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                                                                     EXHIBIT 4.2





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                          REGISTRATION RIGHTS AGREEMENT

                                  BY AND AMONG


                               KOMAG, INCORPORATED

                                       AND

           THE HOLDERS OF REGISTRABLE SECURITIES LISTED ON SCHEDULE 1

                            DATED AS OF JUNE 30, 2002

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<PAGE>

                                TABLE OF CONTENTS


<TABLE>
<S>        <C>                                                               <C>
SECTION 1. Definitions........................................................1

SECTION 2. Securities Subject to this Agreement...............................4
               (a) Registrable Securities.....................................4
               (b) Holders of Registrable Securities..........................4

SECTION 3. Registrations......................................................4
               (a) Piggyback Registration.....................................4
               (b) Shelf Registrations........................................6
               (c) Liquidated Damages.........................................8
               (d) Assignment of Registration Rights..........................8

SECTION 4. Registration Procedures............................................9

SECTION 5. Registration Expenses.............................................13

SECTION 6. Indemnification...................................................15
               (a) Indemnification by Company................................15
               (b) Indemnification by Holder of Registrable Securities.......16
               (c) Contribution..............................................16

SECTION 7. Rule 144..........................................................17

SECTION 8. Participation in Underwritten Registrations.......................17

SECTION 9. Miscellaneous.....................................................18
               (a) Termination...............................................18
               (b) No Inconsistent Agreements................................18
               (c) Adjustments Affecting Registrable Securities..............18
               (d) Amendments and Waivers....................................18
               (e) Notices...................................................18
               (f) Successors and Assigns....................................19
               (g) Counterparts..............................................19
               (h) Headings..................................................19
               (i) Governing Law.............................................19
               (j) Severability..............................................19
               (k) Entire Agreement..........................................19
</TABLE>


-----------------------

        This Table of Contents does not constitute a part of this Agreement or
        have any bearing upon the interpretation of any of its terms or
        provisions.

<PAGE>

               This REGISTRATION RIGHTS AGREEMENT (this "Agreement") dated as of
June 30, 2002 is made and entered into by and among Komag, Incorporated, a
Delaware corporation (the "Company"), and the holders of Registrable Securities
set forth on Schedule 1 hereto (together with their respective successors and
permitted assigns, the "Holders"). Capitalized terms not otherwise defined
herein have the meanings set forth in Section 1.

               WHEREAS, on August 24, 2001, the Company filed a voluntary
petition for reorganization under Chapter 11 of the title 11, 11 U.S.C.
Sections 101 - 1330 (as amended, the "Bankruptcy Code"), with the United States
Bankruptcy Court for the Northern District of California (San Jose Division)
(the "Bankruptcy Court"), commencing Chapter 11 Case No.
01-54143-JRG (the "Bankruptcy Case");

               WHEREAS, on September 20, 2001, the Company filed that certain
Plan of Reorganization of the Company (as amended, supplemented and modified
from time to time, the "Plan") in the Bankruptcy Case;

               WHEREAS, the Bankruptcy Court confirmed the Plan pursuant to the
order under Section 1129 of the Bankruptcy Code, dated May 9, 2002 (the
"Confirmation Order");

               WHEREAS, pursuant to the Plan and the Confirmation Order, the
Holders will receive in the aggregate on the Effective Date (as defined in the
Plan), among other things, twelve million five hundred and twenty-five thousand
(12,525,000) shares of Common Stock and Notes in the principal amount of
$128,832,000; and

               WHEREAS, in order to induce the Holders to support the Plan, the
Company has agreed to provide the registration rights set forth in this
Agreement.

               NOW, THEREFORE, in consideration of the mutual covenants and
agreements set forth in this Agreement, and for other good and valuable
consideration, the receipt and sufficiency of which are hereby acknowledged, the
parties hereto agree as follows:

        SECTION 1. Definitions.

        As used in this Agreement, the following capitalized terms shall have
the following meanings:

        Agreement: See the preamble hereof.

        Allowable Grace Period: See Section 3(b)(5) hereof.

        Common Stock: The common stock, $0.01 par value per share, of the
Company.

        Common Stock Liquidated Damages. See Section 3(c) hereof.

        Company: See the preamble hereof.

        Effectiveness Period: See Section 3(b)(1) hereof.

        Exchange Act: The Securities Exchange Act of 1934, as amended from time
to time.

<PAGE>

        Filing Deadline: See Section 3(b)(1).

        Grace Period: See Section 3(b)(5).

        Holders: See the preamble hereof.

        Indemnified Holder: See Section 6(a).

        Indenture: The Indenture, dated as of the Effective Date, between the
Company and The Bank of New York, as trustee, with respect to the Notes, as
amended or supplemented from time to time in accordance with the terms thereof.

        Initial Shelf Registration: See Section 3(b)(1) hereof.

        Liquidated Damages: Collectively, the Common Stock Liquidated Damages
and the Note Liquidated Damages.

        Majority Common Stock Holders: The holders of a majority of the
outstanding Registrable Common Stock Securities.

        Majority Note Holders: The holders of a majority in aggregate principal
amount of the outstanding Registrable Note Securities.

        NASD: National Association of Securities Dealers, Inc.

        Note Liquidated Damages: See Section 3(c) hereof.

        Notes: The Senior Secured Notes due 2007, as amended or supplemented
from time to time issued by the Company pursuant to the terms of the Indenture.

        Person: An individual, partnership, corporation, limited liability
company, trust or unincorporated organization, or other business entity, or a
government or agency or political subdivision thereof.

        Piggyback Registration: See Section 3(a).

        Piggyback Securities: See Section 3(a)(2).

        Plan: See the recitals hereof.

        Prospectus: The prospectus included in any Registration Statement, as
amended or supplemented by any prospectus supplement with respect to the terms
of the offering of any portion of the Registrable Securities covered by the
Registration Statement and by all other amendments and supplements to the
prospectus, including post-effective amendments and all material incorporated by
reference in such prospectus.

        Registrable Common Stock Securities: The shares of Common Stock
originally issued to the Holders pursuant to the Plan and any securities which
may be issued or distributed with respect to, or in exchange for, such
Registrable Common Stock Securities pursuant to a stock


                                       2
<PAGE>

dividend, stock split or other distribution, merger, consolidation,
recapitalization or reclassification or similar transaction; provided, however,
that any such Registrable Common Stock Securities shall cease to be Registrable
Common Stock Securities to the extent (i) a Registration Statement with respect
to the sale of such Registrable Common Stock Securities has been declared
effective under the Securities Act and such Registrable Common Stock Securities
have been disposed of in accordance with the plan of distribution set forth in
such Registration Statement, (ii) subject to Section 3(d) hereof, such
Registrable Common Stock Securities are transferred pursuant to Rule 144 (or any
similar provision then in force) under the Securities Act or (iii) such
Registrable Common Stock Securities shall have been otherwise transferred
pursuant to an exemption from the securities laws, if subsequent transfers of
such securities will not require registration or qualification of such
securities under the Securities Act or any state securities laws then in force
and all restrictive legends shall have been removed from the certificates
representing such Registrable Common Stock Securities; provided, further,
however, that any securities that have ceased to be Registrable Common Stock
Securities cannot thereafter become Registrable Common Stock Securities, and any
securities that are issued or distributed in respect of securities that have
ceased to be Registrable Common Stock Securities are not Registrable Common
Stock Securities.

