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                                                                  EXHIBIT 10.5.1

                    DATE OF LEASE EXECUTION: January 31, 1997



                                    ARTICLE I

                                 REFERENCE DATA


1.1  SUBJECTS REFERRED TO:

     Each reference in this Lease to any of the following subjects shall be
construed to incorporate the data stated for that subject in this Section 1.1:

LANDLORD: CONNECTICUT GENERAL LIFE INSURANCE COMPANY, a Connecticut corporation

MANAGING AGENT: Spaulding and Slye Services Limited Partnership

LANDLORD'S & MANAGING AGENT'S ADDRESS:

     Spaulding and Slye Services Limited Partnership
     c/o Spaulding and Slye Company
     125 High Street
     Boston, Massachusetts 02110
     Attn:  Peter A. DeLuca

LANDLORD'S CONSTRUCTION REPRESENTATIVE: Peter A. DeLuca

TENANT: MEDIA 100 INC., a Delaware corporation

TENANT'S ADDRESS (FOR NOTICE AND BILLING):

     Media 100 Inc.
     290 Donald J. Lynch Boulevard
     Marlborough, Massachusetts 01752
     Attn: Chief Financial Officer

TENANT'S CONSTRUCTION
REPRESENTATIVE:            William Jackson Associates, Inc.

LOT: The land known and numbered as 290 Donald J. Lynch Boulevard, Marlborough,
Massachusetts.

BUILDING: The building located on the Lot.

PREMISES: The space located on the first (1st) and second (2nd) floors of the
Building as shown on Exhibit A.

RENTABLE FLOOR AREA
OF THE PREMISES:           56,508 square feet

TOTAL RENTABLE FLOOR AREA OF THE BUILDING: 87,861 square feet


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DELIVERY DATE: February 5, 1997

TERM COMMENCEMENT DATE: The earlier of (a) April 1, 1997 or (b) the date on
which Tenant commences to use the Premises for business purposes

TERM: Commencing on the Term Commencement Date and continuing until March 31,
2002, unless sooner terminated as provided herein

ANNUAL BASE RENT:   (a)  $480,318 based on $8.50 per square foot of Rentable 
                         Floor Area ("p.r.s.f.") for the first year of the Term,
                         plus the partial month at the beginning of the Term if
                         any ("Year 1")

                    (b)  $508,572 based on $9.00 p.r.s.f. for the second year of
                         the Term, ("Year 2")

                    (c)  $536,826 based on $9.50 p.r.s.f. for the third year of
                         the Term, ("Year 3")

                    (d)  $565,080 based on $10.00 p.r.s.f. for the fourth year
                         of the Term, ("Year 4")

                    (e)  $593,334 based on $10.50 p.r.s.f. for the remainder of
                         the original Term ending March 31, 2002 ("Year 5")

ANNUAL ESTIMATED
OPERATING COSTS
FOR THE BUILDING:   $483,235.50 based on $5.50 p.r.s.f.

ANNUAL ESTIMATED OPERATING
COSTS FOR THE PREMISES
(included in Annual Rent): $310,794

ANNUAL ESTIMATED ELECTRICAL
COST FOR THE PREMISES
(included in Annual Rent): $50,857.20 based on $0.90 p.r.s.f.

ANNUAL RENT (subject to annual adjustment as provided in Article IV):

                    Year 1:   $841,969.20 computed as follows:

                                 $      8.50 Annual Base Rent (p.r.s.f.)
                               + $      5.50 Annual Estimated Operating
                                             Costs (p.r.s.f.)
                               + $       .90 Annual Estimated Electrical
                                             Costs to Tenant's Space
                                 -----------  (p.r.s.f.)
                               = $     14.90 Total Rate (p.r.s.f.)
                               X      56,508 rentable square feet
                                 -----------
                               = $841,969.20 Annual Rent



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                    Year 2:   $870,223.20 computed as follows:

                                 $      9.00 Annual Base Rent (p.r.s.f.)
                               + $      5.50 Annual Estimated Operating
                                             Costs (p.r.s.f.)
                               + $       .90 Annual Estimated Electrical
                                             Costs to Tenant's Space
                                 ----------- (p.r.s.f.)
                               = $     15.40 Total Rate (p.r.s.f.)
                               X      56,508 rentable square feet
                                 -----------
                               = $870,223.20 Annual Rent

                    Year 3:   $898,477.20 computed as follows:

                                 $      9.50 Annual Base Rent (p.r.s.f.)
                               + $      5.50 Annual Estimated Operating
                                             Costs (p.r.s.f.)
                               + $       .90 Annual Estimated Electrical
                                             Costs to Tenant's Space
                                 ----------- (p.r.s.f.)
                               = $     15.90 Total Rate (p.r.s.f.)
                               X      56,508 rentable square feet
                                 -----------
                               = $898,477.20 Annual Rent

                    Year 4:   $926,731.20 computed as follows:

                                 $     10.00 Annual Base Rent (p.r.s.f.)
                               + $      5.50 Annual Estimated Operating
                                             Costs (p.r.s.f.)
                               + $       .90 Annual Estimated Electrical
                                             Costs to Tenant's Space
                                 ----------- (p.r.s.f.)
                               = $     16.40 Total Rate (p.r.s.f.)
                               X      56,508 rentable square feet
                                 -----------
                               = $926,731.20 Annual Rent

                    Year 5:   $954,985.20 computed as follows:

                                 $     10.50 Annual Base Rent (p.r.s.f.)
                               + $      5.50 Annual Estimated Operating
                                             Costs (p.r.s.f.)
                               + $       .90 Annual Estimated Electrical
                                             Costs to Tenant's Space
                                 ----------- (p.r.s.f.)
                               = $     16.90 Total Rate (p.r.s.f.)
                               X      56,508 rentable square feet
                                 -----------
                               = $954,985.20 Annual Rent


PERMITTED USES: Subject to applicable zoning regulations, general office
purposes, the design and manufacture of computer hardware and software, and the
assembly, storage and distribution of same.



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COMMERCIAL GENERAL LIABILITY INSURANCE:

           $2,000,000 combined single limit per occurrence,
           $5,000,000 annual aggregate.

BROKERS:   Spaulding and Slye Properties Limited Partnership and Fallon Hines &
O'Connor

SECURITY DEPOSIT:   $300,000, subject to the provisions of Section 10.16.

1.2  EXHIBITS.

     The exhibits listed below in this section are incorporated in this Lease by
reference and are to be construed as part of this Lease:

         EXHIBIT A       Plan showing Premises.

         EXHIBIT B       Landlord's Work.

         EXHIBIT C       Permitted Structural Alterations.

         EXHIBIT D       Cleaning Schedule

         EXHIBIT E       Rules and Regulations.

         EXHIBIT F       Hazardous Substances Used in Tenant's Business.


1.3  TABLE OF CONTENTS                                                     PAGE

ARTICLE II -- PREMISES AND TERM..............................................  7

      Section 2.1     Description of Premises................................  7
      Section 2.2     Term...................................................  7
      Section 2.3     Option to Extend.......................................  7
      Section 2.4     Right of First Refusal.................................  9

ARTICLE III - CONSTRUCTION................................................... 11

      Section 3.1     Delivery of Premises................................... 11
      Section 3.2     Preparation of Premises for Occupancy.................. 12
      Section 3.3     General Provisions Applicable to
                        Construction......................................... 13
      Section 3.4     Construction Representatives........................... 13
      Section 3.5     Alterations and Additions.............................. 14

ARTICLE IV -- RENT........................................................... 15

      Section 4.1     Rent................................................... 15
      Section 4.2     Operating Costs........................................ 15
      Section 4.3     Estimated Premises Expense Payments.................... 19
      Section 4.4     Electricity and Water.................................. 19



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      Section 4.5     Change of Calendar Year................................ 21
      Section 4.6     Payments............................................... 21

ARTICLE V -- LANDLORD'S COVENANTS............................................ 21

      Section 5.1     Landlord's Covenants During the Term................... 21
              5.1.1   Building Services...................................... 21
              5.1.2   Additional Building Services........................... 22
              5.1.3   Repairs................................................ 22
              5.1.4   Tenant Signage......................................... 22
              5.1.5   Quiet Enjoyment........................................ 23
              5.1.6   Insurance.............................................. 23

      Section 5.2     Interruptions.......................................... 23

ARTICLE VI -- TENANT'S COVENANTS............................................. 24

      Section 6.1     Tenant's Covenants During the Term..................... 24
              6.1.1   Tenant's Payments...................................... 24
              6.1.2   Repairs and Yielding Up................................ 24
              6.1.3   Occupancy and Use...................................... 24
              6.1.4   Rules and Regulations.................................. 25
              6.1.5   Safety Appliances...................................... 26
              6.1.6   Assignment and Subletting.............................. 26
              6.1.7   Indemnity.............................................. 28
              6.1.8   Tenant's Insurance..................................... 28
              6.1.9   Tenant's Worker's Compensation
                        Insurance............................................ 29
              6.1.10  Landlord's Right of Entry.............................. 29
              6.1.11  Loading................................................ 30
              6.1.12  Landlord's Costs....................................... 30
              6.1.13  Tenant's Property...................................... 30
              6.1.14  Labor or Materialmen's Liens........................... 31
              6.1.15  Changes or Additions................................... 31
              6.1.16  Holdover............................................... 31
              6.1.17  Security............................................... 31


ARTICLE VII -- DAMAGE AND DESTRUCTION; CONDEMNATION.......................... 32

      Section 7.1     Fire or Other Casualty................................. 32
      Section 7.2     Eminent Domain......................................... 35

ARTICLE VIII -- RIGHTS OF MORTGAGEE.......................................... 36

      Section 8.1     Priority of Lease...................................... 36
      Section 8.2     Rights of Mortgage Holders; Limitation
                        of Mortgagee's Liability............................. 37
      Section 8.3     Mortgagee's Election................................... 37
      Section 8.4     No Prepayment or Modification, Etc..................... 38
      Section 8.5     No Release or Termination.............................. 38
      Section 8.6     Continuing Offer....................................... 38



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ARTICLE IX -- DEFAULT........................................................ 39

      Section 9.1     Events of Default...................................... 39
      Section 9.2     Tenant's Obligations after Termination................. 40

ARTICLE X - MISCELLANEOUS.................................................... 41

      Section 10.1    Notice of Lease........................................ 41
      Section 10.2    Notices from One Party to the Other.................... 41
      Section 10.3    Bind and Inure......................................... 42
      Section 10.4    No Surrender........................................... 42
      Section 10.5    No Waiver, Etc......................................... 42
      Section 10.6    No Accord and Satisfaction............................. 43
      Section 10.7    Cumulative Remedies.................................... 43
      Section 10.8    Right to Cure; Landlord's Default...................... 43
      Section 10.9    Estoppel Certificate................................... 44
      Section 10.10   Waiver of Subrogation.................................. 44
      Section 10.11   Acts of God............................................ 44
      Section 10.12   Brokerage.............................................. 45
      Section 10.13   Submission Not an Offer................................ 45
      Section 10.14   Applicable Law and Construction........................ 45
      Section 10.15   Authority.............................................. 46
      Section 10.16   Security Deposit....................................... 46

















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                                   ARTICLE II

                                PREMISES AND TERM


2.1  DESCRIPTION OF PREMISES.

     Subject to and with the benefit of the provisions of this Lease, Landlord
hereby leases to Tenant, and Tenant leases from Landlord, the Premises.

     Tenant shall have, as appurtenant to the Premises, the right to use in
common with others entitled thereto: (a) the common facilities included in the
Building or on the Lot, including without limitation the parking areas (but not
more than 3.75 spaces per 1,000 square feet of rentable floor area), and (b) the
building service fixtures and equipment serving the Premises.

     Landlord reserves the right from time to time, without unreasonable
interference with Tenant's use, (a) to install, repair, replace, use, maintain
and relocate for service to the Premises, to other parts of the Building, or
both, building service fixtures and equipment wherever located in the Building
or on the Lot and (b) to alter or relocate any common facilities, it being
understood that if any parking spaces are provided, the same may be relocated
from time to time by Landlord, provided that in all events substitutions are
substantially equivalent.

2.2  TERM.

     To have and to hold for a period (the "Term") commencing on the Term
Commencement Date and continuing for the Term, unless sooner terminated as
provided herein.

2.3  OPTION TO EXTEND.

     Tenant shall have the right and option to extend the Term for an additional
period of five (5) years (the "Extension Term") commencing the day after the
expiration of the original Term referred to in Section 1.1 (the "Original
Term"), provided that Tenant shall give Landlord notice of Tenant's exercise of
such option at least nine (9) months prior to the expiration of the Original
Term, and provided further that no event of default, or condition which with the
giving of notice or the passage of time, or both, would constitute an event of
default, exists at the time of giving such notice, unless such condition is
removed or corrected within the applicable cure period, if any. If an event of
default, or condition which with the giving of notice or the passage of time, or
both, would constitute an event of default, exists at the time of commencement
of the Extension Term, Tenant's exercise of such option shall, at the option of
Landlord, be null and void and of no further force and 




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effect unless such condition is removed or corrected within the applicable cure
period, if any. Prior to the exercise by Tenant of such option, the expression
"Term" shall mean the Original Term, and after the exercise by Tenant of such
option, the expression "Term" shall mean the Original Term as it has been then
extended by the Extension Term. Except for this Option to Extend which shall not
apply to the Extension Term and except as expressly otherwise provided in the
following paragraph, all the terms, covenants, conditions, provisions and
agreements in the Lease contained shall be applicable to the additional period
to which the Original Term shall be extended as aforesaid. Subject to the terms
of this Lease, if Tenant shall give notice of its exercise of said option to
extend in the manner and within the time period provided aforesaid, the Term
shall be extended upon the giving of such notice without the requirement of any
further action on the part of either Landlord or Tenant. If Tenant shall fail to
give timely notice of the exercise of any such option as aforesaid, Tenant shall
have no right to extend the Term of this Lease, time being of the essence of the
foregoing provisions.

