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                                  EXHIBIT 3.1

                     RESTATED CERTIFICATE OF INCORPORATION

                                       OF

                         LANDMARK GRAPHICS CORPORATION

Landmark Graphics Corporation, a corporation organized and existing under the
laws of the State of Delaware (the "Corporation"), hereby certifies as follows:

1.       The name of the Corporation is Landmark Graphics Corporation. Landmark
         Graphics Corporation was originally incorporated as LGC-Delaware, Inc.
         and the original Certificate of Incorporation was filed with the
         Secretary of State of  Delaware on April 28, 1987.

2.       This Restated Certificate of Incorporation has been duly adopted in
         accordance with Sections 242 and 245 of the Delaware General 
         Corporation Law.

3.       This Restated Certificate of Incorporation restates and integrates and
         further amends the provisions of the Certificate of Incorporation of
         the Corporation. The text of the Certificate of Incorporation of the
         Corporation is hereby amended and restated to read in its entirety as
         follows:

                                   ARTICLE I

                                      NAME

The name of the Corporation is Landmark Graphics Corporation.

                                   ARTICLE II

                                    DURATION

The period of the Corporation's duration is perpetual.

                                  ARTICLE III

                                    PURPOSE

The purpose of the Corporation is to engage in any or all lawful acts or
activities for which corporations may be organized under the General
Corporation Law of Delaware (the "Act").
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                                   ARTICLE IV

                                    CAPITAL

Section 1.       The aggregate number of shares which the Corporation will have
authority to issue is Fifty-Three Million Six Hundred Thousand (53,600,000),
of which Fifty Million (50,000,000) shares having  a par value of Five Cents
($.05) per share shall be common stock ("Common  Stock"), and Three Million Six
Hundred Thousand (3,600,000) shares having a par value of One Dollar ($1.00)
per share shall be preferred stock ("Preferred Stock").

Section 2.       Shares of Preferred Stock may be issued from time to time in
one or more series, each of which is to have a distinctive serial designation
as determined in the resolution or resolutions of the Board of Directors
providing for the issuance of such Preferred Stock.

Section 3.       The resolution or resolutions of the Board of Directors
providing for the issuance of each series of Preferred Stock may also provide
with respect to such series:

         (a)     the number of shares included within such series;

         (b)     the voting powers, if any, of shares included in such series;

         (c)     the right of the Corporation to redeem the shares included
                 within such series and the terms and conditions of such
                 redemption;

         (d)     the dividend rights and preferences of the shares included
                 within such series in relation to the dividend rights and
                 preferences of any other class or classes or series of stock;

         (e)     the rights and preferences of shares included within such
                 series upon the dissolution of, or upon any distribution of
                 the assets of, the Corporation;

         (f)     the right of the holder of shares included in such series to
                 convert such shares into, or exchange such shares for, shares
                 of any other class or classes, or of any other series of the
                 same class or of any other class or classes, of stock of the
                 Corporation and the terms and conditions of such right;

         (g)     the establishment of a sinking fund or purchase fund to be
                 applied to the purchase or redemption of shares of such series
                 and the terms and conditions thereof;

         (h)     conditions and restrictions upon the creation of indebtedness
                 of the Corporation or any subsidiary, upon the issuance of any
                 additional stock (including additional shares of such series
                 or of any other series) and upon the payment of dividends or
                 the making of other distributions on, and the purchase,
                 redemption or other acquisition of any class of stock by the
                 Corporation; and

         (i)     such other relative, participating, optional or other special
                 rights, and qualifications, limitations or restrictions
                 thereof.





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Except where otherwise set forth in such resolution or resolutions, the number
of shares comprising such series may be increased or decreased (but not below
the number of shares then outstanding) from time to time by action of the Board
of Directors.

Section 4.       Shares of any series of Preferred Stock which have been
redeemed (whether through the operation of a sinking fund or otherwise) or
purchased by the Corporation, or which, if convertible or exchangeable, have
been converted into or exchanged for shares of stock of any other class or
classes will have the status of authorized but unissued shares of Preferred
Stock and may be reissued as a part of the series of which they were
originally a part or may be reclassified and reissued as part of a new series
of Preferred Stock created by resolution or resolutions of the Board of
Directors or as part of any other series of Preferred Stock, all subject to the
conditions or restrictions on issuance set forth in the resolution or
resolutions adopted by the Board of Directors providing for the issuance of
any series of Preferred Stock and to any filing required by law.

