CERTIFICATE OF DESIGNATION
                                       OF
                            SERIES B PREFERRED STOCK
                                       OF
                               INPUT/OUTPUT, INC.

       Pursuant to Section 151(g) of the Delaware General Corporation Law, 
Input/Output, Inc., a corporation organized and existing under the laws of 
the State of Delaware (the "COMPANY"), hereby certifies that the following 
resolution was duly adopted by the Board of Directors of the Company on April 
21, 1999, pursuant to authority conferred upon the Board of Directors by the 
Certificate of Incorporation of the Company (the "CERTIFICATE OF 
INCORPORATION"), which authorizes the issuance of up to 5,000,000 shares of 
preferred stock, $0.01 par value.

       RESOLVED, that pursuant to authority expressly granted to and vested 
in the Board of Directors of the Company and pursuant to the provisions of 
the Certificate of Incorporation, the Board of Directors hereby creates a 
series of preferred stock, herein designated and authorized as the Series B 
Preferred Stock, $0.01 par value per share, which shall consist of 40,000 of 
the 5,000,000 shares of preferred stock which the Company now has authority 
to issue, and the Board of Directors hereby fixes the powers, designations, 
preferences and relative, participating, optional and other special rights of 
the shares of such series, and the qualifications, limitations and 
restrictions thereof as follows:

       1.   NUMBER AND RANK.  The number of shares constituting the Series B 
Preferred Stock shall be 40,000.   The Series B Preferred Stock shall rank 
senior to the Company's Series A Preferred Stock with respect to the payment 
of dividends and distributions on Liquidation.

       2.   DEFINITIONS.  Unless the context otherwise requires, when used 
herein the following terms shall have the meaning indicated.

       "ADJUSTED STATED VALUE" with respect to each share of Series B 
Preferred Stock means the Stated Value (a) increased at an annual rate of 8% 
thereof, compounded quarterly, less (b) the amount of cash dividends actually 
paid with respect to such share, in each case commencing on the Issue Date 
and accruing through the applicable Conversion Date, or, in the case of a 
redemption being effected pursuant to SECTIONS 6(H) OR 6(I), through the date 
of payment of the redemption price.  

       "AFFILIATE" means with respect to any Person, any other Person 
directly, or indirectly through one or more intermediaries, controlling, 
controlled by or under common control with such Person.  For purposes of this 
definition, the term "control" (and correlative terms "controlling," 
"controlled by" and "under common control with") means possession of the 
power, whether by contract, equity ownership or otherwise, to direct the 
policies or management of a Person.



       "AVERAGE MARKET PRICE"  means, for a given security, the average 
Market Price for such security for the ten Trading Day period ending on and 
including the Trading Day prior to the date of determination; PROVIDED, 
HOWEVER, that if during such period the Company takes any action or an action 
becomes effective that would require an adjustment to the Conversion Price 
pursuant to SECTION 7 hereof, then such Average Market Price shall be 
appropriately adjusted to reflect such action in a manner consistent with the 
adjustments set forth in SECTION 7.

       "BENEFICIALLY OWN" or "BENEFICIAL OWNERSHIP" has the meaning set forth 
in Rules 13d-3 and 13d-5 of the Exchange Act.

       "BOARD" means the Board of Directors of the Company.  

       "BUSINESS COMBINATION" means (i) any consolidation or merger of the 
Company with or into any Person or (ii) any Change of Control Stock Issuance, 
or (iii) the sale, assignment conveyance, transfer, lease or other 
disposition by the Company of all or substantially all of its assets followed 
by a liquidation of the Company.

       "BUSINESS DAY" means any day except Saturday, Sunday and any day which 
shall be a legal holiday or a day on which banking institutions in Houston, 
Texas generally are authorized or required by law or other governmental 
actions to close.

       "CAPITAL STOCK" means (i) with respect to any Person that is a 
corporation, any and all shares, interests, participations or other 
equivalents (however designated) of capital or capital stock of such Person 
and (ii) with respect to any Person that is not a corporation, any and all 
partnership or other equity interests of such Person. 

       "CERTIFICATE" means the Certificate of Incorporation of the Company, 
as amended (including any certificate of designation establishing a series of 
preferred stock).

       "CERTIFICATE OF DESIGNATION" means this Certificate of Designation of 
the Series B Preferred Stock.

       "CHANGE OF CONTROL STOCK ISSUANCE" shall mean any issuance, in a 
single transaction or series of related transactions, by the Company of 
shares of Common Stock or Common Stock Equivalents in connection with the 
acquisition of assets (including cash) or securities by the Company or a 
Subsidiary of the Company (including by way of a merger of a Subsidiary of 
the Company with or into a Person),  except where (i) the shareholders of the 
Company immediately prior to such issuance own (in substantially the same 
proportion relative to each other as such shareholders owned the Common Stock 
or Voting Stock of the Company, as the case may be, immediately prior to such 
consummation) (x) more than 50% of the Voting Stock of the Company 
immediately after such issuance, and (y) more than 50% of the outstanding 
Common Stock immediately after such issuance, (ii) the members of the Board 
immediately prior to entering into the agreement relating to such issuance 
(or if no such agreement is entered into, then immediately prior to the 
consummation of such issuance) constitute at least a majority of the Board 
immediately after such issuance, with no agreements or arrangements in place 
immediately after such consummation that would result in the members of the 
Board immediately prior to the entering into the agreement relating to such 
issuance 


                                      -2-


ceasing to constitute at least a majority of the Board and (iii) no Person or 
Group of Persons immediately after such issuance is the Beneficial Owner of 
40% or more of the total outstanding Voting Stock of the Company or Common 
Stock.  In calculating the percentage of the Voting Stock of the Company 
owned by the shareholders of the Company immediately prior to an issuance of 
Common Stock or Common Stock Equivalents in which there is more than one 
class or series of Voting Stock, the percentage of the Voting Stock shall be 
calculated based on the number of votes eligible to be cast in the election 
of the directors of the Company generally.  In calculating the percentages of 
Voting Stock and Common Stock owned for purposes of this definition, such 
calculation shall be calculated on a basis assuming the exercise or 
conversion in full of all Common Stock Equivalents and on a basis 
disregarding all Common Stock Equivalents, and the percentage which results 
in the lower percentage owned by the shareholders of the Company shall apply 
in the application of clause (i) above.

       "COMMON STOCK" means the Company's common stock, par value $.01 per 
share, and any Capital Stock for or into which such Common Stock hereafter is 
exchanged, converted, reclassified or recapitalized by the Company or 
pursuant to a Business Combination to which the Company is a party.

       "COMMON STOCK EQUIVALENTS" means (without duplication with any other 
Common Stock  or Common Stock Equivalents) rights, warrants, options, 
convertible securities or exchangeable securities, exercisable for or 
convertible or exchangeable into, directly or indirectly, Common Stock, 
whether at the time of issuance or upon the passage of time or the occurrence 
of some future event.

       "COMPANY" means Input/Output, Inc. a Delaware corporation.

       "CONVERSION DATE" is defined in SECTION 6(D).

       "CONVERSION PRICE" means $8.00, as adjusted from time to time in 
accordance with SECTION 7.
       