     The Annual Base Rate payable during the Extension Term shall be the amount
being the greater of (i) the Annual Base Rate in effect for the Lease Year
immediately preceding the commencement of the Extension Term or (ii) the Fair
Market Rent for the Premises as of the commencement of the Extension Term. The
Fair Market Rent shall be determined in accordance with the provisions set forth
below. If for any reason the Annual Base Rate payable during the Extension Term
has not been determined as of the commencement of the Extension Term, Tenant
shall pay the Annual Base Rate payable during the Original Term until the Annual
Base Rate for the Extension Term is determined, at which time, an appropriate
adjustment, if any, shall be made.

     Fair Market Rent shall mean the then current rent, including provisions for
subsequent increases and other adjustments, as of the commencement of the period
in question under market conditions then existing for new leases then currently
being negotiated or executed in comparable space used for office purposes
located in comparable buildings located in Marlborough, Massachusetts and the
so-called MetroWest market area of Massachusetts. In determining Fair Market
Rent, the following factors, among others, shall be taken into account and given
effect: size, location of premises, lease term, and services provided by the
Landlord. Landlord shall initially designate the Fair Market Rent and shall
furnish copies of the data, if any, on which it based such designation. If
Tenant disagrees with Landlord's designation of Fair Market Rent, Landlord and
Tenant agree to negotiate in good faith a mutually agreeable Annual Base Rent to
be payable during the Extension Term; provided that if Landlord and Tenant are
unable to agree upon the Fair Market Rent in the period between Tenant's
exercise of its option to extend and that date which is at least eight (8)
months prior to the commencement of the Extension Term 




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<PAGE>   9

(the "Discussion Period"), then Tenant shall have the right, by written notice
given on or before the last day of the Discussion Period, to either withdraw its
exercise of its option to extend or, by failing to so withdraw, to submit the
determination of Fair market Rent to an appraisal made as hereinafter provided
by a board of three reputable commercial real estate consultants, appraisers, or
brokers, each of whom shall have at least ten years of experience in the eastern
Massachusetts office rental market and each of whom is hereinafter referred to
as "appraiser". Tenant and Landlord shall each appoint one such appraiser and
the two appraisers so appointed shall appoint the third appraiser. The cost and
expenses of each appraiser appointed separately by Tenant and Landlord shall be
borne by the party who appointed the appraiser. The cost and expenses of the
third appraiser shall be shared equally by Tenant and Landlord. Landlord and
Tenant shall appoint their respective appraisers no later than ten days after
the end of the Discussion Period and shall designate the appraisers so appointed
by notice to the other party. The two appraisers so appointed and designated
shall appoint the third appraiser no later than ten days after both of them have
been appointed and shall designate such appraiser by notice to Landlord and
Tenant. The board of three appraisers shall determine the Fair Market Rent of
the space in question as of the commencement of the Extension Term and shall
notify Landlord and Tenant of their determinations at least six months prior to
the commencement of the Extension Term. If the determinations of the Fair Market
Rent of any two or all three of the appraisers shall be identical in amount,
said amount shall be deemed to be the Fair Market Rent of the subject space. If
the determinations of all three appraisers shall be different in amount, the
average of the two values nearest in amount shall be deemed the Fair Market
Rent. The Fair Market Rent of the subject space determined in accordance with
the provisions of this Section shall be binding and conclusive on Tenant and
Landlord.

     Notwithstanding the foregoing, if the determination of Fair Market Rent is
to be made by an appraisal as provided herein and either party shall fail to
appoint its appraiser within the period specified above (such party referred to
hereinafter as the "failing party"), the other party may serve notice on the
failing party requiring the failing party to appoint its appraiser within ten
days of the giving of such notice and if the failing party shall not respond by
appointment of its appraiser within said ten-day period, then the appraiser
appointed by the other party shall be the sole appraiser whose determination of
the Fair Market Rent shall be binding and conclusive upon Tenant and Landlord.

2.4  RIGHT OF FIRST REFUSAL.

     Subject to the conditions subsequently set forth, and provided this Lease
is in full force and effect, and provided that no event of default, or condition
which with the giving of 




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<PAGE>   10

notice or the passage of time, or both, would constitute an event of default,
exists at the time Tenant exercises its right of first refusal or at the
commencement of the term for the Additional Space (as defined herein) (other
than the existence of a mechanic's lien provided the same attached to the
Premises less than 30 days prior to such time and that such lien is released of
record by payment or posting of proper bond within 30 days after the lien
attached to the Premises) and provided further that Tenant has not assigned or
sublet the Premises or any portion thereof and Tenant is the then occupant of
the entire Premises, Tenant shall have the right of first refusal (the "Right of
First Refusal") to lease the remaining rentable space in the Building (the
"Additional Space") in accordance with the provisions hereof. Tenant understands
that, in the event Tenant leases the remainder of the Building, the Total
Rentable Floor Area of the Building will increase to 90,972 (which shall also be
the Total Floor Area of the Premises) as a result of the inclusion of additional
areas (such as demising walls between the existing Premises and other tenant
areas) in the Premises. Tenant's right to lease the Additional Space shall arise
only upon the execution of a letter of intent or instrument of similar import
between Landlord and another party unaffiliated with Landlord setting forth the
business terms on which Landlord and such other party have agreed to a lease of
the Additional Space or any portion thereof.

     In such event, if this Right of First Refusal is applicable in accordance
with the foregoing, Landlord shall give notice to Tenant of the business terms
upon which Landlord and such other party have agreed to a lease of the
Additional Space or portion thereof. Tenant shall have ten (10) days from the
giving of such notice in which to elect to lease (a) if Landlord's agreement
with such other party is for forty percent (40%) or more of the Additional
Space, either (i) all of the Additional Space (even if Landlord's agreement with
such other party is for less than all of the Additional Space) or (ii) all of
the remaining Additional Space which is not subject to Landlord's agreement with
such other party, or (b) if Landlord's agreement with such other party is for
less than forty percent (40%) of the Additional Space, the Additional Space
which is subject to Landlord's agreement with such other party. In any case, if
Tenant elects to lease Additional Space in accordance with the foregoing, such
lease shall be on the same business terms set forth in Landlord's notice, with
an appropriate adjustment to reflect the square feet of rentable floor area of
space included in the Additional Space to be leased by Tenant, and otherwise on
the terms set forth in this Lease with respect to the Premises, except that if
the term with respect to the Additional Space commences before the third
anniversary of the Term Commencement Date, the term with respect to the
Additional Space shall be coterminous with the Term hereunder, and if the term
with respect to the Additional Space commences on or after the third anniversary
date of the Term Commencement Date, the term with respect to the Additional
Space shall be as set forth in 



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Landlord's Notice. If Tenant fails to notify Landlord within the time specified
herein or chooses not to so lease the Additional Space, then the Right of First
Refusal shall terminate and Landlord shall be free to lease the Additional
Space, in its sole discretion, to such other party or any other party or
parties without first offering it to Tenant, on monetary terms which are not
substantially more favorable to the Tenant than the monetary terms set forth in
Landlord's notice, it being understood that the Right of First Refusal is a
one-time only opportunity only. For purposes hereof, monetary terms shall not
be considered substantially more favorable to the Tenant if the value of all
monetary terms of the Lease of the Additional Space, as executed, considered as
a whole, are not less than ninety-five percent (95%) of the value of all
monetary terms as set forth in Landlord's notice, considered as a whole. If
Tenant chooses to so lease the Additional Space, then the Additional Space
shall become a part of the Premises hereunder under the terms specified above,
and Tenant shall execute an amendment to the Lease to include the Additional
Space under such terms; provided, however, that in such event Tenant shall have
the election, exercisable by at least 60 days prior notice to Landlord, (i) to
pay all electricity charges directly to the utility responsible therefor, in
which event Tenant shall pay all bills therefor before they become due, and
(ii) to contract directly for all interior janitorial services, in which event
Tenant shall be responsible for keeping the Premises neat and clean and for
paying all charges therefor before they become due.


                                 ARTICLE III
                                      
                                 CONSTRUCTION


3.1  DELIVERY OF PREMISES.

     Tenant acknowledges that Tenant has had a reasonable opportunity to inspect
the Premises. The Premises, shall be delivered to Tenant As Is, Where Is with
all faults and without representation, warranty or guaranty of any kind by
Landlord to Tenant, except that base building systems shall be in good working
condition on the Delivery Date. Notwithstanding the foregoing, Landlord shall be
responsible for the cost of repainting and recarpeting lobbies and lavatories
located in common areas on the first and second floors of the Building using
Building standard materials and upgrading the Building's life safety system
within the common areas of the Building and demising the Premises in accordance
with applicable fire safety requirements as specified on Exhibit B ("Landlord's
Work"). Landlord shall either (a) bid Landlord's Work for construction and
completion by Tenant's contractor and pay Tenant's contractor directly therefor
or (b) provide an allowance to Tenant sufficient for Tenant's contractor to do
such work, the 




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amount of such allowance to be subject to Tenant's reasonable concurrence and to
be payable to Tenant upon presentation to Landlord by Tenant of invoices from
Tenant's Contractor therefor.

     The Premises shall be delivered to Tenant on the Delivery Date in order
that Tenant may prepare the Premises for Tenant's occupancy in accordance with
plans and specifications theretofore approved by Landlord in accordance with the
provisions hereof. Tenant's occupancy for such purposes prior to the Term
Commencement Date shall nonetheless be subject to all of the terms and
provisions hereof (including the payment of charges for Tenant's electricity in
accordance with Section 4.3 hereof), other than the payment of Annual Base Rent,
Annual Estimated Operating Costs for the Premises and Tenant's Share of Premises
Expenses. All of Tenant's construction, installation of furnishings, and later
changes or additions shall be coordinated with any work being performed by
Landlord in such manner as to maintain harmonious labor relations and not to
damage the Building or Lot or interfere with Building operations.

     Landlord will not approve any construction, alterations, or additions
requiring unusual expense to readapt the Premises to normal office use on lease
termination or increasing the cost of construction, insurance or taxes on the
Building or of Landlord's services called for by Section 5.1 unless Tenant first
gives assurances reasonably acceptable to Landlord that such readaptation will
be made prior to such termination without expense to Landlord and makes
provisions reasonably acceptable to Landlord for payment of such increased cost.

3.2  PREPARATION OF PREMISES FOR OCCUPANCY.

     As soon as practicable, Tenant shall provide to Landlord for its reasonable
approval (such approval not to be unreasonably withheld or delayed) complete
sets of construction drawings and specifications (the "Complete Plans"),
including but not limited to:

     a.   Dimensioned Partition Plans;
     b.   Dimensioned Electrical and Telephone Outlet Plans;
     c.   Reflected Ceiling Plans;
     d.   Door and Hardware Schedules;
     e.   Room Finish Schedules, including wall, carpet and floor tile colors;
     f.   Electrical, mechanical and structural engineering plans; and
     g.   All necessary construction details and specifications for work not 
specified in Exhibit B.

     Tenant may submit partial plans for review and approval by Landlord.
Landlord shall consult with Tenant on an ongoing basis about the plans submitted
by Tenant and shall cooperate 



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<PAGE>   13

with Tenant in order that the Complete Plans may be approved in a reasonably
diligent manner. The Complete Plans shall also provide for the installation of
check meters to measure (a) Tenant's lights and outlet consumption in the
Premises and (b) Tenant's water usage in its production facilities and cafeteria
to be located at the Premises.

     Landlord and Tenant shall initial the Complete Plans after the same have
been submitted by Tenant and approved by Landlord as set forth above except for
installation of furnishings and the installation of telephone outlets; provided
that if Landlord shall not have submitted to Tenant a written approval to the
Complete Plans or a written objection to the Complete Plans or any revised
version thereof within five (5) business days of being provided such plans by
Tenant (which written objection shall set forth with reasonable specificity each
reason for such objection), Tenant may provide written notice to Landlord
indicating that Landlord has failed to approve or object to the Complete Plans
within such five-day period, in which case Landlord shall conclusively be deemed
to have approved such plans if Landlord shall not have submitted to Tenant a
written objection to the Complete Plans or any revised version thereof within
five (5) business days of being provided such notice by Tenant (which written
objection shall set forth with reasonable specificity each reason for such
objection). All work described in the Complete Plans shall be performed by
Tenant by a general contractor approved by Landlord, such approval not to be
unreasonably withheld or delayed.

3.3  GENERAL PROVISIONS APPLICABLE TO CONSTRUCTION.

     All construction work required or permitted by this Lease, whether by
Landlord or by Tenant, shall be done in a good and workmanlike manner and in
compliance with all applicable laws and all lawful ordinances, regulations and
orders of governmental authority and insurers of the Building and the Lot.
Either party may inspect the work of the other at reasonable times and promptly
shall give notice of observed defects. Landlord's obligations under Section 3.1
shall be deemed to have been performed when Tenant commences to occupy any
portion of the Premises for the Permitted Uses except for items which are
incomplete or do not conform with the requirements of Section 3.1 and as to
which Tenant shall in either case have given written notice to Landlord within
ten (10) days after written notice from Landlord to Tenant that Landlord's Work
has been completed or substantially completed.

3.4  CONSTRUCTION REPRESENTATIVES.

     Each party authorizes the other to rely in connection with their respective
rights and obligations under this Article III upon approval and other actions on
the party's behalf by any person designated as its construction representative
in Section 1.1 hereof or by any other person designated by such 




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<PAGE>   14

party as its construction representative by notice to the party relying.


