EXHIBIT 10.7
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                          COMMERCIAL SECURITY AGREEMENT


Borrower:        PERSONICS CORPORATION
                 234 Ballardvale Street
                 Wilmington, MA 01887

Lender:          Silicon Valley Bank a California-chartered bank
                 doing business as Silicon Valley East
                 45 William Street
                 Wellesley, MA 02181


THIS COMMERCIAL SECURITY AGREEMENT is entered into between PERSONICS CORPORATION
(referred to below as "Grantor"); and Silicon Valley Bank (referred to below as
"Lender"). For valuable consideration, Grantor grants to Lender a security
interest in the Collateral to secure the Indebtedness and agrees that Lender
shall have the rights stated in this Agreement with respect to the Collateral,
in addition to all other rights which Lender may have by law.

DEFINITIONS. The following words shall have the following meanings when used in
this Agreement. Terms not otherwise defined in this Agreement shall have the
meanings attributed to such terms in the Uniform Commercial Code. All references
to dollar amounts shall mean amounts in lawful money of the United States of
America.

          AGREEMENT. The word Agreement means this Commercial Security Agreement
          together with all exhibits and schedules attached to this Commercial
          Security Agreement from time to time, if any, as amended from time to
          time.

          COLLATERAL. The word "Collateral" means the following described
          property of Grantor, whether now owned or hereafter acquired, whether
          now existing or hereafter arising, and wherever located:

                   INVENTORY, CHATTEL PAPER, ACCOUNTS, CONTRACT RIGHTS, DEPOSIT
                   ACCOUNTS, DOCUMENTS, INSTRUMENTS, EQUIPMENT, GENERAL
                   INTANGIBLES AND FIXTURES

          In addition, the word "Collateral" includes all the following, whether
          now owned or hereafter acquired, whether now existing or hereafter
          arising, and wherever located:

          (a) All attachments, accessions, accessories, tools, parts, supplies,
          increases, and additions to and all replacements of and substitutions
          for any property described above.

          (b) All products and produce of any of the property described in this
          Collateral section.

          (c) All accounts, contract rights, general intangibles, instruments,
          rents, monies, payments, and all other rights, arising out of a sale,
          lease, or other disposition of any of the property described in this
          Collateral section.

          (d) All proceeds (including insurance proceeds) from the sale,
          destruction, loss, or other disposition of any of the property
          described in this Collateral section.

          (e) All records and data relating to any of the property described in
          this Collateral section, whether in the form of a writing, photograph,
          microfilm, microfiche, or electronic media, together with all


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          of Grantor's right, title, and interest in and to all computer
          software required to utilize, create, maintain, process any such
          records or data on electronic media.

          EVENT OF DEFAULT. The words "Event of Default" mean and include
          without limitation any of the Events of Default set forth below in the
          section titled "Events of Default."

          GRANTOR. The word "Grantor" means PERSONICS CORPORATION, its
          successors and assigns.

          GUARANTOR. The word "Guarantor" means and includes without limitation
          each and all of the guarantors, sureties, and accommodation parties in
          connection with the Indebtedness.

          INDEBTEDNESS. The word "Indebtedness" means the indebtedness evidenced
          by the Note, including all principal and interest, together with all
          other indebtedness and costs and expenses for which Grantor is
          responsible under this Agreement or under any of the Related
          Documents.

          LENDER. The word "Lender" means Silicon Valley Bank, its successors
          and assigns.

          NOTE. The word "Note" means the notes, letters of credits or credit
          agreements in any principal amount from Borrower to Lender, together
          with all renewals of, extensions of, modifications of, refinancings
          of, consolidations of and substitutions for the notes, letters of
          credit or credit agreements.

          RELATED DOCUMENTS. The words "Related Documents" mean and include
          without limitation all promissory notes, credit agreements, loan
          agreements, environmental agreements, guaranties, security agreements,
          mortgages, deeds of trust, and all other instruments, agreements and
          documents, whether now or hereafter existing, executed in connection
          with the Indebtedness.

