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EXHIBIT 10.21

COMMERCIAL LEASE AGREEMENT

Jackson Shaw Technology Center II
Limited Partnership

to

Testchip Technologies, Inc.

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TABLE OF CONTENTS

1.   LANDLORD   3 2.   TENANT   3 3.   LEASED PREMISES   3 4.   TERM   3 5.  
BASE RENT AND SECURITY DEPOSIT   4 6.   ADDITIONAL RENTAL   5 7.   TENANT
REPAIRS AND MAINTENANCE   7 8.   LANDLORD'S REPAIRS   8 9.   UTILITY SERVICE   8
10.   SIGNS   8 11.   USAGE   8 12.   INSURANCE   9 13.   RELOCATION   9 14.  
COMPLIANCE WITH LAWS, RULES AND REGULATIONS   9 15.   ASSIGNMENT AND SUBLETTING
  9 16.   ALTERATIONS AND IMPROVEMENTS   10 17.   CONDEMNATION   11 18.   FIRE
AND CASUALTY   12 19.   CASUALTY INSURANCE   13 20.   WAIVER OF SUBROGATION   13
21.   HOLD HARMLESS   13 22.   QUIET ENJOYMENT   13 23.   LANDLORD'S RIGHT OF
ENTRY   13 24.   ASSIGNMENT OF LANDLORD'S INTEREST IN LEASE   14 25.   LANDLORDS
LIEN   14 26.   DEFAULT BY TENANT   14 27.   REMEDIES FOR TENANT'S DEFAULT   14
28.   TERMINATION OF OPTIONS   15 29.   WAIVER OF DEFAULT OR REMEDY   16 30.  
CHOICE OF LAW; VENUE; ATTORNEY'S FEES   16 31.   HOLDING OVER   16 32.   RIGHTS
OF MORTGAGEE   17 33.   ESTOPPEL CERTIFICATES   17 34.   SUCCESSORS   17 35.  
REAL ESTATE COMMISSION   18 36.   DEFAULT BY LANDLORD   18 37.   MECHANIC'S
LIENS   18 38.   HAZARDOUS WASTE   18 39.   ENTIRE AGREEMENT AND LIMITATION OF
WARRANTIES   19 40.   FINANCIAL STATEMENTS   19 41.   FORCE MAJEURE   19 42.  
MISCELLANEOUS   20 43.   NOTICE   21 44.   LIMITATION ON TENANT'S DAMAGES   21

EXHIBITS:

Exhibit A—Legal Description
Exhibit B—Tenant Improvements
Exhibit C—Sign Criteria
Exhibit D—Rules & Regulations
Exhibit E—Renewal Option
Exhibit F—Expansion Right of First Refusal

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COMMERCIAL LEASE AGREEMENT

        THIS LEASE AGREEMENT is entered into by and between:

        1.    LANDLORD:    Jackson-Shaw Technology Center II Limited Partnership

        2.    TENANT:    TestChip Technologies, Inc.

        3.    LEASED PREMISES:    In consideration of the rents, terms and
covenants of this Commercial Lease Agreement (this "Lease"), Landlord hereby
leases to Tenant certain premises (the "Leased Premises") consisting of
approximately 18,302 square feet within the 83,286 square foot building (the
"Building") located at 2600 Technology Drive, Suite 600, Plano, Texas, 75074,
together with the non-exclusive light to use, in common with other tenants, the
common areas of the Project, which are all areas neither exclusively leased to
another tenant nor expressly reserved to or by Landlord. The land upon which the
Building is located is described in the attached Exhibit A and, together with
the Building, landscaping, parking and driveway areas, sidewalks, and other
improvements thereon, shall be referred to in this Lease as the "Project."

        4.    TERM:    

        (a)  The term of this Lease shall be 66 months commencing on August 1,
2000, the "Commencement Date" and terminating on the last day of the 66th month
following the Commencement Date (the "Termination Date"). This Commencement Date
may be subject to change, however, pursuant to Paragraph 4(c) below.

        (b)  Tenant acknowledges that it accepts the Leased Premises as suitable
for Tenant's purposes subject only to Paragraph 4(c) below, if applicable. If
this Lease is executed before the Leased Premises become available for
occupancy, or if Landlord cannot acquire possession of the Leased Premises prior
to the Commencement Date stated above, Tenant agrees to accept possession of the
Leased Premises at such time as Landlord is able to tender the same, which date
shall then be the Commencement Date of the Lease term.

        (c)  Landlord agrees to install at its cost and expense the
improvements, if any, described in the plans and specifications described in
Exhibit B. If such improvements are not completed and the Leased Premises are
not ready for occupancy on the Commencement Date stated above, other than as a
result of the omission, delay or default by Tenant or anyone acting under or on
behalf of Tenant, the rent under this Lease shall not commence until substantial
completion of the work described in said plans and specifications, and the
Commencement Date of the Lease term shall be the date of such substantial
completion and Tenant secures Certificate of Occupancy. Landlord shall notify
Tenant in writing as soon as such improvements are substantially completed and
ready for occupancy. If Tenant believes that such improvements have not been
substantially completed as aforesaid, Tenant shall notify Landlord in writing of
its objections within three (3) days after receipt of the completion notice from
Landlord. Landlord shall have a reasonable time after receipt of such notice
(but in no event more than 10 days) in which to commence such corrective action
as may be necessary and shall notify Tenant in writing as soon as it deems such
corrective action has been completed so that the Leased Premises are completed
and ready for occupancy. In the event of any dispute as to substantial
completion or work performed or required to be performed by Landlord, the
certificate of a registered architect shall be conclusive and binding on all
parties.

        (d)  Tenant acknowledges that no representations or promises regarding
construction, repairs, alterations, remodeling, or improvements to the Leased
Premises have been made by Landlord, its agents, employees, or other
representatives, unless such are expressly set forth in this Lease or any
Exhibit hereto. Tenant is solely responsible for applying for and obtaining a
Certificate of Occupancy for the Leased Premises and will satisfy itself as to
the business park restrictions and all zoning and similar restrictions and
regulations prior to commencement of any construction. Failure of Tenant to
provide written notice of such objections prior to commencement of construction
shall be deemed

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acceptance by Tenant. Tenant agrees that if its occupancy of the Leased Premises
is delayed under the circumstances described in Paragraphs 4(b) and (c) above,
this Lease shall nonetheless continue in full force and effect. Adjustment of
the rent commencement date as above provided shall constitute full settlement of
all claims by Tenant against Landlord by reason of any such delay in possession
of the Leased Premises. Tenant's taking possession of the Leased Premises shall
conclusively establish that the improvements, if any, to be made by Landlord
under the terms of this Lease have been completed in accordance with the plans
and specifications therefor and that the Leased Premises are in good and
satisfactory condition as of the date of Tenant's possession, unless Tenant
notifies Landlord in writing specifying any bona fide deficiencies after taking
possession. Landlord shall use reasonable diligence to repair promptly such
items but Tenant shall have no claim for damages or rebate or abatement of rent
by reason thereof. In conjunction with, or at any time after, the Commencement
Date, Tenant shall, upon demand, execute and deliver to Landlord an Estoppel
letter (as referred to in paragraph 33 herein) to acknowledge the Commencement
Date.

        5.    BASE RENT AND SECURITY DEPOSIT:    

        (a)  Tenant agrees to pay to Landlord the following rental amounts
(sometimes referred to in this Lease as the "Base Rent" or "Base Rental"):
months 1 and 4 through 6, $155,568.00 per year payable in monthly installments
of $12,964.00 each, Months 7-66, $205,908.00 per year payable in monthly
installments of $17,159.00 each. Landlord agrees to waive months 2 and 3 of the
primary Lease Term. Payment of rent is subject to proration for partial months
and to adjustment for early or delayed occupancy under the terms hereof, and, if
the area of the Leased Premises is, on the Commencement Date, different than the
area stated in Paragraph 3 above, then Base Rent shall be adjusted to reflect
the then applicable per square foot rate. On the commencement date of the Lease
Agreement the first month's Base Rent shall be payable. All subsequent payments
shall be made to Landlord monthly, in advance, without demand, deduction or
offset, in lawful money of the United States of America at the address stated
below. All installments of Base Rent shall be due and payable on or before the
first (1st) day of each month during the Lease term.

        (b)  Upon the date Tenant executes the Lease Agreement, there shall be
due and payable by Tenant a Security Deposit in the amount of $17,159.00. Such
deposit shall be held by Landlord (without any obligation to pay interest
thereon or segregate such money from Landlord's general funds except as may be
required by applicable law) as security for the performance of Tenant's
obligations under this Lease. Tenant agrees to increase such Security Deposit
from time to time so that it is at all times equal to one monthly Base Rental
installment plus the average monthly additional rentals arising pursuant to
Paragraph 6 below.

        Tenant shall deposit cash with Landlord in an amount sufficient so to
increase the Security Deposit to such amount within five (5) days after written
demand by Landlord. It is expressly understood that the Security Deposit is not
an advance payment of rental or a measure of Landlord's damages in the event of
Tenant's default under this Lease. Upon the occurrence of any event of default
by Tenant under this Lease, Landlord may, from time to time, without prejudice
to any other remedy provided herein or provided by law, use, apply, or retain
all or part of the Security Deposit for the payment of (i) any Base Rent,
(ii) additional rentals arising under Paragraph 6 below, and (iii) other sums
due hereunder, including without limitation any amount which Landlord may spend
or become obligated to spend by reason of Tenant's default or to compensate
Landlord for any damage, injury, expense or liability caused to Landlord by such
default or breach (all of which items (i), (ii) and (iii) are sometimes referred
to in the aggregate as "Rent"). If any portion of the Security Deposit is so
used or applied, Tenant shall, within five (5) days after written demand
thereof, deposit cash with Landlord in an amount sufficient to restore the
Security Deposit to the amount required by this Paragraph. Tenant's failure to
do so shall be an event of default under this Lease. The balance of the Security
Deposit shall be returned by Landlord to Tenant at such time after termination
of this Lease that all of Tenant's obligations have been fulfilled.