3.5  ALTERATIONS AND ADDITIONS.

     This Section 3.5 shall apply before and during the Term. Tenant shall not
make any alterations and additions to the Premises exceeding the cost of $25,000
in any one calendar year except in accordance with plans and specifications
first approved by Landlord, such approval not to be unreasonably withheld or
delayed; provided that in no event shall any alterations or additions be made by
Tenant without Landlord's prior written approval, which approval may be withheld
in Landlord's sole discretion, which (a) involve or might affect any structural
or exterior element of the Building or Building mechanical, electrical or other
base Building systems, including the common facilities of the Building, except
as set forth in Exhibit C, or (b) will require unusual expense to readapt the
Premises to normal office use on Lease termination or increase the cost of
construction or of insurance or taxes on the Building or the Lot unless Tenant
first gives assurances reasonably acceptable to Landlord that such readaptation
will be made prior to such termination without expense to Landlord and makes
provisions reasonably acceptable to Landlord for payment of such increased cost.
All alterations and additions shall become a part of the Premises, unless and
until Landlord, at its option, shall specify the same for removal pursuant to
Section 6.1.2. All of Tenant's alterations and additions and installation and
delivery of telephone systems, furnishings, and equipment shall be coordinated
with any work being performed by Landlord and shall be performed in such manner,
and by such persons as shall maintain harmonious labor relations and not cause
any damage to the Building or interference with Building construction or
operation and, except for installation of furnishings, equipment and telephone
systems, and except as otherwise expressly set forth herein, shall be performed
by general contractors first approved by Landlord, such approval not to be
unreasonably withheld or delayed. Before commencing any work Tenant shall:
secure all licenses and permits necessary therefor; deliver to Landlord a
statement of the names of all its contractors and subcontractors (the identity
of which must have been previously approved by Landlord as hereinabove
contemplated) and the estimated cost of all labor and material to be furnished
by them; and cause each contractor to carry (i) workmen's compensation insurance
in statutory amounts covering all the contractor's and subcontractor's employees
and (ii) comprehensive public liability insurance with such limits as Landlord
may reasonably require, but in no event less than a combined single limit of
$1,000,000 or such higher amount as may be reasonable under the circumstances
(all such insurance to be written in companies approved by Landlord, such
approval not to be unreasonably withheld or delayed, and naming Landlord and
Tenant as additional insureds), and to deliver to Landlord 




                                       14
<PAGE>   15

certificates of all such insurance. Tenant shall pay within fourteen (14) days
after being billed therefor by Landlord, as additional rent, one hundred percent
(100%) of any increase in real estate taxes on the Premises not otherwise billed
to Tenant which shall, at any time after the commencement of the Term, result
from any alteration, addition or improvement to the Premises made by or on
behalf of Tenant.

                                   ARTICLE IV

                                      RENT


4.1  RENT.

     Tenant agrees to pay rent to Landlord without any offset or reduction
whatever, except as expressly provided in this Lease, equal to 1/12th of the
Annual Rent in equal monthly installments in advance on the first day of each
calendar month included in the Term after the Term Commencement Date; and for
any portion of a calendar month at the beginning or end of the Term, at the
proportionate rate payable for such portion, in advance.

     Notwithstanding the foregoing, if the Term Commencement Date begins prior
to April 1, 1997, and Tenant has not then occupied the entire Premises for
business purposes, Tenant shall only pay Annual Rent (other than electricity
charges which shall be paid with respect to the entire Premises) with respect to
the Floor Segments (as defined hereinafter) which Tenant has occupied in whole
or in part for business purposes, until April 1, 1997, at which time Annual Rent
and all other charges with respect to the Premises shall be due and payable. For
purposes hereof, a "Floor Segment" shall equal approximately one-half of each
floor of the Premises, divided roughly by the elevator bank on each floor. If
Tenant occupies any portion of a Floor Segment for business purposes, Tenant
shall be deemed to occupy the entire Floor Segment for business purposes and
shall thereupon, with respect to each Floor Segment so occupied, commence paying
Annual Rent and all other charges relating thereto with respect to one-half of
the square feet of rentable floor area on the floor on which the Floor Segment
is located.

4.2  OPERATING COSTS.

     A.   Tenant shall pay to Landlord, as additional rent, Tenant's Share of
Premises Expenses (as defined below), if any, on or before the 30th day
following receipt by Tenant of Landlord's Statement (as defined below). As soon
as practicable after the end of each fiscal year ending during the Term and
after Lease termination, Landlord shall render a statement ("Landlord's
Statement") in reasonable detail and according to usual accounting practices
according to GAAP certified by Landlord and showing for the preceding calendar
year or fraction thereof, as the case may be, Landlord's Operating Costs,



                                       15
<PAGE>   16

     EXCLUDING the interest and amortization on mortgages for the Building and
the Lot or leasehold interests therein, depreciation on the Building and the
lot, real estate brokers' commissions, capital expenditures (except as
specifically set forth below) or tenant finish expenses for other tenants, and
the cost of special services rendered to tenants (including Tenant) for which a
special charge is made,

     BUT INCLUDING, without limitation: real estate taxes (as defined below) on
the Building and the Lot; installments and interest on assessments for public
betterments or public improvements; expenses of any proceedings for abatement of
taxes and assessments with respect to any fiscal year or fraction of a fiscal
year; premiums for insurance (including, without limitation, fire, casualty and
liability insurance); fees payable to third parties for financial audits of
Landlord's Operating Costs; compensation and all fringe benefits, worker's
compensation insurance premiums and payroll taxes paid by Landlord to, for or
with respect to all persons engaged in the operating, maintaining, or cleaning
of the Building and the Lot, including, without limitation, a superintendent
available to the Building; all electricity charges related to the common areas
of the Building and heat pumps servicing the Building, and all utility charges
incurred in the operation and maintenance of the Premises, the Building and the
Lot not billed directly to tenants by Landlord or by the utility company; all
costs of cleaning the common areas of the Building and all windows on the
exterior of the Building; all costs of maintenance, repairing, managing and
operating the Building (including without limitation, all structural components
and common facilities of the Building); payments to independent contractors
under service contracts for cleaning the common areas and windows of the
Building as aforesaid and for operating, managing, maintaining and repairing the
Building and the Lot (which payments may be to affiliates of Landlord or
Managing Agent provided the same are at reasonable rates consistent with the
type of occupancy); management fees at the prevailing rate for management
services charged by professional management companies for the operation of
similar buildings (such fees in any event not to exceed the rate of five percent
(5%) of the aggregate fixed rent for the Building); all charges, costs and
expenses assessed to or incurred by Landlord under the Declaration of Covenants
and Easements for Marlborough Business Centre dated April 29, 1991 and recorded
with Middlesex South Registry of Deeds in Book 21127, Page 3 and filed for
registration with Middlesex South Registry District of the Land Court as
Document No. 841886; and all charges to Landlord allocable to the Building and
the Lot for services performed by the manager of the office park in which the
Building and the Lot are located or costs incurred with respect to such office
park and, to the extent Landlord incurs additional charges applicable to the
Building and another building or buildings located in the office park, the
Building's pro rata share (as reasonably determined by Landlord) of such




                                       16
<PAGE>   17

charges; and all other reasonable and necessary expenses paid in connection with
the cleaning, operating, managing, maintaining and repairing of the Building and
the Lot, or either, and properly chargeable against income, it being agreed that
if Landlord installs a new or replacement capital item for the purpose of
reducing Landlord's Operating Costs or which is required by law or the purpose
of which is to maintain the Building as a first-class office building, the cost
thereof as reasonably amortized by Landlord, with interest at the prime
commercial rate in effect from time to time at BankBoston in Boston,
Massachusetts on the unamortized amount, shall be included in Landlord's
Operating Costs; provided, however, that in any fiscal year in which the average
annual occupancy of the Building is less than 95%, Landlord's Operating Costs as
defined herein shall also include such additional costs as would reasonably have
been incurred by Landlord with respect to the operating, administration,
cleaning, repair, maintenance and management of the Property with 95% average
annual occupancy.

     The term "real estate taxes" as used above shall mean all taxes of every
kind and nature assessed by any governmental authority on the Lot, Building and
improvements, which Landlord shall become obligated to pay because of or in
connection with the ownership, leasing and operation of the Lot, Building and
improvements, subject to the following: There shall be excluded from such taxes
all income taxes, excess profits taxes, excise taxes, franchise taxes, and
estate, succession, inheritance and transfer taxes, provided, however, that if
at any time during the Term the present system of ad valorem taxation of real
property shall be changed so that in lieu of the whole or any part of the ad
valorem tax on real property, there shall be assessed on Landlord a capital levy
or other tax on the gross rents received with respect to the Lot, Building and
improvements, or both, or a federal, state, county, municipal, or other local
income, franchise, excise or similar tax, assessment, levy or charge (distinct
from any now in effect) measured by or based, in whole or in part, upon any such
gross rents, then any and all of such taxes, assessments, levies or charges, to
the extent so measured or based, shall be deemed to be included within the term
"real estate taxes", except that such shall not be deemed to include any
enhancement of said tax attributable to other income or other ownerships of
Landlord.

     If Tenant provides written notice to Landlord that it intends to seek an
abatement of the real estate taxes, and Landlord does not within ten (10)
business days of such notice provide written notice to Tenant that it will seek
such abatement, Tenant shall have the right, by itself or together with other
tenants of the Building, and at its sole expense, to contest the validity of and
seek an abatement of the real estate taxes in the name of Landlord, and Landlord
agrees to cooperate with Tenant in any such contest at no out-of-pocket expense
to Landlord and in connection therewith shall make available to Tenant such
information and shall execute such authorizations or 




                                       17
<PAGE>   18

instruments as Tenant may reasonably request. The proceeds of any abatement
award shall be applied first to reimburse the parties for the costs and
expenses, including attorneys' fees, of obtaining such abatement; second, to
reimburse Tenant and other tenants in the Building for any payments made to
landlord which were attributable to the increased taxes; and third, to Landlord.

     B.   "Premises Expenses" shall mean one hundred (100%) percent of 
Landlord's Operating Costs attributable to the Building and the Lot.

     C.   If with respect to any fiscal year falling within the Term or for any
fraction of any fiscal year falling at the beginning or end of the Term,
Premises Expenses for a full fiscal year exceed the Annual Estimated Operating
Costs for the Building or for any such fraction of a fiscal year, exceed the
corresponding fraction of the Annual Estimated Operating Costs for the Building,
then Tenant shall pay to Landlord, as additional rent, an amount equal to the
product of (i) the amount of such excess and (ii) a fraction, the numerator of
which shall be the Rentable Floor Area of the Premises and the denominator of
which shall be the Total Rentable Floor Area of the Building (such amount being
referred to as "Tenant's Share of Premises Expenses"). In the event that Tenant
leases all Rentable Floor Area of the Building, Tenant shall pay all of such
excess.

     D.   If with respect to any fiscal year falling within the Term or for any
fraction of any fiscal year falling at the beginning or end of the Term,
Premises Expenses for a full fiscal year are less than the Annual Estimated
Operating Costs for the Building or for any such fraction of a fiscal year, are
less than the corresponding fraction of the Annual Estimated Operating Costs for
the Building, then Tenant shall receive a credit from Landlord against future
payments of Annual Rent equal to the product of (i) the amount of such shortfall
and (ii) a fraction, the numerator of which shall be the Rentable Floor Area of
the Premises and the denominator of which shall be the Total Rentable Floor Area
of the Building. In the event that Tenant leases all Rentable Floor Area of the
Building, Tenant shall receive a credit for all of such shortfall.

     E.   Notwithstanding any other provision of this Section 4.2, if the Term
expires or is terminated as of a date other than the last day of a fiscal year,
then for such fraction of a fiscal year at the end of the Term, Tenant's last
payment to Landlord under this Section 4.2 shall be made on the basis of
Landlord's best estimate of the items otherwise includable in Landlord's
Statement and shall be made on or before the later of (a) 10 days after Landlord
delivers such estimate to Tenant or (b) the last day of the Term, with an
appropriate payment or refund to be made upon submission of Landlord's
Statement.



                                       18
<PAGE>   19

     F.   Landlord agrees to keep books and records with respect to Premises
Expenses. Tenant, its authorized agent or representative, or a public accounting
firm selected by Tenant, shall have the right upon advance written notice to
Landlord to inspect those portions of the books of Landlord relating to Premises
Expenses at the offices of Landlord's Managing Agent during business hours for
the purpose of verifying information set forth in Landlord's Statements. In the
event that, as a result of Tenant's inspection, it is determined that Landlord's
Statement overstated Landlord's Operating Costs for any fiscal year by more than
ten percent (10%) of the actual amount of such costs, Landlord shall reimburse
Tenant for all reasonable costs incurred in conjunction with such inspection.


4.3  ESTIMATED PREMISES EXPENSE PAYMENTS.

     If, with respect to any fiscal year or fraction thereof during the Term
(other than 1997), Landlord estimates in good faith that Tenant shall be
obligated to pay Tenant's Share of Premises Expenses, then Tenant shall pay, as
additional rent, on the first day of each month of such fiscal year and each
ensuing fiscal year thereafter, estimated monthly Premises Expense payments
(hereinafter "Estimated Monthly Premises Expense Payments") equal to 1/12th of
the Tenant's Share of Premises Expenses for the respective calendar year, with
an appropriate additional payment (or credit by Landlord against Tenant's future
payments of Annual Rent) to be made within 30 days after Landlord's Statement is
delivered to Tenant. Landlord shall, in good faith, make such an estimate each
year, it being understood that the amount of Premises Expenses may increase or
decrease in any given year. Landlord may adjust such Estimated Monthly Premises
Expense Payments from time to time and at any time during a fiscal year, and
Tenant shall pay, as additional rent, on the first day of each month following
receipt of Landlord's notice thereof, the adjusted Estimated Monthly Premises
Expense Payment.