OBLIGATIONS OF GRANTOR. Grantor warrants and covenants to Lender as follows:

          PERFECTION OF SECURITY INTEREST. Grantor agrees to execute such
          financing statements and to take whatever other actions are requested
          by Lender to perfect and continue Lender's security interest in the
          Collateral. Upon request of Lender, Grantor will deliver to Lender any
          and all of the documents evidencing or constituting the Collateral,
          and Grantor will note Lender's interest upon any and all chattel paper
          if not delivered to Lender for possession by Lender. Grantor hereby
          appoints Lender as its irrevocable attorney-in-fact for the purpose of
          executing any documents necessary to perfect or to continue the
          security interest granted in this Agreement. Lender may at any time,
          and without further authorization from Grantor, file a carbon,
          photographic or other reproduction of any financing statement or of
          this Agreement for use as a financing statement. Grantor will
          reimburse Lender for all expenses for the perfection and the
          continuation of the perfection of Lender's security interest in the
          Collateral. Grantor promptly will notify Lender before any change in
          Grantor's name including any change to the assumed business names of
          Grantor. THIS IS A CONTINUING SECURITY AGREEMENT AND WILL CONTINUE IN
          EFFECT EVEN THOUGH ALL OR ANY PART OF THE INDEBTEDNESS IS PAID IN FULL
          AND EVEN THOUGH FOR A PERIOD OF TIME GRANTOR MAY NOT BE INDEBTED TO
          LENDER.

          NO VIOLATION. The execution and delivery of this Agreement will not
          violate any law or agreement governing Grantor or to which Grantor is
          a party, and its certificate or articles of incorporation and bylaws
          do not prohibit any term or condition of this Agreement.

          ENFORCEABILITY OF COLLATERAL. To the extent the Collateral consists of
          accounts, contract rights, chattel paper, or general intangibles, the
          Collateral is enforceable in accordance with its terms,


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                          COMMERCIAL SECURITY AGREEMENT
                                    CONTINUED


          is genuine, and complies with applicable laws concerning content and
          manner of preparation and execution, and all persons appearing to be
          obligated on the Collateral have authority and capacity to contract
          and are in fact obligated as they appear to be on the Collateral.

          LOCATION OF THE COLLATERAL. Grantor, upon request of Lender, will
          deliver to Lender in form satisfactory to Lender a schedule of real
          properties and Collateral locations relating to Grantor's operations,
          including without limitation the following: (a) all real property
          owned or being purchased by Grantor; (b) all real property being
          rented or leased by Grantor; (c) all storage facilities owned, rented,
          leased, or being used by Grantor; and (d) all other properties where
          Collateral is or may be located. Except in the ordinary course of its
          business, Grantor shall not remove the Collateral from as existing
          locations without the prior written consent of Lender.

          REMOVAL OF COLLATERAL. Grantor shall keep the Collateral (or to the
          extent the Collateral consists of intangible property such as
          accounts, the records concerning the Collateral) at Grantor's address
          shown above, or at such other locations as are acceptable to Lender.
          Except in the ordinary course of its business, including the sales of
          inventory, Grantor shall not remove the Collateral from its existing
          locations without the prior written consent of Lender. To the extent
          that the Collateral consists of vehicles, or other titled property,
          Grantor shall not take or permit any action which would require
          application for certificates of title for the vehicles outside the
          Commonwealth of Massachusetts, without the prior written consent of
          Lender.

