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                                                                 Exhibit 10.8

                      FIRST AMENDMENT TO CREDIT AGREEMENTS

                  THIS FIRST AMENDMENT TO CREDIT AGREEMENTS, dated as of March
30, 2001 (this "Amendment"), is by and among BLACK BOX CORPORATION OF
PENNSYLVANIA, a Delaware corporation (the "Borrower"), BLACK BOX CORPORATION, a
Delaware corporation (the "Parent"), the other guarantors to the Credit
Agreement and Short Term Credit Agreement (together with the Parent, the
"Guarantors"), the lenders, parties to the Credit Agreement and Short Term
Credit Agreement (the "Lenders") and MELLON BANK, N.A., a national banking
association, as agent for the Lenders (the "Agent").

                              W I T N E S S E T H:

                  WHEREAS, the Borrower, the Guarantors, the Lenders and the
Agent are parties to a Credit Agreement, dated as of April 4, 2000 (the "Credit
Agreement"), pursuant to which the Lenders have agreed, on the terms and subject
to the conditions described therein, to make Loans to the Borrower; and

                  WHEREAS, the Borrower, the Guarantors, the Lenders and the
Agent are parties to a Short Term Credit Agreement, dated as of April 4, 2000
(the "Short Term Credit Agreement" and together with the Credit Agreement, the
"Credit Agreements"), pursuant to which the Lenders have agreed, on the terms
and subject to the conditions described therein, to make Loans to the Borrower;
and

                  WHEREAS, the Borrower has requested the Lenders and the Agent
to make certain changes to the Credit Agreements; and

                  WHEREAS, the Lenders and the Agent are willing to amend the
Credit Agreements as set forth below; and

                  WHEREAS, capitalized terms used herein and not otherwise
defined shall have the meanings assigned to them in the Credit Agreement or the
Short Term Credit Agreement as applicable;

                  NOW, THEREFORE, in consideration of the premises and of the
mutual covenants herein contained, and intending to be legally bound hereby, the
parties hereto agree as follows:

                  SECTION 1. Amendments to Credit Agreement. The Credit
Agreement is hereby amended as follows:

                  1.1. Section 3.01(c) of the Credit Agreement is amended by
deleting the text of such section in its entirety and inserting the following in
lieu thereof:

                           "Terms of Letters of Credit. The Borrower shall not
         request any Letter of Credit to be issued, except within the following
         limitations: (i) no Letter of Credit shall be issued on or after the
         Revolving Credit Maturity Date, (ii) at the time any Letter of Credit
         is issued, the aggregate Revolving Credit Extensions of Credit (after
         giving effect to issuance of the requested Letter of Credit) shall not


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         exceed the sum of the Revolving Credit Committed Amounts of the Lenders
         at such time, (iii) each Letter of Credit shall have an expiration date
         no later than one (1) year from the date of issuance thereof, or if
         earlier thirty (30) days before the Revolving Credit Maturity Date,
         (iv) each Letter of Credit shall be denominated in Dollars or any Other
         Currency , (v) each Letter of Credit shall be payable only against
         sight drafts (and not time drafts) and such other certificates and
         documents as may be required by such Letter of Credit, and (vi) at any
         time any Letter of Credit is issued, the aggregate Letter of Credit
         Obligations (after giving effect to issuance of the requested Letter of
         Credit) shall not exceed the Dollar Equivalent of $15,000,000."

                  SECTION 2. Amendments to Short Term Credit Agreement. The
Short Term Credit Agreement is hereby amended as follows:

                  2.1. The definition of the term "Revolving Credit Maturity
Date" appearing in Section 1.01 of the Short Term Credit Agreement is hereby
amended to read as follows:

                           "Revolving Credit Maturity Date" shall mean April 3,
         2002.

                  2.2. Section 2.13(d) of the Short Term Credit Agreement is
amended by deleting the text of such section in its entirety and inserting the
following in lieu thereof:

                           "Amortization and Maturity. The principal of the Term
         Loan made on the Revolving Credit Maturity Date shall be due and
         payable in four (4) equal quarterly installments each in an amount
         equal to one-fourth (1/4) of the original amount of the Term Loan,
         commencing on the last Business Day of the fiscal quarter next
         following the Revolving Credit Maturity Date and continuing on the last
         Business Day of each fiscal quarter thereafter, with the final
         installment of the then unpaid principal amount of the Term Loan due
         and payable on the day which is the first anniversary of the Revolving
         Credit Maturity Date."

