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                                                                   EXHIBIT 10.12
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                                PROMISSORY NOTE
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March 23, 1999                                                       $378,100.00


          William Seibel ("Maker"), hereby promises to pay to the order of ZC
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Acquisition Corp. (the "Company"), the principal amount of $378,100.00 together
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with interest thereon calculated from the date hereof in accordance with the
provisions of this Note.

          This Note is the Executive Note referred to in the Senior Management
Agreement, dated as of March 23, 1999, between the Company and Maker (the
"Management Agreement").  Section 1(a) of the Management Agreement contains
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provisions for the issuance of this Note upon the terms and conditions specified
herein.  Capitalized terms used herein and not otherwise defined shall have the
meanings given to them in the Management Agreement.

     1.   Interest.  Interest shall accrue on the outstanding principal amount
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of this Note at a rate equal to the lesser of (i) 5% per annum or (ii) the
highest rate permitted by applicable law, compounded annually on each
anniversary of the date hereof.


     2.   Payment on Note.
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          (a)  Term.  Subject to Section 2(b) below, the entire principal amount
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of this Note and all accrued interest thereon shall be due and payable on the
fifth anniversary of the date hereof.

          (b)  Mandatory Prepayments.  Notwithstanding anything in Section 2(a)
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to the contrary, the Maker shall make the following mandatory prepayments:

               (i) Upon the purchase of Stock from time to time by the Investors
     pursuant to Section 1B(b) of the Purchase Agreement dated as of the date
     hereof (the "Purchase Agreement"), Maker shall make a payment of principal
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     in an amount equal to the product of (A) $380,000, multiplied by (B) the
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     quotient of (x) the amount paid to the Company in connection with such
     purchase of Stock by Investors, divided by (y) $100,000,000, plus all
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     accrued interest on such principal amount (or such lesser principal amount
     then outstanding).  For purposes hereof, "Stock" shall have the meaning set
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     forth in the Purchase Agreement.

               (ii) In the event Maker receives any net cash proceeds (A) in
     connection with the payment of a dividend or other distribution by the
     Company or (B) relating to any other transaction or series of transactions
     in which Maker sells any of the Executive Stock, Maker shall prepay any
     amounts owed pursuant to this Note by applying all of such proceeds first,
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     to any accrued interest and second, to any principal then outstanding.
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     Upon a Sale of the Company, Executive shall pay the entire principal amount
     then outstanding and any accrued interest to the Company.  For purposes
     hereof, a "Sale of the Company" and "Executive Stock" shall have the
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     meanings set forth in the Management Agreement.
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          (c)  Optional Prepayments.  Maker may, at any time and from time to
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time without premium or penalty, prepay all of the outstanding principal amount
of the Note; provided that any prepayment will be accompanied by a payment of
accrued interest on the portion being prepaid.


          (d)  Right of Offset.  Upon an Event of Default (as described in
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Section 3 hereof) or the Company's repurchase of Executive Stock pursuant to
Section 3(e) of the Management Agreement, the Company shall be entitled to
offset any amounts owed to the Company by the Maker, now existing or hereinafter
arising, pursuant to this Note against any amounts payable by the Company to the
Maker pursuant to and as set forth in the Management Agreement between the
Company and the Maker.


     3.   Events of Default.
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          (a)  Definition.   For purposes of this Note, an Event of Default
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shall be deemed to have occurred if:

          (i)  Maker fails to pay (A) within 30 days after the date when due,
     the full amount of interest then accrued or (B) when due, the fall amount
     of any principal payment; or

          (ii) Maker makes an assignment for the benefit of creditors or admits
     in writing his inability to pay his debts generally as they become due; or
     an order, judgment or decree is entered adjudicating Maker bankrupt or
     insolvent; or any order for relief with respect to Maker is entered under
     the Federal Bankruptcy Code; or Maker petitions or applies to any tribunal
     for the appointment of a custodian, trustee, receiver or liquidator of any
     substantial part of Maker's assets, or commences any proceeding relating to
     Maker under any bankruptcy, reorganization, arrangement, insolvency,
     readjustment of debt, dissolution or liquidation law of any jurisdiction;
     or any such petition or application is filed, or any such proceeding is
     commenced, against Maker and either (A) Maker by any act indicates its
     approval thereof, consent thereto or acquiescence therein or (B) such
     petition, application or proceeding is not dismissed within 60 days.