        Registrable Note Securities: The Notes originally issued to the Holders
pursuant to the Plan; provided, however, that any such Registrable Note
Securities shall cease to be Registrable Note Securities to the extent (i) a
Registration Statement with respect to the sale of such Registrable Note
Securities has been declared effective under the Securities Act and such
Registrable Note Securities have been disposed of in accordance with the plan of
distribution set forth in such Registration Statement, (ii) subject to Section
3(d) hereof, such Registrable Note Securities are transferred pursuant to Rule
144 (or any similar provision then in force) under the Securities Act or (iii)
such Registrable Note Securities shall have been otherwise transferred pursuant
to an exemption from the securities laws, if subsequent transfers of such
securities will not require registration or qualification of such securities
under the Securities Act or any state securities laws then in force and all
restrictive legends shall have been removed from the certificates representing
such Registrable Note Securities; provided, further, however, that any
securities that have ceased to be Registrable Note Securities cannot thereafter
become Registrable Note Securities, and any securities that are distributed in
respect of securities that have ceased to be Registrable Note Securities are not
Registrable Note Securities.

        Registrable Securities: Collectively, the Registrable Common Stock
Securities and the Registrable Note Securities.

        Registration: A Piggyback Registration (as defined in Section 3(a)) or
Shelf Registration of the Company's securities for sale to the public under a
Registration Statement.

        Registration Default. See Section 3(c) hereof.

        Registration Expenses: See Section 5(a) hereof.

        Registration Statement: Any registration statement of the Company filed
with the SEC under the rules and regulations promulgated under the Securities
Act, including the Prospectus, amendments and supplements to such Registration
Statement, including post-effective


                                       3
<PAGE>

amendments, and all exhibits and all material incorporated by reference in such
Registration Statement.

        Securities Act: The Securities Act of 1933, as amended from time to
time.

        SEC: The Securities and Exchange Commission.

        Shelf Registration: The Initial Shelf Registration, any Short Form Shelf
Registration and any Subsequent Shelf Registration.

        Short Form Shelf Registration: See Section 3(b)(2) hereof.

        Subsequent Shelf Registration: See Section 3(b)(3) hereof.

        Underwritten Registration or Underwritten Offering: A Registration in
which securities of the Company are sold to an underwriter for reoffering to the
public.

        SECTION 2. Securities Subject to this Agreement.

               (a) Registrable Securities. The securities entitled to the
benefits of this Agreement are the Registrable Securities.

               (b) Holders of Registrable Securities. Subject to Section 10(f),
a Person is deemed to be a Holder of Registrable Securities whenever such Person
owns Registrable Securities.

        SECTION 3. Registrations.

               (a) Piggyback Registrations.

                      (1) Participation. Subject to Section 3(a)(2) hereof, if
        at any time from and after the date hereof the Company proposes to file
        a Registration Statement under the Securities Act with respect to any
        offering of any of its securities of the same class as any of the
        Registrable Common Stock Securities (excluding a registration relating
        to a transaction under Rule 145 of the Act), whether or not by the
        Company for its own account (other than (i) a registration on Form S-4
        or S-8 or any successor form to such Forms, or (ii) any registration of
        securities as it relates to an offering and sale by any employee stock
        plan or other employee benefit plan arrangement), then, as promptly as
        practicable, the Company shall give written notice of such proposed
        filing to each Holder of Registrable Common Stock Securities and such
        notice shall offer the Holders of Registrable Common Stock Securities
        the opportunity to register such number of Registrable Common Stock
        Securities as each such Holder may request (a "Piggyback Registration").
        Subject to Section 3(b), the Company shall include in such Registration
        Statement all Registrable Common Stock Securities requested within 15
        days after the receipt of any such notice (which request shall specify
        the Registrable Common Stock Securities intended to be disposed of by
        such Holder) to be included in the Registration for such offering
        pursuant to a Piggyback Registration. Each Holder of Registrable Common
        Stock Securities shall be permitted to withdraw all or part of such
        Holder's Registrable Common Stock Securities from a Piggyback
        Registration at any time prior to the earlier of the effective date or
        any request


                                       4
<PAGE>

        for the acceleration of the effective date thereof. The Company shall
        keep any Registration Statement filed pursuant to this Section 3(a)(1)
        current and effective for a period expiring on the earlier of six months
        from the effective date of such Registration Statement or until all of
        the Registrable Common Stock Securities registered pursuant to this
        Section 3(a) have been sold. Notwithstanding the foregoing, in the event
        that, in the good faith judgment of the Company's Board of Directors, it
        is advisable to suspend use of the Prospectus (solely with respect to a
        Piggyback Registration) due to impending corporate developments, public
        filings with the SEC or similar events, the Company shall deliver
        promptly a written certificate to each Holder of Registrable Common
        Stock Securities included in such Registration Statement and the
        managing underwriters, if any, to the effect that the use of the
        Prospectus is to be suspended until the Company shall deliver a written
        notice that the use of the Prospectus may be resumed. Thereafter, the
        use of the Prospectus shall be suspended, and the Company shall not be
        required to maintain the effectiveness of, or amend or update the
        Registration Statement, or amend or supplement the Prospectus; provided,
        however, that at any time a Shelf Registration shall not be effective
        under the Securities Act (i) the Company shall only be permitted to
        suspend the use of the Prospectus for a period not to exceed 45 days in
        any six-month period or two periods not to exceed an aggregate of 90
        days in any 12-month period, (ii) the Company will use its best efforts
        to ensure that the use of the Prospectus may be resumed as soon as, in
        the good faith judgment of the Company's Board of Directors, disclosure
        of the material relating to such pending development, filing or event
        would not have a materially adverse effect on the Company and (iii) if
        the Company shall give any suspension notice pursuant to this Section
        3(a)(1), the period contemplated by Section 4(b) hereof shall be
        extended by the number of days during such period from and including the
        date of giving notice to and including the date of giving such notice to
        and including the date when each Holder of Registrable Common Stock
        Securities shall have received notice that the use of the Prospectus may
        be resumed.