                  SECTION 3.  Miscellaneous.

                  3.1. Effect of Amendment. This Amendment shall become
effective upon the execution by the Borrower and delivery to the Agent. Each of
the Credit Agreement and the Short Term Credit Agreement, as amended by this
Amendment, is in all respects ratified, approved and confirmed and shall, as so
amended, remain in full force and effect.

                  3.2. Governing Law. This Amendment shall be governed by and
construed in accordance with the laws of the Commonwealth of Pennsylvania
without giving effect to the conflict of law principles thereof.

                  3.3. Counterparts. This Amendment may be executed in any
number of counterparts and by the different parties hereto on separate
counterparts, each of which, when so executed, shall be deemed an original, but
all such counterparts shall constitute but one and the same instrument.

                         [SIGNATURES BEGIN ON NEXT PAGE]


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                       SIGNATURE PAGE 1 OF 8 TO AMENDMENT

                  IN WITNESS WHEREOF, the parties hereto, by their officers
thereunto duly authorized, have executed and delivered this Amendment as of the
date first above written.

                             BORROWER:

                             BLACK BOX CORPORATION OF
                             PENNSYLVANIA

                             By:
                                      ------------------------------------------

                             Name:
                                      ------------------------------------------

                             Title:
                                       -----------------------------------------



                             GUARANTORS:

                             BLACK BOX CORPORATION and each of the
                             DOMESTIC SUBSIDIARIES listed on Annex C
                             attached hereto and made a part hereof

                             By:
                                      ------------------------------------------

                             Name:
                                      ------------------------------------------

                             Title:
                                       -----------------------------------------

                                      of Black Box Corporation and of each of
                                      the Domestic Subsidiaries listed on
                                      Annex C hereto



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                       SIGNATURE PAGE 2 OF 8 TO AMENDMENT

                              AGENT:

                              MELLON BANK, N.A.

                              By:
                                       ----------------------------------------

                              Name:
                                       ----------------------------------------

                              Title:
                                        ---------------------------------------



                              BANKS:

                              MELLON BANK, N.A.

                              By:
                                       ----------------------------------------

                              Name:
                                       ----------------------------------------

                              Title:
                                        ---------------------------------------



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                       SIGNATURE PAGE 3 OF 8 TO AMENDMENT

                              FIRST UNION NATIONAL BANK

                              By:
                                       ----------------------------------------

                              Name:
                                       ----------------------------------------

                              Title:
                                        ---------------------------------------



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                       SIGNATURE PAGE 4 OF 8 TO AMENDMENT

                              FLEET NATIONAL BANK

                              By:
                                       ----------------------------------------

                              Name:
                                       ----------------------------------------

                              Title:
                                        ---------------------------------------





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                       SIGNATURE PAGE 5 OF 8 TO AMENDMENT

                              NATIONAL CITY BANK OF
                              PENNSYLVANIA

                              By:
                                       ----------------------------------------

                              Name:
                                       ----------------------------------------

                              Title:
                                        ---------------------------------------



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                       SIGNATURE PAGE 6 OF 8 TO AMENDMENT

                                COMERICA BANK

                                By:
                                         --------------------------------------

                                Name:
                                         --------------------------------------

                                Title:
                                          -------------------------------------



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                       SIGNATURE PAGE 7 OF 8 TO AMENDMENT

                                FIRSTAR BANK, N.A.

                                By:
                                         --------------------------------------

                                Name:
                                         --------------------------------------

                                Title:
                                          -------------------------------------



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                       SIGNATURE PAGE 8 OF 8 TO AMENDMENT

                             KEYBANK NATIONAL ASSOCIATION

                             By:
                                      ----------------------------------------

                             Name:
                                      ----------------------------------------

                             Title:
                                       ---------------------------------------



<PAGE>   11



                                     ANNEX C