       "CONVERSION RATIO" is defined in SECTION 6(C).

       "DGCL" means the General Corporation Law of the State of Delaware, as 
amended, or any successor statute or other legislation.

       "DIVIDEND PAYMENT DATE" is defined in SECTION 3(A).

       "DIVIDEND PERIOD" is defined in SECTION 3(A).

       "EXCHANGE ACT" means the Securities Exchange Act of 1934, as amended, 
or any successor statute, and the rules and regulations promulgated 
thereunder.

       "EXCLUDED STOCK" means (i) shares of Common Stock issued by the 
Company as a stock dividend payable in shares of Common Stock, or upon any 
subdivision or split-up of the outstanding shares of Capital Stock in each 
case which is subject to SECTION 7(B), or upon conversion of shares of 
Capital Stock (but not the issuance of such Capital Stock which will be 
subject to the provisions


                                      -3-


of SECTION 7(A)(iii)), (ii) shares of Common Stock 
to be issued to employees, directors, consultants and advisors of the Company 
pursuant to Stock Plans in accordance with their respective terms.

       "GROUP" means a group as contemplated by Section 13(d)(3) of the 
Exchange Act.

       "HOLDER" means a holder of record of Series B Preferred Stock.

       "HSR ACT" means the Hart-Scott-Rodino Antitrust Improvements Act of 
1976, as amended.

       "HSR EXPIRATION DATE" shall mean the expiration or earlier termination 
of the applicable waiting period under the HSR Act relating to the 
transaction described in the filings referred to in Section 5.4 of the 
Purchase Agreement.

       "INITIAL CONVERSION DATE" means the first to occur of any of the 
following:  (i) the third anniversary of the date on which shares of Series B 
Preferred Stock are first issued pursuant to the Purchase Agreement, (ii) an 
agreement providing for a Business Combination is approved by the Board or a 
Business Combination is consummated, (iii) a Tender Offer for Common Stock is 
approved or recommended by the Board or (iv) there is a redemption, 
repurchase or reacquisition by the Company of Rights issued pursuant to the 
Rights Agreement or any waiver of the application of the Rights Agreement to 
any Beneficial Owner other than Purchaser or its Affiliates except in the 
case of this clause (iv) as approved by the Purchaser's representative to the 
Board.

       "ISSUE DATE" means with respect to any shares of Series B Preferred 
Stock the original date of issuance of such shares of Series B Preferred 
Stock.

       "JUNIOR SECURITIES" means Capital Stock that, with respect to 
dividends and distributions upon Liquidation, ranks junior to the Series B 
Preferred Stock.

       "LIQUIDATION" means the voluntary or involuntary liquidation, 
dissolution or winding up of the Company; PROVIDED, HOWEVER, that a merger or 
consolidation shall not be deemed a Liquidation nor shall the sale of assets 
not requiring shareholder approval be deemed to be a Liquidation.

       "LIQUIDATION PREFERENCE" is defined in SECTION 5.

       "MANDATORY CONVERSION DATE" is defined in SECTION 6(B).

       "MARKET PRICE" means, with respect to a particular security, on any 
given day, the last reported sale price regular way or, in case no such 
reported sale takes place on such day, the average of the last closing bid 
and asked prices regular way, in either case on the principal national 
securities exchange on which the applicable security is listed or admitted to 
trading, or if not listed or admitted to trading on any national securities 
exchange, (i) the closing sale price for such day reported by the Nasdaq 
Stock Market if such security is traded over-the-counter and quoted in the 
Nasdaq Stock Market, or (ii) if such security is so traded, but not so 
quoted, the average of the closing reported bid and asked prices of such 
security as reported by the Nasdaq Stock Market or any comparable system, or 
(iii) if such security is not listed on the Nasdaq Stock Market or any 
comparable system but is actively traded, the average of the closing bid and 
asked prices as furnished by two members of the 


                                      -4-


National Association of Securities Dealers, Inc. selected from time to time 
by the Company for that purpose.  If such security is not listed and traded 
in a manner that the quotations referred to above are available for the 
period required hereunder, the Market Price shall be deemed to be the fair 
value per share of such security as determined by a nationally recognized 
investment banking firm selected by the Board and reasonably acceptable to 
the Holders of a majority of the outstanding shares of Series B Preferred 
Stock. 

       "ORDINARY CASH DIVIDENDS" means any cash dividend or distribution 
which, when combined on a per share of Common Stock basis with the per share 
amounts of all other cash dividends and distributions paid on the Common 
Stock during the 365-day period ending on the date of declaration of such 
dividend or distribution (as adjusted to appropriately reflect any of the 
events referred to in SECTION 7 and excluding cash dividends or distributions 
that resulted in an adjustment to the Conversion Price), does not exceed 5% 
of the Market Price of a share of Common Stock on the Trading Day immediately 
preceding the date of declaration of such dividend or distribution.

       "PARITY SECURITIES" means Capital Stock that, with respect to 
dividends or distributions upon Liquidation, is PARI PASSU with the Series B 
Preferred Stock.

       "PERMITTED PARITY SECURITIES" means up to 35,000 shares of Preferred 
Stock of the Company constituting no more than two series of Preferred Stock, 
each share of which (i) has a liquidation preference of not more than $1,000 
per share exclusive of accrued and unpaid dividends, (ii) has a dividend rate 
of not more than one percent per annum, (iii) has no more than one vote per 
share with respect to matters on which it votes together with the Series B 
Preferred Stock and other Permitted Parity Securities as a single class and 
(iv) is PARI PASSU with the Series B Preferred Stock with respect to the 
payment of dividends and distributions upon Liquidation.  The Series C 
Preferred Stock that may be issued pursuant to the Purchase Agreement shall 
be considered Permitted Parity Securities for purposes of the foregoing.  

       "PERSON" means an individual or a corporation, partnership, trust, 
incorporated or unincorporated association, limited liability company, joint 
venture, joint stock company, government (or an agency or political 
subdivision thereof) or other entity of any kind.

       "PRO RATA REPURCHASE" means any purchase of shares of Common Stock by 
the Company or any Affiliate thereof pursuant to any tender offer or exchange 
offer subject to Section 13(e) of the Exchange Act, or pursuant to any other 
offer available to substantially all holders of Common Stock, whether for 
cash, shares of capital stock of the Company, other securities of the 
Company, evidences of indebtedness of the Company or any other person or any 
other property (including, without limitation, shares of capital stock, other 
securities or evidences of indebtedness of a subsidiary of the Company), or 
any combination thereof; PROVIDED, HOWEVER, that "Pro Rata Repurchase" shall 
not include any purchase of shares by the Company or any Affiliate thereof 
made in accordance with the requirements of Rule 10b-18 as in effect under 
the Exchange Act.  The "effective date" of a Pro Rata Repurchase shall mean 
the date of acceptance of shares for purchase or exchange under any tender or 
exchange offer which is a Pro Rata Repurchase or the date of purchase with 
respect to any Pro Rata Repurchase that is not a tender or exchange offer.