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        (c)  Other remedies for nonpayment of Rent notwithstanding, if the
monthly Base Rental payment is not received by Landlord on or before the tenth
(10th) day of the month for which such rent is due, or if any other Rent payment
due Landlord by Tenant hereunder is not received by Landlord within ten
(10) days of the due date, a service charge of two hundred ($200.00) dollars
shall be additionally due and payable by Tenant as an administrative charge for
the excess efforts necessitated by such tardiness in payment. Such service
charge shall be cumulative of any other remedies Landlord may have for
nonpayment of Rent and other sums payable under this Lease.

        (d)  If three (3) consecutive monthly Base Rental payments or any ten
(10) [in total, cumulative from the beginning of the Lease term] monthly Base
Rental payments during the Lease term (or any renewal or extension thereof) are
not received by Landlord within ten (10) days of the due date, the Base Rent
hereunder shall automatically become due and payable by Tenant in advance in
quarterly installments equal to three (3) months' Base Rent each. The first of
such quarterly Base Rent payments shall be due and payable on the first day of
the next succeeding month and on the first day of every third (3rd) month
thereafter. This remedy shall be cumulative of any other remedies of Landlord
under this Lease for nonpayment of Rent.

        6.    ADDITIONAL RENTAL:    

        (a)    Taxes and Insurance:    

        (1)  "Tax and Insurance Costs" shall mean all of the following paid or
payable by Landlord with respect to the Project or any portion thereof: (i) all
federal, state and local sales, use, ad valorem, rental, value added, and other
taxes (other than Landlord's income or franchise taxes) and special assessments
and other governmental charges; and (ii) all insurance premiums, including,
without limitation, public liability, casualty, rental and property damage
insurance.

        (2)  Landlord shall pay all Tax and Insurance Costs; however, Landlord
may in its discretion defer such payment to the extent permitted by applicable
laws so long as contested by Landlord in good faith and so long as Tenant's
occupancy of the Premises is not lawfully disturbed.

        (3)  For each calendar year of the term of this Lease, Tenant shall pay
to Landlord as additional Rent hereunder its "pro rata portion" of the Tax and
Insurance Costs computed by multiplying the Tax and Insurance Costs by a
fraction, the numerator of which is the number of rentable square feet in the
Leased Premises, and the denominator of which is the number of rentable square
feet in the Building.

        (4)  Along with the Base Rent Tenant shall pay one-twelfth of' its pro
rata portion of Tax and Insurance Costs as estimated from time to time by
Landlord, during the term of this Lease. As soon as available after the
expiration of each calendar year during the term of this Lease, Landlord shall
submit a reconciliation statement to Tenant setting forth (i) Tenant's pro rata.
portion of the Tax and Insurance Costs due from Tenant for the preceding
calendar year, (ii) the amount of Tax and Insurance Costs paid by Tenant during
such calendar year, and (iii) the amount, if any, either overpaid or remaining
due from Tenant to Landlord. Within (10) days after receipt of such statement,
Tenant shall remit to Landlord the amount said statement shows to be due from
Tenant or, if Tenant has overpaid, Landlord shall credit the amount overpaid to
Tenant's pro rata portion of Tax and Insurance Costs next due. If Tenant is not
in default and this Lease terminated at the end of such prior year, Landlord
shall refund such overpayment to Tenant.

        (5)  For the calendar years in which this Lease commences and
terminates, Tenant's liability for its pro rata portion of the Tax and Insurance
Costs for such partial calendar years shall be subject to pro rata adjustment
based upon the number of days of the term elapsing during such partial year.
Where the applicable charges are not available prior to the end of the term
hereof, then the aforesaid adjustment shall be made between Landlord and Tenant
after Landlord shall

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have received the charges for such period, it being specifically agreed that
Landlord's and Tenant's obligations under this Paragraph shall survive the
expiration of the term of this Lease.

        (6)  The failure of Landlord to exercise its rights hereunder to
estimate Tax and Insurance Costs and require payment of same as additional Rent
shall not constitute a waiver of such rights which rights may be exercised from
time to time at Landlord's discretion.

        (b)    Common Area Maintenance:    

        (1)  "Common Area Maintenance Expenses" shall mean any and all expenses
(other than the Tax and Insurance Costs described above) arising from the
maintenance, repair, replacement and operation of, and modifications and
improvements to comply with governmental mandate to, the Project's common areas
and any portions of the Project for which Landlord is responsible hereunder
(excluding only expenses associated with structural integrity of the roof,
foundation, and exterior walls) including, but not limited to, management fees,
utility expenses (if furnished by Landlord), wages and fringe benefits payable
to employees of Landlord whose duties are connected with the operation and
maintenance of the Project, amounts paid to contractors or subcontractors for
work or services performed in connection with the operation and maintenance of
the Project, including without limitation common areas and parking areas and
roof, exterior wall and foundation work that is not related to structural
integrity. Any capitalized expenditures included within the foregoing (together
with reasonable finance charges) will be amortized for purposes of this
Paragraph over the useful life of the improvement.

        (2)  The term "Common Area Maintenance Expenses" shall not include
repair, restoration or other work occasioned by fire, windstorm or other
casualty with respect to which Landlord actually receives insurance proceeds,
income and franchise taxes of Landlord, expenses incurred in leasing to or
procuring of tenants, leasing commissions, advertising expenses, expenses for
the renovating of space for new tenants, interest or principal payments or any
mortgage or other indebtedness of Landlord, compensation paid to any employee of
Landlord above the grade of building superintendent, or depreciation allowance
or expense.

        (3)  Tenant agrees to pay as additional Rent its pro rata portion (as
defined in Paragraph 6(a)(3) above) of the Common Area Maintenance Expenses.
Along with the Base Rent Tenant shall pay one-twelfth of its pro rata portion of
Common Area Maintenance Expenses as estimated from time to time by Landlord,
during the term of this Lease. As soon as available after the expiration of each
calendar year during the term of this Lease, Landlord shall submit a statement
to Tenant setting forth (i) Tenant's pro rata portion of the Common Area
Maintenance Expenses due from Tenant for the preceding calendar year, (ii) the
amount of Common Area Expenses paid by Tenant during such calendar year, and
(iii) the amount, if any, either overpaid or remaining due from Tenant to
Landlord. Within ten (10) days after receipt of such statement, Tenant shall
remit to Landlord the amount said statement shows to be due from Tenant or, if
Tenant has overpaid, Landlord shall credit the amount overpaid to Tenant's pro
rata portion of Common Area Maintenance Expenses next due. Landlord agrees to
provide a cap on controllable expenses including but not limited to management
fees, landscape maintenance, general maintenance and insurance of six percent
(6%) per year. If Tenant is not in default and this Lease terminated at the end
of such prior year, Landlord shall refund such overpayment to Tenant.

        (4)  For the calendar years in which this Lease commences and
terminates, Tenant's liability for its pro rata portion of the Common Area
Maintenance Expenses for such partial calendar years shall be subject to pro
rata adjustment based upon the number of days of the term elapsing during such
partial year. Where the applicable expenses are not available prior to the end
of the term hereof, then the aforesaid adjustment shall be made between Landlord
and Tenant after Landlord shall have received. all of the expenses for such
period, it being specifically agreed that

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Landlord's and Tenant's obligations under this Paragraph shall survive the
expiration of the term of this Lease.

        (5)  The failure of Landlord to exercise its nights hereunder to
estimate expenses and require payment of same as additional Rent shall not
constitute a waiver of such rights which rights may be exercised from time to
time at Landlord's discretion.

        (c)  In any event, Tenant shall be responsible for insuring and paying
all taxes upon Tenant's furniture, machinery, goods, supplies, fixtures,
Alterations (below defined) or other improvements, and other property on the
Project.

        7.    TENANT REPAIRS AND MAINTENANCE:    

        (a)  Tenant shall maintain all parts of the Leased Premises and their
appurtenances (except those for which Landlord is expressly responsible under
this Lease) in good, clean and sanitary condition, at its own expense. Tenant
shall promptly make all necessary repairs and replacements to the Leased
Premises, including but not limited to electric light lamps or tubes, windows,
glass and plate glass, interior and exterior doors, any special office entry,
interior walls and finish work, floors and floor coverings, downspouts, gutters,
heating and air conditioning systems,, dock boards, truck doors, dock bumpers,
and plumbing work and fixtures. Replacement and repair parts, materials and
equipment shall be of quality equivalent to those initially installed within the
Leased Premises, and repair and maintenance work shall be done in a good and
workmanlike manner and in accordance with existing laws, rules, regulations and
ordinances.

        (b)  Tenant shall not damage or disturb the integrity, structural
integrity, or support of any wall, roof, or foundation of the Building. Any
damage to these areas caused by Tenant or Tenant's Representatives (defined in
Paragraph 7(g)) shall be promptly repaired by Tenant at its sole cost and
expense.

