severance, pension, medical, dental, life, short
     term disability, long term disability or other insurance or benefits of any
     kind.

4.   I understand UNISPHERE will not be required to provide the payments and
     benefits set forth in Paragraph 2 of this AGREEMENT unless and until I sign
     this AGREEMENT and this AGREEMENT becomes effective pursuant to Paragraph
     18 hereof.

5.   I understand that this AGREEMENT does not constitute an admission by
     UNISPHERE or myself of any (a) violation of any statute, law or regulation;
     (b) breach of contract, actual or implied; or (c) commission of any tort.

6.   In consideration for the payments and benefits set forth in Paragraph 2 of
     this AGREEMENT, I do, on behalf of myself, my legal representatives, heirs,
     executors, administrators, successors and assigns, agree and promise not to
     sue and to forever release UNISPHERE, its affiliates, subsidiaries, and
     divisions and their respective predecessors, successors and assigns and
     their current and former directors, representatives, agents, employees,
     officers and shareholders, both individually and in their official
     capacities, (the "Releasees") from any and all claims, actions, causes of
     action, suits, demands, liabilities, complaints, contracts, agreements,
     promises and charges of every kind, nature and description, whenever they
     arose and whether in law or in equity, which may by law be waived
     including, but not limited to, claims related to my employment with
     UNISPHERE, the compensation, benefits, terms and conditions of my
     employment with UNISPHERE, or the cessation of my employment with UNISPHERE
     as well as any application for re-employment that has been made prior to
     this date with UNISPHERE. This release includes but is not limited to any
     claim, charge or action arising under any federal, state or local
     discrimination statute, which include, but are not limited to, Title VII of
     the Civil Rights Act of 1964 and 1991, The Age Discrimination in Employment
     Act, the Rehabilitation Act of 1973, the Older Workers Benefit Protection
     Act, the Massachusetts Fair Employment Practices Act, the Fair Labor
     Standards Act, the Americans with Disabilities Act, the Occupational Health
     and Safety Act, the Family and Medical Leave Act, and the National Labor
     Relations Act. This release also includes

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     any other federal, state, county, city or local law, statute, ordinance,
     regulation, public policy, contract or tort law having any bearing
     whatsoever on the terms and conditions of my employment or the cessation of
     that employment, including, but not limited to, those laws relating to
     discrimination on the basis of age, sex, race, national origin, religion,
     marital status, sexual orientation or payment of wages, or under any other
     theory of law or contract, including but not limited to, fraud, wrongful
     termination or intentional or negligent infliction of emotional or mental
     distress, libel or slander. I intend to waive and release any rights I may
     have under these and other laws which I ever had, now have or shall have as
     of the date of this Agreement, but I do not intend to nor am I waiving any
     rights or claims that may arise after the date I sign this AGREEMENT, or
     that may arise from UNISPHERE's breach of this AGREEMENT.

7.   I understand and acknowledge that the payments and benefits set forth under
     this AGREEMENT completely satisfy any obligations which UNISPHERE may have
     towards me under the Plan.

8.   I acknowledge and agree that nothing in this AGREEMENT shall be deemed to
     reduce in any way the obligations I have under any non-competition
     agreement, employee patent and secrecy agreement or confidentiality
     agreements which apply to me.

     I agree to strictly maintain the confidentiality of the terms of this
     AGREEMENT and shall not disclose any information relating thereto to any
     individual other than my immediate family members, counsel and tax advisor.

9.   This AGREEMENT shall be governed by and construed in accordance with the
     laws of the Commonwealth of Massachusetts without regard to principles of
     conflicts of law.

10.  The terms and provisions of this AGREEMENT are severable. If one or more
     provisions or terms of this AGREEMENT shall be ruled unenforceable,
     UNISPHERE may elect to enforce the remainder of this AGREEMENT.

11.  I understand that this AGREEMENT may not affect the rights and
     responsibilities of the Equal Employment Opportunity Commission
     ("Commission") to enforce the Age Discrimination in Employment Act ("ADEA")
     or be used to justify

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     interfering with the protected right of an employee to file a charge under
     the ADEA or participate in an investigation or proceeding conducted by the
     Commission under the ADEA. I further understand that this AGREEMENT may not
     affect the rights and responsibilities of the Massachusetts Commission
     Against Discrimination ("MCAD") to enforce the laws of the Commonwealth of
     Massachusetts prohibiting discrimination in employment or be used to
     justify interfering with the protected right of an employee to file a
     charge under such laws or participate in an investigation or proceeding
     conducted by the MCAD under those laws.

12.  I was given a copy of this AGREEMENT on or before the Termination Date. I
     have had an opportunity to consult an attorney before signing it and was
     given a period of at least twenty-one (21) days or until August 2, 2000 to
     consider this AGREEMENT. In the event that I sign this Agreement within
     less than twenty-one (21) days of receipt, I acknowledge that I did so
     voluntarily and with knowledge of the opportunity to consider this
     Agreement for the entire twenty-one (21) day period. I acknowledge that in
     signing this AGREEMENT I have relied only on the promises written in this
     AGREEMENT and not on any other promise made by UNISPHERE.