                      (2) Underwriter's Cutback. The Company shall use its
        commercially reasonable efforts to cause the managing underwriter or
        underwriters of a proposed Underwritten Offering to permit the
        Registrable Common Stock Securities requested to be included in the
        Registration for such offering under Section 3(a)(1) (the "Piggyback
        Securities"), to be included on the same terms and conditions as any
        similar securities included therein. Notwithstanding the foregoing, if
        the managing underwriter of any such proposed Underwritten Offering
        determines that marketing factors require a limitation of the number of
        securities to be underwritten, the managing underwriter may limit or
        exclude the amount of Registrable Common Stock Securities to be included
        in the registration and underwriting as follows: the Company will
        include in such registration (i) first, all of the securities the
        Company proposes to sell and (ii) second, the Piggyback Securities and
        other securities sought to be registered, on a pro rata basis, based
        upon the number of shares of Common Stock sought to be registered by the
        Holders of the Piggyback Securities and the Holders of the other
        securities sought to be registered. If the managing underwriter makes
        such a determination, the Company shall promptly advise the Holders of
        the Registrable Common Stock Securities, in writing, that a limitation
        or inclusion of fewer than all of the Piggyback Securities is likely. If
        a reduction in the total amount of securities to be included in such
        offering is necessary as described in the prior sentence, the Company
        shall not treat


                                       5
<PAGE>

        the Holders of the Piggyback Securities less favorably than directors,
        officers, controlling stockholders and their affiliates seeking
        piggyback registration rights.

               (b) Shelf Registration.

                      (1) Initial Shelf Registration. The Company shall
        carefully prepare and file with the SEC as soon as practicable, but in
        no event later than sixty (60) days after the Effective Date (such date,
        the "Filing Deadline"), one or more Registration Statements for an
        offering to be made on a continuous basis pursuant to Rule 415 covering
        all of the Registrable Securities issued pursuant to the Plan (the
        "Initial Shelf Registration"). The Initial Shelf Registration shall be
        on Form S-1 or another appropriate form permitting registration of such
        Registrable Securities for resale by the Holders in the manner or
        manners designated by them (including, without limitation, one or more
        underwritten offerings). The Company shall not permit any securities
        other than the Registrable Securities to be included in the Initial
        Shelf Registration or any Subsequent Shelf Registration. No Holder may
        include any of its Registrable Securities in any Shelf Registration
        pursuant to this Agreement unless and until such Holder furnishes to the
        Company in writing, within 15 business days after receipt of a request
        therefore, such information as the Company may reasonably request for
        use in connection with any Shelf Registration or Prospectus or
        preliminary prospectus included therein. Each Holder as to which any
        Shelf Registration is being effected agrees to furnish promptly to the
        Company all information to be disclosed in order to make the information
        previously furnished to the Company by such Holder not materially
        misleading. The Company shall use its commercially reasonable efforts to
        cause the Initial Shelf Registration to be declared effective under the
        Securities Act as soon as practical after the Filing Deadline and,
        subject to Allowable Grace Periods, to keep the Initial Shelf
        Registration continuously effective under the Securities Act until the
        fifth anniversary of the Filing Deadline (the "Effectiveness Period"),
        or such shorter period ending when (i) all Registrable Securities
        covered by the Initial Shelf Registration have been sold in the manner
        set forth and as contemplated in the Initial Shelf Registration, (ii) a
        Subsequent Shelf Registration covering all of the Registrable Securities
        has been declared effective under the Securities Act or (iii) during any
        period in which all Registrable Securities may be sold pursuant to Rule
        144(k) under the Securities Act.

                      (2) Short Form Registration. If, during the Effectiveness
        Period, the Company becomes eligible to utilize SEC Form S-2 or Form S-3
        for offers and sales by Holders of Registrable Securities, then the
        Company may, in its discretion, amend the Registration Statement on Form
        S-2 or Form S-3 or terminate the Shelf Registration and concurrently
        file a Registration Statement on Form S-2 or Form S-3 pursuant to Rule
        415 covering all of the Registrable Securities required to have been
        included in the Initial Shelf Registration (a "Short Form Shelf
        Registration").

                      (3) Subsequent Shelf Registrations. If the Initial Shelf
        Registration, Short Form Shelf Registration or any Subsequent Shelf
        Registration ceases to be effective for any reason at any time during
        the Effectiveness Period (other than because of the sale of all of the
        securities registered thereunder), the Company shall use its
        commercially reasonable efforts to obtain the prompt withdrawal of any
        order suspending the


                                       6
<PAGE>

        effectiveness thereof, and in any event shall within 30 days of such
        cessation of effectiveness amend the Shelf Registration in a manner
        reasonably expected to obtain the withdrawal of the order suspending the
        effectiveness thereof, or file an additional Registration Statement
        pursuant to Rule 415 covering all of the Registrable Securities required
        to have been included in the Initial Shelf Registration (a "Subsequent
        Shelf Registration"). If a Subsequent Shelf Registration is filed, the
        Company shall use its commercially reasonable efforts to cause the
        Subsequent Shelf Registration to be declared effective as soon as
        practicable after such filing and, subject to any Allowable Grace
        Periods, to keep such Registration Statement continuously effective for
        a period equal to the number of days in the Effectiveness Period less
        the aggregate number of days during which the Initial Shelf Registration
        or any Subsequent Shelf Registration was previously continuously
        effective.

                      (4) Supplements and Amendments. The Company shall promptly
        supplement and amend the Shelf Registration if required by the rules,
        regulations or instructions applicable to the registration form used for
        such Shelf Registration, if required by the Securities Act, or if
        requested in writing by any underwriter of such Registrable Securities.

                      (5) Grace Periods. Notwithstanding anything to the
        contrary herein, at any time after a Registration Statement has been
        declared effective by the SEC, the Company may delay the disclosure of
        material non-public information concerning the Company if the disclosure
        of such information at the time is not, in the good faith judgment of
        the Board of Directors of the Company, in the best interests of the
        Company (a "Grace Period"); provided, however, that the Company shall
        promptly (i) notify the Holders in writing of the existence of material
        non-public information giving rise to a Grace Period (provided that the
        Company need not disclose the content of such material non-public
        information to the Holders) and the date on which the Grace Period will
        begin, and (ii) notify the Holders in writing of the date on which the
        Grace Period ends; provided further, that no single Grace Period shall
        exceed forty-five (45) consecutive days, during any three hundred
        sixty-five (365) day period, the aggregate of all of the Grace Periods
        shall not exceed an aggregate of sixty (60) days and the first day of
        any Grace Period must be at least two (2) trading days after the last
        day of any prior Grace Period (an "Allowable Grace Period"). For
        purposes of determining the length of a Grace Period, the Grace Period
        shall be deemed to begin on and include the date the Holders receive the
        notice referred to in clause (i) and shall end on and include the later
        of the date the Holders receive the notice referred to in clause (ii)
        and the date referred to in such notice; provided, however, that no
        Grace Period shall be longer than an Allowable Grace Period.