        (c)  Intentionally Deleted

        (d)  Tenant shall, at its own cost and expense, enter into a regularly
scheduled preventive maintenance service contract with a maintenance contractor
for servicing all heating, ventilation and air conditioning systems and
equipment within, and any other equipment or machinery installed by Landlord in,
or to serve, the Leased Premises. The maintenance contractor and the contract
are subject to Landlord approval which shall not be unreasonably withheld. The
service contract must include all services suggested by the equipment
manufacturer within the operation/maintenance manual and must become effective
(and a copy delivered to Landlord) within thirty (30) days of the date Tenant
takes possession of the Leased Premises. If Tenant fails to enter into such
service contract as required, Landlord shall have the right to do so on Tenant's
behalf, and Tenant agrees to pay Landlord the direct cost and direct expense of
same upon demand, and such amount shall be considered additional Rent.

        (e)  Tenant shall at its own expense keep the Leased Premises pest-free
and pay all charges for pest control and extermination within the Leased
Premises.

        (f)    At the termination of this Lease, Tenant shall deliver the Leased
Premises "broom clean" to Landlord in the same good order and condition as
existed at the Commencement Date of this Lease, ordinary wear, natural
deterioration beyond the control of Tenant, and damage by fire, tornado or other
casualty excepted. Tenant shall give written notice to Landlord at least thirty
(30) days prior to vacating the Leased Premises and shall arrange to meet with
Landlord for a joint inspection of the Leased Premises prior to vacating. In the
event of Tenant's failure to give such notice or arrange such joint inspection,
Landlord's inspection at or after Tenant's vacating the Leased Premises shall be
conclusively deemed correct for purposes of determining Tenant's responsibility
for repairs and restoration.

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        (g)  Not in limitation on the foregoing, it is expressly understood that
Tenant shall repair and pay for all damage caused by the negligence of Tenant,
Tenant's employees, officers, directors, partners, agents, invitees, licensees,
contractors, representatives, or others for whom Tenant is legally responsible
(all such persons and entities being herein collectively referred to as
"Tenant's Representatives") or caused by Tenant's default hereunder.

        (h)  If Landlord shall give Tenant written notice of defects or need for
repairs for which Tenant is responsible under this Lease, and if Tenant shall
fall to make same within 30 days of Landlord's written notification or such
shorter time as reasonable if expedited repair is needed to avoid injury or
damage, Landlord shall have the option to cure said defect or repair, and Tenant
shall pay to Landlord all costs and expenses incurred on demand.

        8.    LANDLORD'S REPAIRS:    

        (a)  Landlord shall be responsible, at its expense, for, but only for,
the structural integrity of the roof, foundation and exterior walls of the
Building. In further limitation on Landlord's responsibilities hereunder,
(i) any repair to the roof, foundation or exterior walls occasioned by the act
of omission of Tenant or Tenant's Representatives shall be the responsibility of
Tenant; (ii) the term "walls" as used in this Paragraph 8 shall not include
windows, glass or plate glass, interior doors, special store fronts, office
entries or exterior doors; and (iii) Landlord's liability with respect to any
defects, repairs or maintenance for which Landlord is responsible at its expense
under this Lease shall be limited to the cost of such repairs or maintenance or
the curing of such defect. Tenant shall promptly give Landlord written notice of
defects or need for repairs, after which Landlord shall have 30 days to commence
to repair or cure such defect.

        (b)  Landlord shall perform the work which gives rise to Common Area
Maintenance Expenses, subject to payment therefor by Tenant pursuant to the
provisions of Paragraph 6(b) above. If the need for any such work shall come to
the attention of Tenant, Tenant will promptly so notify Landlord in writing.

        9.    UTILITY SERVICE:    Tenant shall pay the cost of all utility
services including, but not limited to, initial connection charges and deposits
and all charges for gas, water, trash disposal, sewer, telephone or other
telecommunications, and electricity used on the Leased Premises. Tenant shall
pay all costs caused by Tenant introducing excessive pollutants into the
sanitary or storm sewer system, including permits, fees, assessments, and
charges levied by any governmental subdivision for any pollutants or solids
other than ordinary human waste.

        10.    SIGNS:    No sign, door plaques, advertisement, or notice shall
be displayed,. painted or affixed by Tenant on any part of the Project,
Building, parking facilities, or Leased Premises without prior written consent
of Landlord, not to be unreasonably withheld. The color, size, character, style,
material, placement and location and method of attachment to the Building shall
be subject to Landlord's approval, and to any applicable governmental laws,
ordinances, regulations, project specifications, and other requirements. Signs,
if approved by Landlord, shall be placed by a contractor approved by Landlord
and paid for by Tenant. Tenant shall remove all such signs at the termination of
this Lease. Such installations and removals shall be made in such manner as to
avoid injury or defacement of the Project and other improvements, and Tenant, at
its sole expense, shall repair any injury or defacement, including, without
limitation, any discoloration caused by such installation and/or removal.
Landlord may erect a sign or signs on the Leased Premises indicating that the
Leased Premises are for lease during the six (6) month period prior to the
expiration of this Lease.

        11.    USAGE:    Tenant warrants and represents to Landlord that the
Leased Premises shall be used and occupied only for the purpose of: general
office. Any change in the stated usage purposes shall be subject to the prior
written approval of Landlord not to be unreasonably withheld. Tenant shall
occupy the Leased Premises, conduct its business, and control Tenant's
Representatives in a lawful and reputable way and as not to create any nuisance.
Tenant shall not commit, or allow to be committed,

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any waste on the Leased Premises or the Project. Tenant may not use the Leased
Premises for the use, storage, or distribution of hazardous or environmentally
offensive substances, for underground storage, or for any unlawful purposes.

        12.    INSURANCE:    

        (a)  Tenant shall not permit the Leased Premises to be used in any way
which would be hazardous or which would in any way increase the cost of or
render void any insurance on the improvements, and Tenant shall immediately, on
demand, cease any use which violates the foregoing or to which Landlord's
insurer or any governmental or regulatory authority objects. If at any time
during the term of this Lease Tenant's use or vacancy shall cause an increase in
premiums, and in particular, but without limitation, if the State Board of
Insurance or other insurance authority disallows any of Landlord's sprinkler
credits or imposes an additional penalty or surcharge in Landlord's insurance
premiums because of Tenant's original or subsequent placement or use of storage
racks or bins or method of storage or because of the nature of Tenant's
inventory or any other act of Tenant, Tenant agrees to pay as additional Rent
the increase in Landlord's insurance premiums.

        (b)  Tenant, at its sole cost and expense, shall procure and maintain
throughout the term of this Lease a policy or policies of insurance insuring
Landlord, Landlord's management company and lender, and Tenant against all
claims for property damages, personal injury or death of others occurring on or
in connection with: (i) the Leased Premises; (ii) the condition of the Leased
Premises; (iii) Tenant's operations in and maintenance and use of the Leased
Premises; (iv) Tenant's and Tenant's Representatives' use of the common areas of
the Project, and (v) Tenant's liability assumed under this Lease. The limits of
such policy or policies shall be not less than $1,000,000.00 combined single
limit coverage per occurrence for injury to persons (including death) and/or
property damage or destruction, including loss of use.

        (c)  All such policies shall be procured by Tenant from insurance
companies satisfactory to Landlord naming the following as co-insureds:
(i) Landlord; (ii) Landlord's management company, Jackson-Shaw Company; and,
(iii) Landlord's mortgage holder, if any. Certified copies of such policies
together with receipt for payment of premiums, shall be delivered to Landlord
prior to the Commencement Date of this Lease. Not less than fifteen (15) days
prior to the expiration date of any such policies, certified copies of renewal
policies and evidence of the payment of renewal premiums shall be delivered to
Landlord. All such original and renewal policies shall provide for at least
thirty (30) days written notice to Landlord before such policy may be canceled
or changed to reduce insurance coverage provided thereby. Upon request of
Landlord, Tenant further agrees to complete and return to Landlord an insurance
questionnaire (such form to be provided by Landlord) regarding Tenant's
insurance coverage and intended use of the Leased Premises. Tenant warrants and
represents that all information contained in such questionnaire shall be true
and correct as of the date thereof and shall be updated by Tenant from time to
time upon Landlord's request.

        13.    Intentionally Deleted    

        14.    COMPLIANCE WITH LAWS, RULES AND REGULATIONS:    Tenant shall
comply with all applicable laws, ordinances, orders, rules and regulations of
state, federal, municipal, or other agencies or bodies relating to, the use,
condition and occupancy of and business conducted on the Leased Premises,
including without limitation, the Americans with Disabilities Act, the Resource
Conservation and Recovery Act, the Comprehensive Environmental Response Act, and
the rules, regulations and directives of the U.S. Environmental Protection
Agency.