                                      -5-


       "PURCHASE AGREEMENT" means the Purchase Agreement dated as of April 
21, 1999 between the Company and the Purchaser providing for the purchase by 
the Purchaser of 40,000 shares of Series B Preferred Stock and up to 15,000 
shares of Series C Preferred Stock from the Company, including all schedules 
and exhibits thereto.

       "PURCHASER" means SCF-IV, L.P., a Delaware limited partnership.

       "RECORD DATE" is defined in SECTION 3(A).

       "REGISTRATION RIGHTS AGREEMENT" means the Registration Rights 
Agreement dated as of the date of the Initial Closing under the Purchase 
Agreement between the Company and the Purchaser providing for certain 
registration rights under the Securities Act with respect to the Common Stock 
into which the Series B Preferred Stock and Series C Preferred Stock may be 
converted.

       "RIGHTS AGREEMENT"  has the meaning set forth in SECTION 6(G).

       "SECURITIES ACT" means the Securities Act of 1933, as amended, or any 
successor statute, and the rules and regulations promulgated thereunder.

       "SENIOR SECURITIES" means Capital Stock that, with respect to 
dividends or distributions upon Liquidation, ranks senior to the Series B 
Preferred Stock.

       "SERIES C PREFERRED STOCK" means the Series C Preferred Stock of the 
Company that may be issued to Purchaser pursuant to the Purchase Agreement. 

       "STATED VALUE" is an amount equal to $1,000.00 per share of Series B 
Preferred Stock.

       "STOCK PLANS"  means the Company's stock option, stock incentive, 
restricted stock, employee stock purchase or other similar plans, in each 
case that have been approved by the Company's shareholders.

       "SUBSIDIARY" of a Person means (i) a corporation, a majority of whose 
stock with voting power, under ordinary circumstances, to elect directors is 
at the time of determination, directly or indirectly, owned by such Person or 
by one or more Subsidiaries of such Person, or (ii) any other entity (other 
than a corporation) in which such Person or one or more Subsidiaries of such 
Person, directly or indirectly, at the date of determination thereof has a 
majority ownership interest or, with respect to a limited partnership, is a 
general partner of such limited partnership.

       "TENDER OFFER" means any transaction to which Regulation 14D of the 
Exchange Act applies.

       "TRADING DAY" means a day on which the principal market with respect 
to the security in question is regularly scheduled to be open for trading, or 
if there is not such principal market, then a day on which the New York Stock 
Exchange is regularly scheduled to be open for trading.


                                      -6-


       "VOTING STOCK" of a Person means Capital Stock of such Person of the 
class or classes pursuant to which the holders thereof have the general 
voting power under ordinary circumstances to vote in the election of the 
board of directors, managers or trustees of such Person.

       The foregoing definitions will be equally applicable to both the 
singular and plural forms of the defined terms.

       3.   DIVIDENDS AND DISTRIBUTIONS.

            (A)    The holders of Series B Preferred Stock shall be entitled
       to receive out of the assets of the Company legally available for that
       purpose, cumulative preferential cash dividends at a rate per annum of
       one percent (1%) of the Stated Value (equivalent to $10 per annum or
       $2.50 per quarter) for each share of Series B Preferred Stock, and,
       except as provided in SECTION 3(B), no more, to be paid in accordance
       with the terms of this SECTION 3.  Such dividends shall be cumulative
       from the Issue Date and shall be payable in arrears, when and as
       declared by the Board, on March 31, June 30, September 30 and
       December 31 of each year (each such date being herein referred to as a
       "DIVIDEND PAYMENT DATE"), commencing on June 30, 1999; PROVIDED that if
       any Dividend Payment Date shall not be a Business Day, then the Dividend
       Payment Date shall be on the next succeeding day that is a Business Day.
       The period from the Issue Date to the next Dividend Payment Date and
       each quarterly period between consecutive Dividend Payment Dates shall
       hereinafter be referred to as "DIVIDEND PERIODS."  Dividends for the
       initial Dividend Period shall be pro rated on a daily basis commencing
       on and including the Issue Date on the basis of a 360-day year.  Each
       such dividend shall be paid to the holders of record of the Series B
       Preferred Stock as their names appear on the share register of the
       Company on the corresponding Record Date.  As used above, the term
       "RECORD DATE" means, with respect to the dividend payable on March 31,
       June 30, September 30 and December 31, respectively, of each year, the
       preceding March 15, June 15, September 15 and December 15, or such other
       record date designated by the Board with respect to the dividend payable
       on such respective Dividend Payment Date not exceeding 30 days preceding
       such Dividend Payment Date.  Dividends on account of arrears for any
       past Dividend Periods may be declared and paid, together with any
       accrued but unpaid interest thereon to and including the date of
       payment, at any time, without reference to any Dividend Payment Date, to
       holders of record on a date designated by the Board, not exceeding 30
       days preceding the payment date thereof, as may be fixed by the Board.

            (B)    If, on any Dividend Payment Date, the Company fails to pay 
       dividends, then until the dividends that were scheduled to be paid on 
       such date are paid, such dividends shall cumulate and shall accrue 
       additional dividends with respect to such unpaid dividends to and 
       including the date of payment thereof at the rate of one percent (1%) 
       per annum, compounded on a quarterly basis.  Dividends for any period 
       less than a full quarterly Dividend Period or for a period commencing 
       on a Dividend Payment Date and ending on a Conversion Date shall 
       cumulate on a day-to-day basis and shall be computed on the basis of a 
       360-day year.

            (C)    So long as any shares of the Series B Preferred Stock 
       shall be outstanding, (i) the Company shall not declare or pay any 
       dividend whatsoever, whether in cash, property 


                                      -7-


       or otherwise, set aside any cash or property for the payment of 
       dividends, or make any other distribution on any Junior Securities 
       (except a dividend or distribution payable solely in shares of Junior 
       Securities), (ii) the Company shall not declare or pay any dividend 
       whatsoever, whether in cash, property or otherwise, set aside any cash 
       or property for the payment of dividends, or make any other 
       distribution on any Parity Securities ranking on parity with the 
       Series B Preferred Stock with respect to dividends or distributions 
       (except a dividend or distribution payable solely in shares of Junior 
       Securities), unless declared and paid PRO RATA with the Series B 
       Preferred Stock in proportion to the full amount to which they would 
       otherwise be respectively entitled, and (iii) the Company shall not 
       and shall cause its Subsidiaries not to repurchase, redeem or 
       otherwise acquire or set aside any cash or property for the repurchase 
       or redemption of any Junior Securities or Parity Securities, unless in 
       each such case all dividends to which the holders of the Series B 
       Preferred Stock shall have been entitled for all previous Dividend 
       Periods shall have been paid or declared and a sum of money sufficient 
       for the payment thereof shall have been set aside.

       4.   VOTING RIGHTS.  The Holders shall have the following voting 
rights with respect to the Series B Preferred Stock:

            (A)    Subject to applicable law, the shares of Series B Preferred 
       Stock shall have no voting rights other than as set forth in this 
       SECTION 4.

