1
                                                                  EXHIBIT 10.21 
                             ----------------------

                             KEY EMPLOYEE AGREEMENT
 
                             ----------------------




To:        David E. Merry, Jr.                               As of April 1, 1997
           37 Moriarty Road
           Ware, Massachusetts 01082

           The undersigned, Centennial Technologies, Inc., a Delaware
corporation (the "Company"), hereby agrees with you as follows:

           1.        POSITION AND RESPONSIBILITIES.

                     1.1 You shall serve as the Vice President - Engineering of
the Company or in a comparable position with similar responsibilities, as
designated by the Company's Board of Directors, and shall perform such functions
as are customarily associated with such capacity from time to time at the
Company's headquarters or such place or places as are appropriate and necessary
in connection with such employment. It is expressly agreed that any change in
your shall not provide cause for this agreement to be terminated by either
party.

                     1.2 You will, to the best of your ability, devote your full
time and best efforts to the performance of your duties hereunder and the
business and affairs of the Company. You agree to perform such duties consistent
with your position as may be lawfully and reasonably assigned to you by the
Company's Board of Directors from time to time. Such duties may include similar
responsibilities with companies in which the Company has a majority ownership
interest. If assuming such responsibilities would require you to move outside of
the Greater Boston area, such responsibilities will only be required of you on
terms mutually agreeable by you and the Company.

                     1.3 You will duly, punctually and faithfully perform and
observe any and all lawful rules and regulations which the Company may now or
shall hereafter establish governing the conduct of its business.

           2.        TERM OF EMPLOYMENT.



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                     2.1 The initial term of this Agreement shall be for one
year, subject to earlier termination in accordance with Section 2.2 hereof.
Thereafter, this Agreement may be renewed upon the written agreement of you and
the Company.

                     2.2 The Company shall have the right to terminate your
employment at any time either (a) immediately without prior written notice for
"cause" (as defined herein), or (b) upon at least ten (10) days' written notice
without cause. If the Company terminates your employment for cause, the Company
shall be obligated to pay you an amount equal to your salary and vacation pay
which is accrued and unpaid up to the date of such termination. If the Company
terminates your employment without cause, the Company shall be obligated to pay
you your Base Salary (as defined in EXHIBIT A attached hereto) for a period of
time equal to the greater of (i) six months, or (ii) that period of time which
commences on the date of such termination and ends with the expiration in the
initial term of employment set forth in Section 2.1 (the "Severance Period").
The Company shall also continue in full force and effect for the Severance
Period all health and insurance benefits that you enjoyed at the time of your
termination without cause, and all other benefits which applicable law requires
to be continued. Should you continue to be employed by the Company beyond the
term of this Agreement without a mutually agreed upon renewal or modification of
this Agreement, a six month severance provision for termination without cause as
described above shall apply.

                     2.3 For purposes of Section 2.2 hereof, the term "cause"
shall mean the following: (i) your involvement in any felony crime, material
arrestable criminal offense (excluding road traffic offenses for which a fine or
non-custodial penalty is imposed), or any crime in connection with your
employment with the Company (including theft of Company assets); or (ii)
material insubordination or your knowing or intentional failure to take actions
permitted by law and necessary to implement strategies or policies of the
Company and which are consistent with your positions and duties, following
written warning of such material insubordination or unreasonable failure; or
(iii) drunkenness or use of any drug or narcotic which adversely affects your
job performance; or (iv) any knowing or intentional misrepresentation of
significant information important to the operating condition of the Company; or
(v) acting in material breach or contravention of any non-competition,
non-disclosure or non-solicitation covenants hereof.

           3.        COMPENSATION. You shall receive the compensation and
benefits set forth on Exhibit A hereto ("Compensation") for all services to be
rendered by you hereunder and for your transfer of property rights, if any,
pursuant to an agreement relating to proprietary information and inventions of
even date herewith attached hereto and made a part hereof as EXHIBIT C between
you and the Company (the "Proprietary Information and Inventions Agreement"). If
you remain as a full-time employee of the Company until the later of six months
from the date of the execution of this Agreement or November 30, 1997 (the
"Bonus Date"), the Company will pay you, in a lump-sum payment within two (2)
weeks following the Bonus Date, a "stay bonus" 



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equal to the sum of $20,000. In the event you are terminated involuntarily and
not for "cause" as described in Section 2.3 above prior to the Bonus Date, you
will receive within two (2) weeks of such termination a pro-rated share of such
"stay bonus" for that period between the date of execution of this Agreement and
the Bonus Date that you remain employed by the Company.