          (b)  Consequences of Events of Default.
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          If an Event of Default of the type described in subparagraph 3(a)(ii)
has occurred the aggregate principal amount of the Note (together with all
accrued interest thereon and all other amounts payable in connection therewith)
shall become immediately due and payable without any action on the part of the
Company, and Maker shall immediately pay to the Company all amounts due and
payable with respect to the Note.

          If an Event of Default of the type described in subparagraph 3(a)(i)
has occurred and continued for 5 days, the Company may declare all or any
portion of the outstanding principal amount of the Note (together with all
accrued interest thereon and all other amounts due in connection therewith) due
and payable and demand immediate payment of all or any portion of the
outstanding principal amount of the Note.

          Maker, or his successors and assigns, hereby waives diligence,
presentment, protest and demand and notice of protest and demand, dishonor and
nonpayment of this Note, and expressly agrees that this Note, or any payment
hereunder, may be extended from time to time and that the
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Company may accept security for this Note or release security for this Note, all
without in any way affecting the liability of Maker hereunder.


          In the event that Maker fails to pay any amounts due hereunder when
due, Maker shall pay to the Company, in addition to such amounts due, all costs
of collection, including reasonable attorneys fees.

     4.   Amendment and Waiver.  Except as otherwise expressly provided herein,
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the provisions of the Note may be amended and Maker may take any action herein
prohibited, or omit to perform any act herein required to be performed by it,
only if Maker has obtained the written consent of the Company.

     5.   Cancellation.  After all principal and accrued interest at any time
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owed on this Note has been paid in full, this Note shall be surrendered to Maker
for cancellation and shall not be reissued.

     6.   Place of Payment.  Payments of principal and interest are to be
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delivered to the Company at the following address:

                    ZC Acquisition Corp.
                    1048 Tremont Street
                    Duxbury, MA 02332
                    Attention: Chief Financial Officer

or to such other address or to the attention of such other person as specified
by prior written notice to Maker.

     7.   Usury Laws.  It is the intention of the Company and Maker to conform
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strictly to all applicable usury laws now or hereafter in force, and any
interest payable under this Note shall be subject to reduction to the amount not
in excess of the maximum legal amount allowed under the applicable usury laws as
now or hereafter construed by the courts having jurisdiction over such matters.
If the maturity of this Note is accelerated by reason of an election by the
Company resulting from an Event of Default, voluntary prepayment by Maker or
otherwise, then earned interest may never include more than the maximum amount
permitted by law, computed from the date hereof until payment, and any interest
in excess of the maximum amount permitted by law shall be canceled automatically
and, if theretofore paid, shall at the option of the Company either be rebated
to Maker or credited on the principal amount of this Note, or if this Note has
been paid, then the excess shall be rebated to Maker.  The aggregate of all
interest (whether designated as interest, service charges, points or otherwise)
contracted for, chargeable, or receivable under this Note shall under no
circumstances exceed the maximum legal rate upon the unpaid principal balance of
this Note remaining unpaid from time to time.  If such interest does exceed the
maximum legal rate, it shall be deemed a mistake and such excess shall be
canceled automatically and, if theretofore paid, rebated to Maker or credited on
the principal amount of this Note, or if this Note has been repaid, then such
excess shall be rebated to Maker.

     8.   Governing Law.  This Note is made under and governed by the internal
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law, not the laws of conflicts, of the State of Delaware.

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          IN WITNESS WHEREOF, Maker has executed and delivered this Note as of
the date first above written.

                                  /s/ William Seibel
                              _________________________________________
                              William Seibel - Maker