13.  I have seven (7) days to revoke this AGREEMENT after I sign it by sending
     written notice to UNISPHERE addressed as follows: Unisphere Solutions,
     Inc., One Executive Drive, Chelmsford, MA 01824, Attention: Director of
     Human Resources, which notice must be postmarked within seven (7) days of
     my execution hereof. If the seventh day is a Saturday, Sunday or legal
     holiday in Massachusetts, then the revocation period shall not expire until
     the next following day which is not a Saturday, Sunday or legal holiday.
     This AGREEMENT will not become effective or enforceable until ten (10) days
     after UNISPHERE has received my signed copy of this AGREEMENT (the
     "Effective Date") provided the revocation period expires without my having
     exercised the right to revoke. No benefits will be made hereunder until the
     revocation period has expired without exercise and the Agreement becomes
     effective as set forth herein.

14.  This AGREEMENT may not be modified or changed orally. Any modifications or
     amendments must be in writing and signed by the parties hereto. The parties
     agree that this Agreement represents the entire agreement of the parties
     and supersedes all prior communications, agreements or

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     understandings, either oral or written, if any, regarding the same.

15.  Any and all disputes, complaints, controversies, claims and grievances
     (excluding those specifically excepted herein) arising under, out of, in
     connection with, or in any manner related to this AGREEMENT or the relation
     of the parties hereunder shall be submitted to final and binding
     arbitration to be conducted by the American Arbitration Association in
     accordance with its Rules applicable to these types of disputes,
     complaints, claims or grievances, by a neutral and impartial arbitrator
     acceptable to me and UNISPHERE. If such an arbitrator has not been selected
     by me and UNISPHERE within 60 days after AAA first provides a list of
     eligible arbitrators, or within thirty days after the occurrence of a
     vacancy, a neutral and impartial arbitrator shall be selected and appointed
     by the American Arbitration Association, in accordance with its Rules.
     Unless otherwise required under applicable law, the arbitration proceedings
     shall be conducted in Boston, Massachusetts or in the city where the
     principal place of business of UNISPHERE is situated at the date of this
     AGREEMENT or a city mutually agreed to by the parties, and the procedural
     rules of the place of arbitration shall apply. Arbitration proceedings
     hereunder may be commenced by written notice from either party hereto to
     the other party. Such proceedings and evidence shall be confidential. The
     arbitrator shall have the power and the authority to make such decisions
     and awards as he/she shall deem appropriate, including granting
     compensatory damages and costs to the prevailing party (including fees of
     the arbitrator, but excluding punitive, exemplary, consequential or special
     damages, and attorneys' fees), and the granting or issuance of such
     mandatory directions, prohibitions, orders, restraints and other
     injunctions (other than any of the foregoing that would reestablish the
     employment relationship formerly existing between UNISPHERE and myself)
     that he/she may deem necessary or advisable directed to or against any of
     the parties, including a direction or order requiring specific performance
     of any covenant, agreement or provision of this AGREEMENT as a result of a
     breach or threatened breach thereof. The cost of such arbitration shall be
     borne equally by the parties except that each party shall bear its own cost
     of attorneys' fees and expenses. Any decision and award of the arbitrator
     shall be final, binding and conclusive upon all of the parties hereto and
     said decision and award may be entered as a final judgment in any court of
     competent jurisdiction. It is expressly agreed that

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     arbitration as provided herein shall be the exclusive means for
     determination of all matters as above provided and neither of the parties
     hereto shall institute any action or proceeding in any court of law or
     equity, state or federal, other than respecting enforcement of the
     arbitrator's award hereunder. The foregoing sentence shall be a bona fide
     defense in any action or proceeding instituted contrary to this AGREEMENT.
     Notwithstanding the foregoing, nothing contained herein shall prevent or
     restrain in any manner UNISPHERE from instituting an action or claim in any
     court, or such other forum as may be appropriate to enforce the terms of
     any employee patent and secrecy agreement, (or similar agreement relating
     to UNISPHERE's confidential or proprietary business information or trade
     secrets) to protect UNISPHERE's proprietary or confidential business
     information or trade secrets, to enforce or protect UNISPHERE's patent,
     copyright, trademark, trade name or trade dress rights, to redress claims
     for product disparagement or trade libel, or to protect UNISPHERE's
     reasonable business expectations or relations with third parties, or to
     enforce the terms of any non-competition agreement. To the extent this
     paragraph sets forth different procedures, or remedies, or provides the
     arbitrator different powers than are set forth in the Rules of the American
     Arbitration Association, the terms of this paragraph shall take precedence.