4.4  ELECTRICITY AND WATER.

     Tenant will be billed for electricity for Tenant's lights and outlet
consumption on a monthly basis based on an annual estimate of $0.90 per rentable
square foot with respect to fiscal year 1997. With respect to each fiscal year
thereafter during the Term, if Landlord determines in good faith that the annual
estimates for such electrical charges should be adjusted based upon the check
meters for Tenant's electrical consumption to be installed in the Premises as
part of Tenant's initial construction work in the Premises, Landlord shall give
to Tenant on or before the first day of such fiscal year a written good faith
estimate of the average expense to Landlord per square foot for Tenant's
electricity for such fiscal year, and Tenant will be billed for electricity for
Tenant's lights and outlet 




                                       19
<PAGE>   20

consumption on a monthly basis based on such updated annual estimate. Should the
actual average expense to Landlord per square foot for Tenant's electricity be
different, an additional charge or a credit will be made at the end of each
year's occupancy to be paid with or credited against the next monthly charge for
Tenant's electricity (or after the conclusion of the Term, to be paid by
Landlord to Tenant or Tenant to Landlord, as the case may be, within 30 days
after Landlord determines the same and provides notice thereof to Tenant).
Notwithstanding the foregoing, Landlord reserves the right to, in good faith,
from time to time during each fiscal year to adjust the annual estimates for
such electrical charges based on the check meters. Such charges for Tenant's
electricity shall be paid by Tenant as additional rent at the same time and in
the same manner as payments of Annual Base Rent. In the event that Tenant leases
all Rentable Floor Area of the Building, Tenant shall pay for all electricity
charges relating to the Building and the Lot.

     Tenant covenants and agrees that its use of electric current shall not
exceed 5.0 watts per square foot of usable floor area and that its total
connected lighting load will not exceed the maximum load from time to time
permitted by applicable governmental regulations. In the event Tenant introduces
into the Premises personnel or equipment which overloads the capacity of the
Building system or in any other way interferes with the system's ability to
perform adequately its proper functions, supplementary systems including check
meters may, if and as needed, at Landlord's option, be provided by Landlord, at
Tenant's expense. Landlord shall not in any way be liable or responsible to
Tenant for any loss or damage or expense which Tenant may sustain or incur if,
during the Term of this Lease, either the quantity or character of electric
current is changed or electric current is no longer available or suitable for
Tenant's requirements due to a factor or cause beyond Landlord's control.

     Tenant also covenants to pay as additional rent Landlord's usage of water
in its production facilities and cafeteria based upon the check meters for such
usage by Tenant to be installed as part of Tenant's initial construction work in
the Premises. Such payment shall be made no later than ten (10) days after
invoice by Landlord to Tenant from time to time, but not more often than
monthly.




                                       20
<PAGE>   21


4.5  CHANGE OF FISCAL YEAR.

     Landlord shall have the right from time to time to change the periods of
accounting under Section 4.2 to any annual period other than a calendar year
(excepting, however, during the current calendar year), and upon any such change
all items referred to in this Section 4.4 shall be appropriately apportioned. In
all Landlord's Statements rendered under this Section 4.4, amounts for periods
partially within and partially without the accounting periods shall be
appropriately apportioned, and any items which are not determinable at the time
of a Landlord's Statement shall be included therein on the basis of Landlord's
estimate, and with respect thereto Landlord shall render promptly after
determination a supplemental Landlord's Statement, and appropriate adjustment
shall be made according thereto. All Landlord's Statements shall be prepared on
an accrual basis of accounting.


4.6  PAYMENTS.

     All payments of Annual Rent and additional rent shall be made to Managing
Agent, or to such other person as Landlord may from time to time designate in
writing. If any installment of Annual Base Rent or additional rent is paid more
than 10 days after the due date thereof, at Landlord's election, it shall bear
interest at a rate equal to the average prime commercial rate from time to time
established by the BankBoston in Boston, Massachusetts plus 4% per annum from
such due date, which interest shall be immediately due and payable as further
additional rent.



                                    ARTICLE V

                              LANDLORD'S COVENANTS


5.1  LANDLORD'S COVENANTS DURING THE TERM.

     Landlord covenants during the Term:

     5.1.1 Building Services - To furnish during normal working hours heat,
air-conditioning, cleaning service in accordance with the schedule set forth in
Exhibit D, hot and chilled water service during the Term. "Normal working hours"
shall mean the hours of 8:00 A.M. through 6:00 P.M. Monday through Friday and
the hours of 8:00 A.M. through 1:00 P.M. on Saturdays, and no hours on legal
holidays and Sundays; provided, however, that Tenant shall have access to the
Building (including access to at least one loading dock) 24 hours a day, 365
days a year, by means of a key or keys or other access device or devices to the
main lobby of the Building and the loading dock to be provided 




                                       21
<PAGE>   22

to Tenant by Landlord. Landlord shall also keep all common areas in clean and
orderly condition. During all times that Tenant shall have access to the
Building, Landlord shall maintain utility services for the Building (subject to
Sections 4.4 and 5.2), and shall furnish elevator service and reasonable
lighting to all common areas (including without limitation lobbies, lavatories,
stairs, sidewalks and parking areas), and shall not (except as may be required
in an emergency, or in connection with use of the Loading Dock by other tenants
and Landlord, from time to time, or a repair to the Building) in any way
obstruct Tenant's use of the loading dock. Landlord is not and shall not be
required to furnish to Tenant or any other occupant of the Premises telephone or
other communication service.

     5.1.2 Additional Building Services - To furnish, through Landlord's
employees or independent contractors, reasonable additional Building operation
services (including heat or air-conditioning during hours other than normal
working hours) upon reasonable advance request of Tenant at equitable rates from
time to time established by Landlord to be paid by Tenant;

     5.1.3 Maintenance and Repairs - Except as otherwise provided in Article
VII, to maintain and make such repairs to the roof, exterior walls, floor slabs,
windows, sidewalks, parking areas, driveways, other structural components and
common facilities of the Building and the Lot as may be necessary to keep them
in serviceable condition as a first class office building, including without
limitation snow removal with respect to the sidewalks, parking areas and
driveways on the Lot; and

     5.1.4 Tenant Signage - To include Tenant's name on the Tenant directory
maintained by Landlord in the main lobby of the Building. So long as Tenant
occupies not less than 50% of the rentable area of the Building, Landlord shall
also permit Tenant to install and maintain at Tenant's sole cost and expense,
and provided that the same are maintained by Tenant in good condition and repair
and that Tenant first obtains Landlord's approval, which approval shall not be
unreasonably withheld or delayed, (a) one exterior sign on the facade of the
Building facing Route I-290 and (b) one monument sign at the entrance to the
Building, provided that such monument sign is designed in a manner which will
permit up to two (2) additional tenants to be named thereon, which Landlord
shall have the election to do, from time to time, at the expense of Landlord or
such other tenant or tenants. All such signage shall be consistent with other
signage in the office park and subject to zoning, municipal and other applicable
legal requirements. No other tenant of the Building shall have more favorable
signage rights than Tenant does hereunder so long as Tenant occupies not less
than 50% of the rentable floor area of the Building.



                                       22
<PAGE>   23

     5.1.5 Quiet Enjoyment - That Landlord has the right to make this Lease and
that Tenant on paying the rent and performing its obligations hereunder shall
peacefully and quietly have, hold and enjoy the Premises throughout the Term
without any manner of hindrance or molestation from Landlord or anyone claiming
under Landlord, subject however to all the terms and provisions hereof.

     5.1.6 Insurance - Landlord shall carry during the Term of this Lease "all
risk" insurance for the full replacement cost of the Building and liability
insurance having coverage amounts and deductibles consistent with similar
first-class office buildings in the metropolitan Boston area.


5.2  INTERRUPTIONS.

     Landlord shall not be liable to Tenant for any compensation or reduction of
rent by reason of inconvenience or annoyance or for loss of business arising
from any failure or interruption of utility systems or services due to a factor
or cause beyond Landlord's control; provided that Landlord shall diligently
pursue the restoration of such systems or services. Landlord shall not be liable
for such failure or interruption, nor shall the same be construed as a
constructive eviction of Tenant, provided, however, that if such failure shall
prevent Tenant from doing business in the ordinary course for a period of five
(5) consecutive business days, Annual Rent shall equitably abate until such
systems or services are restored. Landlord shall not be liable to Tenant for any
compensation or reduction of rent by reason of inconvenience or annoyance or
loss of business arising from the necessity of Landlord's entering the Premises
for any of the purposes in this Lease authorized, or for repairing the Premises
or any portion of the Building or the Lot. In case Landlord is prevented or
delayed from making any repairs, alterations or improvements, or furnishing any
service or performing any other covenant or duty to be performed on Landlord's
part, by reason of any cause beyond Landlord's reasonable control, Landlord
shall not be liable to Tenant therefor, nor, except as expressly otherwise
provided in Article VII and in this Section 5.2, shall Tenant be entitled to any
abatement or reduction of rent by reason thereof, nor shall the same give rise
to a claim in Tenant's favor that such failure constitutes actual or
constructive total or partial, eviction from the Premises. The provisions hereof
are subject to the provisions of Article VII of the Lease.

     Subject to the other provisions of this Section 5.2, Landlord reserves the
right to stop any service or utility system when necessary by reason of accident
or emergency or until necessary repairs have been completed. Except in case of
emergency repairs, Landlord will give Tenant reasonable advance notice of any
contemplated stoppage and will in all events use reasonable efforts to avoid
unnecessary inconvenience to Tenant 




                                       23
<PAGE>   24

by reason thereof.

     Landlord also reserves the right to institute such reasonable policies,
programs and measures as may be necessary, required or expedient for the
conservation or preservation of energy or energy services or as may be necessary
or required to comply with applicable codes, rules, regulations or standards.


                                   ARTICLE VI

                               TENANT'S COVENANTS


6.1  TENANT'S COVENANTS DURING THE TERM.

     Tenant covenants during the Term and such further time as Tenant occupies
any part of the Premises:

     6.1.1 Tenant's Payments - To pay when due (a) all Annual Rent and
additional rent, (b) all taxes which may be imposed on Tenant's personal
property in the Premises (including, without limitation, Tenant's fixtures and
equipment) regardless to whomever assessed, (c) all charges by public utilities
for electricity, telephone (including service inspections therefor) and other
services rendered to the Premises not otherwise required hereunder to be
furnished by Landlord without charge and not consumed in connection with any
services required to be furnished by Landlord without charge, and (d) as
additional rent, all charges to Landlord for services rendered pursuant to
Section 5.1.2 hereof.

     6.1.2 Repairs and Yielding Up - Except as otherwise provided in Article VII
and Section 5.1.3, to keep the Premises in good order, repair and condition,
reasonable wear only excepted; and at the expiration or termination of this
Lease peaceably to yield up the Premises and all alterations and additions
therein in such order, repair and condition, first removing all goods and
effects of Tenant and any alterations and additions, the removal of which
alterations and additions is required by agreement or specified to be removed by
Landlord by notice to Tenant, and repairing all damage caused by such removal
and restoring the Premises and leaving them broom clean and neat.

     6.1.3 Occupancy and Use - Continuously from the Term Commencement Date, to
use and occupy the Premises only for the Permitted Uses; not to injure or deface
the Building or the Lot; to keep the Premises clean and in a neat and orderly
condition; and not to permit in the Building any use thereof which is improper,
offensive, contrary to law or ordinances, or liable to create a nuisance or to
invalidate or increase the premiums for any insurance on the Building or its
contents or liable to render necessary any alteration or addition to the
Building; not 




                                       24
<PAGE>   25

to dump, flush, or in any way introduce any hazardous substances or any other
toxic substances into the septic, sewage or other waste disposal system serving
the Premises; not to generate, store or dispose of hazardous substances in or on
the Premises, or the Lot or dispose of hazardous substances from the Premises to
any other location, other than those required in connection with Tenant's
business (as set forth on Exhibit F attached hereto and made a part hereof or
otherwise approved by Landlord in writing from time to time, such approval not
to be unreasonably withheld or delayed) and then only pursuant to any required
permits and otherwise in compliance with the Resource Conservation and Recovery
Act of 1976, as amended, 42 U.S.C. ss.6901 et seq., and all other applicable
laws, ordinances and regulations; to notify Landlord of any incident which would
require the filing of a notice under applicable federal, state, or local law; to
provide to Landlord upon written request copies of any permits required in
connection with Tenant's handling, storage or disposal of hazardous substances;
and to comply with the orders and regulations of all governmental authorities
with respect to zoning, building, fire, health and other codes, regulations,
ordinances or laws applicable to the Premises. "Hazardous substances" as used in
this paragraph shall mean "hazardous substances" as defined in the Comprehensive
Environmental Response Compensation and Liability Act of 1980, as amended, 42
U.S.C. ss.9601 and regulations adopted pursuant to said Act, and "hazardous
substances", "hazardous wastes", "toxic substances", "toxic wastes" and terms of
similar import under other applicable federal and state statutes and regulations
adopted pursuant thereto. Landlord shall endeavor to include a provision in the
leases of all other tenants of the Building which does not deviate materially
from this Section 6.1.3, or if a provision which does deviate materially from
this Section 6.1.3 is included in any such lease, shall provide a copy of such
provision to Tenant.

     The provisions of this Section 6.1.3 shall not prohibit the use, storage
and disposal by Tenant of reasonable and necessary quantities of office
equipment, supplies and other substances normally utilized by businesses for
office purposes, provided such use, storage and disposal shall comply with all
applicable environmental laws.