          TRANSACTIONS INVOLVING COLLATERAL. Except for inventory sold or
          accounts collected in the ordinary course of Grantor's business,
          Grantor shall not sell, offer to sell, or otherwise transfer or
          dispose of the Collateral. VVhile Grantor is not in default under this
          Agreement, Grantor may sell inventory, but only in the ordinary course
          of its business and only to buyers who qualify as a buyer in the
          ordinary course of business. A sale in the ordinary course of
          Grantor's business does not include a transfer in partial or total
          satisfaction of a debt or any bulk sale. Grantor shall not pledge,
          mortgage, encumber or otherwise permit the Collateral to be subject to
          any lien, security interest, encumbrance, or charge, other than the
          security interest provided for in this Agreement, without the prior
          written consent of Lender. This includes security interests even if
          junior in right to the security interests granted under this
          Agreement. Unless waived by Lender, all proceeds from any disposition
          of the Collateral (for whatever reason) shall be held in trust for
          Lender and shall not be commingled with any other funds; provided
          however, this requirement shall not constitute consent by Lender to
          any sale or other disposition. Upon receipt, Grantor shall immediately
          deliver any such proceeds to Lender.

          TITLE. Grantor represents and warrants to Lender that it holds good
          and marketable tale to the Collateral, free and clear of all liens and
          encumbrances except for the lien of this Agreement. No financing
          statement covering any of the Collateral is on file in any public
          office other than those which reflect the security interest created by
          this Agreement or to which Lender has specifically consented. Grantor
          shall defend Lenders rights in the Collateral against the claims and
          demands of all other persons.

          COLLATERAL SCHEDULES AND LOCATIONS. Insofar as the Collateral consists
          of inventory, Grantor shall deliver to Lender, as often as Lender
          shall require, such lists, descriptions, and designations of such
          Collateral as Lender may require to identify the nature, extent, and
          location of such

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          Collateral. Such information shall be submitted Grantor and each of
          its subsidiaries or related companies.

          MAINTENANCE AND INSPECTION OF COLLATERAL. Grantor shall maintain all
          tangible Collateral in good condition and repair. Grantor will not
          commit or permit damage to or destruction of the Collateral or any
          part of the Collateral. Lender and its designated representatives and
          agents shall have the right at all reasonable times to examine,
          inspect, and audit the Collateral wherever located. Grantor shall
          immediately notify Lender of all cases involving the return,
          rejection, repossession, loss or damage of or to any Collateral; of
          any request for credit or adjustment or of any other dispute arising
          with respect to the Collateral; and generally of all happenings and
          events affecting the Collateral or the value or the amount of the
          Collateral.

          TAXES, ASSESSMENTS AND LIENS. Grantor will pay when due all taxes,
          assessments and liens upon the Collateral, its use or operation, upon
          this Agreement, upon any promissory note or notes evidencing the
          Indebtedness, or upon any of the other Related Documents. Grantor may
          withhold any such payment or may elect to contest any lien if Grantor
          is in good faith conducting an appropriate proceeding to contest the
          obligation to pay and so long as Lender's interest in the Collateral
          is not jeopardized in Lender's sole opinion. If the Collateral is
          subjected to a lien which is not discharged within fifteen (15) days,
          Grantor shall depose with Lender cash, a sufficient corporate surety
          bond or other security satisfactory to Lender in an amount adequate to
          provide for the discharge of the lien plus any interest, costs,
          attorneys' fees or other charges that could accrue as a result of
          foreclosure or sale of the Collateral. In any contest Grantor shall
          defend itself and Lender and shall satisfy any final adverse judgment
          before enforcement against the Collateral. Grantor shall name Lender
          as an additional obliges under any surety bond furnished in the
          contest proceedings.

          COMPLIANCE WITH GOVERNMENTAL REQUIREMENTS. Grantor shall comply
          promptly with all laws, ordinances, rules and regulations of all
          governmental authorities, now or hereafter in effect, applicable to
          the ownership, production, disposition, or use of the Collateral.
          Grantor may contest in good faith any such law, ordinance or
          regulation and withhold compliance during any proceeding, including
          appropriate appeals, so long as Lender's interest in the Collateral,
          in Lender's opinion, is not jeopardized.

