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                                                                    EXHIBIT 10.T

               AMENDMENT NO. 9 TO THE LOAN AND SECURITY AGREEMENT

      AMENDMENT NO. 9 to the Loan and Security Agreement dated as of September
30, 2001 ("Amendment No. 9") by and between NAPCO SECURITY SYSTEMS, INC., a New
York corporation having a place of business at 333 Bayview Avenue, Amityville,
New York 11701 (the "Debtor") and HSBC BANK USA F/K/A MARINE MIDLAND BANK,
having a place of business at 534 Broad Hollow Road, Melville, New York 11747
(the "Secured Party").

                              W I T N E S S E T H :

      WHEREAS, as of May 12, 1997, Debtor and Secured Party had entered into a
certain loan and security agreement, as amended by amendment no. 1 to the loan
and security agreement dated as of May 28, 1998, as amended by amendment no. 2
to the loan and security agreement dated as of June 30, 1999, as amended by
amendment no. 3 to the loan and security agreement dated as of February 9, 2000,
as amended by amendment no.4 to the loan and security agreement dated as of July
27, 2000, as amended by amendment no. 5 to the loan and security agreement dated
as of September 22, 2000, as amended by amendment no. 6 to the loan and security
agreement dated as of November 22, 2000, as amended by amendment no. 7 to the
loan and security agreement dated as of February 14, 2001, as amended by
amendment no. 8 to the loan and security agreement dated as of May 15, 2001, as
may be amended from time to time (the "Agreement");

      WHEREAS, the Debtor has requested that the Secured Party modify certain
financial covenants and the Secured Party has agreed to do so, in the manner set
forth below, provided however, that, among other things, Debtor execute this
Amendment No. 9.

      NOW, THEREFORE, in consideration of the mutual promises and for other good
and valuable consideration, the receipt of which is hereby acknowledged, the
parties hereto agree as follows:

      1. The definition of "Transaction Documents" contained in Section 1.1. of
the Agreement is hereby amended to read in its entirety as follows:

      TRANSACTION DOCUMENTS means, individually, jointly, severally and
      collectively, the Agreement (including all amendments to date, including
      this Amendment No. 9) and all documents, instruments, notes and agreements
      by Debtor, Continental Systems or any other Third Party or any Responsible
      Party in favor


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      of Secured Party, whether in existence now or hereinafter created,
      executed and delivered to Secured Party, as the same may be extended,
      re-executed, modified or otherwise amended from time to time, including,
      without limitation, the Term Loan Note, the Continental Term Loan Note,
      the Note, collateral documents, letter of credit agreements, notes,
      acceptance credit agreements, security agreements, pledges, guaranties,
      mortgages, title insurance, assignments, and subordination agreements
      required to be executed by Debtor, Continental Systems any other Third
      Party, or any Responsible Party pursuant hereto or in connection herewith,
      or in connection with a letter of credit application and reimbursement
      agreement, each dated as of May 12, 1997, as may be reaffirmed or restated
      from time to time, a certain uncommitted trade line established by Secured
      Party in favor of Debtor to provide for commercial and standby letters of
      credit, evidenced by, among other documents, a continuing letter of credit
      agreement, and a continuing indemnity agreement, each dated as of May 12,
      1997, as may be re-executed, amended, extended or otherwise modified from
      time to time, the Term Loan Note in the principal sum of $2,500,000.00, as
      may be extended or otherwise modified from time to time, the Note, the
      Continental Term Loan Note in the principal sum of $8,250,000, that
      certain ISDA master agreement dated as of July 27, 2000 by and between
      Continental Systems and Secured Party, inclusive of all schedules thereto,
      as the same may be modified from time to time (the "Master Agreement") and
      all such other mortgages, security agreements, guaranties and other
      documents as may be executed and delivered to Secured Party to evidence,
      guaranty and secure the Continental Term Loan Note, and the obligations
      thereunder, as may be extended or otherwise modified from time to time,
      and uncommitted line of credit facility to be used by Debtor to finance
      certain acquisitions, as may be executed and delivered to Secured Party
      from time to time to evidence and secure the obligations under such
      facilities pursuant to the terms that the Secured Party shall


