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                                                                   EXHIBIT 10.71


                      EIGHTH AMENDMENT TO CREDIT AGREEMENT


          THIS EIGHTH AMENDMENT TO CREDIT AGREEMENT ("Eighth Amendment") is
                                                      ----------------
effective as of August 3, 1999, and is entered into by and among P-COM, INC., a
Delaware corporation ("Borrower"); the financial institutions signatory hereto
                       --------
(each individually a "Lender" and collectively the "Lenders"); UNION BANK OF
                      ------                        -------
CALIFORNIA, N.A., for itself, as a Lender, and as administrative agent for
Lenders (in such capacity, "Agent"); and BANK OF AMERICA NATIONAL TRUST AND
                            -----
SAVINGS ASSOCIATION (for itself, as a Lender, and as syndication agent for
Lenders (in such capacity, "Syndication Agent").
                            -----------------

                                    RECITALS
                                    --------

          A.  Borrower, Lenders, Agent, and Syndication Agent have entered into
that certain Credit Agreement dated as of May 15, 1998, as amended
(collectively, the "Credit Agreement"), pursuant to which Agent, Syndication
                    ----------------
Agent, and Lenders agreed to provide financial accommodations to or for the
benefit of Borrower upon the terms and conditions contained therein.  Unless
otherwise defined herein, capitalized terms or matters of construction defined
or established in the Credit Agreement shall be applied herein as defined or
established therein.

          B.  Events of Default have occurred and are continuing under Sections
                                                                       --------
6.2(c),  6.2(d) and 6.2(w) of the Credit Agreement for the period ending and as
------   ------     ------
of June 30, 1999 (collectively, the "Applicable Defaults").
                                     -------------------

          C.  Borrower has requested that Agent, Syndication Agent, and Lenders
waive the Applicable Defaults and make certain amendments to the Credit
Agreement in connection therewith.  Agent, Syndication Agent, and Lenders are
willing to do so subject to the terms and conditions of this Eighth Amendment.

                                   AGREEMENT
                                   ---------

          NOW, THEREFORE, in consideration of the continued performance by
Borrower of its promises and obligations under the Credit Agreement and the
other Loan Documents, and for other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, Borrower, Lenders, Agent, and
Syndication Agent hereby agree as follows:

          1.  Ratification and Incorporation of Credit Agreement and Other Loan
              -----------------------------------------------------------------
Documents.  Except as expressly modified under this Eighth Amendment, (a)
---------
Borrower hereby acknowledges, confirms, and ratifies all of the terms and
conditions set forth in, and all of its obligations under, the Credit Agreement
and the other Loan Documents, and (b) all of the terms and conditions set forth
in the Credit Agreement and the other Loan Documents are incorporated

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herein by this reference as if set forth in full herein. Without limiting the
generality of the foregoing, each of Borrower and each other Loan Party
acknowledges and agrees that as of August 3, 1999, the sum of (i) the aggregate
outstanding principal amount of all Loans, plus (ii) the aggregate outstanding
                                           ----
Letter of Credit Usage was $29,750,000. Each of Borrower and each other Loan
Party represents that it has no offset, defense, counterclaim, dispute or
disagreement of any kind or nature whatsoever with respect to the amount of such
Debt.

          2.  Amendments to Credit Agreement.
              ------------------------------

              (a)  The definition of "Qualified Financial Institution" is hereby
deleted in its entirety and the following is substituted therefor:

              "Qualified Financial Institution":   Any Lender, or any
               -------------------------------
          commercial bank organized under the laws of the United States of
          America or of any State thereof and having a combined capital and
          surplus of at least $100,000,000; provided, that, on and after the
                                            --------
          effective date of the Eighth Amendment to Credit Agreement, "Qualified
                                                                       ---------
          Financial Institution" shall mean Silicon Valley Bank.
          ---------------------

              (b)  Section 2.5(a) is hereby amended by deleting the reference to
                   --------------
"$5,000,000" and substituting "$3,425,000" therefor.