          HAZARDOUS SUBSTANCES. Grantor represents and warrants that the
          Collateral never has been, and never will be so long as this Agreement
          remains a lien on the Collateral, used for the generation,
          manufacture, storage, transportation, treatment, disposal, release or
          threatened release of any hazardous waste or substance, as those terms
          are defined in the Comprehensive Environmental Response, Compensation,
          and Liability Act of 1980, as amended, 42 U.S.C. Section 9601, et seq.
          ("CERCLA"), the Superfund Amendments and Reauthorization Act of 1986,
          Pub. L. No. 99-499 ("SARA"), the Hazardous Materials Transportation
          Act, 49 U.S.C. Section 1801, et seq., the Resource Conservation and
          Recovery Act, 49 U.S.C. Section 6901, et seq., or other applicable
          state or Federal laws, rules, or regulations adopted pursuant to any
          of the foregoing. The terms "hazardous waste" and "hazardous
          substance" shall also include, without limitation, petroleum and
          petroleum by-products or any fraction thereof and asbestos. The
          representations and warranties contained herein are based on Grantors
          due diligence in investigating the Collateral for hazardous wastes and
          substances. Grantor hereby (a) releases and waives any future claims
          against Lender for indemnity or contribution in the event Grantor
          becomes liable for cleanup or other costs

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          under any such laws, and (b) agrees to indemnify and hold harmless
          Lender against any and ail claims and losses resulting from a breach
          of this provision of this Agreement. This obligation to indemnify
          shall survive the payment of the Indebtedness and the satisfaction of
          this Agreement.

          MAINTENANCE OF CASUALLY INSURANCE. Grantor shall procure and maintain
          all risks insurance, including without limitation fire, then and
          liability coverage together with such other insurance as Lender may
          require with respect to the Collateral, in form, amounts, coverages
          and basis reasonably acceptable to Lender and issued by a company or
          companies reasonably acceptable to Lender. Grantor, upon request of
          Lender, will deliver to Lender from time to time the policies or
          certificates of insurance in form satisfactory to Lender, including
          stipulations that coverages will not be cancelled or diminished
          without at least ten (10) days' prior written notice to Lender and not
          including any disclaimer of the insurer's liability for failure to
          give such a notice. Each insurance policy also shall include an
          endorsement providing that coverage in favor of Lender will not be
          impaired in any way by any act, omission or default of Grantor or any
          other person. In connection with all policies covering assets in which
          Lender holds or is offered a security interest, Grantor will provide
          Lender with such loss payable or other endorsements as Lender may
          require. If Grantor at any time fails to obtain or maintain any
          insurance as required under this Agreement, Lender may (but shall not
          be obligated to) obtain such insurance as Lender deems appropriate,
          including if it so chooses "single interest insurance", which will
          cover only Lender's interest in the Collateral.

          APPLICATION OF INSURANCE PROCEEDS. Grantor shall promptly notify
          Lender of any loss or damage to the Collateral. Lender may make proof
          of loss if Grantor fails to do so within fifteen (15) days of the
          casualty. All proceeds of any insurance on the Collateral, including
          accrued proceeds thereon, shall be held by Lender as part of the
          Collateral. If Lender consents to repair or replacement of the damaged
          or destroyed Collateral, Lender shall, upon satisfactory proof of
          expenditure, pay or reimburse Grantor from the proceeds for the
          reasonable cost of repair or restoration. If Lender does not consent
          to repair or replacement of the Collateral, Lender shall retain a
          sufficient amount of the proceeds to pay all of the Indebtedness, and
          shall pay the balance to Grantor. Any proceeds which have not been
          disbursed within six (6) months after their receipt and which Grantor
          has not commuted to the repair or restoration of the Collateral shall
          be used to prepay the Indebtedness.