        15.    ASSIGNMENT AND SUBLETTING:    The Tenant agrees not to assign,
transfer, or mortgage this Lease or any right or interest therein or sublet the
Leased Premises or any part thereof, without the prior written consent of
Landlord such consent not to be unreasonably withheld. No assignment or
subletting shall relieve Tenant of its obligations hereunder, and Tenant shall
continue to be liable as a principal (and not as a guarantor or surety) to the
same extent as though no assignment or subletting

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had been made. Consent by Landlord to any one assignment or subletting shall not
be construed to be consent to any additional assignment or subletting. Each such
successive act shall require similar consent of Landlord. Landlord shall be
reimbursed by Tenant for any costs or expenses incurred as a result of Tenant's
request for consent to any such assignment or subletting, including legal costs
not to exceed $800.00. In the event Tenant subleases the Leased Premises, or any
portion thereof, or assigns this Lease with the consent of the Landlord at an
annual Base Rental exceeding that stated herein, such excess shall be paid by
Tenant to Landlord as additional Rent hereunder within ten (10) days after
receipt by Tenant. Upon the occurrence of an "event of default" as defined
below, if all or any part of the Leased Premises is then assigned or sublet,
Landlord may, in addition to any other remedies provided by this Lease or
provided by law, collect directly from the assignee or subtenant all rents due
to Tenant. Landlord shall have a security interest in all property on the Leased
Premises to secure payment of such sums. Any collection directly by Landlord
from the assignee or subtenant shall not be construed, however, to constitute a
novation or a release of Tenant from the further performance of its obligations
under the Lease. Notwithstanding the foregoing, it is expressly agreed that if
this Lease is assigned to any person or entity pursuant to the provisions of the
Bankruptcy Code, 11 U.S.C. Sec. 101, et. seq., as amended (the "Bankruptcy
Code"), any and all monies or other considerations payable or otherwise to be
delivered in connection with such assignment shall be paid or delivered to
Lessor, shall be and remain the exclusive property of Landlord and shall not
constitute property of Tenant or of the estate of Tenant within the meaning of
the Bankruptcy Code. Any and all monies or other considerations constituting
Landlord's Property under the preceding sentence not paid or delivered to
Landlord shall be held in trust for the benefit of Landlord and be promptly paid
or delivered to Landlord. Any person or entity to which this Lease is assigned
pursuant to the provisions of the Bankruptcy Code shall be deemed without
further act or deed to have assumed all of the obligations arising under this
Lease on and after the date of such assignment. Any such assignee shall upon
demand execute and deliver to Landlord an instrument confirming such assumption.

        16.    ALTERNATIONS AND IMPROVEMENTS:    

        (a)  Tenant shall not make or perform, or permit the making or
performance of, any initial or subsequent tenant finish work or any alterations,
installations, decorations, improvements, additions or other physical changes in
or about the Leased Premises that are structural in nature or exceed $5000.00 in
costs (referred to collectively as "Alterations") without Landlord's prior
consent, such consent not to be unreasonably withheld. Landlord shall be under
no obligation to allow Alterations of any kind and may withhold its consent
without cause. Notwithstanding the foregoing provisions or Landlord's consent to
any Alterations, all Alternations shall be made and performed in conformity with
and subject to the following provisions: All Alternations shall be made and
performed at Tenant's sole cost and expense in a good and workmanlike manner.
Alternations shall be made only by contractors or mechanics approved by
Landlord, such approval not to be unreasonably withheld. Tenant shall submit to
Landlord detailed plans and specifications (including architectural layout,
mechanical and structural drawings) for each proposed Alteration and shall not
commence any such Alteration without first obtaining Landlord's written approval
of such plans and specifications. Prior to the commencement of each proposed
Alteration, Tenant shall furnish to Landlord a certificate evidencing worker's
compensation insurance coverage for all persons to be employed in connection
with such Alterations, including those to be employed by all contractors and
subcontractors, and of comprehensive public liability insurance (including
property damage coverage) in which Landlord, its agents, and any lessor under
any ground or underlying lease, and any mortgagee of the Building shall be named
as parties insured, which policies shall be issued by companies and shall be in
form and amounts satisfactory to Landlord and shall be maintained by Tenant
until the completion of such Alteration. Tenant shall cause its contractor and
each subcontractor to provide Landlord with a Certificate of Completion of the
Alterations and a Bills Paid Affidavit and full Lien Waiver. Tenant shall, if
required by Landlord at the time of Landlord's consent to the Alterations, agree
to restore the Leased Premises at the termination of this Lease to their
condition prior to making such Alterations. All permits, approvals and
certificates

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required by all governmental authorities shall be timely obtained by Tenant and
submitted to Landlord. Notwithstanding Landlord's approval of plans and
specifications for any Alterations, all Alterations shall be made and performed
in full compliance with all applicable laws, orders, rules, standards and
regulations of Federal, State, County, and Municipal authorities, including,
without limitation, all directions, pursuant to law, of all public officers, and
with all applicable rules, orders, regulations and requirements of the local
Board of Fire Underwriters or any similar body ("Applicable Laws"). Landlord's
approval shall not in any way be considered an indication that the plans and
specifications comply with Applicable Laws. All materials and equipment to be
incorporated in the Leased Premises as a result of all Alterations shall be new
and first quality. No such materials or equipment shall be subject to any lien,
encumbrance, chattel mortgage or title retention or security agreement. Whether
such Alterations are being performed by Tenant in connection with Tenant's
initial occupancy of the Leased Premises or subsequently, Tenant agrees to make
proper application for, and obtain, a Building Permit and a Certificate of
Occupancy from the city in which the Leased Premises are located. Tenant shall
furnish copies of such permit and certificate to Landlord promptly after
issuance of same.

        (b)  All appurtenances, fixtures, improvements, and other property
attached to or installed in the Leased Premises, whether by Landlord or Tenant
or others, and whether at Landlord's expense or Tenant's expense, or the joint
expense of Landlord and Tenant, shall be and remain the property of Landlord,
except that any such fixtures, improvements, additions, and other property which
have been installed at the sole expense of Tenant and which are removable
without material damage to the Leased Premises shall be and remain the property
of Tenant. If no event of default has occurred, Tenant may, and if Landlord so
elects Tenant shall, remove any property belonging to Tenant at the end of the
term hereof, and Tenant shall repair or, at Landlord's option, shall pay to
Landlord the cost of repairing any damage arising from such removal. Any
replacements of any property of Landlord, whether made at Tenant's expense or
otherwise, shall be and remain the property of Landlord.

        17.    CONDEMNATION:    

        (a)  If, during the term (or extension or renewal) of this Lease, all or
a. substantial part of the Leased Premises are taken for any public or
quasi-public use under any governmental law, ordinance or regulation, or by
right of eminent domain or by private purchase in lieu thereof, and the taking
would prevent or materially interfere with the then current use of the Leased
Premises, this Lease shall terminate and the Rent shall be prorated during the
unexpired portion of this Lease effective on the date physical possession is
taken by the condemning authority.

        (b)  If a portion of the Leased Premises is taken and this Lease is not
terminated as provided in Paragraph 17(a) above, if condemnation proceeds are
sufficient and if restoration is feasible, Landlord may, at its option restore
the Project (other than Alterations) in order to make it reasonably tenantable
and suitable for Tenant's approved use. During such restoration, Rent shall be
reduced by the amount of business or rent interruption insurance proceeds
actually received by Landlord. Upon completion of such restoration, the Rent
payable under this Lease during the unexpired portion of the term shall be
adjusted to such an extent as may be fair and reasonable under the
circumstances.

        (c)  In the event of such taking or private purchase in lieu thereof,
Tenant may seek a separate award for any loss of improvements made or paid for
by Tenant, its personal property, and its moving expenses (so long as no such
claim diminishes Landlord's claim or award), but all other claims of any nature
shall belong to Landlord. In the event Tenant does not receive such a separate
award, Landlord shall be entitled to receive any and all sums awarded for the
taking.

        (d)  Notwithstanding anything herein to the contrary, if the holder of
any indebtedness secured by a mortgage or deed of trust covering the Building
and/or Project requires that the condemnation proceeds be applied to such
indebtedness, then Landlord shall have the right to terminate this Lease by
delivering written notice of termination to Tenant within fifteen (15) days
after such requirement is imposed. All rights and obligations under this Lease
shall then cease. If Landlord does not receive

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condemnation proceeds sufficient for restoration (such as when its mortgagee
does not allow the proceeds to be used for such purposes) and if restoration is
economically reasonably feasible, Tenant will have the option of supplementing
available proceeds to allow restoration, and Tenant's actual costs will be
reimbursed through a monthly prorata credit against rent beginning after
Landlord's mortgage has been paid in full.

        18.    FIRE AND CASUALTY:    

        (a)  If the Building should be damaged or destroyed by fire, tornado, or
other casualty, Tenant shall give immediate verbal and written notice thereof to
Landlord.

        (b)  If the Building should be totally destroyed by fire, tornado, or
other casualty, or if it should be so damaged thereby that rebuilding or repairs
cannot reasonably be completed within one hundred eighty (180) days after the
date on which Landlord is notified by Tenant of such damage, at the option of
either Landlord or Tenant, this Lease shall terminate, and the Rent shall be
abated during the unexpired portion of this Lease effective upon the date of
occurrence of such damage.

        (c)  If the Building should be damaged by any peril that will be wholly
compensated (subject to deductibles) by the insurance maintained by Landlord or
if Landlord, in its sole discretion, so chooses notwithstanding a deficiency in
such proceeds, and if rebuilding or repairs can reasonably be completed within
one hundred eighty (180) days after the date on which Landlord is notified by
Tenant of such damage, this Lease shall not terminate, and Landlord shall then
proceed with reasonable diligence to rebuild and repair the Building to
substantially the same condition in which it existed prior to such damage.
Landlord shall not be required, however, to rebuild, repair, or replace Tenant's
furniture, fixtures, Alterations, inventory or other personal property. If the
Leased Premises are untenantable in whole or in part during restoration, the
Rent payable hereunder during the period in which they are untenantable shall be
reduced by untenantable portion in both Tenant and Landlords reasonable
discretion. If Landlord should fall to complete such repairs and rebuilding
within one hundred eighty (180) days after the date on which Landlord is
notified by Tenant of such damage, Tenant may terminate this Lease by delivering
written notice of termination to Landlord. Such termination shall be Tenant's
exclusive remedy and all rights and obligations of the parties under the Lease
shall then cease. Notwithstanding the foregoing provisions of this
Paragraph 18(c), Tenant agrees that if the Leased Premises, the Building and/or
Project are damaged by fire or other casualty caused by the fault or negligence
of Tenant or Tenant's Representatives, Tenant shall have no option to terminate
this Lease even if the damage cannot be repaired within one hundred eighty
(180) days, and the Rent shall not be abated or reduced before or during the
repair period.