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      request, and all other documents, agreements, reaffirmations, certificates
      and resolutions related thereto, and amendments or supplements thereto,
      all such other agreements, resolutions, certificates, resolutions and
      opinion letters executed and/or issued as a condition precedent to or in
      connection with the Agreement, the Term Loan Note, Note, the Continental
      Term Loan Note, and all such other documents, agreements, and instruments
      delivered hereunder or as a supplement or amendment thereto or as Secured
      Party may reasonably require from time to time in order to evidence,
      guaranty and/or secure any and all indebtedness of Debtor and/or
      Continental Systems, as the case may be, to Secured Party or to create,
      perfect, continue the perfection or protect the Secured Party's security
      interest in the Collateral or any of the other collateral specified in the
      other Transaction Documents.

      2. Section 9.26. of the Agreement is hereby amended in its entirety to
read as follows:

            (a) The Debtor and its Consolidated Subsidiaries shall maintain, on
      a consolidated basis, a ratio of Total Liabilities to Tangible Net Worth
      of not greater than (to be tested quarterly based upon the financial
      statements required to be presented to Secured Party pursuant to Section
      9.1. of the Agreement):

            during the period commencing as of the date hereof and thereafter,
            while any Indebtedness remains outstanding, 1.50 to 1.

            (b) The Debtor and its Consolidated Subsidiaries shall maintain, on
      a consolidated basis, a minimum Tangible Net Worth (to be tested quarterly
      based upon the financial statements required to be presented to Secured
      Party pursuant to Section 9.1. hereof) of not less than:

            (i) during the period commencing on June 30, 2001 through June 30,
            2002, $23,258,000, and


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            (ii) during the period commencing on July 1, 2002 through June 29,
            2003, $27,000,000, and

            (iii) during the period commencing on June 30, 2003 through June 29,
            2004, and thereafter while any Indebtedness remains outstanding,
            $30,000,000.

            (c) At all times, Debtor and its Consolidated Subsidiaries shall
      maintain, on a consolidated basis, a ratio of Current Assets to Current
      Liabilities, to be tested each fiscal quarter end of each fiscal year,
      based upon the financial statements required to be presented to Secured
      Party pursuant to Section 9.1. of the Agreement:

            (i) of not less than 3.50 to 1 from the date hereof through the
            fiscal year ending June 30, 2001, and

            (ii) of not less than 3.75 to 1 from July 1, 2001 through the fiscal
            year ending June 30, 2002, and

            (iv) of not less than 4.00 to 1 from July 1, 2002 through the fiscal
            year ending June 30, 2003, and thereafter while any Indebtedness
            remains outstanding.

            (d) From the period commencing on June 30, 2001 and through June 30,
      2001, Debtor and its Consolidated Subsidiaries shall maintain, on a
      consolidated basis, a minimum Debt Service Coverage Ratio of .76 to 1, and
      from the period commencing on July 1, 2002 and thereafter, while any
      Indebtedness remains outstanding, Debtor and its Consolidated Subsidiaries
      shall maintain, on a consolidated basis, a minimum Debt Service Coverage
      Ratio of 1.25 to 1, to be tested at the end of each fiscal year, based
      upon the financial statements required to be presented to Secured Party
      pursuant to Section 9.1 of the Agreement.

            (e) At all times, Debtor and its Consolidated Subsidiaries shall
      maintain, on


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      a consolidated basis, a ratio of the aggregate of cash plus total
      Receivables to Current Liabilities, to be tested each fiscal quarter end
      of each fiscal year, based upon the financial statements required to be
      presented to Secured Party pursuant to Section 9.1. of the Agreement:

                  from the date hereof through the fiscal year ending June 30,
            2001, and thereafter while any Indebtedness remains outstanding, of
            not less than 1.25 to 1.

            (f) During any fiscal year, the Debtor and its Consolidated
      Subsidiaries shall not cause Capital Expenditures of Debtor and its
      Consolidated Subsidiaries to exceed, on a combined basis, $1,250,000 per
      fiscal year.