REMAINDER OF PAGE INTENTIONALLY LEFT BLANK

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I HAVE BEEN ADVISED THAT I HAVE TWENTY-ONE (21) DAYS TO CONSIDER THIS AGREEMENT
AND I HAVE BEEN ADVISED IN WRITING TO CONSULT WITH AN ATTORNEY PRIOR TO
EXECUTION OF THIS AGREEMENT. I FURTHER UNDERSTAND THAT I MAY REVOKE THIS
AGREEMENT FOR A PERIOD OF SEVEN (7) DAYS FOLLOWING THE DAY I EXECUTE THE
AGREEMENT AND SAID AGREEMENT SHALL NOT BECOME EFFECTIVE OR ENFORCEABLE UNTIL THE
REVOCATION PERIOD HAS EXPIRED. I UNDERSTAND THAT THIS AGREEMENT WILL BE A
BINDING LEGAL DOCUMENT AND THAT MY SIGNATURE WILL COMMIT ME TO ITS TERMS. I HAVE
READ THIS AGREEMENT, AND I UNDERSTAND ALL OF ITS TERMS. HAVING ELECTED TO
EXECUTE THIS AGREEMENT, TO FULFILL THE PROMISES SET FORTH HEREIN, AND TO RECEIVE
THEREBY THE SUMS AND BENEFITS AS SET FORTH HEREIN, I FREELY AND KNOWINGLY, AND
AFTER DUE CONSIDERATION, VOLUNTARILY ENTER INTO THIS AGREEMENT INTENDING TO
WAIVE, SETTLE AND RELEASE ALL CLAIMS I HAVE, HAD OR MIGHT HAVE AGAINST
UNISPHERE.

                                           /s/ George Donahue
                                           ---------------------------
                                           George Donahue

                                           Date:  7/31/00
                                                 ---------------------

STATE OF FLORIDA     )
                           :ss
COUNTY OF                )

On this 31st day of July, 2000 before me personally came George Donahue to me
known and known to be the individual who executed the foregoing AGREEMENT AND
GENERAL RELEASE before me and duly acknowledged to me that he/she executed the
same as his/her free act and deed.

NOTARY PUBLIC * STATE OF FLORIDA            /s/ LuAnn S. McDaniel
OFFICIAL NOTARY SEAL                        ------------------------
LUANN S. MCDANIEL                           Notary Public
COMMISSION NUMBER                           My Commission Expires:
CC786911                                    Nov. 19, 2002
MY COMMISSION EXPIRES:
NOV. 19, 2002

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                                           Unisphere Solutions, Inc.

                                           BY: /s/ Ann Laporte
                                              ----------------------

                                           Date: 8/4/00
                                                --------------------

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                                                                   EXHIBIT 10.27

                                Midway Games Inc.
                          3401 North California Avenue
                                Chicago, IL 60618

                                   May 4, 2000

Mr. Neil D. Nicastro
999 North Sheridan Road
Lake Forest, Illinois 60045

Dear Mr. Nicastro:

         Reference is made to your Employment Agreement dated July 1, 1996 (the
"Midway Employment Agreement") between Midway Games Inc. ("Midway") and you, as
amended March 5, 1998 and November 5, 1999.

         This letter will reflect our agreement that, for a period of one year
beginning July 1, 2000 and ending June 30, 2001, you agree to waive your right
to receive base salary under subparagraph 3(a) of the Midway Employment
Agreement (pursuant to which you are entitled to be paid a base salary at the
annual rate of $600,000), and in lieu thereof you shall be granted today an
option expiring June 30, 2005 to purchase 300,000 shares of Midway common stock
pursuant to Midway's 1996 and/or 1999 Stock Option Plans. The option shall be
exercisable in all events on or after June 30, 2001, or earlier if there is a
change of control of Midway on or prior to such date. The exercise price shall
be the closing market price of the Midway common stock on the date that Midway's
Board of Directors approves this Agreement (the "Effective Date").
Notwithstanding the one year waiver of base salary provided herein, if any
provisions of the Midway Employment Agreement which refer to annual base salary
for measuring any payment (including without limitation, paragraphs 6(a), 6(b)
and 9(b)) shall become applicable during the one year waiver period, the annual
base salary shall be deemed to be $600,000.

         In addition, effective on the Effective Date, clause (II) of
subparagraph 9(b)(i) of the Midway Employment Agreement is hereby amended, to
read as follows:

                  (II) the aggregate bonus which would have been payable to
         Nicastro pursuant to subparagraph 3(b) of this Agreement during the
         remaining term hereof, assuming pre-tax income of Midway during the
         remaining term hereof is earned at the highest level achieved in any of
         the last five (5) full fiscal years prior to such termination; and

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Mr. Neil D. Nicastro                       2                         May 4, 2000

         In all other respects, the Midway Employment Agreement is hereby
confirmed and is in full force and effect.

         Please indicate your agreement to the foregoing by signing this letter
in the place provided below.

                                           Very truly yours,

                                           MIDWAY GAMES INC.

                                           By: /s/  Harold H. Bach, Jr.
                                              ----------------------------------
                                              Harold H. Bach, Jr.
                                              Executive Vice President - Finance

Accepted and Agreed to:

/s/ Neil D. Nicastro
---------------------------------
NEIL D. NICASTRO

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