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                                                                    EXHIBIT 10.1




                            [WELLS FARGO LETTERHEAD]




                                  May 15, 1997

Intevac, Inc.
3560 Bassett Street
Santa Clara CA 95054

Gentlemen:

         This letter is to confirm the changes agreed upon between Wells Fargo
Bank, National Association ("Bank") and Intevac, Inc. ("Borrower") to the terms
and conditions of that certain letter agreement between Bank and Borrower dated
as of April 30, 1997, as amended from time to time (the "Agreement"). For
valuable consideration, the receipt and sufficiency of which are hereby
acknowledged, Bank and Borrower hereby agree that the Agreement shall be amended
as follows to reflect said changes.

         1. Paragraph I.1(b) shall be renumbered to Paragraph I.1(c).

         2. The following is hereby added to the Agreement as new Paragraph
1.1(b):

                  "(b) Letter of Credit Subfeature. As a subfeature under the
         Line of Credit, Bank agrees from time to time during the term thereof
         to issue standby letters of credit for the account of Borrower to
         finance Borrower's acquisitions of business operations (each, a "Letter
         of Credit" and collectively, "Letters of Credit"); provided however,
         that the form and substance of each Letter of Credit shall be subject
         to approval by Bank, in its sole discretion; and provided further, that
         the aggregate undrawn amount of all outstanding Letters of Credit shall
         not at any time exceed Ten Million Dollars ($10,000,000.00). No Letter
         of Credit shall have an expiration date subsequent to the maturity date
         of the Line of Credit. The undrawn amount of all Letters of Credit
         shall be reserved under the Line of Credit and shall not be available
         for borrowings thereunder. Each Letter of Credit shall be



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         subject to the additional terms and conditions of the Letter of Credit
         Agreement and related documents, if any, required by Bank in connection
         with the issuance thereof. Each draft paid by Bank under a Letter of
         Credit shall be deemed an advance under the Line of Credit and shall be
         repaid by Borrower in accordance with the terms and conditions of this
         letter applicable to such advances; provided however, that if advances
         under the Line of Credit are not available, for any reason, at the time
         any draft is paid by Bank, then Borrower shall immediately pay to Bank
         the full amount of such draft, together with interest thereon from the
         date such amount is paid by Bank to the date such amount is fully
         repaid by Borrower, at the rate of interest applicable to advances
         under the Line of Credit. In such event Borrower agrees that Bank, in
         its sole discretion, may debit any demand deposit account maintained by
         Borrower with Bank for the amount of any such draft."

         3. The following is hereby added to the Agreement as Paragraph II.4:

                  "4. Letter of Credit Fees. Borrower shall pay to Bank fees
         upon the issuance of each Letter of Credit, upon the payment or
         negotiation by Bank of each draft under any Letter of Credit and upon
         the occurrence of any other activity with respect to any Letter of
         Credit (including without limitation, the transfer, amendment or
         cancellation of any Letter of Credit) determined in accordance with
         Bank's standard fees and charges then in effect for such activity."

         4. Except as specifically provided herein, all terms and conditions of
the Agreement remain in full force and effect, without waiver or modification.
All terms defined in the Agreement shall have the same meaning when used herein.
This letter and the Agreement shall be read together, as one document.

         5. Borrower hereby remakes all representations and warranties contained
in the Agreement and reaffirms all covenants set forth therein. Borrower further
certifies that as of the date of Borrower's acknowledgment set forth below there
exists no default or defined event of default under the Agreement or any
promissory note or other contract, instrument or document executed in connection
therewith, nor any condition, act or event




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May 15, 1997
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which with the giving of notice or the passage of time or both would constitute
such a default or defined event of default.

         Your acknowledgment of this letter shall constitute acceptance of the
foregoing terms and conditions.

                                        Sincerely,

                                        WELLS FARGO BANK,
                                        NATIONAL ASSOCIATION


                                        By:
                                           -----------------------------------
                                             John Adams
                                             Vice President


Acknowledged and accepted as of 5-27-97:

INTEVAC, INC.


By:  /s/  CHARLES B. EDDY III
   --------------------------------
     Charles B. Eddy III
     Chief Financial Officer