          INSURANCE RESERVES. Lender may require Grantor to maintain with Lender
          reserves for payment of insurance premiums, which reserves shall be
          created by monthly payments from Grantor of a sum estimated by Lender
          to be sufficient to produce, at least fifteen (15) days before the
          premium due date, amounts at least equal to the insurance premiums to
          be paid. If fifteen (15) days before payment is due, the reserve funds
          are insufficient, Grantor shall upon demand pay any deficiency to
          Lender. The reserve funds shall be held by Lender as a general depose
          and shall constitute a non-interest-bearing account which Lender may
          satisfy by payment of the insurance premiums required to be paid by
          Grantor as they become due. Lender does not hold the reserve funds in
          trust for Grantor, and Lender is not the agent of Grantor for payment
          of the insurance premiums required to be paid by Grantor. The
          responsibility for the payment of premiums shall remain Grantor's sole
          responsibility.

          INSURANCE REPORTS. Grantor, upon request of Lender, shall furnish to
          Lender reports on each existing policy of insurance showing such
          information as Lender may reasonably request including


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          the following: (a) the name of the insurer; (b) the risks insured; (c)
          the amount of the policy; (d) the property insured; (e) the then
          current value on the basis of which insurance has been obtained and
          the manner of determining that value; and (f) the expiration date of
          the policy. In addition, Grantor shall upon request by Lender (however
          not more often than annually) have an independent appraiser
          satisfactory to Lender determine, as applicable, the cash value or
          replacement cost of the Collateral.

GRANTOR'S RIGHT TO POSSESSION. Until default, Grantor may have possession of the
tangible personal property and beneficial use of all the Collateral and may use
it in any lawful manner not inconsistent with this Agreement or the Related
Documents, provided that Grantor's right to possession and beneficial use shall
not apply to any Collateral where possession of the Collateral by Lender is
required by law to perfect Lender's security interest in such Collateral: If
Lender at any time has possession of any Collateral, whether before or after an
Event of Default, Lender shall be deemed to have exercised reasonable care in
the custody and preservation of the Collateral if Lender takes such action for
that purpose as Grantor shall request or as Lender, in Lender's sole discretion,
shall deem appropriate under the circumstances, but failure to honor any request
by Grantor shall not of Itself be deemed to be a failure to exercise reasonable
care. Lender shall not be required to take any steps necessary to preserve any
rights in the Collateral against prior parties, nor to protect, preserve or
maintain any security interest given to secure the Indebtedness.

EXPENDITURES BY LENDER. If not discharged or paid when due, Lender may (but
shall not be obligated to) discharge or pay any amounts required to be
discharged or paid by Grantor under this Agreement, including without limitation
all taxes, liens, security interests, encumbrances, and other claims, at any
time levied or placed on the Collateral. Lender also may (but shall not be
obligated to) pay all costs for insuring, maintaining and preserving the
Collateral. All such expenditures incurred or paid by Lender for such purposes
will then bear interest at the rate charged under the Note from the date
incurred or paid by Lender to the date of repayment by Grantor. All such
expenses shall become a part of the Indebtedness and, at Lender's option, will
(a) be payable on demand, (b) be added to the balance of the Note and be
apportioned among and be payable with any installment payments to become due
during either (i) the term of any applicable insurance policy or (ii) the
remaining term of the Note, or (c) be treated as a balloon payment which will be
due and payable at the Note's maturity. This Agreement also will secure payment
of these amounts. Such right shall be in addition to all other rights and
remedies to which Lender may be entitled upon the occurrence of an Event of
Default.

EVENTS OF DEFAULT. Each of the following shall constitute an Event of Default
under this Agreement:

          DEFAULT ON INDEBTEDNESS. Failure of Grantor to make any payment when
          due on the Indebtedness.

          OTHER DEFAULTS. Failure of Grantor to comply with or to perform any
          other term, obligation, covenant or condition contained in this
          Agreement or in any of the Related Documents or in any other agreement
          between Lender and Grantor.