           4.        OTHER ACTIVITIES DURING EMPLOYMENT.

                     4.1 Except for any outside employments and directorships
currently held by you as listed on EXHIBIT B hereto, if any, and except with the
prior written consent of the Company's Board of Directors (which approval shall
not be unreasonably withheld), you will not during the term of this Agreement
undertake or engage in any other employment, occupation or business enterprise
other than one in which you are an inactive investor.

                     4.2 You hereby agree that, except as disclosed on EXHIBIT B
hereto, during your employment hereunder, you will not, directly or indirectly,
engage (a) individually, (b) as an officer, (c) as a director, (d) as an
employee, (e) as a consultant, (f) as an advisor, (g) as an agent (whether a
salesperson or otherwise), (h) as a broker, or (i) as a partner, coventurer,
stockholder or other proprietor owning directly or indirectly more than one
percent (1%) interest, in any firm, corporation, partnership, trust,
association, or other organization which is engaged in any line of business
engaged in or under demonstrable development by the Company (such firm,
corporation, partnership, trust, association, or other organization being
hereinafter referred to as a "Prohibited Enterprise"). You hereby represent that
you are not presently engaged in any of the foregoing capacities described in
(a) through (i) in any Prohibited Enterprise.

           5.        FORMER EMPLOYERS.

                     5.1 You represent and warrant that your employment by the
Company will not conflict with and will not be constrained by any prior or
current employment, consulting agreement or relationship whether oral or
written. You represent and warrant that you do not possess confidential
information arising out of any such employment, consulting agreement or
relationship which, in your best judgment, would be utilized in connection with
your employment by the Company.

                     5.2 If, in spite of the second sentence of Section 5.1, you
should find that confidential information belonging to any other person or
entity might be usable in connection with the Company's business, you will not
intentionally disclose to the Company or use on behalf of the Company any
confidential information belonging to any of your former employers; but during
your employment by the Company you will use in the performance of your duties
all information which is generally known and used by persons with training and
experience comparable to your own, all information which is common knowledge in
the industry or otherwise legally in the public domain.


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           6.       PROPRIETARY INFORMATION AND INVENTIONS. You agree to
execute, deliver and be bound by the provisions of the Proprietary Information
and Inventions Agreement attached hereto as EXHIBIT C and incorporated herein.

           7.        POST-EMPLOYMENT ACTIVITIES.

                     7.1 You shall not, for a period of one (1) year after the
termination of your employment with the Company (for whatever reason), without
the prior written consent of the Company, directly or indirectly do any business
with or have any dealings whatsoever with any person, firm or company who was a
client, customer, supplier, agent or distributor of the Company during the
period of one (1) year prior to the end of your employment with the Company and
with whom you have contact during the period of one (1) year prior to the end of
your employment with the Company, nor shall you render services similar or
reasonably related to those which you shall have rendered hereunder during such
one (1) year period, to any person or entity whether now existing or hereafter
established which directly competes with (or proposes or plans to directly
compete with) the Company (a "Direct Competitor") in any line of business
engaged in or under development by the Company. Nor shall you entice, induce or
encourage any of the Company's other employees to engage in any activity which,
were it done by you, would violate any provision of the Proprietary Information
and Inventions Agreement which you have executed or this Section 7. As used in
this Section 7.1, the phrase "any line of business engaged in or under
development by the Company" shall be applied as at the date of termination of
your employment with the Company.

                     7.2 For a period of one (1) year after the termination of
your employment with the Company, the provisions of Section 4.2 hereof shall be
applicable to you and you shall comply therewith. As applied to such one (1)
year post-employment period, the term "any other line of business engaged in or
under demonstrable development by the Company," as used in Section 4.2, shall be
applied as at the date of termination of your employment with the Company.

                     7.3 No provision of this Agreement shall be construed to
preclude you from performing the same services which the Company hereby retains
you to perform for any person or entity which is not a Direct Competitor of the
Company upon the expiration or termination of your employment (or any
post-employment consulting arrangement) so long as you do not thereby violate
any term of this Agreement or the Proprietary Information and Inventions
Agreement.