                      (6) Selection of Underwriters. Any and all underwriters or
        other agents involved in any sale of Registrable Common Stock Securities
        pursuant to a Registration Statement contemplated by this Section 3(b)
        shall include such underwriter(s) or other agent(s) as selected by
        Majority Common Stock Holders of the Registrable Common Stock Securities
        being registered and approved of by the Company, which approval shall
        not be unreasonably withheld; provided that any affiliate of a Holder
        included in a Registration shall in all events be approved by the
        Company.


                                       7
<PAGE>

               (c) Liquidated Damages. The Company and the Holders agree that
the Holders of Registrable Securities will suffer damages if the Company fails
to fulfill its obligations under this Section 3 and that ascertaining the extent
of such damages with precision would not be feasible. Accordingly, the Company
agrees to pay liquidated damages with respect to the Registrable Securities held
by each Holder, if:

               (i) the Initial Shelf Registration has not been filed with the
SEC on or prior to the Filing Deadline; or

               (ii) a Registration under Section 3(b)(1) is not declared
effective by the SEC on or prior to 150 days after the Effective Date; or

               (iii) subject to the time limitations with respect to maintaining
the effectiveness of any Registration Statement pursuant to Section 3(b) and
subject to any Allowable Grace Periods, any Registration Statement required to
be filed pursuant to such section is filed and declared effective but shall
thereafter cease to be effective or fail to be usable for its intended purpose
without being succeeded within 30 days after such Registration Statement ceases
to be effective or is unusable for its intended purpose by a post-effective
amendment to such Registration Statement or a new Registration Statement
satisfying the requirements of this Section 3 that cures such failure and that
is itself promptly declared effective (or such Registration Statement is not
otherwise effective and usable for its intended purpose within such time
period);

(each such event in clauses (i) through (iii) above being referred to herein as
a "Registration Default").

               The Company hereby agrees to pay each Holder of Registrable Note
Securities affected by a Registration Default liquidated damages ("Note
Liquidated Damages") in an amount equal to (A) with respect to the first 90-day
period immediately following the occurrence of a Registration Default, $.05 per
week per $1,000 principal amount of the Registrable Note Securities held by such
Holder and required to be so registered in accordance with this Agreement for
each week or portion thereof that any Registration Default continues, plus (B)
an additional $.05 per week per $1,000 in principal amount of such Registrable
Note Securities with respect to each 90-day period subsequent to the first
90-day period, until all Registration Defaults have been cured, up to an amount
equal to $.25 per week per $1,000 in principal amount such Registrable Note
Securities. The Company shall notify the trustee under the Indenture within five
business days after each and every date on which a Registration Default with
respect to the Registrable Note Securities occurs. All accrued Note Liquidated
Damages shall be paid by the Company on or before each applicable interest
payment date to Holders of record of the Registrable Note Securities in the same
manner as interest is payable pursuant to the terms of the Indenture.

               The Company hereby agrees to pay each Holder of Registrable
Common Stock Securities affected by a Registration Default liquidated damages
("Common Stock Liquidated Damages") in an amount equal to (A) with respect to
the first 90-day period immediately following the occurrence of a Registration
Default, $.01 per week for each 100 shares of Registrable Common Stock
Securities held by such Holder and required to be so registered in accordance
with this Agreement for each week or portion thereof that any Registration
Default


                                       8
<PAGE>

continues, plus (B) an additional $.01 per week for each such 100 shares of
Registrable Common Stock Securities with respect to each 90-day period
subsequent to the first 90-day period, until all Registration Defaults have been
cured, up to an amount equal to $.04 per week for each such 100 shares. The
Company shall notify the Holders within five business days after each and every
date on which a Registration Default with respect to the Registrable Common
Stock Securities occurs. All accrued and unpaid Common Stock Liquidated Damages
shall be paid by the Company on each September 30, December 31, March 31 and
June 30 by check mailed to the Holders of record of the Registrable Common Stock
Securities at such address as is set forth on the stock record books of the
Company.

               In the event that the Company reasonably and in good faith
disputes the occurrence of a Registration Default or that Liquidated Damages are
payable to any Holder, any Liquidated Damages which would otherwise be due to be
paid by the Company on such date in respect of such disputed Liquidated Damages
shall be deposited into an escrow account maintained by the Company with an
independent third party escrow agent, the identity of which shall be subject to
the prior approval of the Majority Common Stock Holders or Majority Note Holders
or both, as applicable, specifically for such purpose on or before such date, to
be held in escrow pending the final resolution of such dispute. Each obligation
to pay Liquidated Damages shall be deemed to accrue beginning on the day of the
applicable Registration Default. Following the cure of all Registration
Defaults, the accrual of Liquidated Damages will cease until the next
Registration Default, if any.

               Notwithstanding the foregoing, the Company shall not be obligated
to pay any Liquidated Damages during all or any portion of a Registration
Default period for so long as the related delay by the Company is due to a delay
attributable to any Holder.

               (d) Assignment of Registration Rights. The rights of a Holder
under this Section 3 may be assigned by any Holder in connection with any
transfer or assignment by a Holder of Registrable Securities provided that: (a)
such transfer may otherwise be effected in accordance with applicable securities
laws and (b)(i) such assignee or transferee holds subsequent to such transfer or
assignment not less than 257,300 shares of Registrable Common Stock Securities
or (ii) such assignee or transferee holds subsequent to such transfer or
assignment Registrable Note Securities in the principal amount of not less than
$1,390,000 or (iii) is a subsidiary, wholly-owned entity, successor entity,
parent or affiliate of a Holder.

        SECTION 4. Registration Procedures.