          INSOLVENCY. The dissolution or termination of Grantor's existence as a
          going business, the insolvency of Grantor, the appointment of a
          receiver for any part of Grantor's property, any assignment for the
          benefit of creditors, any type of creditor workout, or the
          commencement of any proceeding under any bankruptcy or insolvency laws
          by or against Grantor.

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          CREDITOR OR FORFEITURE PROCEEDINGS. Commencement of foreclosure or
          forfeiture proceedings, whether by judicial proceeding, self-help,
          repossession or any other method, by any creditor of Grantor or by any
          governmental agency against the Collateral or any other collateral
          securing the Indebtedness. This includes a garnishment of any of
          Grantor's depose accounts with Lender.

          EVENTS AFFECTING GUARANTOR. Any of the preceding events occurs with
          respect to any Guarantor of any of the Indebtedness or such Guarantor
          dies or becomes incompetent.

RIGHTS AND REMEDIES ON DEFAULT. If an Event of Default occurs under this
Agreement, at any time thereafter, Lender shall have all the rights of a secured
party under the Massachusetts Uniform Commercial Code. In addition and without
limitation, Lender may exercise any one or more of the following rights and
remedies:

          ACCELERATE INDEBTEDNESS. Lender may declare the entire Indebtedness,
          including any prepayment penalty which Grantor would be required to
          pay, immediately due and payable, without notice.

          ASSEMBLE COLLATERAL. Lender may require Grantor to deliver to Lender
          all or any portion of the Collateral and any and all certificates of
          tale and other documents relating to the Collateral. Lender may
          require Grantor to assemble the Collateral and make d available to
          Lender at a place to be designated by Lender. Lender also shall have
          full power to enter upon the property of Grantor to take possession of
          and remove the Collateral. If the Collateral contains other goods not
          covered by this Agreement at the time of repossession, Grantor agrees
          Lender may take such other goods, provided that Lender makes
          reasonable efforts to return them to Grantor after repossession.

          SELL THE COLLATERAL. Lender shall have full power to sell, lease,
          transfer, or otherwise deal with the Collateral or proceeds thereof in
          as own name or that of Grantor. Lender may sell the Collateral at
          public auction or private sale. Unless the Collateral threatens to
          decline speedily in value or is of a type customarily sold on a
          recognized market, Lender will give Grantor reasonable notice of the
          time after which any private sale or any other intended disposition of
          the Collateral is to be made. The requirements of reasonable notice
          shall be met if such notice is given at least ten (10) days before the
          time of the sale or disposition. All expenses relating to the
          disposition of the Collateral, including without limitation the
          expenses of retaking, holding, insuring, preparing for sale and
          selling the Collateral, shall become a part of the Indebtedness
          secured by this Agreement and shall be payable on demand, with
          interest at the Note rate from data of expenditure until repaid.

          APPOINT RECEIVER. To the extent permitted by applicable law, Lender
          shall have the following rights and remedies regarding the appointment
          of a receiver (a) Lender may have a receiver appointed as a matter of
          right, (b) the receiver may be an employee of Lender and may serve
          without bond, and (c) all fees of the receiver and his or her attorney
          shall become part of the Indebtedness secured by this Agreement and
          shall be payable on demand, with interest at the Note rate from date
          of expenditure until repaid.

          COLLECT REVENUES, APPLY ACCOUNTS. Lender, either itself or through a
          receiver, may collect the payments, rents, income, and revenues from
          the Collateral. Lender may at any time in its


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          discretion transfer any Collateral into its own name or that of its
          nominee and receive the payments, rents, income, and revenues
          therefrom and hold the same as security for the Indebtedness or apply
          it to payment of the Indebtedness in such order of preference as
          Lender may determine. Insofar as the Collateral consists of accounts,
          general intangibles, insurance policies, instruments, chattel paper,
          choses in action, or similar property, Lender may demand, collect,
          receipt for, settle, compromise, adjust, sue for, foreclose, or
          realize on the Collateral as Lender may determine, whether or not
          Indebtedness or Collateral is then due. For these purposes, Lender
          may, on behalf of and in the name of Grantor, receive, open and
          dispose of mail addressed to Grantor; change any address to which mail
          and payments are to be sent; and endorse notes, checks, drafts, money
          orders, documents of title, instruments and items pertaining to
          payment, shipment, or storage of any Collateral. To facilitate
          collection, Lender may notify account debtors and obligors on any
          Collateral to make payments directly to Lender.

