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                                                                 EXHIBIT 10.N


                                         AMENDMENT and WAIVER dated as of
                                         September 14, 1993 to the CREDIT
                                         AGREEMENT dated as of November 21, 1991
                                         (as the same may be further amended,
                                         supplemented or modified from time to
                                         time in accordance with its terms, the
                                         "Credit Agreement"), among NAPCO
                                         SECURITY SYSTEMS, Inc., a Delaware
                                         corporation (the  "Borrower"), the
                                         Guarantors signatory hereto, the
                                         lenders named in SCHEDULE 2.01 and 2.06
                                         annexed hereto (collectively the
                                         "Lenders") and CHEMICAL BANK, as agent
                                         for the Lenders (in such capacity, the
                                         "Agent").

WHEREAS, the Borrower and the Guarantors wish to amend and waive certain
provisions of the Credit Agreement;

WHEREAS, the Lenders and the Agent have consented to amend and waive the
Credit Agreement to reflect the requests herein set forth;

NOW, THEREFORE, the parties hereby agree as follows:

1.        Waiver of Article VII. NEGATIVE COVENANTS Section 7.10. Current Ratio.
          ----------------------------------------------------------------------

          Compliance with Article VII. Section 7.10. of the Credit Agreement is
          hereby waived for the fiscal year ended June 30, 1993 to permit the
          Current Ratio of the Borrower and its Consolidated subsidiaries to be
          less than 2.25 to 1.0 as of the fiscal year ended June 30, 1993
          provided, however; such ratio was not less than 2.11 to 1.0 as of
          such fiscal year end.

   2.     Waiver of Article VII. COVENANTS Section 7.14. Total Unsubordinated
          -------------------------------------------------------------------
          Liabilities to Tangible Net Worth Ratio.
          ----------------------------------------

          Compliance with Article VII. Section 7.14. of the Credit Agreement is
          hereby waived for fiscal year ended June 30, 1993 to permit the ratio
          of Total Unsubordinated Liabilities of the Borrower and its
          Consolidated subsidiaries to Tangible Net Worth of the Borrower and
          its Consolidated subsidiaries plus Consolidated Subordinated
          Indebtedness to be greater than 1.0 to 1.0 as of the fiscal year
          ended June 30, 1993 provided, however; such ratio was not greater
          than 1.04 to 1.0 as of such fiscal year end.
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   3.     Amendment to Article VII. NEGATIVE COVENANTS Section 7.10. Current
          ------------------------------------------------------------------
          Ratio.
          ------

          Article VII Section 7.10. of the Credit Agreement is hereby amended
          by deleting it in its entirety and substituting therefore the
          following:

          "Section 7.10. CURRENT RATIO.  Permit the Current Ratio of the
          Borrower and its Consolidated subsidiaries at any time to be less
          than (i) 2.0 to 1.0 from July 1, 1993 through and including June 30,
          1994 and (ii) 2.25 to 1.0 at any time thereafter."

   4.     Amendment to Article VII. COVENANTS Section 7.14. Total
          -------------------------------------------------------
          Unsubordinated Liabilities to Tangible Net Worth Ratio.
          -------------------------------------------------------

          Article VII. Section 7.14. of the Credit Agreement is hereby amended
          by deleting it in its entirety and substituting therefore the
          following:

          "SECTION 7.14. TOTAL UNSUBORDINATED LIABILITIES TO TANGIBLE NET WORTH
          RATIO.  Permit the ratio of (x) Total Unsubordinated Liabilities of
          the Borrower and its Consolidated subsidiaries, to (y) Tangible Net
          Worth of the Borrower and its Consolidated subsidiaries plus
          Consolidated Subordinated Indebtedness, at any time to be greater
          than (i) 1.04 to 1.0 from July 1, 1993 through and including June 30,
          1994 and (ii) 1.0 to 1.0 at any time thereafter.


This AMENDMENT and WAIVER shall be construed and enforced in accordance with
the laws of the State of New York.

Except as expressly amended, waived or consented to hereby, the Credit
Agreement shall remain in full force and effect in accordance with the
original terms thereof.

This AMENDMENT and WAIVER herein contained is limited specifically to the
matters set forth above and does not constitute directly or by implication an
amendment or waiver of any other provision of the Credit Agreement or any
default which may occur or may have occurred under the Credit Agreement.

The Borrower hereby represents and warrants that, after giving effect to this
AMENDMENT and WAIVER, no Event of Default or Default exists under the Credit
Agreement or any other related document.

Please be advised that should there be a need for further amendments or
waivers with respect to these covenants or any other covenants, those requests
shall be evaluated by the Agent and the Lenders when formally requested, in
writing, by the Borrower and the Guarantors.
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This AMENDMENT and WAIVER may be executed in two or more counterparts, each of
which shall constitute an original, but all of which when, taken together
shall constitute but one AMENDMENT and WAIVER.  The AMENDMENT and WAIVER shall
become effective when duly executed counterparts hereof which, when taken
together, bear the signatures of each of the parties hereto shall have been
delivered to the Agent.

Capitalized terms used herein and not otherwise defined herein shall have the
same meanings as defined in the Credit Agreement.

IN WITNESS WHEREOF, the Borrower, the Guarantors and the Agent have caused
this AMENDMENT and WAIVER to be duly executed by their duly authorized
officers, all as of the day and year first above written.


                                     NAPCO SECURITY SYSTEMS, INC.



                                     By:  /s/ K. S. Buchel, VP
                                         -----------------------------------
                                     Name:
                                     Title:

                                     Guarantors:


                                     NAPCO SECURITY SYSTEMS INTERNATIONAL INC.
                                     UMI MANUFACTURING CORP.
                                     RALTECH LOGIC, INC.
                                     E.E. ELECTRONIC COMPONENTS, INC.
                                     ALARM LOCK SYSTEMS, INC.
                                     DERRINGER SECURITY SYSTEMS, INC.
                                     
                                     
                                     
                                     By:  /s/ K. S. Buchel, VP
                                         -----------------------------------
                                     Name:
                                     Title:
                                     

CHEMICAL BANK, as Agent and Lender



By: /s/ Frank L. Arceri
    --------------------------
Name: Frank L. Arceri
Title: Vice President