        (d)  Notwithstanding anything herein to the contrary, if the holder of
any indebtedness secured by a mortgage or deed of trust covering the Building
and/or Project requires that the insurance proceeds be applied to such
indebtedness, then Landlord shall have the right to terminate this Lease by
delivering written notice of termination to Tenant within fifteen (15) days
after such requirement is imposed. All rights and obligations under this Lease
shall then cease. If Landlord does not receive insurance proceeds sufficient for
restoration (such as when its mortgagee does not allow the proceeds to be used
for such purposes) and if restoration is economically reasonably feasible,
Tenant will have the option of supplementing available proceeds to allow
restoration, and Tenant's actual costs will be reimbursed through a monthly
prorata credit against rent beginning after Landlord's mortgage has been paid in
full.

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        19.    CASUALTY INSURANCE:    Landlord shall at all times during the
term of this Lease maintain a policy or policies of business or rental
interruption insurance and a policy or policies of insurance insuring the
Building against eighty percent (80%) of full replacement cost for loss or
damage by fire, explosion, and other customary hazards. Such policies will not
insure any personal. property (including, but not limited to any furniture,
machinery, goods, or supplies) of Tenant or which Tenant may have in the Leased
Premises or any fixtures installed by or paid for by Tenant upon or within the
Leased Premises or any Alterations or other improvements which Tenant may
construct or install on the Leased Premises or any signs identifying Tenant's
business located on the exterior of the Building, insurance for all of which
shall be Tenant's responsibility.

        20.    WAIVER OF SUBROGATION:    To the extent that Landlord or Tenant
receives casualty insurance proceeds, such recipient hereby waives and releases
any and all rights, claims, demands and causes of action such recipient may have
against the other on account of any loss or damage occasioned to such recipient
or its businesses, real and personal properties, the Leased Premises, the
Building, the Project, or its contents, arising from any risk or peril covered
by any insurance policy carried by either party and for which such proceeds are
actually received. Inasmuch as the above mutual waivers will preclude the
assignment of any such claim by way of subrogation (or otherwise) to an
insurance company (or any other person), each party hereto agrees immediately to
give to its respective insurance companies written notice of the terms of such
mutual waivers and to have their respective insurance policies properly
endorsed, if necessary, to prevent the invalidation of such insurance coverages
by reason of such waivers. This. provision shall be cumulative of Paragraph 21
below.

        21.    HOLD HARMLESS:    Landlord shall not be liable to Tenant,
Tenant's Representatives, or any other person for any injury to person or damage
to property on or about the Leased Premises or the Project caused by the
negligence or misconduct of Tenant, Tenant's Representatives, or any other
persons entering upon the Leased Premises or the Project. Tenant agrees to
indemnify and hold Landlord harmless from any and all loss, attorney's fees,
expenses, or claims arising out of any such damage, loss or injury. Tenant shall
not be liable to Landlord, Landlord's employees, agents, invitees, licensees or
visitors for any injury to person or damage to property on or about the Leased
Premises or the Project caused by the negligence or misconduct of Landlord, its
agents, employees, agents, invitees, licensees or visitors. Landlord agrees to
indemnify and hold Tenant harmless from any and all loss, attorney's fees,
expenses, or claims arising out of any such damage, loss or injury.

        22.    QUIET ENJOYMENT:    Landlord warrants that it has full right to
execute and to perform this Lease and to grant the estate demised herein and
that Tenant, upon payment of the required Rent and performance of the covenants
and agreements contained in this Lease, shall peaceably and quietly have, hold,
and enjoy the Leased Premises during the full term of this Lease, including any
extensions or renewals thereof.

        23.    LANDLORD'S RIGHT OF ENTRY:    Landlord shall have the night to
enter the Leased Premises for the following reasons: inspection, cleaning or
making repairs, making such alterations or additions as Landlord may deem
necessary or desirable; installation of utility lines servicing the Leased
Premises or any other space in the Building, determining Tenant's use of the
Leased Premises, or for determining if any event of default under this Lease has
occurred. Landlord shall attempt to give twenty-four (24) hours verbal notice to
Tenant prior to such entry, except in cases of emergency or when an event of
default has occurred in which cases Landlord may enter the Leased Premises at
any time and without prior notice. During the period that is six (6) months
prior to the end of the Lease term, Landlord and Landlord's agents and
representatives shall have the right to enter the Leased Premises at any
reasonable time during business hours, with reasonable notice, for the purpose
of showing the Leased Premises and shall have the right to erect on the Leased
Premises a suitable sign indicating the Leased Premises are available for lease.

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        24.    ASSIGNMENT OF LANDLORD'S INTEREST IN LEASE:    Landlord shall
have the right to transfer and assign, in whole or in part, its rights and
obligations with respect to the Project, the Leased Premises, and this Lease,
including Tenant's Security Deposit. Upon and after such transfer, Landlord
shall be released from any further obligation under this Lease and Tenant agrees
to look solely to Landlord's successor for the performance of such obligations.

        25.    Intentionally Deleted    

        26.    DEFAULT BY TENANT:    The following shall be events of default by
Tenant tinder this Lease:

        (a)  Tenant's failure to pay, within ten (10) days after it is due, any
installment of Rent or other payment required pursuant to this Lease;

        (b)  Tenant's abandonment or vacation of any part of the Leased
Premises, and Tenant is in default of the Rent payments due under this Lease;

        (c)  Tenant's failure to comply with any term, provision or covenant of
this Lease, other than the defaults listed in the other subparagraphs of this
Paragraph 26, and the failure is not cured within ten (10) days after written
notice thereof to Tenant;

        (d)  Tenant's filing of a petition or adjudication as a debtor or
bankrupt insolvent under the Bankruptcy Code or any similar law or statute of
the United States or any state; or appointment of a receiver or trustee for all
or substantially all of the assets of Tenant; or Tenant's transfer in fraud of
creditors or assignment for the benefit of creditors of all or substantially all
of Tenant's assets;.

        (e)  Tenant doing or permitting to be done any act which results in a
lien being filed against the Leased Premises and the same is not removed within
sixty (90) days after Landlord's notice thereof to Tenant.

        27.    REMEDIES FOR TENANT'S DEFAULT:    Upon the occurrence of any
event of default, Landlord shall have the option to pursue any one or more of
the following remedies without any prior notice or demand:

        (a)  Landlord may terminate this Lease, in which event Tenant shall
immediately surrender the Leased Premises to Landlord, and if Tenant falls to do
so, Landlord may, without prejudice to any other remedy which it may have, enter
upon and take possession of the Leased Premises, and expel or remove Tenant and
any other person who may be occupying all or any part of the Leased Premises.
Landlord shall not be liable for prosecution or any claim for damages as a
result of such actions. Tenant agrees to pay on demand the amount of all losses,
costs, expenses, deficiencies, and damages, including, without limitation,
reasonable reconfiguration expenses, rental concessions and other inducements to
new tenants, advertising expenses and broker's commissions, which Landlord may
incur or suffer by reason of Tenant's default or the termination of this Lease
under this subparagraph, whether through inability to rent the Leased Premises
on satisfactory terms or otherwise. Tenant acknowledges that its obligation to
pay Base Rent and all additional Rent hereunder is not only compensation for use
of the Leased Premises but also compensation for sums already expended and/or
being expended by Landlord with respect to its obligations hereunder and with
respect to the Leased Premises, and Tenant acknowledges that Tenant's default in
timely payment of all sums due hereunder shall constitute significant financial
loss to Landlord. Tenant further acknowledges that any failure to pay any sum
due hereunder shall evidence Tenant's inability to meet its debts as they become
due. In such event, in addition to Landlord's other remedies hereunder, Landlord
shall be entitled to accelerate all Base Rental remaining unpaid hereunder, the
entirety of which shall at the option of Landlord be immediately due and payable
to the extent allowed by law.

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        (b)  Without termination of this Lease, Landlord may enter upon and take
possession of the Leased Premises and expel or remove Tenant and any other
person who may be occupying all or any part of the Leased Premises (without
being liable for prosecution or any claim for damages therefor) and relet the
Leased Premises on behalf of Tenant and receive directly the rent from the
reletting. Tenant agrees to pay Landlord on demand any deficiency that may arise
by reason of any reletting of the Leased Premises and to reimburse Landlord on
demand for any losses, costs, and expenses, including without limitation,
reconfiguration expenses, rental concessions and other inducements to new
tenants, advertising costs or broker's commissions, which Landlord may incur or
suffer as a result of Tenant's default or in reletting the Leased Premises. In
the event Landlord is successful in reletting the Leased Premises at a rental in
excess of that agreed to be paid by Tenant pursuant to this Lease, Tenant agrees
that Tenant shall not be entitled, under any circumstances, to such excess
rental, and Tenant does hereby specifically waive any claim to such excess
rental.