        In connection with the Company's registration obligations pursuant to
Section 3 hereof, the Company will use its commercially reasonable efforts to
effect such registration to permit the sale of such Registrable Securities in
accordance with the intended methods or methods of disposition thereof, and
pursuant thereto the Company will as expeditiously as possible:

               (a) before filing a Registration Statement or Prospectus or any
amendments or supplements thereto, furnish to the Holders of the Registrable
Securities covered by such Registration Statement and the underwriters, if any,
copies of all such documents proposed to be filed, which documents will be
subject to the review of such Holders and underwriters, and the Company will not
file any Registration Statement or amendment thereto or any Prospectus or


                                       9
<PAGE>

any supplement thereto to which Majority Common Stock Holders or Majority Note
Holders or both, as applicable, covered by such Registration Statement or the
underwriters, if any, shall reasonably object within three days after such
documents are delivered;

               (b) prepare and file with the SEC a Registration Statement or
Registration Statements relating to the applicable Shelf Registration or
Piggyback Registration including all exhibits and financial statements required
by the SEC to be filed therewith, and use its commercially reasonable efforts to
cause such Registration Statement to become effective under the Securities Act;
and prepare and file with the SEC such amendments and post-effective amendments
to such Registration Statement, and such supplements to the Prospectus, as may
be required by the rules, regulations or instructions applicable to the
registration form utilized by the Company or by the Securities Act or rules and
regulations otherwise necessary to keep the Registration Statement effective for
a period of not less than 180 days (or such shorter period which will terminate
when all Registrable Securities covered by such Registration Statement have been
sold or withdrawn) unless, in the case of a Piggyback Registration, a Shelf
Registration shall then be effective under the Securities Act, or, if such
Registration Statement relates to an Underwritten Offering, such longer period
as in the opinion of counsel for the underwriters a Prospectus is required by
law to be delivered in connection with sales of Registrable Securities by an
underwriter or dealer; and cause the Prospectus as so supplemented to be filed
pursuant to Rule 424 under the Securities Act; and comply with the provisions of
the Securities Act and the Exchange Act with respect to the disposition of all
securities covered by such Registration Statement during the applicable period
in accordance with the intended methods of disposition by the sellers thereof
set forth in such Registration Statement or supplement to the Prospectus;

               (c) notify the selling Holders of Registrable Securities and the
managing underwriters, if any, promptly;

                      (1) when the Prospectus or any Prospectus supplement or
        post-effective amendment has been filed, and, with respect to the
        Registration Statement or any post-effective amendment, when the same
        has become effective,

                      (2) of any request by the SEC during the period of
        effectiveness for amendments or supplements to the Registration
        Statement or the Prospectus or for additional information relating to
        the Registration Statement,

                      (3) of the issuance by the SEC of any stop order
        suspending the effectiveness of the Registration Statement or the
        initiation of any proceedings for that purpose,

                      (4) if at any time the representations and warranties of
        the Company contemplated by paragraph (n) below cease to be true and
        correct,

                      (5) of the receipt by the Company of any notification with
        respect to the suspension of the qualification of the Registrable
        Securities for sale in any jurisdiction or the initiation or threatening
        of any proceeding for such purpose, and


                                       10
<PAGE>

                      (6) of the existence of any fact known which results in
        the Registration Statement, the Prospectus or any document incorporated
        therein by reference containing an untrue statement of material fact or
        omitting to state a material fact required to be stated therein or
        necessary to make the statements therein not misleading;

               (d) make every reasonable effort to obtain the withdrawal of any
order suspending the effectiveness of the Registration Statement at the earliest
possible moment;

               (e) if requested by the managing underwriter or underwriters or a
Holder of Registrable Securities being sold in connection with an Underwritten
Offering, immediately incorporate in a Prospectus supplement or post-effective
amendment such information as the managing underwriters require to be included
therein relating to the plan of distribution with respect to such Registrable
Securities, including, without limitation, information with respect to the
amount of Registrable Securities being sold to such underwriters, the purchase
price being paid therefor by such underwriters and with respect to any other
terms of the underwritten (or best efforts underwritten) offering of the
Registrable Securities to be sold in such offering; and make all required
filings of such Prospectus supplement or post-effective amendment as soon as
notified of the matters to be incorporated in such Prospectus supplement or
post-effective amendment;

                (f) deliver to each selling Holder of Registrable Securities and
the underwriters, if any, without charge, as many copies of the Prospectus
(including each preliminary prospectus) and any amendment or supplement thereto
as such Persons may reasonably request (it being understood that the Company
consents to the use of the Prospectus or any amendment or supplement thereto by
each of the selling Holders of Registrable Securities and the underwriters, if
any, in connection with the offering and sale of the Registrable Securities
covered by the Prospectus or any amendment or supplement thereto) and such other
documents as such selling Holder and the underwriters, if any, may reasonably
request in order to facilitate the disposition of the Registrable Securities by
such Holder and underwriters, if any, but only while the Company shall be
required under the provisions hereof to cause the Registration Statement to
remain current;

               (g) prior to any public offering of Registrable Securities, use
its commercially reasonable efforts to register or qualify or cooperate with the
selling Holders of Registrable Securities, the underwriters, if any, and their
respective counsel in connection with the registration or qualification of such
Registrable Securities for offer and sale under the securities or blue sky laws
of such jurisdictions as any selling Holder of Registrable Securities or any
underwriter reasonably requests in writing and do any and all other acts or
things reasonably necessary to enable the disposition in such jurisdictions of
the Registrable Securities covered by the Registration Statement; provided that
the Company will not be required to qualify generally to do business in any
jurisdiction where it is not then so qualified or to take any action which would
subject it to general service of process in any such jurisdiction where it is
not then so subject;

               (h) cooperate with the selling Holders of Registrable Securities
and the managing underwriters, if any, to facilitate the timely preparation and
delivery of certificates representing Registrable Common Stock Securities or
notes representing Registrable Note


                                       11
<PAGE>

Securities to be sold and not bearing any restrictive legends; and enable such
Registrable Securities to be in such denominations and registered in such names
as the managing underwriters may reasonably request at least two business days
prior to any sale of Registrable Securities to the underwriters;

               (i) use its commercially reasonable efforts to cause the
Registrable Securities covered by the applicable Registration Statement to be
registered with or approved by such other governmental agencies or authorities
within the U.S. as may be necessary to enable the seller or sellers thereof or
the underwriters, if any, to consummate the disposition of such Registrable
Securities; provided that the Company will not be required to qualify generally
to do business in any jurisdiction where it is not then so qualified or to take
any action which would subject it to general service of process in any such
jurisdiction where it is not then so subject;

               (j) if any fact contemplated by paragraph (c)(6) above shall
exist, prepare a supplement or post-effective amendment to the Registration
Statement or the related Prospectus or any document incorporated therein by
reference or file any other required document so that, as thereafter delivered
to the purchasers of the Registrable Securities, the Prospectus will not contain
an untrue statement of a material fact or omit to state any material fact
required to be stated therein or necessary to make the statements therein not
misleading, but only while the Company shall be required under the provisions
hereof to cause the Registration Statement to remain current;

               (k) use its commercially reasonable efforts to cause all
Registrable Common Stock Securities covered by the Registration Statement to be
quoted on the NASDAQ National Market or listed on each securities exchange on
which similar securities issued by the Company are then listed;

               (l) enter into agreements (including underwriting agreements) and
take all other appropriate actions that are reasonable, necessary and in typical
form for such transactions in order to expedite or facilitate the disposition of
such Registrable Securities.