     6.1.4 Rules and Regulations - To comply with the Rules and Regulations set
forth in Exhibit E and all other reasonable Rules and Regulations hereafter made
by Landlord, of which Tenant has been given notice, for the care and use of the
Building and the Lot and their facilities and approaches, it being understood
that Landlord shall not be liable to Tenant for the failure of other tenants of
the Building to conform to such Rules and Regulations.






                                       25
<PAGE>   26


     6.1.5 Safety Appliances - To keep the Premises equipped with all safety
appliances required by law or ordinance or any other regulation of any public
authority because of any use made by Tenant and to procure all licenses and
permits so required because of such use and, if requested by Landlord, to do any
work so required because of such use, it being understood that the foregoing
provisions shall not be construed to broaden in any way Tenant's Permitted Uses.

     6.1.6 Assignment and Subletting.

          A. Not without the prior written consent of Landlord to assign,
mortgage, pledge, encumber, sell or transfer this Lease, in whole or in part, to
make any sublease, or to permit occupancy of the Premises or any part thereof by
anyone other than Tenant, voluntarily or by operation of law; as additional
rent, to reimburse Landlord promptly for reasonable legal and other expenses
incurred by Landlord in connection with any request by Tenant for consent to
assignment or subletting; no assignment or subletting shall affect the
continuing primary liability of Tenant (which, following assignment, shall be
joint and several with the assignee); no consent to any of the foregoing in a
specific instance shall operate as a waiver in any subsequent instance.
Landlord's consent to any proposed assignment or subletting is required both as
to the terms and conditions thereof, and (subject to the provisions of
Subsection C of this Section 6.1.6 below) as to the creditworthiness of the
proposed assignee or subtenant and the consistency of the proposed assignee's or
subtenant's business with other uses and tenants in the Building. In the event
that any assignee or subtenant pays to Tenant any amounts in excess of the
Annual Base Rent and additional rent then payable hereunder, or pro rata portion
thereof on a square footage basis for any portion of the Premises, Tenant shall
promptly pay an amount equal to seventy-five (75%) of said excess, after
deducting therefrom Tenant's out-of-pocket costs incurred in procuring such
assignee or subtenant, to Landlord as and when received by Tenant. If Tenant
requests Landlord's consent to assign this Lease or sublet more than 25% of the
Premises, Landlord shall have the option, exercisable by written notice to
Tenant given within 10 days after receipt of such request, to terminate this
Lease in its entirety, with respect to a proposed assignment, or with respect to
any proposed sublease, as to that portion of the Premises proposed to be sublet,
as of a date specified in such notice which shall be not less than 30 or more
than 60 days after the date of such notice.

     If, at any time during the Term of this Lease, Tenant is:

     (i) a corporation or a trust (whether or not having shares of beneficial
interest) and there shall occur any change in the identity of any of the persons
then having power to participate in the election or appointment of the
directors, trustees or other persons exercising like functions and managing the
affairs 





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<PAGE>   27

of Tenant; or

     (ii) a partnership or association or otherwise not a natural person (and is
not a corporation or a trust) and there shall occur any change in the identity
of any of the persons who then are members of such partnership or association or
who comprise Tenant;

Tenant shall so notify Landlord and Landlord may terminate this Lease by notice
to Tenant given within 90 days thereafter if, in Landlord's reasonable judgment,
the credit of Tenant is thereby materially impaired. This paragraph shall not
apply if the initial Tenant named herein is a corporation and the outstanding
voting stock thereof is listed on a recognized securities exchange, including
without limitation the NASDAQ Stock Market.

          B. The foregoing provisions of subparagraph (A) of this Section 6.1.6
shall not be deemed violated by an assignment of this Lease to any parent,
wholly-owned subsidiary of such parent corporation or affiliate of Tenant
("affiliate of Tenant" shall mean any corporation which directly controls,
beneficially owns or is under common control with Tenant); provided however,
that no such assignment shall be binding upon Landlord unless the assignee shall
execute, acknowledge and deliver to Landlord an agreement in recordable form,
whereby the assignee agrees unconditionally to be bound by and to perform all
the terms, covenants and conditions of this Lease on Tenant's part to be
observed and performed, whether or not accruing prior to or after the date of
such assignment and whether or not relating to matters arising prior to such
assignment and further agrees that, notwithstanding such assignment, the
provisions of this Section 6.1.6 shall continue to be binding upon such assignee
with respect to all future assignments.

     Not to assign this Lease to a party which results from a consolidation,
merger, acquisition or sale of substantially all of the assets and stock of
Tenant without obtaining, on each occasion, the prior written consent of
Landlord, which consent shall not be unreasonably withheld or delayed, provided
that such consent shall not be required if such party will have a net worth
after such consolidation, merger, acquisition, or sale equal to or exceeding the
greater of Tenant's net worth as of the date hereof or Tenant's net worth
immediately proceeding the proposed assignment (the "Net Worth Requirement"),
but only if Tenant provides prior notice of the assignment to Landlord,
accompanied by sufficient information to validate that the Net Worth Requirement
will be satisfied to Landlord's reasonable satisfaction.

          C. Landlord agrees not to withhold or delay its consent to an
assignment of this Lease or a sublease of a portion of the Premises by Tenant
provided that (a) Tenant is not in default of any obligation hereunder, (b)
Landlord determines in its sole reasonable discretion that the proposed 




                                       27
<PAGE>   28

assignee or sublessee (i) will use the Premises for office purposes, and (ii)
has a financial standing acceptable to Landlord as evidenced by financial
statements in scope and substance satisfactory to Landlord and in conformity
with generally accepted accounting principles and, if requested by Landlord,
certified by a certified public accountant acceptable to Landlord (provided that
Landlord agrees that if the Net Worth Requirement is satisfied, such financial
standing shall be acceptable to Landlord), (c) the rent charged by Tenant on a
square footage basis shall not be less than the Annual Rent and additional rent
due hereunder, on a square footage basis, and (d) the proposed assignee or
sublessee shall not be (i) a tenant (or an affiliate of a tenant) of the
Building or another building in the office park owned by Landlord or an
affiliate of Landlord or (ii) an entity (or an affiliate of any entity) with
which Landlord was negotiating for space in the Building or another building in
the office park owned by Landlord or an affiliate of Landlord during the
preceding eighteen (18) months. In the case of an assignment, the proposed
assignee must specifically assume and agree in writing to be bound by all of the
obligations of the Tenant hereunder.

     6.1.7 Indemnity - To defend, with counsel approved by Landlord (such
approval not to be unreasonably withheld or delayed), all actions against
Landlord, any partner, trustee, stockholder, officer, director, employee or
beneficiary of Landlord, holders of mortgages secured by the Premises or the
Building and Lot and any other party having an interest in the Premises
("Indemnified Parties") with respect to, and to pay, protect, indemnify and save
harmless, to the extent permitted by law, all Indemnified Parties from and
against, any and all liabilities, losses, damages, costs, expenses (including
reasonable attorneys' fees and expenses), causes of action, suits, claims,
demands or judgments of any nature arising from Tenant's use of the Premises,
except if caused by Landlord's negligence or the negligence of any person or
entity for whom Landlord is legally responsible, or any claims arising from any
breach or default on Tenant's part under the terms of this Lease, or from any
act, fault, omission or other misconduct of Tenant, or its agents, employees,
contractors, licensees, sublessees, invitees, or any person or entity for whom
Tenant is legally responsible, or from injury to or death of any person or
damage to or loss of property, on the Premises, except if caused by Landlord's
negligence or the negligence of any person or entity for whom Landlord is
legally responsible, or from Tenant's generation, storage, disposal or use of
hazardous substances in, upon or about the Premises. Tenant assumes all risk of
damage to or loss of property or injury to or death of persons in, upon or about
the Premises, from any cause other than Landlord's negligence or the negligence
of any person or entity for whom Landlord is legally responsible.









                                       28
<PAGE>   29

     6.1.8 Tenant's Insurance - To maintain (a) all risk property insurance in
amounts sufficient to fully cover Tenant's improvements and all property in the
Premises which is not owned by Landlord and (b) commercial general liability
insurance on the Premises, with Landlord named as an additional insured, in
respect of such commercial general liability insurance indemnifying Landlord and
Tenant against all claims and demands for (i) injury to or death of any person
or damage to or loss of property, on the Premises or connected with the use,
condition or occupancy of the Premises unless caused by the negligence of
Landlord or its servants or agents, (ii) violation of this Lease, or (iii) any
act, fault or omission, or other misconduct of Tenant or its agents, employees,
contractors, licensees, sublessees or invitees, in amounts which shall, at the
beginning of the Term, be at least equal to the limits set forth in Section 1.1,
and from time to time during the Term, shall be for such higher limits, if any,
as are customarily carried in the area in which the Premises are located on
property similar to the Premises and used for similar purposes, and shall be
written on the "Occurrence Basis", and to furnish Landlord with certificates
thereof. Such insurance shall be effected under valid and enforceable policies
with insurers authorized to do business in Massachusetts as stock or mutual
companies that are rated in the current edition of BEST'S KEY RATING GUIDE,
PROPERTY AND CASUALTY as A and as Class VII or higher. Not later than the first
to occur of (a) the Term Commencement Date or (b) the commencement of any
activities by Tenant in or about the Premises and thereafter not less than 30
days prior to the expiration dates of the expiring policies theretofore
furnished pursuant to this Section 6.1.8, Tenant shall deliver to Landlord
certificates of insurance issued by the insurers evidencing all such policies in
form satisfactory to Landlord, accompanied by evidence satisfactory to Landlord
of payment of the first installment of the premiums. Each such policy shall
provide that it may not be cancelled and that its form, terms or conditions may
not be materially changed without at least 30 days prior written notice to each
insured named therein.

     6.1.9 Tenant's Worker's Compensation Insurance - To keep all of Tenant's
employees working in the Premises covered by worker's compensation insurance in
statutory amounts and to furnish Landlord with certificates thereof.

     6.1.10 Landlord's Right of Entry - To permit Landlord and Landlord's agents
entry at all reasonable times during normal business hours and upon reasonable
advance notice (except that no notice is required in the event of an emergency,
in which case Landlord shall be permitted to enter at any time): to examine the
Premises and, if Landlord shall so elect, to make repairs, replacements,
alterations or substitutions as Landlord may deem necessary or desirable
provided that Landlord will not unreasonably interfere with Tenant's business;
to remove, at Tenant's expense, any changes or additions not consented to in
writing by Landlord if such consent was required under the 




                                       29
<PAGE>   30

provisions of this Lease; and to show the Premises to prospective tenants during
the 9 months (or if Tenant has given notice of exercise of Tenant's Option to
Extend in accordance with Section 2.3 hereof, 8 months) preceding expiration of
the Term and to prospective purchasers and mortgagees at all reasonable times
during normal business hours.

     6.1.11 Loading - Not to place Tenant's Property, as defined in Section
6.1.13, upon the Premises so as to exceed a rate of 75 pounds of live load per
square foot with respect to any floor of the Building other than the ground
floor; not to move any safe, vault or other heavy equipment in, about or out of
the Premises except in such manner as Landlord shall in each instance approve
(such approval not to be unreasonably withheld or delayed); and not to leave
Tenant's personal property or equipment in or about the common loading area
serving the Building; Tenant's business machines and mechanical equipment which
cause vibration or noise that may be transmitted to the Building structure shall
be placed and maintained by Tenant in settings of cork, rubber, spring, or other
types of vibration eliminators sufficient to eliminate such vibration or noise.

     6.1.12 Landlord's Costs - In case Landlord shall be made party to any
litigation commenced by or against Tenant or by or against any parties in
possession of the Premises or any part thereof claiming under Tenant, to pay, as
additional rent, all costs including, without implied limitation, reasonable
counsel fees incurred by or imposed upon Landlord in connection with such
litigation (except in connection with litigation involving an alleged breach or
default by Landlord under the terms of this Lease to the extent that Landlord is
held to be in breach or default or litigation involving the alleged negligence
or willful misconduct of Landlord or of any person or entity for whom Landlord
is legally responsible to the extent that Landlord or anyone for whom Landlord
is legally responsible is found to have engaged in negligence or willful
misconduct), and, as additional rent, also to pay all such costs and fees
incurred by Landlord in connection with the successful enforcement by Landlord
of any obligations of Tenant under this Lease.

     6.1.13 Tenant's Property - All the furnishings, fixtures, equipment,
effects and property of every kind, nature and description of Tenant and of all
persons claiming by, through or under Tenant which, during the continuance of
this Lease or any occupancy of the Premises by Tenant or anyone claiming under
Tenant, may be on the Premises or elsewhere in the Building or on the Lot shall
be at the sole risk and hazard of Tenant, and if the whole or any part thereof
shall be destroyed or damaged by fire, water or otherwise, or by the leakage or
bursting of water pipes, steam pipes, or other pipes, by theft, or from any
other cause, no part of said loss or damage is to be charged to or to be borne
by Landlord unless due to the negligence or willful misconduct of Landlord or of
any person or entity for whom Landlord is legally responsible.




                                       30
<PAGE>   31

     6.1.14 Labor or Materialmen's Liens - To pay promptly when due, and to
defend and indemnify Landlord from and against, the entire cost of any work done
on the Premises by Tenant, its agents, employees, or independent contractors,
subject to Tenant's right to contest any claim in good faith so long as
Landlord's interest in the Building or the Lot is not impaired thereby; and to
cause any liens for labor or materials performed or furnished in connection with
any work done on the Premises by or on behalf of Tenant that may attach to the
Premises to be immediately released of record by payment or posting of proper
bond.

