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                                                                    Exhibit 3.9


                  CERTIFICATE OF DETERMINATION OF PREFERENCES
                                       OF
                            SERIES I PREFERRED STOCK
                                       OF
                                   DISC, INC.



         We, J. Richard Ellis and Henry Madrid, hereby certify that we are the
President and the Chief Financial Officer, respectively, of DISC, INC., a
corporation organized and existing under the General Corporation Law of the
State of California, and further, DO HEREBY CERTIFY:

         That pursuant to the authority conferred upon the Board of Directors
by the Articles of Incorporation of the said Corporation, the said Board of
Directors on March 29, 1996 adopted the following resolution creating a series
of 167,065 shares of Preferred Stock designated as Series I Preferred Stock,
none of which shares have been issued:

                 "RESOLVED, that pursuant to the authority vested in the Board
         of Directors of the corporation by the Articles of Incorporation, the
         Board of Directors does hereby provide for the issuance of a series of
         Preferred Stock, no par value, of the Corporation, to be designated
         "Series I Preferred Stock," initially consisting of 167,065 shares and
         to the extent that the designations, powers, preferences and relative
         and other special rights and the qualifications, limitations and
         restrictions of the Series I Preferred Stock are not stated and
         expressed in the Articles of Incorporation, does hereby fix and herein
         state and express such designations, powers, preferences and relative
         and other special rights and the qualifications, limitations and
         restrictions thereof, as follows (all terms used herein which are
         defined in the Articles of Incorporation shall be deemed to have the
         meanings provided therein):

                 Section 1.  Designation and Amount.  The shares of such series
         shall be designated as "Series I Preferred Stock," no par value, and
         the number of shares constituting such series shall be 167,065.

                 Section 2.  Dividends and Distributions.

                          (A)     Subject to the prior and superior right of
         the holders of any shares of Series C Preferred Stock ranking prior
         and superior to the shares of Series I Preferred Stock with respect to
         dividends, and pari passu with the rights of the holders of shares of
         Series D Preferred Stock, Series E Preferred Stock, Series F Preferred
         Stock, Series G Preferred Stock and Series H Preferred Stock with
         respect to dividends, the holders of shares of Series I Preferred
         Stock shall be entitled to receive when, as and if declared by the
         Board of Directors out of funds legally available for the purpose,
         dividends in the same amount per share as declared on the Common
         Stock, treating such number of shares of Series I Preferred Stock for
         this purpose as equal to the number of shares of Common Stock into
         which it is then convertible.  In the event any dividends are declared
         or paid on
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         the outstanding shares of Series D Preferred Stock, Series E Preferred
         Stock, Series F Preferred Stock, Series G Preferred Stock and Series H
         Preferred Stock, dividends shall simultaneously be declared and paid
         on the outstanding shares of Series I Preferred Stock, paripassu with
         the shares of Series D Preferred Stock, Series E Preferred Stock,
         Series F Preferred Stock, Series G Preferred Stock and Series H
         Preferred Stock, based upon the number of shares of Common Stock into
         which shares of Series D Preferred Stock, Series E Preferred Stock,
         Series F Preferred Stock, Series G Preferred Stock, Series H Preferred
         Stock and Series I Preferred Stock are then convertible.  In the event
         the Corporation shall at any time after the date of the filing of this
         Certificate of Determination of Preferences (the "Rights Declaration
         Date") (i) declare any dividend on Common Stock payable in shares of
         Common Stock, (ii) subdivide the outstanding Common Stock, or (iii)
         combine the outstanding Common Stock into a smaller number of shares,
         then in each such case, the amount of Common Stock or other
         consideration to which holders of shares of Series I Preferred Stock
         were entitled immediately prior to such event under the preceding
         sentence shall be adjusted as set forth in Section 4(C) hereof.

                          (B)     The Corporation shall declare a dividend or
         distribution on the Series I Preferred Stock as provided in paragraph
         (A) above prior to declaring a dividend payable on shares of Common
         Stock.