              (c)  Clause (vii) of Section 6.1(b) is hereby deleted in its
                                   --------------
entirety and the following is substituted therefor:

              (vii)  as soon as available, but in any event contemporaneously
          with their delivery to any Qualified Financial Institution that
          purchases Borrower's accounts receivable, copies of all receivables
          agings, reports submitted to credit issuers, and accountings for the
          sale, collection of, and rebates on account of any accounts receivable
          transferred thereunder.

              (d)  Clause (iii) of Section 6.2(f) is hereby amended by deleting
the reference to "$25,000,000" and substituting "$7,000,000" therefor.

              (e)  Clause (ii) of Section 6.2(l) is hereby deleted in its
                                  --------------
entirety and the following is substituted therefor:

                   (ii) the Borrower may assign and sell accounts receivable to
          any Qualified Financial Institutions pursuant to the Receivables
          Facilities; provided, that the total outstanding amount of all
                      --------
          purchased receivables under the Receivables Facilities shall not
          exceed $7,000,000 at any time; and provided, further, that the
                                             --------  -------
          Borrower shall not assign or sell any accounts receivable following
          the occurrence and during the continuation of a Potential Event of
          Default or an Event of Default;

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          (f)  Section 7.1 shall be amended as follows: (i) the word "or" shall
               -----------
be added to the end of paragraph (m); and (ii) a new paragraph (n) shall be
added, which paragraph shall read as follows:

               (n)  the Borrower shall default on its obligations under (i) that
certain Exchange Agreement dated June 4, 1999, between Marshall Capital
Management, Inc. and Borrower, as modified by that certain waiver letter dated
August 6, 1999, (ii) that certain Exchange Agreement dated June 4, 1999, between
Capital Ventures International and Borrower, as modified by that certain waiver
letter dated August 9, 1999, or (iii) that certain Exchange Agreement dated June
4, 1999, between Castle Creek Technology Partners LLC and Borrower, as modified
by that certain waiver letter dated August 4, 1999, including, without
limitation, Borrower's obligations under Section 5(d)(ii) of each such Exchange
Agreement;

      3.  Delivery of Documents
          ---------------------

          (a) Projections.  On or before August 30, 1999, the Borrower shall
              -----------
deliver to Agent an updated business plans and other projections, in form
reasonably satisfactory to Agent, with respect to the Borrower and its
Subsidiaries for the period from July 1, 1999 through and including December 31,
1999, it being understood that such business plans and other projections shall
constitute reasonable good faith estimates of the Borrower as to the matters
addressed therein but shall not constitute any guaranty, representation or
warranty as to such matters.  If Borrower has not delivered such updated
projections to Agent and Lenders by such date, then such failure shall
constitute an Event of Default.

          (b) Waiver Letters.  On or before August 12, 1999, the Borrower shall
              --------------
deliver to Agent waiver letters extending the deadlines established in Section
5(d)(ii) of each of the Exchange Agreements referred to in Section 2(f) of this
Eighth Amendment, in form and substance reasonably satisfactory to Agent.  If
Borrower has not delivered such waiver letters to Agent and Lenders by such
date, then such failure shall constitute an Event of Default.

      4.  Waivers by Agent and Lenders.  Subject to satisfaction of each of
          ----------------------------
the conditions set forth in Section 5 of this Eighth Amendment, Agent and
                            ---------
Lenders hereby waive the Applicable Defaults and agree that, with respect to the
Applicable Defaults only, no Default or Event of Default shall be deemed to have
occurred as a result thereof; provided, that such waiver shall not be deemed
                              --------
effective to the extent that any of the following has occurred (a) with respect
to the Applicable Default under Section 6.2(c), Consolidated Tangible Net Worth
                                --------------
as of June 30, 1999 is less than $45,000,000; (b) with respect to the Applicable
Default under Section 6.2(d), Consolidated Pre-Tax Income of the Borrower and
              --------------
its consolidated Subsidiaries for the fiscal quarter ending June 30, 1999
reflects a loss in excess of $(60,000,000); or
(c) with respect to the Applicable Default under Section 6.2(w), Consolidated
                                                 --------------
EBITDA for the fiscal quarter ending June 30, 1999 is less than $(15,000,000).