          OBTAIN DEFICIENCY. If Lender chooses to sell any or all of the
          Collateral, Lender may obtain a judgment against Grantor for any
          deficiency remaining on the Indebtedness due to Lender after
          application of all amounts received from the exercise of the rights
          provided in this Agreement. Grantor shall be liable for a deficiency
          even if the transaction described in this subsection is a sale of
          accounts or chattel paper.

          OTHER RIGHTS AND REMEDIES. Lender shall have all the rights and
          remedies of a secured creditor under the provisions of the Uniform
          Commercial Code, as may be amended from time to time. In addition,
          Lender shall have and may exercise any or all other rights and
          remedies it may have available at law, in equity, or otherwise.

          CUMULATIVE REMEDIES. All of Lender's rights and remedies, whether
          evidenced by this Agreement or the Related Documents or by any other
          writing, shall be cumulative and may be exercised singularly or
          concurrently. Election by Lender to pursue any remedy shall not
          exclude pursuit of any other remedy, and an election to make
          expenditures or to take action to perform an obligation of Grantor
          under this Agreement, after Grantor's failure to perform, shall not
          affect Lender's right to declare a default and to exercise its
          remedies.

MISCELLANEOUS PROVISIONS. The following miscellaneous provisions are a part of
this Agreement:

          AMENDMENTS. This Agreement, together with any Related Documents,
          constitutes the entire understanding and agreement of the parties as
          to the matters set forth in this Agreement. No alteration of or
          amendment to this Agreement shall be effective unless given in writing
          and signed by the party or parties sought to be charged or bound by
          the alteration or amendment.

          APPLICABLE LAW. This Agreement has been delivered to Lender and
          accepted by Lender in the Commonwealth of Massachusetts. If there is a
          lawsuit, Grantor agrees upon Lenders request to submit to the
          jurisdiction of the courts of the Commonwealth of Massachusetts.
          (Initial Here_________) Lender and Grantor hereby waive the right to
          any jury trial in any action, proceeding, or counterclaim brought by
          either Lender or Grantor against the other. This Agreement shall be
          governed by and construed in accordance with the laws of the
          Commonwealth of Massachusetts.

          ATTORNEYS' FEES; EXPENSES. Grantor agrees to pay upon demand all of
          Lender's reasonable



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          costs and expenses, including reasonable attorneys' fees and Lender's
          legal expenses, incurred in connection with the enforcement of this
          Agreement. Lender may pay someone else to help enforce this Agreement,
          and Grantor shall pay the costs and expenses of such enforcement.
          Costs and expenses include Lender's attorneys' fees and legal expenses
          whether or not there is a lawsuit, including attorneys' fees and legal
          expenses for bankruptcy proceedings (and including efforts to modify
          or vacate any automatic stay or injunction), appeals, and any
          anticipated post-judgment collection services. Grantor also shall pay
          all court costs and such additional fees as may be directed by the
          court.

          CAPTION HEADINGS. Caption headings in this Agreement are for
          convenience purposes only and are not to be used to interpret or
          define the provisions of this Agreement.

          MULTIPLE PARTIES; CORPORATE AUTHORITY. All obligations of Grantor
          under this Agreement shall be joint and several, and all references to
          Grantor shall mean each and every Grantor. This means that each of the
          persons signing below is responsible for all obligations in this
          Agreement.