                     7.4 After your employment with the Company ends, you are
required to notify the Company promptly in writing if you receive any offer of
employment that you wish to accept, if the employment might commence during the
period of restriction described in Section 7.1 above. This notice should
contain: (a) a complete description of the terms of the 



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offer, including the position and the compensation provided and the
responsibilities contemplated thereunder, and (b) confirmation of your intention
to accept the offer if the Company so permits. After you have so notified the
Company, the Company shall have fifteen (15) days to notify you of its election:

                     7.4.1. To release you from Section 7.1 hereof, but only as
it applies to the employment position offered to you, as disclosed in your
notice to the Company; or

                     7.4.2. To insist upon full compliance with Section 7.1;
provided, however, that if you have reported to the Company an offer of
employment that would commence more than six months after the termination of
your employment but within the period of restriction described in Section 7.1,
and the Company elects to insist upon full compliance with Section 7.1 for that
period, the Company shall provide you with the following "Special Benefit" over
such period: the Base Salary provided under this Contract for the period between
the date upon which you would have commenced such employment and the end of the
period described in Section 7.1.

                     During such time as the Company is paying you such "Special
Benefit," you are required to pursue with diligence
other employment opportunities consistent with your general skills and
interests. This Special Benefit is available only if the requirements of this
Section 7.4.2 are met, only during the period of the second six months of the
period of restriction described in Section 7.1, and only so long as you are
unable to obtain suitable employment in compliance with Section 7.1. Any
election by the Company to release you from Section 7.1 with respect to one
offer of employment shall not release you from Section 7.1 with respect to any
subsequent offers of employment, including transfers, reassignments or a change
in duties or responsibilities by the same or different employers.

           8.        REMEDIES. Your obligations under the Proprietary
Information and Inventions Agreement and the provisions of Sections 4.2, 7, 9,
10 and 11 of this Agreement (as modified by Section 12, if applicable) shall
survive the expiration or termination of your employment (whether through your
resignation or otherwise) with the Company. You acknowledge that a remedy at law
for any breach or threatened breach by you of the provisions of this Agreement
or the Proprietary Information and Inventions Agreement would be inadequate and
you therefore agree that the Company shall be entitled to injunctive relief in
case of any such breach or threatened breach.

           9.        ASSIGNMENT. This Agreement and the rights and obligations
of the parties hereto shall bind and inure to the benefit of any successor or
successors of the Company by reorganization, merger or consolidation and any
assignee of all or substantially all of its business and properties, but, except
as to any such successor or assignee of the Company, neither this Agreement nor
any rights or benefits hereunder may be assigned by the Company or by you,
except by operation of law or by a further written agreement by the parties
hereto.



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           10.        CONFIDENTIALITY. You agree to keep confidential, except
as the Company may otherwise consent in writing, and, except for the Company's
benefit, not to disclose or make any use of at any time either during or
subsequent to your employment, any trade secrets, confidential information,
knowledge, data or other information of the Company relating to products,
processes, know-how, techniques, methods, designs, formulas, test data, customer
lists, business plans, marketing plans and strategies, pricing strategies, or
other subject matter pertaining to any business of the Company or any of its
affiliates, which you may produce, obtain, or otherwise acquire during the
course of your employment, except as herein provided. You further agree not to
deliver, reproduce or in any way allow any such trade secrets, confidential
information, knowledge, data or other information, or any documentation relating
thereto, to be delivered to or used by any third parties without specific
direction or consent of a duly authorized representative of the Company.

           11.        ARBITRATION. Any dispute concerning this Agreement
including, but not limited to, its existence, validity, interpretation,
performance or non-performance, arising before or after termination or
expiration of this Agreement, shall be settled by a single arbitrator in Boston,
Massachusetts, in accordance with the expedited procedures of the commercial
rules then in effect of the American Arbitration Association. Judgment upon any
award may be entered in the highest court, state or federal, having
jurisdiction.

           12.        INTERPRETATION. IT IS THE INTENT OF THE PARTIES THAT in
case any one or more of the provisions contained in this Agreement shall, for
any reason, be held to be invalid, illegal or unenforceable in any respect, such
invalidity, illegality or unenforceability shall not affect the other provisions
of this Agreement, and this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. MOREOVER, IT
IS THE INTENT OF THE PARTIES THAT if any one or more of the provisions contained
in this Agreement is or becomes or is deemed invalid, illegal or unenforceable
or in case any provision shall for any reason be held to be excessively broad as
to duration, geographical scope, activity or subject, such provision shall be
construed by amending, limiting and/or reducing it to conform to applicable laws
so as to be valid and enforceable or, if it cannot be so amended without
materially altering the intention of the parties, it shall be stricken and the
remainder of this Agreement shall remain in full force and effect.