                 Section 3.  Voting Rights.  The holders of shares of Series I
         Preferred Stock shall have the following voting rights:

                          (A)      Each holder of Series I Preferred Stock is
         entitled to a number of votes equal to the number of shares of Common
         Stock into which the holder's Series I Preferred Stock is then
         convertible.  Except as provided by law, the Common Stock and Series I
         Preferred Stock (and any series of Preferred Stock which may be
         subsequently authorized which is convertible into shares of Common
         Stock and which has voting rights equal to the number of shares of
         Common Stock into which such series of Preferred Stock is then
         convertible) shall vote together as a single class on all matters to
         come before the shareholders for approval.  In the event the
         Corporation shall at any time after the Rights Declaration Date (i)
         declare any dividend on Common Stock payable in shares of Common
         Stock, (ii) subdivide the outstanding Common Stock, or (iii) combine
         the outstanding Common Stock into a smaller number of shares, then in
         each such case the number of votes per share to which holders of
         shares of Series I Preferred Stock were entitled immediately prior to
         such event shall be adjusted as set forth in Section 4(C) hereof.

                          (B)     Except as otherwise provided herein or by
         law, the holders of shares of Series I Preferred Stock and the holders
         of shares of Common Stock (and any series of Preferred Stock which may
         be subsequently authorized which is convertible into shares of Common
         Stock and which has voting rights equal to the number of shares of
         Common Stock into which such series of Preferred Stock is then
         convertible) shall vote together as one class on all matters submitted
         to a vote of shareholders of the Corporation.

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                          (C)     Except as required by law or under Section 8
         hereof, holders of Series I Preferred Stock shall have no special
         voting rights and their consent shall not be required (except to the
         extent they are entitled to vote with holders of Common Stock as set
         forth herein) for taking any corporate action.

                 Section 4.  Conversion Rights.

                          (A)     Each holder of Series I Preferred Stock may,
         at any time, in such holder's sole discretion, convert all or any part
         of such holder's shares of Series I Preferred Stock into fully paid
         and nonassessable shares of Common Stock at the rate of one (1) share
         of Common Stock for each share of Series I Preferred Stock surrendered
         for conversion.

                          (B)     Such conversion may be effected by surrender
         of such holder's certificate or certificates for the shares of Series
         I Preferred Stock to be converted, duly endorsed, at the principal
         office of the Corporation, with a written notice stating (i) that such
         holder elects to convert all or a specified number of shares of Series
         I Preferred Stock into shares of Common Stock, and (ii) the name in
         which such holder desires a certificate for the shares of Common Stock
         to be issued.  Promptly thereafter, the Company shall issue and
         deliver to such holder a certificate for the number of shares of
         Common Stock to which such holder shall be entitled.  Such conversion
         shall be deemed to have been made at the close of business on the date
         of such surrender, and such holder shall be treated for all purposes
         as the record holder of such shares of Common Stock on that date.

                          (C)     In the event the Corporation shall at any
         time after the Rights Declaration Date (i) declare any dividend on
         Common Stock payable in shares of Common Stock, (ii) subdivide the
         outstanding Common Stock, or (iii) combine the outstanding Common
         Stock into a smaller number of shares, then, in each case, the number
         of shares of Common Stock issuable upon the conversion of each share
         of Series I Preferred Stock shall be adjusted by multiplying such
         amount by a fraction, the numerator of which is the number of shares
         of Common Stock outstanding immediately after such event and the
         denominator of which is the number of shares of Common Stock that are
         outstanding immediately prior to such event.

                          (D)     In the event the Corporation shall at any
         time or from time to time after the Rights Declaration Date make or
         issue, or fix a record date for the determination of holders of Common
         Stock entitled to receive, a dividend or other distribution payable in
         securities of the Corporation or any of its subsidiaries, or of any
         other corporation or third party, other than in shares of Common
         Stock, then, in each such event, provisions shall be made so that the
         holders of Series I Preferred Stock shall receive, upon the conversion
         thereof, securities of the Corporation or any of its subsidiaries or
         of any other corporation or third party which they would have received
         had their stock been converted into Common Stock on the date of such
         event.