The above shall be done at the effectiveness of such Registration Statement,
each closing under any underwriting or similar agreement as and to the extent
required thereunder and from time to time as may be requested by any selling
Holder in connection with the disposition of Registrable Securities pursuant to
such Registration Statement, but only while the Company shall be required under
the provisions hereof to cause the Registration Statement to remain current;

               (m) make available for inspection at reasonable times and upon
reasonable notice by a representative of Majority Common Stock Holders or
Majority Note Holders, as applicable, any underwriter participating in any
disposition pursuant to such Registration Statement, and any attorney or
accountant retained by the sellers or underwriter, all financial and other
records, pertinent corporate documents and properties of the Company, and cause
the Company's officers, directors and employees to supply all information
reasonably requested by any such representative, underwriter, attorney or
accountant in connection with the registration; provided that, with respect to
any records, information or documents that are designated by the Company in
writing as confidential, such Persons shall have agreed, pursuant to
confidentiality agreement on reasonable and customary terms, to keep such
records, information or documents


                                       12
<PAGE>

confidential unless disclosure of such records, information or documents is
required by court or administrative order; and

               (n) otherwise use its commercially reasonable efforts to comply
with all applicable rules and regulations of the SEC, and make generally
available to the Holders, earnings statements satisfying the provisions of
Section 11(a) of the Securities Act.

               The Company may require each seller of Registrable Securities as
to which any registration is being effected to furnish to the Company such
information regarding itself, the Registrable Securities held by it and the
distribution of such securities as the Company may from time to time reasonably
request in writing, and shall take such commercially reasonable action as may be
reasonably required in order to permit the Company and any underwriters to
comply with all applicable requirements of the SEC and the NASD. Such provision
of information and materials is a condition precedent to the obligations of the
Company pursuant to this Agreement.

               Each Holder of Registrable Securities agrees by acquisition of
such Registrable Securities that, upon receipt of any notice from the Company of
the happening of any event of the kind described in Sections 4(c)(3), 4(c)(4),
4(c)(5), 4(c)(6) or 4(j) hereof, such Holder will forthwith discontinue
disposition of Registrable Securities until such Holder's receipt of the copies
of the supplemented or amended Prospectus contemplate by Sections 4(c)(3),
4(c)(4), 4(c)(5), 4(c)(6) or 4(j) hereof, or until it is advised in writing by
the Company that the use of the Prospectus may be resumed, and has received
copies of any additional or supplemental filings which are incorporated by
reference in the Prospectus, and, if so directed by the Company, such Holder
will deliver to the Company (at the Company's expense) all copies, other than
permanent file copies then in such Holder's possession, of the Prospectus
covering such Registrable Securities current at the time of receipt of such
notice. In the event the Company shall give any such notice, the time periods
during which such Registration Statement shall be maintained effective shall be
extended by the number of days during the period from and including the date of
the giving of such notice to and including the date when each seller of
Registrable Securities covered by such Registration Statement either receives
the copies of the supplemented or amended prospectus contemplated by Sections
4(c)(3), 4(c)(4), 4(c)(5), 4(c)(6) or 4(j) hereof or is advised in writing by
the Company that the use of the Prospectus may be resumed.

        SECTION 5. Registration Expenses.

               (a) All expenses incident to the Company's performance of or
compliance with this Agreement will be paid by the Company, regardless of
whether the Registration Statement becomes effective, including without
limitation:

                      (1) all registration and filing fees (including all
        filings required to be made with the SEC and the NASD;

                      (2) reasonable fees and expenses of compliance with
        securities or blue sky laws (including fees and disbursements of counsel
        for the underwriters or selling Holders in connection with blue sky
        qualifications of the Registrable Securities and determination of their
        eligibility for investment under the laws of such jurisdictions as the


                                       13
<PAGE>

        managing underwriters or Majority Common Stock Holders or Majority Note
        Holders or both, as applicable, of the Registrable Securities being sold
        may designate);

                      (3) printing (including expenses of printing certificates
        for the Registrable Common Stock Securities and notes for the
        Registrable Note Securities in a form eligible for deposit with the
        Depository Trust Company and of printing prospectus), messenger,
        telephone and delivery expenses;

                      (4) reasonable fees and disbursements of (i) counsel for
        (X) the Company and (Y) the underwriters and (ii) one counsel for the
        sellers of the Registrable Securities, provided that such fees shall not
        exceed a maximum of $15,000 per Registration Statement (subject to the
        provisions of Section 6(b) hereof);

                      (5) reasonable fees and disbursements of all independent
        certified public accountants of the Company (including the expenses of
        any special audit and "cold comfort" letters required by or incident to
        such performance);

                      (6) reasonable fees and disbursements of underwriters
        (including, if applicable, the fees and expenses of any "qualified
        independent underwriter" (and its counsel) that is required to be
        retained in accordance with the rules and regulations of the NASD, but
        excluding discounts, commissions or fees of underwriters, selling
        brokers, dealer managers or similar securities industry professionals
        relating to the distribution of the Registrable Securities or legal
        expenses of any Person other than the Company, the underwriters and the
        selling Holders);

                      (7) securities acts liability insurance if the Company so
        desires or if the underwriters or the Majority Common Stock Holders or
        Majority Note Holders or both, as applicable, of the Registrable
        Securities being sold so require; and

                      (8) fees and expenses of other Persons retained by the
        Company,

(all such expenses being herein called "Registration Expenses").

               The Company will, in any event, pay its internal expenses
(including, without limitation, all salaries and expenses of its officers and
employees performing legal or accounting duties), the expense of any annual
audit, the fees and expenses incurred in connection with the listing of the
securities to be registered on each securities exchange on which similar
securities issued by the Company are then listed, rating agency fees and the
fees and expenses of any Person, including special experts, retained by the
Company.

               (b) In connection with each Registration Statement required
hereunder, the Company will reimburse the Holders of Registrable Securities
being registered pursuant to such Registration Statement for the reasonable fees
and disbursements of not more than one counsel chosen by Majority Common Stock
Holders and Majority Note Holders, as applicable.


                                       14
<PAGE>

        SECTION 6. Indemnification.