           13.        NOTICES. Any notice which the Company is required to or
may desire to give you shall be given by personal delivery or registered or
certified mail, return receipt requested, addressed to you at your address of
record with the Company, or at such other place as you may from time to time
designate in writing. Any notice which you are required or may desire to give to
the Company hereunder shall be given by personal delivery or by registered or
certified mail, return receipt requested, addressed to the Company at its
principal office, or at such other office as the Company may from time to time
designate in writing with a copy to Peter J. Macdonald, 



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Hale & Dorr, LLP, 60 State Street, Boston, MA 02109. The date of personal
delivery or the date of mailing of any notice under this Section 13 shall be
deemed to be the date of delivery thereof.

           14.       WAIVERS. No waiver of any right under this Agreement
shall be deemed effective unless contained in a writing signed by the party
charged with such waiver, and no waiver of any right arising from any breach or
failure to perform shall be deemed to be a waiver of any future such right or of
any other right arising under this Agreement. If either party should waive any
breach of any provision of this Agreement, such party shall not thereby be
deemed to have waived any preceding or succeeding breach of the same or any
other provision of this Agreement.

           15.       COMPLETE AGREEMENT; AMENDMENTS. The foregoing, including
Exhibits A, B and C hereto, is the entire agreement of the parties with respect
to the subject matter hereof, superseding any previous oral or written
communications, representations, understandings, or agreements with the Company
or any officer or representative thereof. Any amendment to this Agreement shall
be effective only if evidenced by a written instrument executed by the parties
hereto, upon authorization of the Company's Board of Directors.

           16.       HEADINGS. The headings of the Sections hereof are inserted
for convenience only and shall not be deemed to constitute a part hereof nor to
affect the meaning of this Agreement.

           17.       COUNTERPARTS. This Agreement may be signed in two
counterparts, and changes in market opportunities or customer requirements,
each of whichshall be deemed an original and both of which shall together 
constitute one agreement.

           18.       GOVERNING LAW. This Agreement shall be governed by and
construed under Massachusetts law, without regard to its conflict of laws
principles.




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           If you are in agreement with the foregoing, please sign your name
below and also at the bottom of the Proprietary Information and Inventions
Agreement, whereupon this Agreement shall become binding in accordance with its
terms. Please then return this Agreement to the Company. (You may retain for
your records the accompanying counterpart of this Agreement enclosed herewith).

                                          Very truly yours,

                                          CENTENNIAL TECHNOLOGIES, INC.




Date: June 30, 1997                       BY: /s/ Lawrence J. Ramaekers
      ------------------                  --------------------------------------
                                          Lawrence J. Ramaekers
                                          Interim Chief Executive Officer


Accepted and Agreed:



/s/ David E. Merry, Jr.
- ----------------------------------
David E. Merry, Jr.





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                                                                       EXHIBIT A
                                                                       ---------



                   EMPLOYMENT TERM, COMPENSATION AND BENEFITS
                                       OF
                               DAVID E. MERRY, JR.



1.         TERM. The term of the Agreement to which this Exhibit A is annexed
           and incorporated shall be until March 31, 1998.

2.         COMPENSATION. Your Base Salary shall be $80,500 per annum, payable in
           accordance with the payroll policies established by the Company.

3.         STOCK OPTIONS. Upon acceptance of this Agreement, you shall be
           granted an incentive stock option to purchase 10,000 shares of the
           common stock of the Company pursuant to the Company's 1994 Stock
           Option Plan at the fair market value determined by the Company's
           Board of Directors. These incentive stock options shall vest
           one-third on April 1, 1998, one-third on April 1, 1999, and one-third
           on April 1, 2000.

4.         VACATION.  You shall be entitled to 2 weeks paid vacation per year.

5.         OTHER BENEFITS. You shall be eligible for participation in any
           health, group insurance plan, or pension insurance and benefits plan
           that may be established by the Company or which the Company is
           required to maintain by law. You shall also be eligible to receive
           other benefits that are provided to the executive officers of the
           Company from time to time.






                                       A-1
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                    OUTSIDE EMPLOYMENTS AND DIRECTORSHIPS OF


                               DAVID E. MERRY, JR.