      5.  Conditions to Effectiveness.  This Eighth Amendment shall become
          ---------------------------
effective on August 3, 1999 (the "Effective Date"), only upon satisfaction of
                                  --------------
each of the following conditions:

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          (a) receipt by Agent of this Eighth Amendment duly executed by
Borrower, Bank of America National Trust and Savings Association, as Syndication
Agent and Lender, and Union Bank of California, N.A., as Agent and Lender;

          (b) receipt by Agent of the attached Guarantor Consents (individually,
a "Guarantor Consent" and collectively, the "Guarantor Consents"), duly executed
   -----------------                         ------------------
by each Guarantor;

          (c) receipt by Agent of the fully-executed Second Amendment to
Intellectual Property Security Agreement, in form and substance satisfactory to
Agent and its counsel;

          (d) receipt by Agent of copies of resolutions, in form and substance
satisfactory to Agent and its counsel, of the Board of Directors or other
authorizing documents of Borrower, authorizing the execution and delivery of
this Eighth Amendment; and

          (e) the absence of any Potential Events of Default or Events of
Default, after giving effect to Section 4 hereof.
                                ---------

      6.  Representations and Warranties.  In order to induce the Lenders to
          ------------------------------
enter into this Eighth Amendment, Borrower represents and warrants to Agent,
Syndication Agent, and Lenders that the following statements are true, correct
and complete as of the Effective Date of this Eighth Amendment:

          (a) Corporate Power and Authority.  Borrower has all requisite
              -----------------------------
corporate power and authority to enter into this Eighth Amendment and to carry
out the transactions contemplated by, and perform its obligations under, the
Credit Agreement as amended by this Eighth Amendment (the "Amended Agreement").
                                                           -----------------
The Certificate of Incorporation and Bylaws of Borrower have not been amended
since the copies previously delivered to Agent, Syndication Agent, and Lenders.

          (b) Authorization of Agreements.  The execution and delivery of this
              ---------------------------
Eighth Amendment and the performance by Borrower of the Amended Agreement have
been duly authorized by all necessary corporate action on the part of Borrower.

          (c) No Conflict.  The execution and delivery by Borrower of this
              -----------
Eighth Amendment do not and will not contravene (i) any law or any governmental
rule or regulation applicable to Borrower, except to the extend not resulting in
a Material Adverse Effect, (ii) the Certificate of Incorporation or Bylaws of
Borrower, (iii) any order, judgment or decree of any court or other agency of
government binding on Borrower, or (iv) any material agreement or instrument
binding on Borrower, except to the extent not resulting in a Material Adverse
Effect.

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          (d) Governmental Consents.  The execution and delivery by Borrower of
              ---------------------
this Eighth Amendment and the performance by Borrower of the Amended Agreement
do not and will not require any registration with, consent or approval of, or
notice to, or other action to, with or by, any federal, state or other
governmental authority or regulatory body (except routine reports required
pursuant to the Securities Exchange Act of 1934, as amended (as such act is
applicable to any Loan Party), which reports will be made in the ordinary course
of business).

          (e) Binding Obligation.  This Eighth Amendment and the Amended
              ------------------
Agreement have been duly executed and delivered by Borrower and are the binding
obligations of Borrower, enforceable against Borrower in accordance with their
respective terms, except in each case as such enforceability may be limited by
bankruptcy, insolvency, reorganization, liquidation, moratorium or other similar
laws and equitable principles relating to or affecting creditors' rights.

          (f) Incorporation of Representations and Warranties From Credit
              -----------------------------------------------------------
Agreement.  The representations and warranties contained in Section 5.1 of the
---------                                                   -----------
Credit Agreement are correct in all material respects on and as of the Effective
Date of this Eighth Amendment as though made on and as of such date, except (a)
to the extent that a particular representation or warranty by its terms
expressly applies only to an earlier date, or (b) to the extent that Borrower or
any other Loan Party, as applicable, has previously advised Agent in writing as
contemplated under the Credit Agreement.

          (g) Absence of Default.  After giving effect to Sections 2, 3 and 4 of
              ------------------                          ----------  -     -
this Eighth Amendment, no event has occurred and is continuing or will result
from the consummation of the transactions contemplated by this Eighth Amendment
that would constitute an Event of Default or a Potential Event of Default.

