KOMAG, INCORPORATED
                           DEFERRED COMPENSATION PLAN

                              PLAN AMENDMENT NO. 1

                  The  Komag,   Incorporated   Deferred  Compensation  Plan,  as
established effective March 1, 1995 (the "Plan"), is hereby amended as follows:

                  1.       Section 4.01 is hereby amended,  effective January 1,
1997, to read as follows:

                           4.01 Annual Election. Each Participant shall have the
         right to file a  Deferral  Election  to defer  part of the base  salary
         and/or  Bonus  earned for one or more Years of Service  for which he or
         she  remains a  Participant.  However,  the maximum  amount  which such
         Participant  may defer for each Year of Service  shall be determined in
         accordance with the following formula:

                           - up to  twelve  percent  (12%)  of the  base  salary
         earned  for his or her  period  of  participation  during  that Year of
         Service, plus

                           - up to twelve  percent (12%) of any Bonus earned for
         such Year of Service, less

                           - the maximum  dollar amount which may be contributed
         on the Participant's  behalf as a Section 401(k)  Contribution for that
         Year of Service pursuant to the applicable limitations of Code Sections
         401(k) and 402(g).

                  2.       Section  4.03 is hereby  amended,  effective  June 1,
1996, to read as follows:

                           4.03  Commencement of Deferrals.  The actual deferral
         of base salary pursuant to the  Participant's  Deferral  Election shall
         not begin until such time as the maximum  Section  401(k)  Contribution
         permissible  under the Qualified  Plan and Code Section  402(g) for the
         calendar  year in which that base salary is earned shall have been made
         on the  Participant's  behalf to the

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         QualifiedPlan in accordance with his or her Section 401(k) Election for
         that  year or would  have  been made in the  absence  of any  voluntary
         reduction in the  Participant's  Section 401(k) Election for that year.
         The  portion of the Bonus  which is the  subject  of the  Participant's
         Deferral Election shall in fact be deferred under this Plan only if the
         remaining  portion  of that  Bonus is paid  after the  maximum  Section
         401(k)  Contribution  permissible  under  the  Qualified  Plan and Code
         Section  402(g) for the calendar  year of such payment  shall have been
         made on the  Participant's  behalf to the Qualified  Plan in accordance
         with his or her  Section  401(k)  Election  for that year or would have
         been made in the absence of any reduction in the participant's  Section
         401(k)  Election for that year. In the event there is no Section 401(k)
         Election  in effect for the  Participant  at the start of the  calendar
         year to which his or her Deferral  Election  pertains,  then the actual
         deferral of base salary pursuant to that Deferral  Election shall begin
         at such time as the maximum  Section  401(k)  Contribution  permissible
         under the Qualified Plan and Code Section 402(g) for that calendar year
         would have been made on the Participant's  behalf to the Qualified Plan
         had there been in effect for that  individual a Section 401(k) Election
         covering  ten  percent  (10%) or  (effective  January 1,  1997)  twelve
         percent  (12%)  of his or her  eligible  earnings  for the  year,  with
         earnings   to  be   imputed,   solely  for   purposes  of  such  timing
         determination,  to the Participant (based on his or her annualized rate
         of base  salary) for any portion of that year in which such  individual
         was not an  Employee.  The same  principle  shall be in effect  for the
         portion of any Bonus  subject to the  Deferral  Election  filed by such
         Participant.

                  3.       Except as  modified by this Plan  Amendment,  all the
terms and  provisions  of the Plan shall  continue in full force and effect.

         IN WITNESS WHEREOF,  Komag,  Incorporated has caused this instrument to
be executed on its behalf by a duly authorized officer on ____ day of __________
June, 1996.

                                                     KOMAG, INCORPORATED

                                                     By: _____________________

                                                     Title: __________________