                                       B-1
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                                                                       EXHIBIT C
                                                                       ---------



- --------------------------------------------------------------------------------

                PROPRIETARY INFORMATION AND INVENTIONS AGREEMENT

- --------------------------------------------------------------------------------


To:        Centennial Technologies, Inc.                     As of April 1, 1997
           37 Manning Road
           Billerica, Massachusetts 01821

           The undersigned, in consideration of and as a condition of my
services to you and/or to companies which you own, control, or are affiliated
with or their successors in business (collectively, the "Company"), hereby
agrees as follows:

           1. CONFIDENTIALITY. I agree to keep confidential, except as the
Company may otherwise consent in writing, and, except for the Company's benefit,
not to disclose or make any use of at any time either during or subsequent to my
employment with the Company, any Inventions (as hereinafter defined), trade
secrets, confidential information, knowledge, data or other information of the
Company relating to products, processes, know-how, designs, formulas, test data,
customer lists, business plans, marketing plans and strategies, pricing
strategies, or other subject matter pertaining to any business of the Company or
any of its affiliates, which I may produce, obtain, or otherwise acquire during
the course of my employment, except as herein provided. I further agree not to
deliver, reproduce or in any way allow any such trade secrets, confidential
information, knowledge, data or other information, or any documentation relating
thereto, to be delivered to or used by any third parties without specific
direction or consent of a duly authorized representative of the Company.

            2. CONFLICTING EMPLOYMENT; RETURN OF CONFIDENTIAL MATERIAL. I agree
that during my employment with the Company I will not engage in any other
employment, occupation, consulting or other activity relating to the business in
which the Company is now or may hereafter become engaged, or which would
otherwise conflict with my obligations to the Company. In the event my
employment with the Company terminates for any reason whatsoever, I agree to
promptly surrender and deliver to the Company all records, materials, equipment,
drawings, documents and data which I may obtain or produce during the course of
my employment, and I will not take with me any description containing or
pertaining to any confidential information, knowledge or data of the Company
which I may produce or obtain during the course of my employment.



                                      C-1
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           3.        ASSIGNMENT OF INVENTIONS.


                     3.1 I hereby acknowledge and agree that the Company is the
owner of all Inventions. In order to protect the Company's rights to such
Inventions, by executing this Agreement I hereby irrevocably assign to the
Company all my right, title and interest in and to all Inventions.

                     3.2 For purposes of this Agreement, "Inventions" shall mean
all discoveries, processes, designs, technologies, devices, or improvements in
any of the foregoing or other ideas, whether or not patentable and whether or
not reduced to practice, made or conceived by me (whether solely or jointly with
others) during the period of my employment with the Company, which relate in any
manner to the actual or demonstrably anticipated business, work, or research and
development of the Company or its affiliates, or result from or are suggested by
any task assigned to me or any work performed by me for or on behalf of the
Company or its affiliates.

                     3.3 Any discovery, process, design, technology, device, or
improvement in any of the foregoing or other ideas, whether or not patentable
and whether or not reduced to practice, made or conceived by me (whether solely
or jointly with others) which I develop entirely on my own time during the term
of this Agreement not using any of the Company's equipment, supplies,
facilities, or trade secret information ("Personal Invention") is excluded from
this Agreement provided such Personal Invention (a) does not relate to the
actual or demonstrably anticipated business, research and development of the
Company, and (b) does not result, directly or indirectly, from any work
performed by me for the Company.

           4.        DISCLOSURE OF INVENTIONS. I agree that in connection with
any Invention, I will promptly disclose such Invention to the Company in order
to permit the Company to enforce its property rights to such Invention in
accordance with this Agreement. My disclosure shall be received in confidence by
the Company.

           5.        PATENTS AND COPYRIGHTS; EXECUTION OF DOCUMENTS.

                     5.1 Upon request, I agree to assist the Company or its
nominee (at its expense) during and at any time subsequent to my employment with
the Company in every reasonable way to obtain for its own benefit patents and
copyrights for Inventions in any and all countries. Such patents and copyrights
shall be and remain the sole and exclusive property of the Company or its
nominee. I agree to perform such lawful acts as the Company deems to be
necessary to allow it to exercise all right, title and interest in and to such
patents and copyrights.

                     5.2 In connection with this Agreement, I agree to execute,
acknowledge and deliver to the Company or its nominee upon request and at its
expense all documents, including assignments of title, patent or copyright
applications, assignments of such applications, assignments of patents or
copyrights upon issuance, as the Company may determine necessary or desirable to
protect the Company's or its nominee's interest in Inventions, and/or to use in




                                      C-2


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obtaining patents or copyrights in any and all countries and to vest title
thereto in the Company or its nominee to any of the foregoing.

           6.        MAINTENANCE OF RECORDS. I agree to keep and maintain
adequate and current written records of all Inventions made by me (in the form
of notes, sketches, drawings, flowcharts and other records as may be specified
by the Company), which records shall be available to and remain the sole
property of the Company at all times.

