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                                                                   EXHIBIT 10.51
                                                                   
                        AMENDMENT TO OPTION AGREEMENT
                                          
        AMENDMENT made as of this 14th day of August 1995, by and between HADCO
CORPORATION, a Massachusetts corporation with a usual place of business in
Salem, New Hampshire (hereinafter the  "Company") and PATRICK SWEENEY, of
Acton, Massachusetts, (hereinafter the "Optionee"), to the Option Agreement
between the  parties dated November 29, 1993.

        WHEREAS, the parties have reached an understanding regarding a change
of employment status of the Optionee and have, contemporaneously with the
execution of this Amendment to Option Agreement, executed an Agreement
providing for certain compensation, benefits and consulting arrangements
between the Company and the Optionee; and

        WHEREAS, as part of this understanding and new compensation 
arrangement, the parties have agreed to amend the provisions of the Option
Agreement between the parties dated November 29, 1993, and to cancel certain
of the options previously granted under that Agreement.

        NOW, THEREFORE, in consideration of the premises and other mutual
covenants contained herein, and in furtherance of the parties' Agreement to
amend the Option Agreement, it is agreed between the parties as follows:

        1.   Section 1 of the Option Agreement is amended to change the number
of shares subject to the option from 20,000 to 3,000.  The option with respect
to the balance of 17,000 shares is hereby cancelled, being that portion of the
option which was scheduled to accrue at any time subsequent to August 15,
1995.

        2.   The schedule in Section 2(a) of the Option Agreement is changed
to the following:
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Cumulative Percent of Option     
Shares That May Be Purchased                    Date of Vesting
----------------------------                    ---------------
                                          
                   <S>                          <C>
                   100%                         One year anniversary of the date of grant
                                          
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        The effect of this Amendment is to fully vest the right to exercise the
option and purchase the currently outstanding Option Shares (3,000 shares) at
present.

        3.   Except as specifically set forth herein, the original terms and
provisions of the Option Agreement dated November 29, 1993, between the parties
are hereby ratified and confirmed.

        IN WITNESS WHEREOF, the parties have executed this Amendment as of the
day and year first above written.

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<CAPTION>


Witness:
<S>                                             <C>
/s/ Pat Randall                                 /s/ Patrick Sweeney      
---------------------                           ----------------------------
                                                OPTIONEE
         
                                                HADCO CORPORATION
         
/s/ Carol Walton                                /s/ Andrew E. Lietz      
---------------------                           ----------------------------
         
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