            (B)    After the HSR Expiration Date, but only after the HSR 
       Expiration Date, Holders of shares of the Series B Preferred Stock 
       shall be entitled to vote upon all matters upon which holders of 
       Common Stock have the right to vote, and Holders shall have that 
       number of votes on all such matters as is equal to the Conversion 
       Ratio that would apply if such Holder's shares of Series B Preferred 
       Stock were to be converted pursuant to SECTION 6(A) (using the 
       calculation of such Conversion Ratio specified in SECTION 6(C)(i) and 
       not SECTION 6(C)(ii) for such purpose) as of the record date for the 
       determination of the shareholders entitled to vote on such matters, 
       or, if no such record date is established as of the date such vote is 
       taken or any written consent of shareholders is solicited, such votes 
       to be counted together with all other shares of capital stock having 
       general voting powers and not separately as a class.  Fractional votes 
       shall not, however, be permitted and any fractional voting rights 
       resulting from the above formula (after aggregating all shares into 
       which shares of Series B Preferred Stock held by each Holder could be 
       converted) shall be rounded up to the nearest whole number.
       
            (C)    After the HSR Expiration Date, but only after the HSR 
       Expiration Date, the Holders of the Series B Preferred Stock, voting 
       together with Permitted Parity Securities as a separate class with one 
       vote per share of Series B Preferred Stock, shall be entitled to elect 
       one member of the Board at each meeting or pursuant to each consent of 
       the Company's shareholders for the election of directors (unless the 
       term of the director previously elected by the Holders pursuant to 
       this Section 4(C) would continue after such election).  If the 
       director so elected by the Holders shall cease to serve as director 
       before his term shall expire, the Holders may, at a special meeting of 
       such Holders, elect a successor to hold office for the unexpired term 
       of such director.  The Secretary of the Company may call, and upon 
       written request of the Holders of ten percent (10%) or more of the 
       outstanding Series B Preferred 


                                      -8-


       Stock addressed to him at the principal office of the Company shall 
       call, such a special meeting of the Holders for the election of such 
       director as provided herein.  Such meeting shall be held within fifty 
       (50) days after delivery of such request to such Secretary, at the 
       place and upon the notice provided by law and in the Bylaws of the 
       Company for the holding of meetings of its shareholders. Any director 
       who shall have been elected pursuant to this SECTION 4(C), may be 
       removed during the aforesaid term of office, with or without cause, 
       only by the affirmative vote of a majority votes entitled to be cast 
       by the Holders of Series B Preferred Stock and the holders of then 
       outstanding Permitted Parity Securities.
       
            (D)   (i)   The consent of the Holders of at least a majority of 
       the Series B Preferred Stock, voting together with Permitted Parity 
       Securities as a single class with one vote per share, in person or by 
       proxy, either in writing without a meeting or at an annual or a 
       special meeting of shareholders called for the purpose, shall be 
       necessary to:

                        (A)    amend, alter or repeal, by way of merger or 
                 otherwise, any of the provisions of the Certificate, so as 
                 to authorize, create or issue any shares of Parity 
                 Securities (other than Permitted Parity Securities) or 
                 Senior Securities (or amend the provisions of any existing 
                 class of Capital Stock to make such class of Capital Stock 
                 a class of Parity Securities or Senior Securities), 

                        (B)    issue any Parity Securities (other than Permitted
                 Parity Securities) or Senior Securities, or

                        (C)    consummate any Business Combination. 

                  (ii)   The consent of the Holders of at least a majority
            of the Series B Preferred Stock, voting separately as a single
            class with one vote per share, in person or by proxy, either in
            writing without a meeting or at an annual or a special meeting of
            shareholders called for the purpose, shall be necessary to amend,
            alter or repeal, by way of merger or otherwise, any of the 
            provisions of (x) the Certificate of Designation or any
            certificate of designation of terms of any Parity Securities, or
            (y) the Certificate, so as to affect adversely any of the rights,
            preferences or privileges of Holders.  

       5.   LIQUIDATION PREFERENCE.  In the event of any Liquidation, after 
payment or provision for payment by the Company of the debts and other 
liabilities of the Company and the liquidation preference of any Senior 
Securities that rank senior to the Series B Preferred Stock with respect to 
distributions on Liquidation, each Holder shall be entitled to receive an 
amount in cash for each share of the then outstanding Series B Preferred 
Stock held by such Holder equal to the Stated Value per share, plus an amount 
equal to all accrued but unpaid dividends thereon, whether or not earnings 
are available in respect of such dividends or such dividends have been 
declared, to and including the date full payment is tendered to the Holders 
with respect to such Liquidation, and no more (such amount being referred to 
herein as the "LIQUIDATION PREFERENCE"), before any distribution shall be 
made to the holders of any Junior Securities upon the Liquidation of the 
Company.  In case the assets of the Company available for payment to the 
Holders upon a Liquidation are insufficient to pay the full 


                                      -9-


Liquidation Preference on all outstanding shares of the Series B Preferred 
Stock and all outstanding Senior Securities or Parity Securities, in each 
case ranking on parity with the Series B Preferred Stock as to distributions 
on Liquidation, in the amounts to which the holders of such shares are 
entitled, then the entire assets of the Company available for payment to the 
Holders of Series B Preferred Stock and holders of such Senior Securities or 
Parity Securities will be distributed ratably among the Holders of the Series 
B Preferred Stock and the holders of such Senior Securities or Parity 
Securities, based upon the aggregate amount due on such shares upon 
Liquidation. Written notice of any Liquidation of the Company, stating a 
payment date and the place where the distributable amounts shall be payable, 
shall be given by mail, postage prepaid, not less than 30 days prior to the 
payment date stated therein, to the Holders of record of the Series B 
Preferred Stock at their respective addresses as the same shall appear on the 
books of the Company.

       6.   CONVERSION RIGHTS.  The Series B Preferred Stock shall be 
convertible as follows:

            (A)   CONVERSION AT HOLDER'S OPTION.  The Holder of any shares of 
       Series B Preferred Stock shall have the right at such Holder's option, 
       at any time after the Initial Conversion Date and prior to the 
       Mandatory Conversion Date and without the payment of any additional 
       consideration, to convert any or all of such shares of Series B 
       Preferred Stock into a number of fully paid and nonassessable shares 
       of Common Stock for each such share of Series B Preferred Stock equal 
       to the Conversion Ratio, upon the terms hereinafter set forth.  
       
            (B)   MANDATORY CONVERSION.   On the fifth anniversary of the 
       date on which shares of Series B Preferred Stock are first issued 
       pursuant to the Purchase Agreement (the "MANDATORY CONVERSION DATE"), 
       each outstanding share of Series B Preferred Stock shall, without any 
       action on the part of the Holder of such share, be converted 
       automatically into a number of fully paid and nonassessable shares of 
       Common Stock equal to the Conversion Ratio, upon the terms hereinafter 
       set forth; PROVIDED, HOWEVER, that if the shares of Common Stock 
       issuable upon conversion of the Series B Preferred Stock are not 
       immediately freely transferrable under the Securities Act by the 
       Holders thereof, the Mandatory Conversion Date shall be delayed until 
       such time as the resale of the Common Stock issuable upon conversion 
       of such Series B Preferred Stock has been registered under the 
       Securities Act in accordance with the terms of the Registration Rights 
       Agreement.