           7.        PRIOR INVENTIONS. It is understood that all Personal
Inventions, if any, whether patented or unpatented, which I made prior to my
association with the Company, are excluded from this Agreement. To preclude any
possible uncertainty, I have set forth on Schedule A attached hereto a complete
list of all of my prior Personal Inventions, including numbers of all patents
and patent applications and a brief description of all unpatented Personal
Inventions which are not the property of a previous employer. I represent and
covenant that the list is complete and that, if no items are on the list, I have
no such prior Personal Inventions. I agree to notify the Company in writing
before I make any disclosure or perform any work on behalf of the Company which
appears to threaten or conflict with proprietary rights I claim in any Personal
Invention. In the event of my failure to give such notice, I agree that I will
make no claim against the Company with respect to any such Personal Invention.

           8.        OTHER OBLIGATIONS. I acknowledge that the Company from time
to time may have agreements with other persons or with the U.S. Government or
agencies thereof, which impose obligations or restrictions on the Company
regarding Inventions made during the course of work thereunder or regarding the
confidential nature of such work. I agree to be bound by all such obligations
and restrictions and to take all action necessary to discharge the Company's
obligations.

           9.        TRADE SECRETS OF OTHERS. I represent that my performance of
all the terms of this Agreement and as an employee of the Company does not and
will not breach any agreement to keep confidential proprietary information,
knowledge or data acquired by me in confidence or in trust prior to my services
to the Company, and I will not disclose to the Company, or induce the Company to
use, any confidential or proprietary information or material belonging to any
previous client, employer or others. I agree not to enter into any agreement
either written or oral in conflict herewith.

           10.       MODIFICATION. I agree that any subsequent change or changes
in my duties, salary or compensation or in any Employment Agreement between the
Company and me, shall not affect the validity or scope of this Agreement.

           11.       SUCCESSORS AND ASSIGNS. This Agreement shall be binding
upon my heirs, executors, administrators or other legal representatives and is
for the benefit of the Company, its successors and assigns.


                                      C-3
   14



           12.       INTERPRETATION. IT IS THE INTENT OF THE PARTIES THAT in
case any one or more of the provisions contained in this Agreement shall, for
any reason, be held to be invalid, illegal or unenforceable in any respect, such
invalidity, illegality or unenforceability shall not affect the other provisions
of this Agreement, and this Agreement shall be construed as if such invalid,
illegal or unenforceable provision had never been contained herein. MOREOVER, IT
IS THE INTENT OF THE PARTIES THAT in case any one or more of the provisions
contained in this Agreement shall for any reason be held to be excessively broad
as to duration, geographical scope, activity or subject, such provision shall be
construed by limiting and reducing it in accordance with a judgment of a court
of competent jurisdiction, so as to be enforceable to the extent compatible with
applicable law.


           13.       WAIVERS. If either party should waive any breach of any
provision of this Agreement, he or it shall not thereby be deemed to have waived
any preceding or succeeding breach of the same or any other provision of this
Agreement.

           14.       COMPLETE AGREEMENT, AMENDMENTS. I acknowledge receipt of
this Agreement, and agree that with respect to the subject matter thereof it is
my entire agreement with the Company, superseding any previous oral or written
communications, representations, understandings, or agreements with the Company
or any officer or representative thereof. Any amendment to this Agreement or
waiver by either party of any right hereunder shall be effective only if
evidenced by a written instrument executed by the parties hereto, and, in the
case of the Company, upon written authorization of the Company's Board of
Directors.

           15.       HEADINGS. The headings of the sections hereof are inserted
for convenience only and shall not be deemed to constitute a part hereof nor to
affect the meaning hereof.

           16.       COUNTERPARTS. This Agreement may be signed in two
counterparts, each of which shall be deemed an original and both of which shall
together constitute one agreement.

           17.       GOVERNING LAW. This Agreement shall be governed by and
construed under Massachusetts law, excluding its conflict of law principles.

                                          DAVID E. MERRY, JR.


Date: June 30, 1997                       /s/ David E. Merry, Jr.
      ----------------                    --------------------------------------


Accepted and Agreed:

CENTENNIAL TECHNOLOGIES, INC.


By: /s/ Lawrence J. Ramaekers
    ----------------------------------
    Lawrence J. Ramaekers, Interim Chief Executive Officer




                                      C-4

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                                                                      SCHEDULE A
                                                                      ----------
                                                                  (to Exhibit C)

                               PERSONAL INVENTIONS
                                       OF
                               DAVID E. MERRY, JR.







                                      C-5