Section 5. (a)   Except as otherwise provided by law or by the resolutions of
the Board of Directors providing for the issuance of any series of Preferred
Stock, Common Stock will have the exclusive right to vote for the election of
directors and for all other purposes. Each holder of Common Stock will be
entitled to one vote for each share held.

           (b)   Subject to all of the rights of Preferred Stock or any series
thereof, the holders of Common Stock will be entitled to receive, when, as and
if declared by the Board of Directors, out of funds legally available therefor,
dividends payable in cash, in stock or otherwise.

           (c)   Upon any liquidation, dissolution or winding-up of the
Corporation, whether voluntary or involuntary, and after the holders of
Preferred Stock of each series have been paid in full the amounts, if any, to
which they respectively are entitled or a sum sufficient for such payment in
full has been set aside, the remaining net assets of the Corporation will be
distributed pro rata to the holders of Common Stock in accordance with their
respective rights and interests.

                                   ARTICLE V

                              NONCUMULATIVE VOTING

No stockholder of the Corporation will have the right to cumulate his votes in
connection with the election of directors.

                                   ARTICLE VI

                          DENIAL OF PREEMPTIVE RIGHTS

Except as may hereafter be granted pursuant to separate agreements binding upon
the Corporation, no stockholder of the Corporation or other person shall have
any preemptive right to purchase or subscribe to any shares of any class or any
notes, debentures, options, warrants or other securities of the Corporation,
now or hereafter authorized.





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                                  ARTICLE VII

                          REGISTERED OFFICE AND AGENT

The street address of the registered office of the Corporation is 1013 Centre
Road, City of Wilmington, County of New Castle, State of Delaware and the name
of its registered agent at such address is The Prentice-Hall Corporation
System, Inc.

                                  ARTICLE VIII

                               BOARD OF DIRECTORS

Section 1.       The number and qualifications of directors constituting the
Board of Directors of the Corporation will be fixed or determined in the manner
provided in the Bylaws of the Corporation. The number of directors may be
increased or decreased from time to time in the manner set forth in the Bylaws
of the Corporation.

Section 2.       The Board of Directors shall have the power and authority to
alter, amend or repeal the Bylaws of the Corporation in the manner provided in
the Bylaws of the Corporation.

Section 3.       No director of the Corporation shall be liable to the
Corporation or its stockholders for monetary damages arising out of a breach of
fiduciary duty as a director other than liability to the Corporation or its
stockholders (a) resulting from a breach of such director's duty of loyalty to
the Corporation or its stockholders, (b) resulting from acts or omissions of
such director not in good faith or which involve intentional misconduct or a
knowing violation of law, (c) arising under Section 174 of the Act, or (d)
resulting from a transaction from which such director derived an improper
personal benefit.

                                   ARTICLE IX

                                   INDEMNITY

Section 1.       The Corporation shall indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending, or
completed action, suit or proceeding, whether civil, criminal, administrative,
or investigative (other than an action by or in the right of the Corporation)
by reason of the fact that he is or was a director, officer, employee or agent
of the Corporation, or is or was serving at the request of the Corporation as a
director, officer, employee or agent of another corporation, partnership, joint
venture, trust or other enterprise, against expenses (including attorneys'
fees), judgments, fines and amounts paid in settlement actually and reasonably
incurred by him in connection with such action, suit or proceeding if he acted
in good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the Corporation, and, with respect to any criminal action
or proceeding, had no reasonable cause to believe his conduct was unlawful. The
termination of any action, suit, or proceeding by judgment, order, settlement,
conviction or upon a plea of nolo contendere or its equivalent, shall not, of
itself, create a presumption that the person did not act in good faith and in a
manner which he reasonably believed to be in or not opposed to the best
interests of the Corporation, and, with respect to any criminal action or
proceeding, had reasonable cause to believe that his conduct was unlawful.





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Section 2.       The Corporation shall indemnify any person who was or is a
party or is threatened to be made a party to any threatened, pending or
completed action or suit by or in the right of the Corporation to procure a
judgment in its favor by reason of the fact that he is or was a director,
officer, employee or agent of the Corporation, or is or was serving at the
request of the Corporation as a director, officer, employee or agent of another
corporation, partnership, joint venture, trust or other enterprise against
expenses (including attorneys' fees) actually and reasonably incurred by him in
connection with the defense or settlement of such action or suit if he acted in
good faith and in a manner he reasonably believed to be in or not opposed to
the best interests of the Corporation and except that no indemnification shall
be made in respect of any claim, issue, or matter as to which such person shall
have been adjudged to be liable to the Corporation unless and only to the
extent that the Delaware Court of Chancery or the court in which such action or
suit was brought shall determine upon application that, despite the
adjudication of liability but in view of all the circumstances of the case,
such person is fairly and reasonably entitled to indemnity for such expenses
which the Court of Chancery or such other court shall deem proper.