            (C)   CONVERSION RATIO.  In the event of a conversion pursuant
       to SECTION 6(A) OR 6(B), the Conversion Ratio shall be a number of
       shares of Common Stock calculated using either of the following methods
       at the option of the Holder as may be specified by the Holder at the
       time of conversion, or, if no such specification is made, using the
       method that results in the highest number:

                  (i)   the amount determined by dividing (a) the Stated
            Value plus any accrued and unpaid dividends to and including the
            applicable Conversion Date by (b) the Conversion Price in effect
            on the applicable Conversion Date; or 

                  (ii)  the amount determined by dividing (a) the Adjusted
            Stated Value as of the applicable Conversion Date by (b) the
            Average Market Price determined as of the 


                                      -10-



            applicable Conversion Date (but not less than the lesser of 
            $.01 or the par value per share of the Common Stock at the 
            time of conversion). 

            (D)   MECHANICS OF CONVERSION.  The Holder of any shares of 
       Series B Preferred Stock may exercise the conversion right specified 
       in SECTION 6(A) by surrendering to the Company or any transfer agent 
       of the Company the certificate or certificates representing the shares 
       of Series B Preferred Stock to be converted, accompanied by written 
       notice specifying the number of such shares to be converted.  If the 
       certificates representing shares of Common Stock issuable upon 
       conversion of shares of Series B Preferred Stock are to be issued in a 
       name other than the name on the face of the certificates representing 
       such shares of Series B Preferred Stock, such certificates shall be 
       accompanied by such evidence of the assignment and such evidence of 
       the signatory's authority with respect thereto as deemed appropriate 
       by the Company or its transfer agent.  Conversion shall be deemed to 
       have been effected (i) with respect to conversions pursuant to SECTION 
       6(A), on the date when the notice of an election to convert pursuant 
       to SECTION 6(A) and certificates representing the shares being 
       converted are actually received by the Company or any transfer agent 
       of the Company, or (ii) with respect to mandatory conversion pursuant 
       to SECTION 6(B), on the Mandatory Conversion Date.  Such dates that 
       the conversion shall be deemed to be effective shall be referred to 
       herein as the "CONVERSION DATE."  Subject to the provisions of SECTION 
       7(G), as promptly as practicable after the Conversion Date, the 
       Company shall issue and deliver to or upon the written order of such 
       Holder a certificate or certificates for the number of shares of 
       Common Stock to which such Holder is entitled upon such conversion and 
       a check or cash with respect to any fractional interest in a share of 
       Common Stock, as provided in SECTION 6(E).  The person in whose name 
       the certificate or certificates for shares of Common Stock are to be 
       issued shall be deemed to have become a holder of record of such 
       shares of Common Stock on the applicable Conversion Date.  Upon 
       conversion of only a portion of the shares covered by a certificate 
       representing shares of Series B Preferred Stock surrendered for 
       conversion pursuant to SECTION 6(A), the Company shall issue and 
       deliver to or upon the written order of the Holder of the certificate 
       so surrendered for conversion, at the expense of the Company, a new 
       certificate representing the number of shares of Series B Preferred 
       Stock representing the unconverted portion of the certificate so 
       surrendered.
       
            (E)   FRACTIONAL SHARES.  No fractional shares of Common Stock or 
       scrip shall be issued upon conversion of shares of Series B Preferred 
       Stock.  If more than one share of Series B Preferred Stock shall be 
       surrendered for conversion at any one time by the same Holder, the 
       number of shares of Common Stock issuable upon conversion thereof 
       shall be computed on the basis of the aggregate number of shares of 
       Series B Preferred Stock so surrendered.  Instead of any fractional 
       share of Common Stock which would otherwise be issuable upon 
       conversion of any shares of Series B Preferred Stock, the Company 
       shall pay a cash adjustment in respect of such fractional interest in 
       an amount equal to that fractional interest of the Market Price of the 
       Common Stock on the Conversion Date.
       
            (F)   AUTHORIZATION AND ISSUANCE.  The Company covenants and
       agrees that:

                  (i)   the shares of Common Stock issuable upon any
            conversion of any shares of Series B Preferred Stock will be
            deemed to have been issued to the Person 


                                      -11-


            exercising such conversion rights set forth herein on the 
            Conversion Date, and the Person exercising such conversion rights 
            will be deemed for all purposes to have become the record holder 
            of such shares of Common Stock on the Conversion Date;

                  (ii)  all shares of Common Stock which may be issued
            upon any conversion of any Series B Preferred Stock will, upon
            issuance, be fully paid and non-assessable and free from all
            taxes, liens and charges with respect to the issue thereof;

                  (iii) the Company will take all such action as may be
            necessary to assure that all shares of Common Stock issuable upon
            conversion of shares of Series B Preferred Stock may be issued
            without violation of any applicable law or regulation or of any
            requirements of any domestic securities exchange upon which
            securities of the same class may be listed and shall endeavor to
            list the shares of Common Stock required to be delivered upon
            conversion of the shares of Series B Preferred Stock, prior to
            such delivery, upon each national securities exchange, if any,
            upon which the outstanding Common Stock is listed at the time of
            such delivery; 

                  (iv)  the Company will not take any action which would
            result in any adjustment of the Conversion Price if the total
            number of shares of Common Stock issuable after such action upon
            conversion of all shares of Series B Preferred Stock, together
            with all shares of Common Stock then outstanding and all shares
            of Common Stock then issuable upon the exercise of all
            outstanding Common Stock Equivalents, would exceed the total
            number of shares of Common Stock then authorized by the
            Certificate of Incorporation; 

                  (v)   the Company will at all times reserve and keep
            available, out of its authorized but unissued shares of Common
            Stock or out of shares of Common Stock held in its treasury, the
            full number of shares of Common Stock into which all shares of
            the Series B Preferred Stock having conversion privileges from
            time to time outstanding are convertible; and 

                  (vi)  the Company will at no time close its transfer
            books against the transfer of the Series B Preferred Stock or of
            any share of Common Stock issued or issuable upon the conversion
            of the Series B Preferred Stock in any manner which interferes
            with the timely conversion of the Series B Preferred Stock.

            (G)   RIGHTS.  Whenever the Company issues shares of Common Stock 
       upon conversion of Series B Preferred Stock, the Company will issue, 
       together with each such share of Common Stock, one right to purchase 
       Series A Preferred Stock of the Company (or other securities in lieu 
       thereof) pursuant to the Rights Agreement dated as of January 17, 1997 
       by and between the Company and Harris Trust and Savings Bank, as 
       amended (the "RIGHTS AGREEMENT"), or any similar rights, if any, 
       issued to holders of Common Stock in addition thereto or in the 
       replacement therefor (such rights, together with any additional or 
       replacement rights, being collectively referred to as the "RIGHTS"), 
       whether or not such rights shall be exercisable at such time, but only 
       if such Rights are issued and outstanding and held 


                                      -12-


       by other holders of Common Stock (or are evidenced by outstanding 
       share certificates representing Common Stock) at such time and have 
       not expired or been redeemed.
       