            (g) The Debtor and its Consolidated Subsidiaries shall maintain, on
      a consolidated basis, a ratio of Funded Debt to EBIDTA (to be tested
      quarterly, on a rolling four quarter basis, based upon the financial
      statements required to be presented to Secured Party pursuant to Section
      9.1 hereof):

            (i) of not greater than 6.124 to 1 from June 30, 2001 through the
            period ending June 30, 2002, and

            (ii) of not greater than 3.00 to 1 from July 1, 2002 through the
            period ending June 29, 2003, and

            (iii) of not greater than 2.00 to 1 from June 30, 2003 through the
            period ending June 29, 2004, and thereafter while any Indebtedness
            remains outstanding.

            (h) At all times while any Indebtedness remains outstanding, the
      Debtor and its Consolidated Subsidiaries shall maintain,


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      on a consolidated basis, not less than fifty (50%) of the value of all of
      their identifiable assets (as disclosed in the 10K statement) in the
      United States, to be tested annually, at each fiscal year end.

      The above ratios of this Section 9.26. are being calculated assuming that
      in the last year of the Agreement; and Advances under the Revolving Credit
      Facility are viewed as long term debt, unless there is an event of default
      which is continuing under the Revolving Credit Facility.

      3. As an inducement to the Bank modifying some of the provisions of
Section 9.26. of the Agreement pursuant to the terms hereof, Debtor represents
and warrants to Secured Party that, as of the date of execution of this
Amendment No. 9, (i) the representations and warranties set forth in Article 4
of the Agreement and the representations and warranties of Debtor and any Third
Party set forth in the other Transaction Documents to which any is a party are
true and correct in all respects, (ii) no event has occurred and is continuing
which constitutes an "Event of Default" under any of the Transaction Documents
(as "Event of Default" is defined in each of those Transaction Documents"),
(iii) Debtor is in compliance with the covenants set forth in Articles 9 and 10
of the Agreement, as modified herein; and(iv) Debtor will pay Secured Party's
reasonable legal fees and disbursements thereof.

      4. Debtor represents and warrants to Secured Party that there are no
offsets, defenses or counterclaims to the payment of the Indebtedness owing
Secured Party, including the Advances, and


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to the continuing general security interest in the Collateral granted to Secured
Party by Debtor as security for payment of the Indebtedness, as fully described
in the Agreement.

      5. Except as modified herein, all other provisions of the Agreement and
the other Transaction Documents remain unmodified and are in full force and
effect.

      6. Capitalized terms not otherwise defined herein shall have the meanings
ascribed to such terms in the Agreement.

      7. This Amendment No. 9 shall be governed by the laws of the State of New
York.


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      IN WITNESS WHEREOF, the parties have executed this Amendment No. 9 to the
Loan and Security Agreement as of the day and year first above written.

                                      HSBC BANK USA F/K/A MARINE MIDLAND BANK

                                      By:
                                               Roger Coleman
                                               Vice President

                                      NAPCO SECURITY SYSTEMS, INC.

                                      By:
                                                Kevin Buchel
                                                Senior Vice President


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STATE OF NEW YORK    )
                     ) SS:
COUNTY OF __________ )

On this ___ day of ___________, 2001, before me, the undersigned, a Notary
Public in and for said State, personally came ROGER COLEMAN, personally known to
me or proved to me on the basis of satisfactory evidence to be the person, whose
name is subscribed to the within instrument and acknowledged to me that he
executed the same in his capacity and that by his signature on the instrument,
the person or entity upon behalf of which the person acted executed the
instrument.

                                      Notary Public

STATE OF NEW YORK    )
                     ) SS:
COUNTY OF __________ )

On this ___ day of ________, 2001, before me, the undersigned, a Notary Public
in and for said State, personally came KEVIN BUCHEL personally known to me or
proved to me on the basis of satisfactory evidence to be the person, whose name
is subscribed to the within instrument and acknowledged to me that he executed
the same in his capacity and that by his signature on the instrument, the person
or entity upon behalf of which the person acted executed the instrument.

                                      Notary Public


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