          7.  Release.
              -------

              (a)  Each Loan Party acknowledges that Agent, Syndication Agent,
and Lenders would not enter into this Eighth Amendment without the Loan Parties'
assurance that each Loan Party has no claims against Agent, Syndication Agent,
or Lenders, or any of such parties' shareholders, officers, directors,
employees, agents, or attorneys arising out of or related to the Loan Documents
or any other agreement between any Loan Party and any Lender. Except for the
obligations arising hereafter under the Amended Agreement, each Loan Party, for
itself and on behalf of its successors, assigns, and present and future
shareholders, officers, directors, employees, agents, and attorneys, hereby
remises, releases and forever discharges each of Agent, Syndication Agent, and
each Lender and their respective present and former shareholders, officers,
directors, employees, agents, attorneys, successors and assigns from any and all
claims, rights, actions, causes of action, suits, liabilities, defenses, damages
and costs that both (a) exist or may exist as of the Effective Date and (b)
arise from or are otherwise related to the Credit Agreement or the other Loan
Documents, any transaction contemplated thereby, the administration of the Loans
and other financial accommodations made thereunder, the collateral security
given in connection therewith, or any related discussions or negotiations, in
each case

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whether known or unknown, suspected or unsuspected. Each Loan Party waives the
provisions of California Civil Code section 1542, which states:

          A general release does not extend to claims which the creditor does
          not know or suspect to exist in his favor at the time of executing the
          release, which if known by him must have materially affected his
          settlement with the debtor.

               (b)  The provisions, waivers and releases set forth in this
section are binding upon each Loan Party and each Loan Party's shareholders,
agents, employees, assigns and successors in interest. The provisions, waivers
and releases of this section shall inure to the benefit of each Lender, Agent,
Syndication Agent, and each such party's shareholders, agents, employees,
officers, directors, assigns and successors in interest as parties to the Credit
Agreement.

               (c)  The provisions of this section shall survive payment in full
of the obligations, full performance of all the terms of this Eighth Agreement
and the Loan Documents, or Agent's or any Lender's actions to exercise any
remedy available under the Loan Documents or otherwise.

               (d)  Each Loan Party warrants and represents that each such Loan
Party is the sole and lawful owner of all right, title and interest in and to
all of the claims released hereby and each such Loan Party has not heretofore
voluntarily, by operation of law or otherwise, assigned or transferred or
purported to assign or transfer to any Person any such claim or any portion
thereof. Each Loan Party shall indemnify and hold harmless each Lender, Agent,
and Syndication Agent, from and against any claim, demand, damage, debt,
liability (including payment of reasonable attorneys' fees and costs actually
incurred whether or not litigation is commenced) based on or arising out of any
assignment or transfer.

            8. Entire Agreement.  This Eighth Amendment, together with the
               ----------------
Credit Agreement and the other Loan Documents, is the entire agreement between
the parties hereto with respect to the subject matter hereof. This Eighth
Amendment supersedes all prior and contemporaneous oral and written agreements
and discussions with respect to the subject matter hereof.

            9.  Miscellaneous.
                -------------

                (a) Counterparts.  This Eighth Amendment may be executed in
                    ------------
identical counterpart copies, each of which shall be an original, but all of
which shall constitute one and the same agreement; signature pages may be
detached from multiple separate counterparts and attached to a single
counterpart so that all signature pages are physically attached to the same
document. Delivery of an executed counterpart of a signature page to this Eighth
Amendment by facsimile transmission shall be effective as delivery of a manually
executed counterpart thereof.

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          (b) Headings.  Section headings used herein are for convenience of
              --------
reference only, are not part of this Eighth Amendment, and are not to be taken
into consideration in interpreting this Eighth Amendment.

          (c) Recitals.  The recitals set forth at the beginning of this Eighth
              --------
Amendment are true and correct, and such recitals are incorporated into and are
a part of this Eighth Amendment.

          (d) Governing Law.  THIS EIGHTH AMENDMENT SHALL BE GOVERNED BY, AND
              -------------
CONSTRUED AND ENFORCED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF
CALIFORNIA APPLICABLE TO CONTRACTS MADE AND PERFORMED IN SUCH STATE, WITHOUT
REGARD TO THE PRINCIPLES THEREOF REGARDING CONFLICT OF LAWS.