            (H)   CASH REDEMPTION OPTION.  Notwithstanding the provisions of 
       SECTIONS 6(A) OR 6(B), in the event of a conversion of Series B 
       Preferred Stock pursuant to which the Conversion Ratio is determined 
       using SECTION 6(C)(ii) (rather than SECTION 6(C)(i)), then, provided 
       that full cumulative dividends shall have been paid or declared and 
       set apart for payment upon all outstanding shares of Series B 
       Preferred Stock for all past dividend periods, the Company may offer 
       to redeem for cash any or all of such shares of Series B Preferred 
       Stock at a redemption price per share equal to the Adjusted Stated 
       Value (a "REDEMPTION OFFER"),  in lieu of effecting such conversion.  
       To effect a Redemption Offer, the Company must give notice of such 
       election, specifying the redemption price, (a "REDEMPTION OFFER 
       NOTICE") to the Holder of such shares of Series B Preferred Stock (i) 
       with respect to conversions pursuant to SECTION 6(A), within three 
       Business Days after the notice of an election to convert pursuant to 
       SECTION 6(A) is received by the Company or any transfer agent of the 
       Company, or (ii) with respect to mandatory conversion pursuant to 
       SECTION 6(B), on the Mandatory Conversion Date.  If the Company fails 
       to give a Redemption Offer Notice within the foregoing time periods, 
       it may not make a Redemption Offer.  If the Company has given a 
       Redemption Offer Notice with respect to more than 50% of the shares of 
       Series B Preferred Stock to be converted, then within three Business 
       Days following receipt of a Redemption Offer Notice, the Holder may 
       give notice to the Company declining the Company's offer to redeem up 
       to 50% of the shares of Series B Preferred Stock to be converted, in 
       which event the Company will not be entitled to redeem such shares as 
       specified and must convert such shares into Common Stock in accordance 
       with the terms hereof effective as of the Conversion Date.  The 
       Company shall be entitled to redeem all of the shares subject to the 
       Redemption Offer Notice at the redemption price set forth above to the 
       extent the Holder does not properly decline such redemption in 
       accordance with the prior sentence. The Company shall make any such 
       redemption payment by wire transfer to an account specified by the 
       Holder on the first Business Day following the expiration of the three 
       Business Day period after the Holder's receipt of the Redemption Offer 
       Notice, failing which payment the Company shall not be entitled to 
       redeem such shares but shall be obligated to convert all of such 
       Shares into Common Stock in accordance with the terms hereof.
       
            (I)   LIMITATION ON NUMBER OF CONVERSION SHARES. Notwithstanding 
       the provisions of SECTIONS 6(A) OR 6(B), if the Company ever issues 
       Common Stock upon conversion of Series B Preferred Stock pursuant to 
       which the Conversion Ratio is calculated pursuant to SECTION 6(C)(ii) 
       rather than SECTION 6(C)(i), the Company shall not be obligated to 
       issue, in the aggregate, a number of shares of Common Stock in excess 
       of the NYSE Limitation upon conversion of the Series B Preferred 
       Stock. The "NYSE Limitation" shall mean the maximum number of shares 
       of Common Stock that could be issued by the Company pursuant to the 
       conversion of the Series B Preferred Stock and any substantially 
       similar series of Permitted Parity Securities issued to the Holder 
       pursuant to the terms of the Purchase Agreement without triggering a 
       requirement to obtain the approval of the Company's shareholders of 
       such issuance pursuant to Section 312.03(c) of the New York Stock 
       Exchange Listed Company Manual as in effect on the Issue Date.  To the 
       extent that any shares of Series B Preferred Stock are submitted for 
       conversion such that the NYSE Limitation would be 


                                      -13-


       exceeded, such excess shares shall, in lieu of being converted into 
       Common Stock, be redeemed in exchange for a cash payment equal to the 
       Adjusted Stated Value per share.   The Company shall make any such 
       redemption payment by wire transfer to an account specified by the 
       Holder on the second Business Day following the Conversion Date on 
       which the shares of Series B Preferred Stock would otherwise be 
       converted into Common Stock.

       7.   CONVERSION PRICE ADJUSTMENTS.  The Conversion Price shall be
subject to adjustment from time to time as follows:

            (A)   COMMON STOCK ISSUED AT LESS THAN MARKET PRICE OR CONVERSION 
       PRICE.  If the Company issues or sells any Common Stock other than 
       Excluded Stock without consideration or for a consideration per share 
       less than the Market Price per share of Common Stock, on the Trading 
       Day immediately preceding such issuance or sale or less than the 
       Conversion Price in effect immediately prior to such issuance or sale, 
       the Conversion Price in effect immediately prior to each such issuance 
       or sale will immediately (except as provided below) be reduced to the 
       price determined by multiplying the Conversion Price in effect 
       immediately prior to such issuance or sale, by a fraction, (1) the 
       numerator of which shall be (i) the number of shares of Common Stock 
       outstanding immediately prior to such issuance or sale plus (ii) the 
       number of shares of Common Stock which the aggregate consideration 
       received by the Company for the total number of such additional shares 
       of Common Stock so issued or sold would purchase at the higher of (x) 
       the Market Price per share of Common Stock on the Trading Day 
       immediately preceding such issuance or sale and (y) the Conversion 
       Price in effect immediately prior to such issuance or sale and (2) the 
       denominator of which shall be the number of shares of Common Stock 
       outstanding immediately after such issue or sale.  For the purposes of 
       any adjustment of the Conversion Price pursuant to this SECTION 7(A), 
       the following provisions shall be applicable:

                  (i)     in the case of the issuance of Common Stock for
            cash, the amount of the consideration received by the Company
            shall be deemed to be the amount of the cash proceeds received by
            the Company for such Common Stock before deducting therefrom any
            discounts or commissions allowed, paid or incurred by the Company
            for any underwriting or otherwise in connection with the issuance
            and sale thereof;

                  (ii)    in the case of the issuance of Common Stock
            (otherwise than upon the conversion of shares of Capital Stock or
            other securities of the Company) for a consideration in whole or
            in part other than cash, including securities acquired in
            exchange therefor (other than securities by their terms so
            exchangeable), the consideration other than cash shall be deemed
            to be the fair value thereof as reasonably determined by the
            Board, irrespective of any accounting treatment; PROVIDED,
            HOWEVER, that such fair value as determined by the Board shall
            not exceed the aggregate Market Price of the shares of Common
            Stock being issued as of the date the Board authorizes the
            issuance of such shares;

                  (iii)   in the case of the issuance of (a) options,
            warrants or other rights to purchase or acquire Common Stock
            (whether or not at the time exercisable), (b) securities by their
            terms convertible into or exchangeable for Common Stock (whether


                                      -14-


            or not at the time so convertible or exchangeable) or options,
            warrants or rights to purchase such convertible or exchangeable
            securities (whether or not at the time exercisable):

                          (1)    the aggregate maximum number of shares of
                                 Common Stock deliverable upon exercise of
                                 such options, warrants or other rights to
                                 purchase or acquire Common Stock shall be
                                 deemed to have been issued at the time
                                 such options, warrants or rights are
                                 issued and for a consideration equal to
                                 the consideration (determined in the
                                 manner provided in SECTION 7(A)(i) AND
                                 (ii)), if any, received by the Company
                                 upon the issuance of such options,
                                 warrants or rights plus the minimum
                                 purchase price provided in such options,
                                 warrants or rights for the Common Stock
                                 covered thereby;