     6.1.15 Changes or Additions - Only to make changes or additions to the
Premises in accordance with Article III hereto, provided that Tenant shall
reimburse Landlord for all reasonable out-of-pocket costs incurred by Landlord
in reviewing Tenant's proposed changes or additions.

     6.1.16 Holdover - To pay to Landlord the greater of one hundred fifty
percent (150%) of (a) the then fair market rent as conclusively determined by
Landlord in its reasonable judgement or (b) the total of the Annual Base Rent
and additional rent then applicable for each month or portion thereof Tenant
shall retain possession of the Premises or any part thereof after the
termination of this Lease, whether by lapse of time or otherwise, and also to
pay all damages sustained by Landlord on account thereof; the provisions of this
subsection shall not operate as a waiver by Landlord of the right of re-entry
provided in this Lease.

     6.1.17 Security - To indemnify, and save Landlord harmless from any claim
for injury to person or damage to property asserted by any personnel, employee,
guest, invitee or agent of Tenant which is suffered or occurs within the
Premises by reason of the act of any intruder or any other person within the
Premises, unless such intruder's access to the Premises is caused by or the
result of the negligence of Landlord or of any person or entity for whom
Landlord is legally responsible.
















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<PAGE>   32


                                   ARTICLE VII

                      DAMAGE AND DESTRUCTION; CONDEMNATION


7.1  FIRE OR OTHER CASUALTY

     7.1.1 Subject to the provisions of Section 7.1.2 hereof, in the event
during the Term hereof the Premises shall be partially damaged (as distinguished
from "substantially damaged" as such term is hereinafter defined) by fire,
explosion, casualty or any other occurrence covered or as may be required to be
covered, as herein provided, by Landlord's insurance or by such casualty plus
required demolition, or by action taken to reduce the impact of any such event,
Landlord shall forthwith proceed to repair such damage and restore the Premises,
or so much thereof as was originally constructed or delivered by Landlord to
substantially its condition at the time of such fire, explosion, casualty or
occurrence, provided that Landlord shall not be obligated to expend for such
repair an amount in excess of the insurance proceeds recovered as a result of
such damage and, further provided that Tenant is not then in default of any of
its obligations under this Lease beyond any applicable cure period. Landlord
shall not be responsible for any delay which may result from any cause beyond
Landlord's reasonable control. If Landlord is not obligated to undertake or to
complete the repair of such damage and the restoration of the Premises, or so
much thereof as was originally constructed or delivered by Landlord, to
substantially its condition at the time of such fire, explosion, casualty or
occurrence, as a result of the unavailability of insurance proceeds in an amount
sufficient to complete such repair and restoration, and Landlord does not elect
to do so, Landlord shall provide written notice to Tenant that it will not so
repair such damages and restore the Premises as soon as practicable after
Landlord determines that it will not so repair such damage and restore the
Premises, and thereupon Tenant shall have the right to terminate this Lease by
notice to Landlord given no later than 30 days after Landlord's notice to
Tenant.

     7.1.2 If, however, (i) the Premises should be damaged or destroyed (a) by
fire or other casualty (1) to the extent of 25% or more of the cost of
replacement, or (2) so that 25% or more of the principal area contained in the
Premises shall be rendered untenantable, or (b) by any casualty other than those
covered by insurance policies required to be maintained by Landlord under this
Lease (hereinafter "substantially damaged"), or (ii) the Premises shall be
damaged in whole or in part during the last 2 years of the Term, or (iii) there
shall be damage to the Premises of a character as cannot reasonably be expected
to be repaired within 12 months from the date of casualty, or (iv) such
restoration involves the demolition of or repair of damage to 25% percent or
more of the Premises, or (v) applicable law requires the demolition of the
Building or forbids the 




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<PAGE>   33

rebuilding of the damaged portion of the Building, or (vi) such restoration
requires repairs in an amount in excess of the insurance proceeds recovered or
recoverable, or (vii) Landlord's mortgagee shall require that the insurance
proceeds from such damage or destruction be applied against the principal
balance due on any mortgage, Landlord may, at its option, either terminate this
Lease or elect to repair the Premises and Landlord shall notify Tenant as to its
election within 60 days after such fire or casualty. If Landlord elects to
terminate this Lease, the Term hereof shall end on the date specified in the
notice (which shall be the end of a calendar month and not sooner than 30 days
after such election was made). If Landlord does not elect to terminate this
Lease, then Landlord shall perform such repairs set forth in Section 7.1.3
hereof and Tenant shall perform such repairs in the Building as set forth in
Section 7.1.4 hereof, and the Term shall continue without interruption and this
Lease shall remain in full force and effect.

     If Landlord has not elected to terminate this Lease and if there shall be
damage to the Premises of a character as cannot (in the reasonable judgment of
Landlord's engineer) reasonably be expected to be repaired within 12 months from
the date of casualty (which judgment shall be made and notice thereof given to
Tenant within 60 days of the fire or other casualty), then Tenant may, at its
option, terminate this Lease provided that Tenant's election shall be made
within 30 days of Landlord's delivery of the estimate of Landlord's engineer as
to the time period required for restoration.

     7.1.3 If neither Landlord nor Tenant elects to terminate this Lease as
provided in Section 7.1.2 hereof and if Tenant is not then in default of any of
its obligations under the Lease beyond any applicable cure period provided for
herein, Landlord shall work diligently to reconstruct as much of the Premises as
was originally constructed or delivered by Landlord (it being understood by
Tenant that Landlord shall not be responsible for any reconstruction of
leasehold improvements, which reconstruction is the sole responsibility of
Tenant) to substantially its condition at the time of such damage. Landlord
shall not be responsible for any delays which may result from any cause beyond
Landlord's reasonable control; provided that if Landlord, for any reason, fails
to substantially complete such reconstruction within twelve (12) months from the
date of the fire or casualty, Tenant, at its option, may terminate this Lease at
the end of such twelve month period by written notice given to Landlord,
provided, however, that so long as Landlord has been and continues to diligently
and continuously pursue such reconstruction to completion, such termination
shall only be effective sixty (60) days after the giving of such notice and then
only if Landlord does not substantially complete such reconstruction within such
sixty-day period. If Landlord has been diligently and continuously pursuing such
reconstruction to completion and does 




                                       33
<PAGE>   34

substantially complete such reconstruction within such sixty-day period, such
termination shall be null and void and this Lease shall continue in full force
and effect for the remainder of the Term, subject to the provisions of the
Lease. For purposes hereof, substantial completion shall mean that the
reconstruction has been completed with the exception of (a) minor items which
can be fully completed without material interference with the use of the
Premises by Tenant for the Permitted Uses, and (b) items which are incomplete
because of delays caused by Tenant.

     7.1.4 If Landlord does not elect to terminate this Lease as provided in
Section 7.1.2 hereof, Tenant shall, at its own cost and expense, repair and
restore the Premises in accordance with the provisions of Section 6.1.15 hereof
to the extent not required to be repaired by Landlord pursuant to the provisions
of this Section 7.1, including, but not limited to, the repairing and/or
replacement of its merchandise, trade fixtures, furnishings and equipment in a
manner and to at least a condition equal to that prior to its damage or
destruction. Tenant agrees to commence the performance of its work when notified
by Landlord that the work to be performed by Tenant can, in accordance with good
construction practices, then be commenced and Tenant shall complete such work as
promptly thereafter as is practicable, but in no event more than 120 days
thereafter.

     7.1.5 All proceeds payable from Landlord's insurance policies with respect
to the Premises shall belong to and shall be payable to Landlord. If Landlord
does not elect to terminate this Lease as provided in Section 7.1.2 hereof,
Landlord shall disburse and apply so much of any insurance recovery as shall be
necessary against the cost to Landlord of restoration and rebuilding of
Landlord's work referred to in Section 7.1.3 hereof, subject to the prior rights
of any lessor under a ground or underlying lease covering the Building and/or
the holder of any mortgage liens against the Building.

     7.1.6 In the event that the provisions of Section 7.1.1 or Section 7.1.2
shall become applicable, the Annual Base Rent and additional rent shall be
abated or reduced proportionately during any period in which, by reason of such
damage or destruction, there is substantial interference with the operation of
the business of Tenant in the Premises, having regard to the extent to which
Tenant may be required to discontinue its business in the Premises, and such
abatement or reduction shall continue for the period commencing with such
destruction or damage and ending with the completion by Landlord of such work of
repair and/or reconstruction as Landlord is obligated to do (or elects to do in
accordance with Section 7.1.1) and the earliest of (i) completion by Tenant of
such work as Tenant is obligated to do, (ii) Tenant's use of the Premises for
the Permitted Uses (provided that the expiration of any such abatement or
reduction as a result of Tenant's use of 




                                       34
<PAGE>   35

the Premises for the Permitted Uses shall be subject to the same phasing of
payments of Annual Rent and other charges in connection with Tenant's occupancy
of Floor Segments as Tenant's initial occupancy of the Premises described in
Section 4.1 hereof), and (iii) provided that Tenant diligently and continuously
pursues Tenant's work to completion, 120 days after the date Tenant is obligated
to commence Tenant's work.

7.2  EMINENT DOMAIN.

     If, after the execution and before termination of this Lease, the entire
Premises or the parking area on the Lot (unless reasonably equivalent substitute
parking is provided) shall be taken by eminent domain or destroyed by the action
of any public or quasi-public authority, or in the event of conveyance in lieu
thereof, the Term shall cease as of the day possession shall be taken by such
authority, and Tenant shall pay rent up to that date with a pro-rata refund by
Landlord of such rent and additional rent as shall have been paid in advance for
a period subsequent to the date of the taking of possession.

     If less than 25% of the Premises or the parking area on the Lot (with due
credit for reasonably equivalent substitute parking provided by Landlord) shall
be so taken or conveyed, this Lease shall cease only as respects the parts so
taken or conveyed, as of the day possession shall be taken, and Tenant shall pay
rent up to that day, with an appropriate refund by Landlord of such rent as may
have been paid in advance for a period subsequent to the date of the taking of
possession, and thereafter the Annual Base Rent shall be equitably adjusted.
Pending agreement of such rental adjustment, Tenant agrees to pay to Landlord
the Annual Base Rent in effect immediately prior to the taking by eminent
domain. Landlord shall at its expense make all necessary repairs or alterations
so as to constitute the remaining premises a complete architectural unit.

     If more than 25% of the Premises shall be so taken or conveyed, then at
Landlord's or Tenant's option upon notice to the other party, the Lease shall
terminate on the date specified in such notice (which shall be the end of a
calendar month and not sooner than thirty (30) days after such election was
made). If neither party elects to terminate the Lease, the Term shall cease only
as respects the part so taken or conveyed, from the day possession shall be
taken, and Tenant shall pay rent to that date with an appropriate refund by
Landlord of such rent as may have been paid in advance for a period subsequent
to the date of the taking of possession. If neither Landlord nor Tenant elects
to terminate the Lease, all of the terms herein provided shall continue in
effect except that the Annual Base Rent shall be equitably adjusted, and
Landlord shall make all necessary repairs or alterations so as to constitute the
remaining premises a complete architectural unit.



                                       35
<PAGE>   36

     All compensation awarded for any such taking or conveyance, whether for the
whole or a part of the Premises, shall be the property of Landlord, whether such
damages shall be awarded as compensation for diminution in the value of the
leasehold or of the fee of or underlying leasehold interest in the Premises, and
Tenant hereby assigns to Landlord all of Tenant's right, title and interest in
and to any and all such compensation; provided, however, that Tenant shall be
entitled to seek a separate award for Tenant's stock, trade fixtures and
relocation expense.

     In the event of any taking of the Premises or any part thereof for
temporary use, this Lease shall be and remain unaffected thereby and rent shall
not abate.



                                  ARTICLE VIII

                               RIGHTS OF MORTGAGEE


8.1  PRIORITY OF LEASE.

     The Building and the Lot are not subject to any presently existing mortgage
or deed of trust covering the Lot or Building or both.

     Unless the option provided for in the next following sentence shall be
exercised, this Lease shall be superior to and shall not be subordinate to, any
mortgage, deed of trust or other voluntary lien hereafter placed on the Lot or
Building or both (the "mortgaged premises"). The holder of any such mortgage,
deed of trust or other voluntary lien shall have the option to subordinate this
Lease to the same, provided that such holder enters into an agreement with
Tenant by the terms of which the holder will agree to recognize the rights of
Tenant under this Lease and to accept Tenant as tenant of the Premises under the
terms and conditions of this Lease in the event of acquisition of title by such
holder through foreclosure proceedings or otherwise and Tenant will agree to
recognize the holder of such mortgage as Landlord in such event, which agreement
shall be made to expressly bind and inure to the benefit of the successors and
assigns of Tenant and of the holder and upon anyone purchasing the mortgaged
premises at any foreclosure sale. Any such mortgage to which this Lease shall be
subordinated may contain such terms, provisions and conditions as the holder
deems usual or customary.


















                                       36
<PAGE>   37

8.2  RIGHTS OF MORTGAGE HOLDERS; LIMITATION OF MORTGAGEE'S LIABILITY.

     The word "mortgage" as used herein includes mortgages, deeds of trust or
other similar instruments evidencing other voluntary liens or encumbrances, and
modifications, consolidations, extensions, renewals, replacements and
substitutes thereof. The word "holder" shall mean a mortgagee, and any
subsequent holder or holders of a mortgage. Until the holder of a mortgage shall
enter and take possession of the Premises for the purpose of foreclosure, such
holder shall have only such rights of Landlord as are necessary to preserve the
integrity of this Lease as security. Upon entry and taking possession of the
Premises for the purpose of foreclosure, such holder shall have all the rights
of Landlord. Notwithstanding any other provision of this Lease to the contrary,
including without limitation Section 10.4, no such holder of a mortgage shall be
liable, either as mortgagee or as assignee, to perform, or be liable in damages
for failure to perform any of the obligations of Landlord unless and until such
holder shall enter and take possession of the Premises for the purpose of
foreclosure, and such holder shall not in any event be liable to perform or for
failure to perform the obligations of Landlord under Section 3.1. Upon entry for
the purpose of foreclosure, such holder shall be liable to perform all of the
obligations of Landlord (except for the obligations under Section 3.1), subject
to and with the benefit of the provisions of Section 10.4, provided that a
discontinuance of any foreclosure proceeding shall be deemed a conveyance under
said provisions to the owner of the equity of the Premises.