               (a) Indemnification by Company. The Company agrees to indemnify
and hold harmless each Holder of Registrable Securities, its officers,
directors, employees and agents and each Person who controls such Holder within
the meaning of either Section 15 of the Securities Act or Section 20 of the
Exchange Act (each such person being sometimes hereinafter referred to as an
"Indemnified Holder") from and against all losses, claims, damages, liabilities
and expenses (including reasonable costs of investigation and legal expenses)
arising out of or based upon any untrue statement or alleged untrue statement of
a material fact contained in any Registration Statement or Prospectus, in any
amendment or supplement thereto or in any preliminary prospectus, or arising out
of or based upon any omission or alleged omission to state therein a material
fact required to be stated therein or necessary to make the statements therein
not misleading, except insofar as such losses, claims, damages, liabilities or
expenses arises out of or are based upon any such untrue statement or omission
or allegation thereof based upon information furnished in writing to the Company
by or on behalf of such Holder expressly for use therein; provided, however,
that the Company shall not be liable in any such case to the extent that any
such loss, claim, damage, liability or expense arises out of or is based upon an
untrue statement or alleged untrue statement or omission or alleged omission in
any such Registration Statement or Prospectus or preliminary prospectus, if such
untrue statement or alleged untrue statement, omission or alleged omission is
completely corrected in an amendment or supplement to such Registration
Statement or Prospectus or preliminary prospectus and if, having previously been
furnished by or on behalf of the Company with copies of the Prospectus or
preliminary prospectus as so amended or supplemented, such Holder thereafter
fails to deliver such Prospectus or preliminary prospectus as so amended or
supplemented, prior to or concurrently with the sale of a Registrable Security
to the Person asserting such loss, claim, damage, liability or expense who
purchased such Registrable Security which is the subject thereof from such
Holder. The indemnity will be in addition to any liability which the Company may
otherwise have. The Company will also indemnify underwriters, selling brokers,
dealer managers and similar securities industry professionals participating in
the distribution, their officers and directors and each Person who controls such
Persons (within the meaning of Section 15 of the Securities Act or Section 20 of
the Exchange Act) to the same extent as provided above with respect to the
indemnification of the Indemnified Holders of Registrable Securities.

               If any action or proceeding (including any governmental
investigation or inquiry) shall be brought or asserted against an Indemnified
Holder in respect of which indemnity may be sought from the Company, such
Indemnified Holder shall promptly notify the Company in writing, and the Company
shall assume the defense thereof, including the employment of counsel
satisfactory to such Indemnified Holder and the payment of all expenses. Such
Indemnified Holder shall have the right to employ separate counsel in any such
action and to participate in the defense thereof, but the fees and expenses of
such counsel shall be at the expense of such Indemnified Holder unless (a) the
Company has agreed to pay such fees and expenses or (b) the Company shall have
failed to assume the defense of such action or proceeding and has failed to
employ counsel reasonably satisfactory to such Indemnified Holder in any such
action or proceeding (including any impleaded parties) include both such
Indemnified Holder and the Company or (c) such Indemnified Holder shall have
been advised in writing by counsel that there is a conflict of interest between
such Indemnified Holder and the Company or that there are additional defenses or
claims that it may assert that are adverse to or not in the interest of the
Company and separate counsel is required to


                                       15
<PAGE>

represent such interests (in which case, if such Indemnified Holder notifies the
Company in writing that it elects to employ separate counsel at the expense of
the Company, the Company shall not have the right to assume the defense of such
action or proceeding on behalf of such Indemnified Holder, it being understood,
however, that the Company shall not, in connection with any one such action or
proceeding or separate but substantially similar or related actions or
proceedings in the same jurisdiction arising out of the same general allegations
or circumstances, be liable for the reasonable fees and expenses of more than
one separate firm of attorneys at any time for such Indemnified Holder and any
other Indemnified Holders, which firm shall be designated in writing by such
Indemnified Holders). The Company shall not be liable for any settlement of any
such action or proceeding effected without its written consent, but if settled
with its written consent, or if there be a final judgment for the plaintiff in
any such action or proceeding for which the Company received notice hereunder,
the Company agrees to indemnify and hold harmless such Indemnified Holder from
and against any loss or liability by reason of such settlement or judgment.

               (b) Indemnification by Holder of Registrable Securities. Each
Holder of Registrable Securities agrees to indemnify and hold harmless the
Company, its directors and officers and each Person, if any, who controls the
Company within the meaning of either Section 15 of the Securities Act or Section
20 of the Exchange Act to the same extent as the foregoing indemnity from the
Company to such Holder, but only with respect to information relating to such
Holder furnished in writing by such Holder expressly for use in any Registration
Statement or Prospectus, or any amendment thereto, or any preliminary
prospectus. In case any action or proceeding shall be brought against the
Company or directors or officers or any such controlling person, in respect of
which indemnity may be sought against a Holder of Registrable Securities, such
Holder shall have the rights and duties given the Company and the Company or its
directors or officers or such controlling person shall have the rights and
duties given to each Holder by the preceding paragraph. In no event shall the
liability of any selling Holder of Registrable Securities hereunder be greater
in amount than the gross amount of the proceeds (before expenses and
commissions) from the sale of Registrable Securities by such Holder giving rise
to such indemnification obligation.

               The Company and each Holder of Registrable Securities shall be
entitled to receive indemnities from underwriters, selling brokers, dealer
managers and similar securities industry professionals participating in the
distribution, to the same extent as provided above with respect to information
so furnished in writing by such Person specifically for inclusion in any
Prospectus or Registration Statement or any amendment or supplement thereto, or
any preliminary prospectus.

               (c) Contribution. If the indemnification provided for in this
Section 7 is unavailable to an indemnified party under Section 7(a) or Section
7(b) hereof (other than by reason of exceptions provided in those Sections) in
respect of any losses, claims, damages, liabilities or expenses referred to
therein, then each applicable indemnifying party, in lieu of indemnifying such
indemnified party, shall contribute to the amount paid or payable by such
indemnified party as a result of such losses, claims, damages, liabilities or
expenses in such proportion as is appropriate to reflect the relative fault of
the Company on the one hand and of the Indemnified Holder on the other in
connection with the statements or omissions which resulted in such losses,
claims, damages, liabilities or expenses, as well as any other relevant
equitable considerations. The relative fault of the Company on the one hand and
of the Indemnified Holder on the other shall be determined by reference to,
among other things, whether the untrue or alleged untrue statement of a


                                       16
<PAGE>

material fact or the omission or alleged omission to state a material fact
relates to information supplied by the Company or by the Indemnified Holder and
the parties' relative intent, knowledge, access to information and opportunity
to correct or prevent such statement or omission. The amount paid or payable by
a party as a result of the losses, subject to the limitations set forth in the
second paragraph of Section 7(a), any legal or other fees or expenses reasonably
incurred by such party in connection with investigating or defending any action
or claim.

               The Company and each Holder of Registrable Securities agree that
it would not be just and equitable if contribution pursuant to this Section 7(c)
were determined by pro rata allocation or by any other method of allocation
which does not take account of the equitable considerations referred to in the
immediately preceding paragraph. Notwithstanding the provisions of this Section
7(c), an Indemnified Holder shall not be required to contribute any amount in
excess of the amount by which the total price at which the Securities sold by
such Indemnified Holder or its affiliated Indemnified Holders and distributed to
the public were offered to the public exceeds the amount of any damages which
such Indemnified Holder or its affiliated Indemnified Holder, has otherwise been
required to pay by reason of such untrue or alleged untrue statement or omission
or alleged omission. No person guilty of fraudulent misrepresentation (within
the meaning of Section 11(f) of the Securities Act) shall be entitled to
contribution from any person who was not guilty of such fraudulent
misrepresentation.