                          (2)    the aggregate maximum number of shares of
                                 Common Stock deliverable upon conversion
                                 of or in exchange for any such convertible
                                 or exchangeable securities, or upon the
                                 exercise of options, warrants or other
                                 rights to purchase or acquire such
                                 convertible or exchangeable securities and
                                 the subsequent conversion or exchange
                                 thereof, shall be deemed to have been
                                 issued at the time such securities were
                                 issued or such options, warrants or rights
                                 were issued and for a consideration equal
                                 to the consideration, if any, received by
                                 the Company for any such securities and
                                 related options, warrants or rights
                                 (excluding any cash received on account of
                                 accrued interest or accrued dividends),
                                 plus the additional consideration
                                 (determined in the manner provided in
                                 SECTION 7(A)(i) AND (ii)), if any, to be
                                 received by the Company upon the
                                 conversion or exchange of such securities,
                                 or upon the exercise of any related
                                 options, warrants or rights to purchase or
                                 acquire such convertible or exchangeable
                                 securities and the subsequent conversion
                                 or exchange thereof;

                          (3)    on any change in the number of shares of
                                 Common Stock deliverable upon exercise of
                                 any such options, warrants or rights or
                                 conversion or exchange of such convertible
                                 or exchangeable securities or any change
                                 in the consideration to be received by the
                                 Company upon such exercise, conversion or
                                 exchange, but excluding changes resulting
                                 from the anti-dilution provisions thereof
                                 (to the extent comparable to the
                                 anti-dilution provisions contained
                                 herein), the Conversion Price as then in
                                 effect shall forthwith be readjusted to
                                 such Conversion Price as would have been
                                 obtained had an adjustment been made upon
                                 the issuance of such options, warrants or
                                 rights not exercised prior to such change,
                                 or of 


                                      -15-


                                 such convertible or exchangeable securities
                                 not converted or exchanged prior to such 
                                 change, upon the basis of such change;

                          (4)    on the expiration or cancellation of any
                                 such options, warrants or rights (without
                                 exercise), or the termination of the right
                                 to convert or exchange such convertible or
                                 exchangeable securities (without
                                 exercise), if the Conversion Price shall
                                 have been adjusted upon the issuance
                                 thereof, the Conversion Price shall
                                 forthwith be readjusted to such Conversion
                                 Price as would have been obtained had an
                                 adjustment been made upon the issuance of
                                 such options, warrants, rights or such
                                 convertible or exchangeable securities on
                                 the basis of the issuance of only the
                                 number of shares of Common Stock actually
                                 issued upon the exercise of such options,
                                 warrants or rights, or upon the conversion
                                 or exchange of such convertible or
                                 exchangeable securities; and

                          (5)    if the Conversion Price shall have been
                                 adjusted upon the issuance of any such
                                 options, warrants, rights or convertible
                                 or exchangeable securities, no further
                                 adjustment of the Conversion Price shall
                                 be made for the actual issuance of Common
                                 Stock upon the exercise, conversion or
                                 exchange thereof; 

               PROVIDED, HOWEVER, that no increase in the Conversion Price shall
               be made pursuant to subclauses (1) or (2) of this SECTION
               7(A)(iii).

            (B)   STOCK SPLITS, SUBDIVISIONS, RECLASSIFICATIONS OR 
       COMBINATIONS.  If the Company shall (1) declare a dividend or make a 
       distribution on its Common Stock in shares of Common Stock, (2) 
       subdivide or reclassify the outstanding shares of Common Stock into a 
       greater number of shares, or (3) combine or reclassify the outstanding 
       Common Stock into a smaller number of shares, the Conversion Price in 
       effect at the time of the record date for such dividend or 
       distribution or the effective date of such subdivision, combination or 
       reclassification shall be proportionately adjusted so that the Holder 
       of any shares of Series B Preferred Stock surrendered for conversion 
       or exchange after such date shall be entitled to receive the number of 
       shares of Common Stock which such holder would have owned or been 
       entitled to receive after such date had such Series B Preferred Stock 
       been converted or exchanged immediately prior to such date. Successive 
       adjustments in the Conversion Price shall be made whenever any event 
       specified above shall occur.
       
            (C)   OTHER DISTRIBUTIONS.  In case the Company shall fix a 
       record date for the making of a distribution to all holders of shares 
       of its Common Stock (1) of shares of any class other than its Common 
       Stock or (2) of evidence of indebtedness of the Company or any 
       Subsidiary or (3) of assets (including cash but excluding Ordinary 
       Cash Dividends, and dividends or distributions referred to in SECTION 
       7(B)), or (4) of rights or warrants, then in 


                                      -16-


       each such case the Conversion Price in effect immediately prior 
       thereto shall be reduced to the price determined by multiplying the 
       Conversion Price in effect immediately prior to such record date by a 
       fraction, (i) the numerator of which shall be an amount equal to the 
       difference resulting from (A) the number of shares of Common Stock 
       outstanding on such record date multiplied by the Market Price per 
       share of Common Stock on such record date, less (B) the fair market 
       value (as reasonably determined by the Board) of said shares or 
       evidences of indebtedness or assets or rights or warrants to be so 
       distributed, and (ii) the denominator of which shall be equal to the 
       number of shares of Common Stock outstanding on such record date 
       multiplied by the Market Price per share of Common Stock on such 
       record date.  Such adjustment shall be made successively whenever such 
       a record date is fixed. In the event that such distribution is not so 
       made, the Conversion Price then in effect shall be readjusted, 
       effective as of the date when the Board determines not to distribute 
       such shares, evidences of indebtedness, assets, rights or warrants, as 
       the case may be, to the Conversion Price that would then be in effect 
       if such record date had not been fixed.
       
            (D)   CERTAIN REPURCHASES OF COMMON STOCK.  In case the Company 
       effects a Pro Rata Repurchase of Common Stock, then the Conversion 
       Price shall be reduced to the price determined by multiplying the 
       Conversion Price in effect immediately prior to the effective date of 
       such Pro Rata Repurchase by a fraction of which (1) the numerator 
       shall be (i) the product of (x) the number of shares of Common Stock 
       outstanding immediately before such Pro Rata Repurchase and (y) the 
       Market Price per share of Common Stock on the Trading Day immediately 
       preceding the first public announcement of the intent to effect such 
       Pro Rata Repurchase, minus (ii) the aggregate purchase price of the 
       Pro Rata Repurchase, and of which (2) the denominator shall be the 
       product of (a) the number of shares of Common Stock outstanding 
       immediately prior to such Pro Rata Repurchase minus the number of 
       shares of Common Stock so repurchased and (b) the Market Price per 
       share of Common Stock on the Trading Day immediately preceding the 
       first public announcement of such Pro Rata Repurchase.
       