8.3  MORTGAGEE'S ELECTION.

     Notwithstanding any other provision to the contrary contained in this
Lease, if prior to substantial completion of Landlord's obligations under
Article III, any holder of a first mortgage on the mortgaged premises enters and
takes possession thereof for the purpose of foreclosing the mortgage, such
holder may elect, by written notice given to Tenant and Landlord at any time
within 90 days after such entry and taking of possession, not to perform
Landlord's obligations under Article III, and in such event such holder and all
persons claiming under it shall be relieved of all obligations to perform, and
all liability for failure to perform, said Landlord's obligations under Article
III, and Tenant may terminate this Lease and all its obligations hereunder by
written notice to Landlord and such holder given within 30 days after the day on
which such holder shall have given its notice as aforesaid.










                                       37
<PAGE>   38

8.4  NO PREPAYMENT OR MODIFICATION, ETC.

     Tenant shall not pay Annual Base Rent, additional rent, or any other charge
more than 10 days prior to the due date thereof. No prepayment of Annual Base
Rent, additional rent or other charge, no assignment of this Lease and no
agreement to modify so as to reduce the rent, change the Term, or otherwise
materially change the rights of Landlord under this Lease, or to relieve Tenant
of any obligations or liability under this Lease, shall be valid unless
consented to in writing by Landlord's mortgagees of record, if any.


8.5  NO RELEASE OR TERMINATION.

     No act or failure to act on the part of Landlord which would entitle Tenant
under the terms of this Lease, or by law, to be relieved of Tenant's obligations
hereunder or to terminate this Lease, shall result in a release or termination
of such obligations or a termination of this Lease unless (i) Tenant shall have
first given written notice of Landlord's act or failure to act to Landlord's
mortgagees of record, if any, specifying the act or failure to act on the part
of Landlord which could or would give basis to Tenant's rights and (ii) such
mortgagees, after receipt of such notice, have failed or refused to correct or
cure the condition complained of within a reasonable time thereafter, but
nothing contained in this Section 8.5 shall be deemed to impose any obligation
on any such mortgagee to correct or cure any such condition. "Reasonable time"
as used above means and includes a reasonable time to obtain possession of the
mortgaged premises, if the mortgagee elects to do so, and a reasonable time to
correct or cure the condition if such condition is determined to exist.


8.6  CONTINUING OFFER.

     The covenants and agreements contained in this Lease with respect to the
rights, powers and benefits of a mortgagee (particularly, without limitation
thereby, the covenants and agreements contained in this Article VIII) constitute
a continuing offer to any person, corporation or other entity, which by
accepting or requiring an assignment of this Lease or by entry or foreclosure
assumes the obligations herein set forth with respect to such mortgagee; such
mortgagee is hereby constituted a party to this Lease as an obligee hereunder to
the same extent as though its name were written hereon as such; and such
mortgagee shall be entitled to enforce such provisions in its own name. Tenant
agrees on request of Landlord to execute and deliver from time to time any
agreement which may reasonably be deemed necessary to implement the provisions
of this Article VIII.




                                       38
<PAGE>   39


                                   ARTICLE IX

                                     DEFAULT


9.1  EVENTS OF DEFAULT.

     If any default by Tenant continues, in case of Annual Base Rent, additional
rent or any other monetary obligation to Landlord for more than 5 days after
written notice to Tenant of the default (provided that if two such notices have
been given in any twelve-month period, notice of any such subsequent default
shall not be required hereunder), or in any other case for more than 30 days
after written notice and such additional time, if any, as is reasonably
necessary to cure the default if the default is of such a nature that it cannot
reasonably be cured in 30 days and Tenant promptly commences to cure such
default and diligently pursues such cure without interruption to completion; or
if Tenant becomes insolvent, fails to pay its debts as they fall due, files a
petition under any chapter of the U.S. Bankruptcy Code, 11 U.S.C. 101 et seq.,
as it may be amended (or any similar petition under any insolvency law of any
jurisdiction), or if such petition is filed against Tenant and not dismissed
within sixty (60) days thereafter; or if Tenant proposes any dissolution,
liquidation, composition, financial reorganization or recapitalization with
creditors, makes an assignment or trust mortgage for benefit of creditors, or if
a receiver, trustee, custodian or similar agent is appointed or takes possession
with respect to any property of Tenant; or if the leasehold hereby created is
taken on execution or other process of law in any action against Tenant; then,
and in any such case, Landlord and the agents and servants of Landlord may, in
addition to and not in derogation of any remedies for any preceding breach of
covenant, immediately or at any time thereafter while such default continues and
without further notice, at Landlord's election, do any one or more of the
following: (1) give Tenant written notice stating that the Lease is terminated,
effective upon the giving of such notice or upon a date stated in such notice,
as Landlord may elect, in which event the Lease shall be irrevocably
extinguished and terminated as stated in such notice without any further action,
or (2) with or without process of law, in a lawful manner enter and repossess
the Premises as of Landlord's former estate, and expel Tenant and those claiming
through or under Tenant, and remove its and their effects, without being guilty
of trespass, in which event the Lease shall be irrevocably extinguished and
terminated at the time of such entry, or (3) pursue any other rights or remedies
permitted by law. Any such termination of the Lease shall be without prejudice
to any remedies which might otherwise be used for arrears of rent or prior
breach of covenant, and in the event of such termination Tenant shall remain
liable under this Lease as hereinafter provided. Tenant hereby waives all
statutory rights (including, without 




                                       39
<PAGE>   40

limitation, rights of redemption, if any) to the extent such rights may be
lawfully waived, and Landlord, without notice to Tenant, may store Tenant's
effects and those of any person claiming through or under Tenant at the expense
and risk of Tenant and, if Landlord so elects, may sell such effects at public
auction or private sale and apply the net proceeds to the payment of all sums
due to Landlord from Tenant, if any, and pay over the balance, if any, to
Tenant.


9.2  TENANT'S OBLIGATIONS AFTER TERMINATION.

     In the event that this Lease is terminated under any of the provisions
contained in Section 9.1 or shall be otherwise terminated for breach of any
obligation of Tenant, Tenant covenants to pay forthwith to Landlord, as
compensation, (i) the present value, discounted at a reasonable discount
determined by Landlord, of the excess of the total rent reserved for the residue
of the Term over the rental value of the Premises for said residue of the Term
and (ii) the unamortized portion of the actual out-of-pocket costs and expenses
incurred by Landlord in completing Landlord's Work, amortized on a straight-line
reduction basis from 100% to 0% over a five (5) year period commencing on the
Term Commencement Date. In calculating the rent reserved, there shall be
included, in addition to the Annual Base Rent and all additional rent, the value
of all other consideration agreed to be paid or performed by Tenant for said
residue. Tenant further covenants as an additional and cumulative obligation
after any such ending to pay punctually to Landlord all the sums and perform all
the obligations which Tenant covenants in this Lease to pay and to perform in
the same manner and to the same extent and at the same time as if this Lease had
not been terminated. In calculating the amounts to be paid by Tenant under the
next foregoing covenant, Tenant shall be credited with any amount paid to
Landlord as compensation as provided in the first sentence of this Section 9.2
and also with the net proceeds of any rents obtained by Landlord by reletting
the Premises, after deducting all Landlord's expenses in connection with such
reletting, including, without implied limitation, all repossession costs,
brokerage commissions, fees for legal services and expenses of preparing the
Premises for such reletting, it being agreed by Tenant that Landlord may (i)
relet the Premises or any part or parts thereof for a term or terms which may at
Landlord's option be equal to or less than or exceed the period which would
otherwise have constituted the balance of the Term and may grant such
concessions and free rent as Landlord in its sole judgment considers advisable
or necessary to relet the same and (ii) make such alterations, repairs and
decorations in the Premises as Landlord in its sole judgment considers advisable
or necessary to relet the same, and no action of Landlord in accordance with the
foregoing or failure to relet or to collect rent under reletting shall operate
or be construed to release or reduce Tenant's liability as aforesaid.



                                       40
<PAGE>   41

     So long as at least 12 months of the Term remain unexpired at the time of
such termination, in lieu of any other damages or indemnity and in lieu of full
recovery by Landlord of all sums payable under all the foregoing provisions of
this Section 9.2, Landlord may by written notice to Tenant, at any time after
this Lease is terminated under any of the provisions contained in Section 9.1,
or is otherwise terminated for breach of any obligation of Tenant and before
such full recovery, elect to recover and Tenant shall thereupon pay, as
liquidated damages, an amount equal to the aggregate of the Annual Base Rent and
additional rent accrued under Article IV in the 12 months ended next prior to
such termination plus the amount of Annual Base Rent and additional rent of any
kind accrued and unpaid at the time of termination and less the amount of any
recovery by Landlord under the foregoing provisions of this Section 9.2 up to
the time of payment of such liquidated damages.

     Nothing contained in this Lease shall, however, limit or prejudice the
right of Landlord to prove and obtain in proceedings for bankruptcy or
insolvency by reason of the termination of this Lease, an amount equal to the
maximum allowed by any statute or rule of law in effect at the time when, and
governing the proceedings in which, the damages are to be proved, whether or not
the amount be greater, equal to, or less than the amount of the loss or damages
referred to above.



                                    ARTICLE X

                                  MISCELLANEOUS


10.1   NOTICE OF LEASE.

       Upon request of either party, both parties shall execute and deliver,
after the Term begins, a short form of this Lease in form appropriate for
recording or registration, and if this Lease is terminated before the Term
expires, an instrument in such form acknowledging the date of termination.


10.2   NOTICES FROM ONE PARTY TO THE OTHER.

       All notices required or permitted hereunder shall be in writing and
addressed, if to the Tenant, at Tenant's Address or such other address as Tenant
shall have last designated by notice in writing to Landlord and, if to Landlord,
at Landlord's Address or such other address as Landlord shall have last
designated by notice in writing to Tenant. Any notice shall have been deemed
duly given if mailed to such address postage prepaid, registered or certified
mail, return receipt requested, 




                                       41
<PAGE>   42

when deposited with the U.S. Postal Service, or if delivered to such address by
hand, when so delivered.


10.3   BIND AND INURE.

       The obligations of this Lease shall run with the land, and this Lease
shall be binding upon and inure to the benefit of the parties hereto and their
respective successors and assigns, except that the Landlord named herein and
each successive owner of the Premises shall be liable only for the obligations
accruing during the period of its ownership. The obligations of Landlord shall
be binding upon the assets of Landlord which comprise the Building and the Lot
but not upon other assets of Landlord. No individual partner, trustee,
stockholder, officer, director, employee or beneficiary of Landlord shall be
personally liable under this Lease and Tenant shall look solely to Landlord's
interest in the Building and the Lot in pursuit of its remedies upon an event of
default hereunder, and the general assets of the individual partners, trustees,
stockholders, officers, employees or beneficiaries of Landlord shall not be
subject to levy, execution or other enforcement procedure for the satisfaction
of the remedies of Tenant.


10.4   NO SURRENDER.

       The delivery of keys to any employee of Landlord or to Landlord's agent
or any employee thereof shall not operate as a termination of this Lease or a
surrender of the Premises.


10.5   NO WAIVER, ETC.

       The failure of Landlord to seek redress for violation of, or to insist
upon the strict performance of any covenant or condition of this Lease or any of
the Rules and Regulations referred to in Section 6.1.4, whether heretofore or
hereafter adopted by Landlord, shall not be deemed a waiver of such violation
nor prevent a subsequent act, which would have originally constituted a
violation, from having all the force and effect of an original violation, nor
shall the failure of Landlord to enforce any of said Rules and Regulations
against any other tenant in the Building be deemed a waiver of any such Rules or
Regulations. The receipt by Landlord of Annual Base Rent or additional rent with
knowledge of the breach of any covenant of this Lease shall not be deemed a
waiver of such breach by Landlord, unless such waiver be in writing and signed
by Landlord. No consent or waiver, express or implied, by Landlord to or of any
breach of any agreement or duty shall be construed as a waiver or consent to or
of any other breach of the same or any other agreement or duty.




                                       42
<PAGE>   43

10.6   NO ACCORD AND SATISFACTION.

       No acceptance by Landlord of a lesser sum than the Annual Base Rent and
additional rent then due shall be deemed to be other than on account of the
earliest installment of such rent due, nor shall any endorsement or statement on
any check or any letter accompanying any check or payment as rent be deemed as
accord and satisfaction, and Landlord may accept such check or payment without
prejudice to Landlord's right to recover the balance of such installment or
pursue any other remedy in this Lease provided.


10.7   CUMULATIVE REMEDIES.

       The specific remedies to which Landlord may resort under the terms of
this Lease are cumulative and are not intended to be exclusive of any other
remedies or means of redress to which it may be lawfully entitled in case of any
breach or threatened breach by Tenant of any provisions of this Lease. In
addition to the other remedies provided in this Lease, Landlord shall be
entitled to the restraint by injunction of the violation or attempted or
threatened violation of any of the covenants, conditions or provisions of this
Lease or to a decree compelling specific performance of any such covenants,
conditions or provisions.