        (c)  Without terminating this Lease, Landlord may enter upon the Leased
Premises (without being liable for prosecution or any claim for damages
therefor) and do whatever Tenant is obligated to do under the terms of this
Lease. Tenant agrees to reimburse Landlord on demand for any losses, costs and
expenses which Landlord may incur in effecting compliance with Tenant's
obligations under this Lease. Tenant further agrees that Landlord shall not be
liable for any damages resulting to Tenant from effecting compliance with
Tenant's obligations under this subparagraph, whether caused by the negligence
of Landlord or otherwise.

        (d)  With respect to Landlord's entry upon the Leased Premises under the
provisions of subparagraphs (a), (b), and (c) above, no restriction of, or
obligation imposed upon Landlord by, Texas Property Code Section 93.002 shall
apply, such Section being superseded hereby. In particular, but without
limitation, Landlord will have no duty or responsibility to Tenant to tender a
key in the event of a change of locks, and Tenant will have no further right of
possession except as otherwise expressly agreed by Landlord in writing.

        (e)  Landlord may pursue any remedy provided at law or in equity.

        (f)    Landlord shall have no duty to relet the Premises, and the
failure of Landlord to do so shall not release or affect Tenant's liability for
Rent and other charges due hereunder or for damages.

        (g)  No re-entry or reletting of the Premises or any filing or service
of an unlawful detainer action or similar action shall be construed as an
election by Landlord to terminate this Lease unless a written notice of such
intention is given by Landlord to Tenant. Notwithstanding any such reletting
without termination, Landlord may at any time thereafter elect to terminate this
Lease and Tenant's right to possession hereunder.

        (h)  Intentionally Deleted.

        28.    TERMINATION OF OPTIONS:    If there exist any options or special
rights which Landlord may have granted Tenant under this Lease including, but
not limited to, options or rights regarding extensions of the term, expansion of
the Leased Premises, or acquisition of any other interesting the Leased
Premises, the Building, or the Project, then all such options and rights
independent of the leasehold estate hereby granted to Tenant by Landlord.
Landlord and Tenant agree and acknowledge that the negotiated consideration for
any such options or special rights is Tenant's entry into this Lease and that no
portion of any sums due and payable by Tenant to Landlord hereunder is
attributable thereto. In addition to, and not in lieu of, the above remedies of
Landlord for Tenant's default, any and

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all such options or special rights shall be automatically terminated upon the
occurrence of the following events:

        (a)  Tenant shall have failed to pay when due any installment of Rent or
other sums payable under this Lease for any three (3) consecutive months during
the Lease term or any renewal or extension thereof, or for any ten (10) months
during the Lease term or any renewal or extension thereof, whether or not said
defaults are cured by Tenant; or

        (b)  Tenant shall have received two (2) or more notices of default under
Paragraph 26(c) within any one calendar year with respect to any other covenant
of this Lease, whether or not such default(s) is/are cured; or

        (c)  Tenant shall have committed or suffered to exist any other event of
default described under Paragraph 26 above, whether or not such default is cured
by Tenant.

        29.    WAIVER OF DEFAULT OR REMEDY:    Failure of Landlord to declare a
default immediately upon its occurrence, or delay in taking any action in
connection with an event of default, shall not be a waiver of the default.
Landlord shall have the right to declare the default at any time and take such
action as its lawful or authorized under this Lease. Pursuit of any one or more
of the remedies set forth in Paragraphs 27 or 28 above shall not preclude
pursuit of any one or more of the other remedies provided therein or elsewhere
in this Lease or as provided by law, nor shall pursuit of any remedy be a
forfeiture or waiver of any Rent or damages accruing to Landlord by reason of
the violation of any of the terms of this Lease. Failure by Landlord to enforce
one or more of its remedies upon an event of default shall not be construed as a
waiver of the default or of any other violation or breach of any of the terms
contained in this Lease.

        30.    CHOICE OF LAW; VENUE; ATTORNEY'S FEES:    It is specifically
stipulated that this Lease shall be interpreted and construed according to the
laws of the State in which the Leased Premises are located, and any suit brought
on this Lease shall be maintained in the county in which the Leased Premises are
located. Further, the prevailing party in any such litigation between the
parties shall be entitled to recover, as a part of its judgment, reasonable
attorney's fees and costs and expenses incurred therein.

        31.    HOLDING OVER:    Tenant will, at the termination of this Lease by
lapse of time or otherwise, surrender immediate possession to Landlord. If
Landlord agrees in writing that Tenant may hold over after the expiration or
termination of this Lease and if the parties do not otherwise agree, the hold
over tenancy shall be subject to termination by Landlord at any time upon not
less than five (5) days advance written notice, or by Tenant at any time upon
not less than thirty (30) days advance written notice. Further, all of the terms
and provisions of this Lease shall be applicable during the hold over period,
except that Tenant shall pay Landlord from time to time upon demand, as Base
Rent for the period of any hold over, an amount equal to 125% of the Base Rent
in effect on the date of termination, computed on a daily basis for each day of
the hold over period, plus all additional Rent and other sums due hereunder. If
Tenant shall fail immediately to surrender possession of the Leased Premises to
Landlord upon termination of this Lease, by lapse of time or otherwise, and
Landlord has not agreed to such continued possession, as above provided, then,
until Landlord can dispossess Tenant under the terms hereof or otherwise, Tenant
shall pay Landlord from time to time upon demand, as Base Rent for the period of
any such hold over, an amount equal to twice the Base Rent in effect on the date
of termination, computed on a daily basis for each day of the hold over period,
plus all additional Rent and other sums due hereunder. No holding over by
Tenant, whether with or without consent of Landlord, shall operate to extend
this Lease except as otherwise expressly agreed by the parties. The preceding
provisions of this Paragraph shall not be construed as Landlord's consent for
Tenant to hold over.

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        32.    RIGHTS OF MORTGAGEE:    Tenant accepts this Lease subject and
subordinate to any recorded mortgage, deed of trust or other lien (a "Mortgage")
presently existing or hereafter to exist with respect to the Leased Premises.
Further, but without limiting the preceding sentence, Landlord is hereby
irrevocably vested with full power and authority to subordinate and/or to
evidence such subordination of Tenant's interest under this Lease to any
Mortgage hereafter placed on the Leased Premises, and Tenant agrees upon demand
to execute such additional instruments subordinating this Lease, and further
defining the terms of such subordination, as well as the attornment discussed
below, as Landlord or the holder of any such Mortgage, may require. Tenant
agrees to provide to the holder of any such Mortgage, whose name and address
have been provided to Tenant (a "Mortgagee"), a copy of each notice to Landlord
which alleges any act, omission, or condition that might constitute a default by
Landlord hereunder and Mortgagee, in its sole discretion, shall have all rights
of Landlord hereunder to cure any such default. If the interests of Landlord
under this Lease shall be transferred by reason of foreclosure or other
proceedings for enforcement of any Mortgage on the Leased Premises, at the
election of the transferee (sometimes called the "Purchaser") Tenant shall be
bound to the Purchaser under the terms and conditions of this Lease for the
balance of the remaining Lease term, including any extensions or renewals, with
the same force and effect as if the Purchaser were Landlord under this Lease;
provided, however, that such Purchaser shall not be liable or bound to Tenant
(i) for any act or omission of any prior landlord, (ii) for any offsets or
defenses which Tenant might have against any prior landlord, (iii) for or by any
Rent which Tenant might have paid for more than the current month, (iv) by any
amendment modification of, or consensual termination agreement with respect to,
the Lease made without the Mortgagee's consent, (v) for any Security Deposit
given by Tenant to a prior landlord unless such deposit is actually received by
such Purchaser, (vi) for any repairs or replacements required by this Lease
arising prior to the date Purchaser takes possession of the Leased Premises, or
(vii) for any moving, relocation or refurbishment allowance or any construction
of or payment or allowance for tenant improvements to the Leased Premises or any
part thereof for the benefit of Tenant except as set forth in this Lease. Tenant
further agrees at the election of the Purchaser to attorn to the Purchaser,
including the Mortgagee if it be the Purchaser, as its Landlord. Such attornment
shall be effective without the execution of any further instruments upon the
Purchaser's succeeding to the interest of Landlord under this Lease. The
respective rights and obligations of Tenant and the Purchaser upon the
attornment, to the extent of the then remaining balance of the term of this
Lease and any extensions and renewals, shall be and are the same as those set
forth in this Lease, but Tenant agrees upon demand to execute such additional
instruments defining the terms of such attornment as Landlord or the Purchaser
may require. Each such Mortgagee and each such Purchaser shall be a third-party
beneficiary of the provisions of this Paragraph.

        33.    ESTOPPEL CERTIFICATES:    Tenant agrees to furnish on the
Commencement Date of this Lease and from time to time within ten (10) days of
request by Landlord or Landlord's mortgagee, a statement certifying that the
Tenant is in possession of the Leased Premises; the Leased Premises are
acceptable; this Lease is in full force and effect; this Lease is unmodified;
Tenant claims no present charge, lien, or claim of offset against Rent; the Rent
is paid for the current month but is not paid and will not be paid for more than
one month in advance (except estimated additional Rent under Paragraph 6); there
is no existing default under this Lease; and such other matters as may be
reasonably required by Landlord or Landlord's mortgagee.

        34.    SUCCESSORS:    This Lease shall be binding upon and inure to the
benefit of Landlord and Tenant and their respective heirs, personal
representatives, successors and assigns. It is hereby covenanted and agreed that
should Landlord's interest in the Leased Premises cease to exist for any reason
during the term of the Lease, then notwithstanding the happening of such even at
the election of Landlord's successor herein, this Lease shall nevertheless
remain unimpaired and in full force and effect and Tenant hereunder agrees to
attorn to the then owner of the Leased Premises.

