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                                 EXHIBIT 10.67

    AMENDMENT OF CREDIT AGREEMENT BETWEEN BANK OF AMERICA NT & SA AND THE
                         COMPANY DATED MARCH 31, 1994
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                     EIGHTH AMENDMENT TO CREDIT AGREEMENT

         This EIGHTH AMENDMENT TO CREDIT AGREEMENT (this "Amendment"), dated as
of  March 31, 1994,  is entered into by and between KLA INSTRUMENTS
CORPORATION (the "Borrower") and BANK OF AMERICA NATIONAL TRUST AND SAVINGS
ASSOCIATION ("the Bank").

                                    Recitals

         A.  The Bank and the Borrower are parties to a Credit Agreement, dated
as of November 15, 1991 (the "Original Credit Agreement"),  as amended by a
Waiver and First Amendment,  dated as of July 29, 1992, by a Second Amendment
to Credit Agreement,  dated as of October 28, 1992, by a Third Amendment to
Credit Agreement,  dated as of December 31, 1992, by a Fourth Amendment to
Credit Agreement,  dated as of February 28, 1993, by a Fifth Amendment to
Credit Agreement, dated as of March 31, 1993, by a Sixth Amendment to Credit
Agreement, dated as of June 1, 1993 and by a Seventh Amendment to Credit
Agreement, dated as of December 31, 1993 (the Original Credit Agreement, as so
amended, is referred to herein as the "Credit Agreement") , pursuant to which
the Bank has extended certain credit facilities to the Borrower and certain of
its subsidiaries.

         B.  The Borrower has requested that the Bank extend the Credit
Agreement, as set forth in this Eighth Amendment.

         C.   The Bank is willing to amend the Credit Agreement subject to the
terms and conditions of this Amendment.

         NOW, THEREFORE, for valuable consideration, the receipt and adequacy
of which are hereby acknowledged, the parties hereto hereby agree as follows:


         1.   Defined Terms.  Unless otherwise defined herein, capitalized
terms used herein shall have the meanings, if any, assigned to them in the
Credit Agreement.


         2.   Amendments to Credit Agreement.

                 (a)   The first sentence of Paragraph 1.1 of the Credit
         Agreement is hereby amended by replacing the phrase "March 31, 1994"
         with the phrase "April 30, 1994".





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                 (b)   The sixth sentence of Paragraph 1.2(b) of the Credit
         Agreement is hereby amended by replacing the phrase "March 31, 1994"
         with the phrase "April 30, 1994".

                 (c)  The first sentence of Paragraph 1.9 of the Credit
         Agreement             is hereby amended by replacing the phrase "March
         31, 1994" with the phrase "April 30, 1994".

                 (d)  The second sentence of Paragraph 1.9 of the Credit
         Agreement is hereby amended by replacing the phrase "and the last
         period which shall end on March 31, 1994" with the phrase "and the
         last period which shall end on April 30, 1994".

                 (e)  The third sentence of Paragraph 1.9 of the Credit
         Agreement is hereby amended by replacing the phrase "March 31, 1994"
         with the phrase "April 30, 1994".


         3.   Representations and Warranties.   The Borrower hereby represents
              and warrants to the Bank as follows:

                 (a)  No Event of Default has occurred and is continuing, and
         no event has occurred or condition exists which with notice or the
         passage of time would become an Event of Default.

                 (b)  The execution, delivery, and performance by the Borrower
         of this Amendment have been duly authorized by all necessary corporate
         and other action and do not and will not require any registration
         with, consent or approval of, notice to or action by, any person
         (including any governmental agency) in order to be effective and
         enforceable.  The Credit Agreement as amended by this Amendment
         constitutes the legal, valid, and binding obligations of the Borrower,
         enforceable against it in accordance with its respective terms,
         without defense, counterclaim or offset.

                 (c)  All representations and warranties of the Borrower
         contained in the Credit Agreement are true and correct.

                 (d)   The Borrower is entering into this Amendment on the
         basis of its own investigation and for its own reasons, without
         reliance upon the Bank or any other person.


         4.   Effective Date.  This Amendment will become effective as of MARCH
31, 1994 (the" Effective Date") provided that each of the following conditions
precedent has been satisfied:





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                 (a)   The Bank has received from the Borrower a duly executed
         original of this Amendment.

                 (b)   All representations and warranties contained herein are
         true and correct as of the Effective Date.


         5.   Reservation of Rights.  The Borrower acknowledges and agrees that
the execution and delivery by the Bank of this Amendment shall not be deemed to
create a course of dealing or otherwise obligate the Bank to forbear or execute
similar amendments under the same or similar circumstances in the future.

         6. Miscellaneous.

                 (a)   Except as herein expressly amended, all terms,
         covenants, and provisions of the Credit Agreement are and shall remain
         in full force and effect and all references therein to such Credit
         Agreement shall henceforth refer to the Credit Agreement as amended by
         this Amendment.  This Amendment shall be deemed incorporated into, and
         a part of, the Credit Agreement.

                 (b)   This Amendment shall be binding upon and inure to the
         benefit of the parties hereto and thereto and their respective
         successors and assigns.  No third party beneficiaries are intended in
         connection with this Amendment.

                 (c)   This Amendment shall be governed by and construed in
         accordance with the law of the State of California.

                 (d)   This Amendment may be executed in any number of
         counterparts, each of which shall be deemed an original, but all such
         counterparts together shall constitute but one and the same
         instrument.

                 (e)   This Amendment, together with the Credit Agreement,
         contains the entire and exclusive agreement of the parties hereto with
         reference to the matters discussed herein and therein.  This Amendment
         supersedes all prior drafts and communications with respect thereto.
         This Amendment may not be amended except in writing executed by both
         of the parties hereto.

                 (f)   If any term or provision of this Amendment shall be
         deemed prohibited by or invalid under any applicable law, such
         provision shall be invalidated without affecting the remaining
         provisions of this Amendment or the Credit Agreement, respectively.

                 (g)  The Borrower covenants to pay to or reimburse the Bank,
         upon demand, for all costs and expenses ( including allocated costs of
         in-house counsel) incurred in





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          connection with the development, preparation, negotiation, execution 
          and delivery of this Amendment, including without limitation 
          appraisal, audit, search and filing fees incurred in connection 
          therewith.



IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Amendment as of the date first above written.


                                  KLA INSTRUMENTS CORPORATION


                                  By: _________________________________  

                                  Title:



                                  BANK OF AMERICA NATIONAL TRUST
                                  AND SAVINGS ASSOCIATION

                                  By:_____________________________________
                                  Stephen L Parry, Vice President





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