            (E)   BUSINESS COMBINATIONS.  In case of any Business Combination 
       in which the holders of shares of Common Stock are entitled to receive 
       stock, securities or property by virtue of their ownership of Common 
       Stock or a reclassification of Common Stock (other than a 
       reclassification of Common Stock referred to in SECTION 7(B)), each 
       share of Series B Preferred Stock shall after the date of such 
       Business Combination or reclassification be convertible into the 
       number of shares of stock or other securities or property (including 
       cash) to which the Common Stock issuable upon conversion of such share 
       of Series B Preferred Stock immediately prior to such Business 
       Combination or reclassification would have been entitled upon such 
       Business Combination or reclassification; and in any such case, if 
       necessary, the provisions set forth herein with respect to the rights 
       and interests thereafter of the Holders of the shares of Series B 
       Preferred Stock shall be appropriately adjusted so as to be 
       applicable, as nearly as may reasonably be, to any shares of stock or 
       other securities or property thereafter deliverable on the conversion 
       of the shares of Series B Preferred Stock.  In determining the kind 
       and amount of stock, securities or the property receivable upon 
       consummation of such Business Combination, if the holders of Common 
       Stock have the right to elect the kind or amount of consideration 
       receivable upon consummation of such Business Combination, then the 
       Holder of the Series B Preferred Stock shall have the right to make a 


                                      -17-


       similar election as of the Conversion Date with respect to the number 
       of shares of stock or other securities or property into which the 
       Series B Preferred Stock shall be convertible.
       
             (F)   ROUNDING OF CALCULATIONS; MINIMUM ADJUSTMENTS.  All 
       calculations under this SECTION 7 shall be made to the nearest one 
       tenth (1/10th) of a cent or to the nearest one hundredth (1/100th) of 
       a share, as the case may be. Any provision of this SECTION 7 to the 
       contrary notwithstanding, no adjustment in the Conversion Price shall 
       be made if the amount of such adjustment would be less than $0.01, but 
       any such amount shall be carried forward and an adjustment with 
       respect thereto shall be made at the time of and together with any 
       subsequent adjustment which, together with such amount and any other 
       amount or amounts so carried forward, shall aggregate $0.01 or more.  
       In addition, in no event shall be Conversion Price be adjusted to less 
       than the lesser of $.01 per share or the par value of the Common 
       Stock.  
       
            (G)   TIMING OF ISSUANCE OF ADDITIONAL COMMON STOCK UPON CERTAIN 
       ADJUSTMENTS. In any case in which the provisions of this SECTION 7 
       shall require that an adjustment shall become effective immediately 
       after a record date for an event, the Company may defer until the 
       occurrence of such event (1) issuing to the Holder of any share of 
       Series B Preferred Stock converted after such record date and before 
       the occurrence of such event the additional shares of Common Stock 
       issuable upon such conversion by reason of the adjustment required by 
       such event over and above the shares of Common Stock issuable upon 
       such conversion before giving effect to such adjustment and (B) paying 
       to such Holder any amount of cash in lieu of a fractional share of 
       such Common Stock; PROVIDED, HOWEVER, that the Company upon request 
       shall deliver to such Holder a due bill or other appropriate 
       instrument evidencing such Holder's right to receive such additional 
       shares, and such cash, upon the occurrence of the event requiring such 
       adjustment.
       
            (H)   STATEMENT REGARDING ADJUSTMENTS. Whenever the Conversion 
       Price shall be adjusted as provided in SECTION 7 the Company shall 
       forthwith file, at the office of any transfer agent for the Series B 
       Preferred Stock and at the principal office of the Company  a 
       statement showing in reasonable detail the facts requiring such 
       adjustment and the Conversion Price that shall be in effect after such 
       adjustment and the Company shall also cause a copy of such statement 
       to be sent by mail, first class postage prepaid, to each Holder at its 
       address appearing in the Company's records.  
       
            (I)   NOTICES.  In the event that the Company shall propose to 
       take any action of the type described in SECTION 7 (but only if the 
       action of the type described in SECTION 7 would result in an 
       adjustment in the Conversion Price or a change in the type of 
       securities or property to be delivered upon a conversion or exchange 
       of Series B Preferred Stock), the Company shall give notice to each 
       Holder, in the manner set forth in SECTION 7(H), which notice shall 
       specify the record date, if any, with respect to any such action and 
       the approximate date on which such action is to take place.  Such 
       notice shall also set forth the facts with respect thereto as shall be 
       reasonably necessary to indicate the effect on the Conversion Price 
       and the number, kind or class of shares or other securities or 
       property which shall be deliverable upon conversion of shares of the 
       Series B Preferred Stock. In the case of any action which would 
       require the fixing or a record date, such notice shall be given at 


                                      -18-


       least 10 days prior to the date so fixed, and in case of all other 
       action, such notice shall be given at least 15 days prior to the 
       taking of such proposed action.  Failure to give such notice, or any 
       defect therein, shall not affect the legality or validity of any such 
       action.
       
            (J)   NO IMPAIRMENT.  The Company will not, by amendment of its 
       Certificate of Incorporation or through any reorganization, transfer 
       of assets, consolidation, merger, dissolution, issue or sale of 
       securities or any other voluntary action, avoid or seek to avoid the 
       observance or performance of any of the terms to be observed or 
       performed hereunder by the Company, but will at all times in good 
       faith assist in the carrying out of all the provisions of SECTIONS 6 
       and 7 and in taking of all such action as may be necessary or 
       appropriate in order to protect the conversion rights of the Holders 
       of the Series B Preferred Stock against impairment. 
       
            (K)   NO DUPLICATION OF ADJUSTMENTS.  If any action would require 
       adjustment of the Conversion Price pursuant to more than one of the 
       provisions of this SECTION 7, only one adjustment shall be made and 
       such adjustment shall be the adjustment that results in the lowest 
       Conversion Price after giving effect to such adjustment. 

       8.   LIMITATIONS ON SERIES B PREFERRED STOCK. No share or shares of 
Series B Preferred Stock the Company acquires through redemption, option, 
exchange or otherwise will be reissued as Series B Preferred Stock, and all 
such shares will be canceled, retired and eliminated from the shares of 
Series B Preferred Stock which the Company will be authorized to issue, and 
will be restored to the status of authorized but undesignated preferred stock 
of the Company eligible for designation and reissuance subject to the terms 
hereof and the Certificate.  The Company will not issue any further shares of 
Series B Preferred Stock.  

       9.   WAIVERS.  With the written consent of Holders of a Majority of 
the Series B Preferred Stock, the obligations of the Company and the rights 
of the Holders under this Certificate of Designation may be waived (either 
generally or in a particular instance, either retroactively or prospectively 
and either for a specified period of time or indefinitely).  Upon the 
effectuation of each such waiver, the Company will promptly give written 
notice thereof to the Holders who have not previously consented thereto in 
writing.

       10.  REDEMPTION.  Except as expressly set forth herein, the Company 
shall have no right or obligation to redeem the Series B Preferred Stock.

                 REMAINDER OF PAGE INTENTIONALLY LEFT BLANK.
                                       


                                      -19-


       IN WITNESS WHEREOF, this Certificate has been signed on behalf of the 
Company by its President and attested to by its Secretary, all as of the 6th 
day of May, 1999.

                                        INPUT/OUTPUT, INC.


                                        By: /s/ Axel M. Sigmar       
                                            -------------------------
                                                President

ATTEST:


By: /s/ Ronald A. Harris         
    -----------------------------
        Assistant Secretary




                                      -20-