10.8   RIGHT TO CURE; LANDLORD'S DEFAULT.

       If Tenant shall at any time default in the performance of any obligation
under this Lease, Landlord shall have the right, but shall not be obligated, to
enter upon the Premises and to perform such obligation, notwithstanding the fact
that no specific provision for such substituted performance by Landlord is made
in this Lease with respect to such default. In performing such obligation,
Landlord may make any payment of money or perform any other act. All sums so
paid by Landlord (together with interest at the rate of 4% per annum in excess
of the then prime commercial rate of interest being charged by the BankBoston in
Boston, Massachusetts) and all necessary incidental costs and expenses in
connection with the performance of any such act by Landlord, shall be deemed to
be additional rent under this Lease and shall be payable to Landlord immediately
on demand. Landlord may exercise the foregoing rights without waiving any other
of its rights or releasing Tenant from any of its obligations under this Lease.

       Landlord shall not be deemed to be in default in the performance of any
of its obligations hereunder unless it shall fail to perform such obligations
and such failure shall continue for a period of thirty (30) days or such
additional time as is reasonably required to commence or complete the correction
of, and thereafter correct, any such default after notice has been 




                                       43
<PAGE>   44

given by Tenant to Landlord specifying the nature of Landlord's alleged default.

10.9   ESTOPPEL CERTIFICATE.

       Tenant agrees, from time to time, upon not less than 15 days' prior
written request by Landlord, to execute, acknowledge and deliver to Landlord a
statement in writing certifying that this Lease is unmodified and in full force
and effect; that Tenant has no defenses, offsets or counterclaims against its
obligations to pay the Annual Base Rent and additional rent and to perform its
other covenants under this Lease; that there are no uncured defaults of Landlord
or Tenant under this Lease (or, if there have been modifications, that this
Lease is in full force and effect as modified and stating the modifications,
and, if there are any defenses, offsets, counterclaims, or defaults, setting
them forth in reasonable detail); and the dates to which the Annual Base Rent,
additional rent and other charges have been paid. Any such statement delivered
pursuant to this Section 10.10 shall be in a form reasonably acceptable to and
may be relied upon by any prospective purchaser or mortgagee of premises which
include the Premises or any prospective assignee of any such mortgagee.


10.10  WAIVER OF SUBROGATION.

       Any insurance carried by either party with respect to the Premises and
property therein or occurrences thereon shall include a clause or endorsement
denying to the insurer rights of subrogation against the other party to the
extent rights have been waived by the insured prior to occurrences of injury or
loss. Each party, notwithstanding any provisions of this Lease to the contrary,
hereby waives any rights of recovery against the other for injury or loss due to
hazards covered by insurance containing such clause or endorsement to the extent
of the indemnification received thereunder.


10.11  ACTS OF GOD.

       In any case where either party hereto is required to do any act, delays
caused by or resulting from Acts of God, war, civil commotion, fire, flood or
other casualty, labor difficulties, shortages of labor, materials or equipment,
government regulations, unusually severe weather, or other causes beyond such
party's reasonable control shall not be counted in determining the time during
which work shall be completed, whether such time be designated by a fixed date,
a fixed time or a "reasonable time", and such time shall be deemed to be
extended by the period of such delay.




                                       44
<PAGE>   45

10.12  BROKERAGE.

       Tenant and Landlord represent and warrant that they dealt with no brokers
in connection with this transaction other than the Brokers and agree to defend,
with counsel approved by the other, indemnify and save the other harmless from
and against any and all cost, expense or liability for any compensation,
commissions or charges claimed by a broker or agent claiming through the
indemnitor, other than the Brokers in connection with this Lease. Landlord
hereby agrees to pay the brokerage fees to the Brokers in connection with the
execution and delivery of this Lease.


10.13  SUBMISSION NOT AN OFFER.

       The submission of a draft of this Lease or a summary of some or all of
its provisions does not constitute an offer to lease or demise the Premises, it
being understood and agreed that neither Landlord nor Tenant shall be legally
bound with respect to the leasing of the Premises unless and until this Lease
has been executed by both Landlord and Tenant and a fully executed copy has been
delivered to each of them.


10.14  APPLICABLE LAW AND CONSTRUCTION.

       This Lease shall be governed by and construed in accordance with the laws
of the state in which the Premises are located. If any term, covenant, condition
or provision of this Lease or the application thereof to any person or
circumstances shall be declared invalid or unenforceable by the final ruling of
a court of competent jurisdiction having final review, the remaining terms,
covenants, conditions and provisions of this Lease and their application to
persons or circumstances shall not be affected thereby and shall continue to be
enforced and recognized as valid agreements of the parties, and in the place of
such invalid or unenforceable provision, there shall be substituted a like, but
valid and enforceable provision which comports to the findings of the aforesaid
court and most nearly accomplishes the original intention of the parties.

       There are no oral or written agreements between Landlord and Tenant
affecting this Lease. This Lease may be amended, and the provisions hereof may
be waived or modified, only by instruments in writing executed by Landlord and
Tenant.

       The titles of the several Articles and Sections contained herein are for
convenience only and shall not be considered in construing this Lease.

       Unless repugnant to the context, the words "Landlord" and "Tenant"
appearing in this Lease shall be construed to mean those named above and their
respective heirs, executors, 




                                       45
<PAGE>   46

administrators, successors and assigns, and those claiming through or under them
respectively. If there be more than one tenant, the obligations imposed by this
Lease upon Tenant shall be joint and several.


10.15  AUTHORITY

       Each of Landlord and Tenant represents and warrants to the other party
(which representations and warranties shall survive the delivery of this Lease)
that: (a) such party (i) is duly organized, validly existing and in good
standing under the laws of its state of incorporation, (ii) has the corporate
power and authority to carry on businesses now being conducted and is qualified
to do business in every jurisdiction where such qualification is necessary and
(iii) has the corporate power to execute and deliver and perform its obligations
under this Lease and (b) the execution, delivery and performance by such party
of its obligations under this Lease have been duly authorized by all requisite
corporate action and will not violate any provision of law, any order of any
court or other agency of government, the corporate charter or by-laws of the
such party or any indenture, agreement or other instrument to which it is a
party or by which it is bound.

10.16  SECURITY DEPOSIT

       Upon execution of the Lease, Tenant shall provide to Landlord either a
cash deposit in the amount of the Security Deposit, or, at Tenant's election, an
irrevocable and unconditional standby documentary letter of credit in the amount
of the Security Deposit (in either case, the "Security Deposit") issued by a
bank or other institution satisfactory to Landlord in its sole discretion,
naming Landlord, its successors and assigns as the beneficiary, expiring no less
than one (1) year from the Term Commencement Date and renewing automatically
each year (or at the end of the applicable term thereof) unless the issuing bank
has given Landlord notice at least 45 days prior to expiration that the same
will not be renewed, and otherwise in form and substance satisfactory to
Landlord in its sole discretion (the "Letter of Credit"). Landlord shall be
permitted to draw upon the Security Deposit, whether in the form of cash or
Letter of Credit, in the event of (i) default by Tenant in the payment of Annual
Rent or additional rent or otherwise in any obligation hereunder beyond all
applicable cure periods, in which event Landlord may draw upon all or a portion
of the Security Deposit and apply the proceeds as described below, or (ii)
failure by Tenant to provide to Landlord either a cash deposit in the amount of
the Security Deposit or a replacement or substitute Letter of Credit in the
amount of the Security Deposit, as the same may reduce as set forth below, and
otherwise subject to the conditions set forth above, no less than thirty (30)
days prior to the expiration date of the Letter of Credit then held by Landlord,
in which event Landlord may 




                                       46
<PAGE>   47

draw upon all of the Letter of Credit and, in such event, shall hold the cash
proceeds thereof as the Security Deposit hereunder. If the Security Deposit is
provided to or held by Landlord in cash, and the same is not the result of a
default by Tenant, it shall be held in an interest-bearing account to be
selected by Landlord in its sole discretion, with interest to be added to the
Security Deposit, and to be deemed a part of the Security Deposit. If the
Security Deposit is held by Landlord in cash as the result of a default by
Tenant, the Security Deposit shall be held in an account to be selected by
Landlord in its sole discretion, with no interest thereon to Tenant, and may be
commingled with other funds of Landlord.

       The Security Deposit is being delivered by Tenant to Landlord as security
for the faithful performance and observance by Tenant of the terms, provisions
and conditions of this Lease. It is understood and agreed that if any default by
Tenant occurs hereunder and continues beyond all applicable cure periods,
Landlord may (but shall not be required to) use, apply or retain the whole or
any part of the Security Deposit so deposited to the extent required for payment
of any sum as to which Tenant is in default beyond applicable cure periods, if
any, or for any sum which Landlord may expend or may be required to expend by
reason of any default by Tenant hereunder beyond applicable cure periods, if
any, including, but not limited to, any damage or deficiency accrued before or
after summary proceedings or other reentry by Landlord. Any cash portion of the
Security Deposit not so applied shall be held by Landlord as further security
hereunder. It is agreed that Landlord shall always have the right (but not the
obligation) to apply the Security Deposit or any part thereof, as aforesaid,
without prejudice to any other remedy or remedies which Landlord may have, or
Landlord may pursue any other such remedy or remedies in lieu of applying the
Security Deposit or any part thereof.

       Provided that on each date on which the Security Deposit would otherwise
be reduced in accordance with the provisions hereof, Tenant is not then in
default of any of its obligations under the Lease beyond any applicable cure
period provided for herein, or if any condition exists which with the giving of
notice, or the passage of time, or both, would constitute a default exists, if
such condition is not removed or corrected within the applicable cure period, if
any, then the Security Deposit shall be reduced to (a) $250,860.76 on the first
anniversary of the Term Commencement Date, (b) $196,807.60 on the second
anniversary of the Term Commencement Date and (c) $137,944.79 on the third
anniversary of the Term Commencement Date; provided, however, that in the event
(i) Tenant shall be in default of any of its obligations under the Lease beyond
any applicable cure period provided for herein on any date on which the Security
Deposit would otherwise be reduced hereunder, or Tenant does not so remove or
correct any such condition which exists on any such date within the applicable
cure period, if any, or (ii) Landlord has drawn upon 




                                       47
<PAGE>   48

the Security Deposit to cure a default of Tenant and Tenant has not restored the
Security Deposit to the required amount prior to a scheduled reduction in the
amount of the Security Deposit, then in either of such events there shall be no
further reductions in the Security Deposit hereunder. If a condition exists on
any date on which the Security Deposit would otherwise be reduced hereunder
which with the giving of notice, or the passage of time, or both, would
constitute an event of default hereunder, and Tenant removes or corrects such
condition within the applicable cure period, if any, then the Security Deposit
shall be reduced in accordance with the foregoing within ten (10) days of the
completion of such cure. If the Security Deposit is given in the form of a
Letter of Credit, the Letter of Credit shall by its terms provide that scheduled
reductions in the amount of the Letter of Credit shall themselves be
ineffective, as provided above, pursuant to instructions from Landlord to the
issuer of the Letter of Credit, provided, however, that upon Tenant's cure of
all defaults and restoration of the Security Deposit, if applicable, on or
before the date of a scheduled reduction in the amount of the Security Deposit,
or upon removal or correction of a condition which with the giving of notice, or
the passage of time, or both, would constitute an event of default on or before
the expiration of the applicable cure period, if any, Landlord shall direct the
issuer of the Letter of Credit to allow the scheduled reduction in the amount of
the Letter of Credit to occur. In the event the Security Deposit consists partly
of cash and partly of a letter of credit, the reductions contemplated hereunder
shall be made from the cash portion first until the same has been fully
disbursed and thereafter shall be effected under the Letter of Credit.

       If Landlord shall apply the Security Deposit or any part thereof, as
aforesaid, Tenant shall upon demand pay to Landlord an amount of cash or restore
the Letter of Credit to the amount required prior to such application or deliver
to Landlord a replacement Letter of Credit in such amount in order, in all
cases, to restore the Security Deposit to the amount required prior to such
application. The Security Deposit, if any, or any balance thereof after
application of the Security Deposit to uncured defaults of Tenant, shall be
returned to Tenant within 30 days after the expiration of the Lease Term or
termination of the same and after delivery of possession of the entire Premises
to Landlord.

       In the event of a sale or other transfer of the Premises or leasing of
the Premises, Landlord shall transfer the Security Deposit to the grantee,
transferee or lessee and upon acceptance and assumption by such grantee,
transferee or lessee of the Security Deposit and Landlord's obligations
hereunder, Landlord shall be released by Tenant from any and all liability with
respect to the Security Deposit, its application and return, and Tenant agrees
in such case to look solely to the grantee, transferee or lessee. It is further
understood that the provisions of the immediately preceding sentence shall also




                                       48
<PAGE>   49

apply to subsequent grantees, transferees and lessees. Tenant covenants that it
will not assign or encumber nor attempt to assign or encumber the Security
Deposit and that neither Landlord nor its successors or assigns shall be bound
by any such assignment, encumbrance, attempted assignment or attempted
encumbrance. Any assignment or encumbrance of the Security Deposit by Tenant
shall be null and void and without force or effect at law or in equity.

       EXECUTED as a sealed instrument in two or more counterparts on the day
and year first above written.

                                             LANDLORD:

                                             CONNECTICUT GENERAL LIFE INSURANCE
                                             COMPANY

                                             By:  CIGNA Investments, Inc.



                                                  By:  /s/ James H. Rogers
                                                       ------------------------
                                                       Its: Managing Director

 
                                             TENANT:

                                             MEDIA 100 INC.



                                             By:   /s/ John A. Molinari
                                                   ------------------------
                                                   Name: John A. Molinari
                                                   Title: President
                                                   Hereunto duly authorized

                                             A copy of Tenant's corporate
                                             authorization for such execution is
                                             attached hereto.












                                       49