          (e) Effect.  Upon the effectiveness of this Eighth Amendment, from and
              ------
after the date hereof, each reference in the Credit Agreement to "this
Agreement," "hereunder," "hereof," or words of like import shall mean and be a
reference to the Credit Agreement as amended hereby and each reference in the
other Loan Documents to the Credit Agreement, "thereunder," "thereof," or words
of like import shall mean and be a reference to the Credit Agreement as amended
hereby.

          (f) No Novation.  Except as expressly provided in this Eighth
              -----------
Amendment, the execution, delivery, and effectiveness of this Eighth Amendment
shall not (i) limit, impair, constitute a waiver of, or otherwise affect any
right, power, or remedy of Agent or any Lender under the Credit Agreement or any
other Loan Document, (ii) constitute a waiver of any provision in the Credit
Agreement or in any of the other Loan Documents, or (iii) alter, modify, amend,
or in any way affect any of the terms, conditions, obligations, covenants, or
agreements contained in the Credit Agreement, all of which are ratified and
affirmed in all respects and shall continue in full force and effect.

          (g) Conflict of Terms.  In the event of any inconsistency between the
              -----------------
provisions of this Eighth Amendment and any provision of the Credit Agreement,
the terms and provisions of this Eighth Amendment shall govern and control.

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<PAGE>

          IN WITNESS WHEREOF, this Eighth Amendment to Credit Agreement has been
duly executed as of the date first written above.

                              P-COM, INC.


                              By: /s/ Robert E. Collins
                                 -------------------------------------
                              Name: Robert E. Collins
                                   -----------------------------------
                              Title: Vice President & CFO
                                    ----------------------------------

                              UNION BANK OF CALIFORNIA, N.A.,
                              as Agent and a Lender


                              By: /s/ Patricia Lee
                                 -------------------------------------
                              Name: Patricia Lee
                                   -----------------------------------
                              Title: Vice President
                                    ----------------------------------

                              BANK OF AMERICA NATIONAL TRUST AND SAVINGS
                              ASSOCIATION, as Syndication Agent and a Lender

                              By: /s/ M. Duncan McAuliffe
                                 -------------------------------------
                              Name: M. Duncan McAuliffe
                                   -----------------------------------
                              Title: Managing Director
                                    ----------------------------------

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                               GUARANTOR CONSENTS

          Each of the undersigned hereby (i) ratifies and reaffirms, as of the
date hereof, all of the provisions of that certain Subsidiary Guaranty in favor
of Agent dated as of May 15, 1998 (the "Guaranty"), (ii) acknowledges receipt of
                                        --------
a copy of the Eighth Amendment to Credit Agreement effective as of August 3,
1999 (the "Eighth Amendment"), (iii) consents to all of the provisions of the
           ----------------
Eighth Amendment, and (iv) acknowledges and agrees that nothing contained in the
Eighth Amendment in any way affects the validity and enforceability of the
Guaranty.


Effective as of August 3, 1999        CONTROL RESOURCES CORPORATION

                                      By: /s/ W.J
                                         -------------------------------------
                                      Name:
                                           -----------------------------------
                                      Title:
                                            ----------------------------------

Effective as of August 3, 1999        P-COM NETWORK SERVICES, INC.

                                      By: /s/ W.J
                                         -------------------------------------
                                      Name:
                                           -----------------------------------
                                      Title:
                                            ----------------------------------

Effective as of August 3, 1999        P-COM FINANCE CORPORATION

                                      By: /s/ W.J
                                         -------------------------------------
                                      Name:
                                           -----------------------------------
                                      Title:
                                            ----------------------------------


Effective as of August 3, 1999        P-COM UNITED KINGDOM, INC.

                                      By: /s/ W.J
                                         -------------------------------------
                                      Name:
                                           -----------------------------------
                                      Title:
                                            ----------------------------------

Effective as of August 3, 1999        TELEMATICS, INC.

                                      By: /s/ W.J
                                         -------------------------------------
                                      Name:
                                           -----------------------------------
                                      Title:
                                            ----------------------------------

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