Section 3.       To the extent that a director, officer, employee or agent of
the Corporation has been successful on the merits or otherwise in defense of
any action, suit or proceeding referred to in Sections 1 and 2, or in defense
of any claim, issue or matter therein, he shall be indemnified against expenses
(including attorneys' fees) actually and reasonably incurred by him in
connection therewith.

Section 4.       Any indemnification under Sections 1 and 2 (unless ordered by
a court) shall be made by the Corporation only as authorized in the specific
case upon a determination that indemnification of the director, officer,
employee or agent is proper in the circumstances because he has met the
applicable standard of conduct set forth in Sections 1 and 2. Such
determination shall be made (i) by the Board of Directors by a majority vote of
a quorum consisting of directors who were not parties to such action, suit or
proceeding, or (ii) if such a quorum is not obtainable, or, even if obtainable,
if a quorum of disinterested directors so directs, by independent legal counsel
in a written opinion, or (iii) by the stockholders. Notwithstanding the
foregoing, a director, officer, employee or agent of the Corporation shall be
able to contest any determination that the director, officer, employee or agent
has not met the applicable standard of conduct set forth in Sections 1 and 2 by
petitioning a court of appropriate jurisdiction.

Section 5.       Expenses incurred in defending or settling a civil or criminal
action, suit or proceeding by a director, officer, employee or agent who may be
entitled to indemnification pursuant to Sections 1 and 2 of this Article IX
shall be paid by the Corporation in advance of the final disposition of such
action, suit or proceeding, upon receipt of an undertaking by or on behalf of
the director, officer, employee or agent to repay such amount if it shall
ultimately be determined that he is not entitled to be indemnified by the
Corporation as authorized in this Article IX.

Section 6.       The indemnification and advancement of expenses provided by,
or granted pursuant to, the other sections of this Article IX shall not be
deemed exclusive of any other rights to which those seeking indemnification or
advancement of expenses may be entitled under any Bylaw, agreement, vote of
stockholders or disinterested directors or otherwise, both as to action in his
official capacity and as to action in another capacity while holding such
office.





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Section 7.       The Corporation shall have the power to purchase and maintain
insurance on behalf of any person who is or was a director, officer, employee
or agent of the Corporation, or is or was serving at the request of the
Corporation as a director, officer, employee or agent of another corporation,
partnership, joint venture, trust or other enterprise against any liability
asserted against him and incurred by him in any such capacity, or arising out
of his status as such, whether or not the Corporation would have the power to
indemnify him against such liability under the provisions of this Article IX.

Section 8.       For purposes of this Article IX, references to "the
Corporation" shall include, in  addition to the Corporation, any constituent
corporation (including any constituent of a constituent) absorbed in a
consolidation or merger which, if its separate existence had continued, would
have had power and authority to indemnify its directors, officers, and
employees or agents, so that any person who is or was a director, officer,
employee or agent of such constituent corporation, or is or was serving at the
request of such constituent corporation as a director, officer, employee or
agent of another corporation, partnership, joint venture, trust or other
enterprise, shall stand in the same position under the provisions of this
Article IX with respect to the Corporation as he would have with respect to
such constituent corporation if its separate existence had continued.

Section 9.       For purposes of this Article IX, references to "other
enterprises" shall include employee benefit plans; references to "fines" shall
include any excise taxes assessed on a person with respect to an employee
benefit plan; and references to "serving at the request of the Corporation"
shall include any service as a director, officer, employee or agent of the
Corporation which imposes duties on, or involves services by, such director,
officer, employee or agent with respect to an employee benefit plan, its
participants or beneficiaries; and a person who acted in good faith and in a
manner he reasonably believed to be in the interest of the participants and
beneficiaries of an employee benefit plan shall be deemed to have acted in a
manner "not opposed to the best interests of the Corporation" as referred to
in this Article IX.

Section 10.      The indemnification and advancement of expenses provided by,
or granted pursuant to, this Article IX shall, unless otherwise provided when
authorized or ratified, continue as to a person who has ceased to be a
director, officer, employee or agent and shall inure to the benefit of the
heirs, executors and administrators of such a person.

IN WITNESS WHEREOF, Landmark Graphics Corporation has caused this Restated
Certificate of Incorporation to be signed by its Secretary this 14th day of
December, 1995.

                                                            /s/ Patti L. Massaro
                                                            --------------------
                                                            Patti L. Massaro
                                                            Secretary





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