          NOTICES. All notices required to be given under this Agreement shall
          be given in writing and shall be effective when actually delivered or
          when deposited with a nationally recognized overnight courier or
          deposited in the United States mail, first class, postage prepaid,
          addressed to the party to whom the notice is to be given at the
          address shown above. Any party may change its address for notices
          under this Agreement by giving formal written notice to the other
          parties, specifying that the purpose of the notice is to change the
          party's address. To the extent permitted by applicable law, if there
          is more than one Grantor, notice to any Grantor will constitute notice
          to all Grantors. For notice purposes, Grantor agrees to keep Lender
          informed at all times of Grantor's current address(es).

          POWER OF ATTORNEY. Grantor hereby appoints Lender as its true and
          lawful attorney-in-fact, irrevocably, with full power of substitution
          to do the following, after the occurrence and continuation of an Event
          of Default: (a) to demand, collect, receive, receipt for, sue and
          recover all sums of money or other property which may now or hereafter
          become due, owing or payable from the Collateral; (b) to execute, sign
          and endorse any and all claims, instruments, receipts, checks, drafts
          or warrants issued in payment for the Collateral; (c) to settle or
          compromise any and all claims arising under the Collateral, and, in
          the place and stead of Grantor, to execute and deliver its release and
          settlement for the claim; and (d) to file any claim or claims or to
          take any action or institute or take part in any proceedings, either
          in its own name or in the name of Grantor, or otherwise, which in the
          discretion of Lender may seem to be necessary or advisable. This power
          is given as security for the Indebtedness, and the authority hereby
          conferred is and shall be irrevocable and shall remain in full force
          and effect until renounced by Lender.

          SEVERABILITY. If a court of competent Jurisdiction Ends any provision
          of this Agreement to be invalid or unenforceable as to any person or
          circumstance, such finding shall not render that provision invalid or
          unenforceable as to any other persons or circumstances. If feasible,
          any such offending provision shall be deemed to be modified to be
          within the limes of enforceability or validity; however, if the
          offending provision cannot be so modified, it shall be stricken and
          all other provisions of this Agreement In all other respects shall
          remain valid and enforceable.

          SUCCESSOR INTERESTS. Subject to the limitations set forth above on
          transfer of the Collateral, this


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<PAGE>

                          COMMERCIAL SECURITY AGREEMENT
                                    CONTINUED



          Agreement shall be binding upon and inure to the benefit of the
          parties, their successors and assigns.

          WAIVER. Lender shall not be deemed to have waived any rights under
          this Agreement unless such waiver is given in writing and signed by
          Lender. No delay or omission on the part of Lender in exercising any
          right shall operate as a waiver of such right or any other right. A
          waiver by Lender of a provision of this Agreement shall not prejudice
          or constitute a waiver of Lender's right otherwise to demand strict
          compliance with that provision or any other provision of this
          Agreement. No prior waiver by Lender, nor any course of dealing
          between Lender and Grantor, shall constitute a waiver of any of
          Lender's rights or of any of Grantors obligations as to any future
          transactions. Whenever the consent of Lender is required under this
          Agreement, the granting of such consent by Lender in any instance
          shall not constitute continuing consent to subsequent instances where
          such consent is required and in all cases such consent may be granted
          or withheld in the sole discretion of Lender.


GRANTOR ACKNOWLEDGES HAVING READ ALL THE PROVISIONS OF THIS COMMERCIAL SECURITY
AGREEMENT, AND GRANTOR AGREES TO ITS TERMS. THIS AGREEMENT IS DATED NOVEMBER 1,
1994. THIS COMMERCIAL SECURITY AGREEMENT IS EXECUTED UNDER SEAL.

GRANTOR:

PERSONICS CORPORATION

By: /s/ Bruce R. Gardner
    ----------------------
Name:   Bruce R. Gardner
    ----------------------
Title:  Treasurer
    ----------------------

















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