        SECTION 7. Rule 144.

               The Company covenants that it will file the reports required to
be filed by it under the Securities Acts and the Exchange Act and rules and
regulations adopted by the SEC thereunder (or, if the Company is not required to
file such reports, it will, upon the request of any Holder of Registrable
Securities made after the first anniversary of the date hereof, make publicly
available such information as necessary to permit sales pursuant to Rule 144
under the Securities Act), and it will take such further action as any Holder of
Registrable Securities may reasonably request, all to the extent required from
time to time to enable such Holder to sell Registrable Securities without
registration under the Securities Act within the limitation of the exemptions
provided by (a) Rule 144 under the Securities Act, as such Rule may be amended
from time to time, or (b) any similar rule or regulation hereafter adopted by
the SEC. Upon the request of any Holder of Registrable Securities, the Company
will deliver to such Holder a written statement as to whether it had complied
with such information and requirements.

        SECTION 8. Participation in Underwritten Registrations.

               No Person may participate in any Underwritten Registration
hereunder unless such Person (a) agrees to sell such Person's securities on the
basis provided in any underwriting arrangements approved by the Persons entitled
hereunder to approve such arrangements and (b) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements and
other documents required under the terms of such underwriting arrangements.

        SECTION 9. Miscellaneous.

               (a) Termination. The registration rights set forth in this
Agreement shall terminate with respect to any Holder (a) at any time, upon
mutual agreement in writing of such


                                       17
<PAGE>

Holder and the Company or (b) upon such time as all of the Registrable
Securities then held by such Holder can be sold by such Holder in a three-month
period in accordance with Rule 144 under the Securities Act. Notwithstanding the
foregoing, the obligations of each party to this Agreement pursuant to Section 6
hereof, shall survive the termination of registration rights sets forth in this
Agreement.

               (b) No Inconsistent Agreements. The Company will not on or after
the date of this Agreement enter into any agreement with respect to its
securities which is inconsistent with the rights granted to the Holders of
Registrable Securities in this Agreement or otherwise conflicts with the
provisions hereof.

               (c) Adjustments Affecting Registrable Securities. The Company
will not take any action, or permit any change to occur, with respect to the
Registrable Securities which would (i) adversely affect the ability of the
Holders of Registrable Securities to include such Registrable Securities in a
registration undertaken pursuant to this Agreement or (ii) adversely affect the
marketability of such Registrable Securities in any such registration.

               (d) Amendments and Waivers. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given without the written consent of the Company, Majority Common
Stock Holders and/or Majority Note Holders, as applicable, affected by such
amendment. Notwithstanding the foregoing, a waiver or consent to departure from
the provisions hereof that relates exclusively to the rights of Holders of
Registrable Securities whose securities are being sold pursuant to a
Registration Statement and that does not directly or indirectly affect the
rights of other Holders of Registrable Securities may be given by Majority
Common Stock Holders and/or Majority Note Holder, as applicable, of the
Registrable Securities being sold.

               (e) Notices. All notices and other communications provided for or
permitted hereunder shall be made in writing by hand-delivery, registered
first-class mail, telex, telecopier, or air courier guaranteeing overnight
delivery:

                      (i) if to a Holder of Registrable Securities, at the most
           current address given by such Holder to the Company in accordance
           with the provisions of this Section 10(e).

                      (ii) if to the Company, initially to:

                             Komag, Incorporated
                             1710 Automation Parkway
                             San Jose, California 95131-1873
                             Facsimile: 408-944-9234
                             Attention: Chief Financial Officer

                      and thereafter at such other address, notice of which is
                      given in accordance with the provisions of this Section
                      10(e),


                                       18
<PAGE>

               All such notices and communications shall be deemed to have been
duly given: at the time delivered by hand, if personally delivered; five
business days after being deposited in the mail, postage prepaid, if mailed;
when answered back, if telexed; when receipt acknowledged, if telecopied; and on
the next business day, if timely delivered to an air courier guaranteeing
overnight delivery.

               (f) Successors and Assigns. This Agreement shall inure to the
benefit of and be binding upon the successors and permitted assigns of each of
the parties.

               (g) Counterparts. This Agreement may be executed in any number of
counterparts and by the parties hereto in separate counterparts, each of which
when so executed shall be deemed to be an original and all of which taken
together shall constitute one and the same agreement.

               (h) Headings. The headings in this Agreement are for convenience
of reference only and shall not limit or otherwise affect the meaning hereof.

               (i) Governing Law. This Agreement shall be governed by and
construed in accordance with the laws of the State of California.

               (j) Severability. In the event that any one or more of the
provisions contained herein, or the application thereof in any circumstance, is
held invalid, illegal or unenforceable, the validity, legality and
enforceability of any such provision in every other respect and of the remaining
provisions contained herein shall not be affected or impaired thereby.

               (k) Entire Agreement. This Agreement is intended by the parties
as a final expression of their agreement and intended to be a complete and
exclusive statement of the agreement and understanding of the parties hereto in
respect of the subject matter contained herein.

                           [Signature Pages To Follow]



                                       19
<PAGE>

               IN WITNESS WHEREOF, the parties have executed this Agreement as
of the date first written above.

KOMAG, INCORPORATED


By:_______________________________

Title:____________________________

Address:
1710 Automation Parkway
San Jose, California 95131-1873
Facsimile: (408) 944-9234
Attention: Chief Financial Officer

<PAGE>


JDS CAPITAL, L.P.

By: JDS Capital Management, LLC

By:_______________________________

Title:____________________________


DIMENSIONAL PARTNERS, L.P.

By: JDS Asset Management, LLC

By:_______________________________

Title:____________________________


DIMENSIONAL PARTNERS, LTD.

By: JDS Capital Management, Inc.

By:_______________________________

Title:____________________________

<PAGE>

CERBERUS PARTNERS, L.P.

By:_______________________________

Title:____________________________


<PAGE>

                                   SCHEDULE 1

                        HOLDERS OF REGISTRABLE SECURITIES


<TABLE>
<CAPTION>
Holder                                                    Number of Shares Held
------                                                    ---------------------
<S>                                                       <C>
JDS Capital, L.P.                                         2,756,912

Dimensional Partners, L.P.                                717,344

Dimensional Partners, Ltd.                                672,368

Cerberus Partners, L.P.                                   9,722,142

Rutland Partners, L.P.                                    185,867
</TABLE>