                 Section 5.  Reacquired Shares.  Any shares of Series I
         Preferred Stock purchased or otherwise acquired by the Corporation in
         any manner whatsoever shall be retired and





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        canceled promptly after the acquisition thereof.  All such shares shall
        upon their cancellation become authorized but unissued shares of
        Preferred Stock and may be reissued as part of a new series of Preferred
        Stock to be created by resolution or resolutions of the Board of
        Directors, subject to the conditions and restrictions on issuance set
        forth herein.

                 Section 6.  Liquidation, Dissolution or Winding Up.

                          (A)     Upon any liquidation (voluntary or
         otherwise), dissolution or winding up of the Corporation, following
         the first priority liquidation preference of the Series C Preferred
         Stock in the amount of $5.00 per share plus any declared but unpaid
         dividends, and pari passu with the liquidation preference of the
         Series D Preferred Stock in the amount of $5.00 per share plus any
         declared but unpaid dividends ("Series D Liquidation Preference"), the
         liquidation preference of the Series E Preferred Stock in the amount
         of $4.00 per share plus any declared but unpaid dividends ("Series E
         Liquidation Preference"), the liquidation preference of the Series F
         Preferred Stock in the amount of $8.00 per share plus any declared but
         unpaid dividends ("Series F Liquidation Preference"), the liquidation
         preference of the Series G Preferred Stock in the amount of $20.00 per
         share plus any declared but unpaid dividends ("Series G Liquidation
         Preference"), the liquidation preference of the Series H Preferred
         Stock in the amount of $38.30 per share plus any declared but unpaid
         dividends ("Series H Liquidation Preference"), no distribution shall
         be made to the holders of shares of stock ranking junior (either as to
         dividends or upon liquidation, dissolution or winding up) to the
         Series I Preferred Stock unless, prior thereto, the holders of shares
         of Series I Preferred Stock shall have received an amount equal to
         $4.19 per share of Series I Preferred Stock plus any declared but
         unpaid dividends ("Series I Liquidation Preference").

                          (B)     In the event, however, that there are not
         sufficient assets available to permit payment in full of the Series D
         Liquidation Preference, the Series E Liquidation Preference, the
         Series F Liquidation Preference, the Series G Liquidation Preference,
         the Series H Liquidation Preference, Series I Liquidation Preference
         and the liquidation preferences of all other series of Preferred
         Stock, if any, which rank on a parity with the Series I Preferred
         Stock, then such remaining assets shall be distributed ratably to the
         holders of such parity shares in proportion to their respective
         liquidation preferences.

                 Section 7.  No Redemption.  The shares of Series I Preferred
         Stock shall not be redeemable.

                 Section 8.  Amendment.  The Articles of Incorporation of the
         Corporation shall not be further amended in any manner which would (a)
         alter or change the powers, preferences or special rights or
         privileges of the Series I Preferred Stock so as to affect them
         adversely or (b) grant to any other class of shares any rights
         superior to those of the Series I Preferred Stock without the
         affirmative vote of the holders of a majority or more of the
         outstanding shares of Series I Preferred Stock, voting separately as a
         class.





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                 Section 9.  Fractional Shares.  Series I Preferred Stock may
         be issued in fractions of a share which shall entitle the holder, in
         proportion to such holder's fractional shares, to exercise voting
         rights, receive dividends, participate in distributions and to have
         the benefit of all other rights of holders of Series I Preferred
         Stock."

         The undersigned declare under penalty of perjury that the matters set
forth in the foregoing Certificate are true of their own knowledge.

             Executed at Milpitas, California on November 15, 1996.



                                      /s/ Richard Ellis 
                                      ----------------------------------
                                      J. Richard Ellis
                                      President and Chief Executive Officer



                                      /s/ Henry Madrid 
                                      -----------------------------------
                                      Henry Madrid 
                                      Chief Financial Officer





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