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        35.    REAL ESTATE COMMISSION:    Tenant represents and warrants that is
has dealt with no other broker, agent, or other person other than Jackson &
Cooksey in connection with this transaction, and that no other broker, agent, or
other person brought about this transaction. Landlord and Tenant each agree to
indemnify and hold the other harmless from and against any claims by any broker,
agent, or other person claiming a commission or other form of compensation by
virtue of having dealt with Tenant or Landlord respectively with regard to this
transaction. The provisions of this Paragraph shall survive the termination of
this Lease.

        36.    DEFAULT BY LANDLORD:    Landlord shall not be in default, and
Tenant shall have no right to any remedy at law or in equity, unless the act,
omission, or condition allegedly giving rise to such default shall have
continued uncured or unabated for a period of thirty (30) days following written
notice to Landlord (with a copy to any Mortgagee as provided in Paragraph 32
above) or, if such cure or abatement cannot be accomplished within said 30-day
period, then, so long as Landlord or Mortgagee has commenced such cure or
abatement within such 30-day period and diligently pursues same, such period
shall be extended a reasonable time to allow completion of the cure or
abatement.

        37.    MECHANIC'S LIENS:    Tenant shall have no authority, express or
implied, to create or place any lien or encumbrance of any kind or nature
whatsoever upon, or in any manner to bind, the interest of Landlord in the
Leased Premises or the Project or to charge the Rent payable hereunder for any
claim in favor of any person dealing with Tenant, including those who may
furnish materials or perform labor for any construction or repairs. Each such
claim shall affect, and each such lien shall attach to, if at all, only the
leasehold interest granted to Tenant by this Lease. Tenant covenants and agrees
that it will pay or cause to be paid all sums legally due and payable by it on
account of any labor performed or materials furnished in connection with any
work performed on the Leased premises on which any lien is or can be validly and
legally asserted against its leasehold interest in the Leased Premises or the
improvements thereon. Tenant further agrees to save and hold Landlord harmless
from any and all loss, cost, or expense based on or arising out of claims or
liens asserted by parties by virtue of their dealings with Tenant and
encumbering the leasehold estate or the right, title and interest of the
Landlord in the Leased Premises or the Project. Under no circumstances shall
Tenant be or hold itself out to be the agent or representative of Landlord with
respect to any Alterations of the Leased Premises whether or not consented to or
approved by Landlord hereunder.

        38.    HAZARDOUS WASTE:    The term "Hazardous Substances," as used in
this Lease shall mean petroleum and petroleum products and by-products, crude
oil, pollutants, contaminants, toxic or hazardous wastes, or any other
substances, the use of which is regulated, restricted, prohibited or penalized,
or the removal or disposal of which is required, by any "Environmental Laws,"
which term shall mean any and all federal, state or local law, ordinance or
other statute of a governmental or quasi-governmental authority relating to the
pollution or protection of the environment. Tenant hereby agrees that (i) no
activity will be conducted on the Leased Premises that will produce any
Hazardous Substances; (ii) the Leased Premises will not be used in any manner
not in compliance with local and federal laws for the storage of any Hazardous
Substances; (iii) no portion of the Leased Premises will be used as a landfill
or a dump; (iv) Tenant will not install any underground tanks of any type;
(v) Tenant will not allow any surface or subsurface conditions to exist or come
into existence that constitute, or with the passage of time may constitute, a
public or private nuisance, (vi) Tenant will not permit any Hazardous Substances
to be brought onto the Leased Premises, and if so brought thereon, then the same
shall be stored and used in compliance with all local and federal laws regarding
same. Landlord or Landlord's representative shall have the right but not the
obligation to enter the Leased Premises for the purpose of ensuring compliance
with all Environmental Laws. If Tenant in any manner contaminates the Leased
Premises, then Tenant shall promptly and diligently institute proper and
thorough clean-up procedures at Tenant's sole cost. Landlord hereby agrees to
defend, indemnify and hold Tenant, its employees, partners, agents, contractors,
officers and directors and their heirs, successors, and assigns harmless from
any and all costs (including costs of litigation), reasonable

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attorney's fees, expenses, liabilities, claims, damages or judgments arising or
alleged to occur, and that result, or are alleged to result from the actual, or
threatened discharge, dispersal, disposal, release or escape of Hazardous
Substances or other wastes or pollutants (including, but not limited to
asbestos, solid, liquid, gaseous or thermal irritants or contaminants, smoke,
vapor, soot, fumes, acids, alkalis, chemicals, and water materials to be
recycled, reconditioned or reclaimed), but only as the same are a direct result
of any act or omission of Landlord or its agents, employees, contractors or
subcontractors. Tenant hereby agrees to defend, indemnify and hold Landlord, its
employees, agents, partners, contractors, officers and directors of their heirs,
successors, and assigns harmless from any and all costs (including costs of
litigation), reasonable attorneys' fees, expenses, liabilities, claims, damages
or judgments arising or alleged to occur, and that result, or are alleged to
result from the actual, or threatened discharge, dispersal, disposal, release or
escape of Hazardous Substances or other wastes or pollutants (including, but not
limited to asbestos, solid, liquid, gaseous or thermal irritants or
contaminants, smoke, vapor, soot, fumes, acids, alkalis, chemicals, and water
materials to be recycled, reconditioned or reclaimed), but only as the same are
a direct result of any act or omission of Tenant or Tenant's Representatives.
Landlord also agrees not to bring hazardous materials into the Leased Premises.

        39.    ENTIRE AGREEMENT AND LIMITATION OF WARRANTIES:    It is expressly
agreed by Tenant, as a material consideration for the execution of this Lease,
that this Lease is the entire agreement of the parties and that there are and
were no verbal representations, warranties, understandings, stipulations
agreements, or promises pertaining to this Lease not incorporated in this Lease.
Tenant expressly agrees that there are and shall be no implied warranties of
merchantability, fitness, habitability, or of any other kind and that Tenant's
acceptance of the Leased Premises shall be "as is." It is likewise agreed that
this Lease may not be altered, waived, amended, or extended except by an
instrument in writing signed by both Landlord and Tenant. Not in limitation upon
the foregoing, Landlord agrees that to the extent assignable, all warranties, if
any shall exist, from contractors or suppliers with respect to the improvements
to the Leased Premises hereunder are hereby partially assigned to Tenant to the
extent necessary to avail Tenant of the benefits thereof with respect to its
leasehold estate and property located at the Leased Premises.

        40.    FINANCIAL STATEMENTS:    From time to time Landlord may need to
obtain financing or renew financing on the Project, or perform calculations for
various reasons regarding the value of the Project. Tenant hereby agrees to
provide to Landlord financial statements on its business when requested, but not
more than once annually, indicating the most current year end and quarterly
financial status of the business. Landlord will not deliver such financial
statement to any third party except in confidence and only as required by
Landlord's lenders or in conjunction with appraisals of the Project.

        41.    FORCE MAJEURE:    

        (a)  Landlord shall not be required to perform any covenant or
obligation of this Lease or be liable in damages to Tenant for that time period
during which the performance or non-performance of the covenant or obligation is
delayed, caused by, or prevented by Tenant or Tenant's Representatives or by an
act of God or force majeure.

        (b)  Except with respect to the payment of Rent or any other sum due
hereunder, Tenant shall not be required to perform any covenant or obligation of
this Lease or be liable in damages to Landlord for that time period during which
the performance or non-performance of the covenant or obligation is delayed,
caused by, or prevented by Landlord or Landlord's Representatives or by an act
of God or force majeure.

        (c)  An "act of God" or "force majeure" is defined for purposes of this
Lease as strikes, lockouts, sit-downs, material or labor restrictions by any
governmental authority, riots, floods, washouts, explosions, earthquakes, fire
storms, acts of the public enemy, wars, insurrections and

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any other similar cause not reasonably within the control of Landlord and which
by the exercise of due diligence Landlord is unable, wholly or in part, to
prevent or overcome.

        42.    MISCELLANEOUS:    

        (a)  Words of any gender used in this Lease shall be held and construed
to include any other gender; and words in the singular number shall be held to
include the plural, unless the context otherwise requires.

        (b)  Each party agrees to furnish to the other, promptly upon demand, a
corporate resolution, proof of due authorization by partners, or other
appropriate documentation evidencing the due authorization and power of such
party to enter into this Lease and the empowerment and authority of the
individual signing below to bind his or her principal.

        (c)  The captions inserted in this Lease are for convenience only and in
no way define, limit, or otherwise describe the scope or intent of this Lease or
any provision hereof, or in any way affect the interpretation of this Lease.

        (d)  If any clause or provision of this Lease is illegal, invalid, or
unenforceable under present or future laws effective during the term of this
Lease, then and in that event, it is the intention of the parties hereto that
the remainder of this Lease shall not be affected thereby; and it is also the
intention of the parties to this Lease that in lieu of each clause or provision
of this Lease that is illegal, invalid, or unenforceable there be added as a
part of this Lease a clause as similar in terms to such illegal, invalid, or
unenforceable clause or provision as may be possible and be legal, valid, and
enforceable.

        (e)  Intentionally deleted.

        (f)    All references in this Lease to "the date hereof' or similar
references shall be deemed to refer to the last date, in point of time, on which
all parties hereto have executed this Lease.

        (g)  In the event that Tenant shall fail to perform any duty or
obligation hereunder, whether maintenance, repair or replacement of the Leased
Premises, maintenance of insurance, or otherwise, then Landlord may, but shall
in no event be obligated to, without notice of any kind, take such actions as
Landlord deems necessary or appropriate to remedy such Tenant failure, and any
sums expended by Landlord together with fair and just compensation for the time
and effort of Landlord in such efforts shall be deemed additional Rent hereunder
due and payable by Tenant on demand.

        (h)  If Tenant shall fail to pay, when the same is due and payable, any
Rent or any other sum due hereunder, such unpaid amount shall bear interest from
the clue date thereof to the date of remittance at the rate of the lesser of 12%
per annum and the maximum rate allowed by law.

        (i)    Landlord does not in any way or for any purpose become a partner
with Tenant in the conduct of its business or otherwise, nor a member of a joint
venture with Tenant.

        (j)    Tenant shall not record this Lease without the prior written
consent of Landlord. However, upon the request of either party hereto, the other
party shall join in the execution of a memorandum or so-called "short form" of
this Lease for the purposes of recordation.

        (k)  Time is of the essence in the performance of all the covenants,
conditions, and agreements contained in this Lease.

        (l)    Any duty, obligation, or debt and any right or remedy arising
hereunder and not otherwise consummated and/or extinguished by the express terms
hereof at or as of the time of termination of this Lease, whether at the end of
the term hereof or otherwise, shall survive such termination as continuing
duties, obligations, and debts of the obligated party to the other or continuing
rights and remedies of the benefitted party against the other.

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        (m)  This Agreement may be executed in one or more counterparts, each of
which counterpart shall for all purposes be deemed to be an original; but all
such counterparts together shall constitute but one instrument.

        (n)  Attached hereto, marked Exhibit "A" through Exhibit "F", are
certain exhibits to this Lease all of which are hereby incorporated herein by
reference

        (o)  Landlord agrees to allow Tenant at Tenant's sole cost and expense
to install a basketball goal on the Leased Premises as long as such installation
does not materially interfere with or reduce the available parking for the
Project. Tenant agrees to restore the Leased Premises to its original condition
upon Lease termination or Tenant's vacating of the Leased Premises.

        43.    NOTICE:    

        (a)  All Rent and other payments required to be made by Tenant to
Landlord shall be payable to Landlord at the address set forth below or any
other address that Landlord may specify from time to time by written notice
delivered to Tenant.

        (b)  All payments, if any, required to be made by Landlord to Tenant
shall be payable to Tenant at the address set forth below or at any other
address that Tenant may specify from time to time by written notice delivered to
Landlord.

        (c)  Any notice or document required or permitted to be delivered by
this Lease shall be deemed to be delivered (whether or not actually received)
when deposited in the United States Mail, postage prepaid, certified mail return
receipt requested, addressed to the parties at the respective addresses set
forth below or such other address as hereinafter specified by notice given in
accordance with this paragraph.

        44.    LIMITATION ON TENANT'S DAMAGES:    Tenant agrees that any
liability of Landlord under this Lease shall be limited solely to Landlord's
interest in the Project, and no other assets of Landlord shall be subject to
levy or execution.

        Executed by Landlord and Tenant as of this            day
of                        , 2000.

LANDLORD   TENANT
Jackson-Shaw Technology Center II Limited Partnership
 
TestChip Technologies, Inc.
4890 Alpha Road, Suite 100
 
Address:
 

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Dallas, Texas 75244   Dallas, Texas  

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By:
 

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Stephen S. Kurth
 
By:
 

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Its:   First Vice President                

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(please print)
 
 
 
 
Its:
 

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Leased Premises:
2600 Technology Drive, Suite 600
Dallas, Texas 75074

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EXHIBIT B

TENANT IMPROVEMENTS

        Landlord will supply Tenant with a construction allowance of $457,550.00
($25.00 psf) to be used for Tenant Improvements. Should the actual construction
costs exceed this amount, Tenant shall pay such excess to Landlord prior to the
commencement of the construction.

        Landlord's architect will supply floor plans and construction drawings
with MEP drawings to be provided by the subcontractors. The Tenant Improvements
shall be constructed in accordance to plans and specifications approved by
Landlord and Tenant. Landlord agrees to work diligently with Tenant to keep the
improvement costs at the allocated allowance and Landlord at, no cost to Tenant
or deduction from the Tenant Improvement allowance, shall obtain three (3) bids
from qualified sub-contractors. The Landlord is responsible for the costs to
construct the Building to its shell condition. The shell condition is defined as
the slab, roof, exterior walls, overhead doors, storefronts and fire sprinkler
system will be in place and water, gas, and electrical service will be nm to the
Building.

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[JUPITER BUSINESS CENTER]

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EXHIBIT "D"

RULES AND REGULATIONS

        The following Rules and Regulations are prescribed by Landlord in order
to provide and maintain, to the best of Landlord's ability, orderly, clean and
desirable premises, building and parking facilities for the Tenants therein and
to regulate conduct in and use of the Lease Premises, the Building and parking
facilities in such a manner as to minimize interference by others in the proper
use of the Leased Premises by Tenant. All references to Tenant include not only
the Tenant, but also Tenant's agents, employees, invitees, licensees, visitors,
assignees, and/or sublesses:

        1.    Tenant shall not block or obstruct any of the entries, passages,
or doors of Building or parking area, or place, empty, or throw rubbish, litter,
trash, or material of any nature into such areas, or permit such areas to be
used at any time except for ingress or egress of Tenants.

        2.    Landlord will not be responsible for lost or stolen personal
property, equipment, money, or any article taken from the Leased Premises,
Building, or parking facilities regardless of how or when loss occurs.

        3.    The plumbing facilities shall not be used for any other purpose
than that of which they are constructed, and no foreign substance of any kind
shall be placed therein, and the expense of any breakage, stoppage, or damage
resulting from a violation of this provision shall be borne by Tenant.

        4.    Any additional keys or locks required by Tenant during the term of
the Lease shall be the Tenant's responsibility.

        5.    The common parking facilities are available for use by any and all
tenants. Landlord agrees to reserve four (4) parking spaces directly in front of
the Leased Premises designated Visitor Parking and the cost of designating such
parking to be the sole responsibility of Tenant. Landlord reserves the right to
assign or allocate parking in the event of conflicts, abuse, or improper use. It
is generally understood that any Tenant should utilize only those parking spaces
immediately adjacent to that Tenant's Leased Premises.

        6.    Vehicles that are abandoned, disabled, have expired registration
stickers, obstructing any means of ingress or egress to any leased premises, or
in any way a general nuisance or hazard are subject to removal without notice by
Landlord. All costs associated with such removal shall be at the
Tenants's/vehicle owner's expense.

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EXHIBIT "E"

RENEWAL OPTION

        Tenant is granted the option to extend the term of this Lease for 1
extended term of five(5) years, provided no event of default exists at the time
of exercise of the option and no condition exists which with the giving of
notice or the passage of time or both would constitute an event of default, and
Tenant gives written notice of its exercise of the option at least one hundred
twenty (120) days prior to the expiration of the original term. The extension
terms(s) shall be upon the same terms and conditions as set forth herein, except
Tenant shall have no further night of renewal after the 2nd extension term
prescribed above, and the base Rental will be equal to the then prevailing rate
for comparable space for a comparable term.

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EXHIBIT "F"

EXPANSION RIGHT OF FIRST REFUSAL

        During the term of this Lease, if no event of default exists beyond any
applicable cure period, in the event that Landlord receives an offer to lease
all or any portion of the Building of which space is contiguous to the Leased
Premises outlined herein and which offer is not a renewal with an existing
tenant in the Building and which offer Landlord is prepared to accept, Landlord
shall give Tenant notice (the "Notice'), in accordance with Section 43(c) above,
of such offer which Notice shall contain all of the pertinent terms of such
offer. Tenant shall have a period of five (5) business days from the date the
Notice is given to Tenant in which to commit irrevocably to lease all of the
space covered by the Notice under all of the terms of the Notice, failing in any
element of which election Tenant shall be deemed to have waived its rights under
this Exhibit "F", time being especially of the essence herein. If Tenant so
elects to exercise such option, Landlord and Tenant will immediately execute a
lease amendment substantially in accordance with this Lease except that the
terms of the Notice shall apply therein. If Tenant does not so elect, or is
deemed not to have so elected, or if Tenant so elects but fails or refuses with
in five (5) days of receipt of the proposed lease to execute same, Landlord may
proceed with the lease transaction described in the Notice. This Exhibit "F"
shall remain in effect for subsequent leasing of space in the Building. If
Tenant has an express option under this Lease to extend the term of this Lease,
and if Tenant shall not timely so elect, then the provisions of this Exhibit "F"
shall not apply subsequent to the expiration of said extension election option.

        2.)  If during the term of this Lease Agreement, Landlord leases to
Tenant a space of a size larger than the present Lease Premises by an amount
which is a minimum of 50% larger than the present Lease Premises in any
development owned by Landlord or affiliate of Landlord, Tenants' then remaining
obligations due under this Lease Agreement shall be terminated upon the
commencement date of the new lease

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QuickLinks

EXHIBIT 10.21

COMMERCIAL LEASE AGREEMENT
EXHIBIT B TENANT IMPROVEMENTS
EXHIBIT "D" RULES AND REGULATIONS
EXHIBIT "E" RENEWAL OPTION
EXHIBIT "F" EXPANSION RIGHT OF FIRST REFUSAL