Document:

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                            THIRD AMENDMENT TO LEASE

      THIS THIRD AMENDMENT TO LEASE (the "Third Amendment") is made and entered
into as of this ___ day of September, 1998 by and between MARTIN/CAMPUS
ASSOCIATES NO. 4, L.P., a Delaware limited partnership ("Landlord") and AMPEX
CORPORATION, a Delaware corporation ("Tenant").

                                R E C I T A L S:

      This Third Amendment is entered into upon the basis of, and with reference
to the following facts, understandings and intentions of the parties:

      A. Martin/Campus Associates, L.P., a Delaware limited partnership
("Original Landlord"), and Tenant entered into that certain Lease dated January
19, 1996 which demised those certain premises located at 1228 Douglas Avenue
(Building 8), 1250 Douglas Avenue (Building 20) and 550 Broadway (Building 10),
Redwood City, California as more particularly described in the Lease (the
"Premises"), which Lease has been amended by a certain First Amendment Lease
dated December 20, 1996 (the "First Amendment") and by a certain Amendment to
Bay Road Lease and Douglas/Broadway Lease dated July 14, 1998 (the "Second
Amendment") (the Lease, the First Amendment and the Second Amendment are
hereinafter collectively referred to as the "Lease").

      B. Original Landlord assigned all of its right, title and interest as
landlord under the Lease to Landlord pursuant to that certain Assignment and
Assumption of Tenant Leases dated as of September 22, 1997 (the "Assignment of
Lease").

      C. Landlord and Tenant desire to modify and amend the terms of the Lease
(i) to provide for the surrender of that portion of the Premises located at 1250
Douglas Avenue and commonly referred to as Building 20 together with the
exclusive use of the Outside Area (the "Released Premises") on the Effective
Date (as defined in that certain Partial Termination of Lease Agreement of even
date herewith), (ii) to release each other from their respective obligations
under the Lease with respect to the Released Premises arising after the
Effective Date and (iii) to designate common areas for which Landlord shall
assume maintenance obligations, a proportionate share of the cost therefor to be
paid by Tenant, all as more fully set forth herein.

      NOW, THEREFORE, for good and valuable consideration, including the mutual
covenants contained in the Lease and in this Third Amendment, Landlord and
Tenant hereby agree as follows:

      1. Defined Terms. Except as expressly provided in this Third Amendment to
the contrary, terms which are defined in the Lease shall have the same meaning
when used in this Third Amendment.

      2. Title Page. The last two lines of the Title Page of the Lease are
hereby deleted and the following lines are inserted in place thereof:

                  "For the approximately 99,638 SF Premises at
          1228 Douglas Avenue and 550 Broadway, Redwood City, CA 94063"

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      3. Lease Summary. The Building Addresses, the Total Building Square
Footage, the Monthly Rent and the Security Deposit terms contained in the Lease
Summary are hereby deleted and the following terms are inserted in place
thereof:

         "Building Addresses:               1228 Douglas Avenue and 550 Broadway
                                            Redwood City, CA 94063

                                      * * *

         "Total Building Square Footage:    99,638 square feet

                                      * * *

         "Monthly Rent (net):               $87,233.07

                                      * * *

         "Security Deposit                  $87,233.07"

      4. Premises. Paragraph 2 of the Lease is hereby deleted in its entirety
and the following Paragraph is inserted in place thereof:

      "Landlord hereby leases to Tenant and Tenant hereby leases from Landlord
      those certain premises consisting of a total area of approximately 99,638
      square feet in those certain buildings, commonly known as 1228 Douglas
      Avenue (Building 8) and 550 Broadway (Building 10), consisting of
      approximately 32,000 square feet and 67,638 square feet, respectively
      (each, a "Building," but collectively, the "Buildings") in the City of
      Redwood City, County of San Mateo, State of California, as more
      particularly shown on EXHIBIT A (collectively, the "Premises"). The
      Premises also include the appurtenant right to use in common with other
      tenants of the Property (as defined below) the Common Area (as defined
      below) of the Property owned by Landlord."

      5. Definitions. Paragraph 3 of the Lease is hereby amended (a) to delete
in its entirety Paragraph 3. J (the definition of "Outside Area") and (b) to
insert the following new definitions:

      "C.1. Common Area. All areas and facilities within the Property which are
      not within buildings wholly or partially leased to or occupied by tenants
      or not otherwise appropriated to the exclusive occupancy of tenants,
      including the Parking Area, the sidewalks, pedestrian ways, driveways,
      signs (other than Tenant's signs), pools, ponds, service delivery and
      loading facilities, common storage areas, common utility facilities and
      all other areas on the Property established by Landlord and/or its
      successors for non-exclusive use. Landlord may, by written notice to
      Tenant, elect in its sole discretion to increase and/or decrease the
      Common Area from time to time during the Term for any reason whatsoever
      (including without limitation an election by Landlord and/or its
      successors in their sole discretion to make changes to the buildings
      situated on the Property, and/or to subdivide, sell, exchange, dispose of,
      transfer, or change the configuration of all or any portion of the Common
      Area from time to time), so long as Landlord does not (i) unreasonably
      interfere with ingress to or egress from the Buildings; (ii) permanently
      reduce the number of parking spaces available for Tenant's use below the
      minimum requirements set forth in paragraph 37; (iii) move the Parking
      Area materially farther from the Buildings; (iv) materially decrease the
      visibility of Tenant's signage located on the Buildings or within the
      Property as of the date of this Third Amendment or future Tenant's
      identification signage installed on the exterior of the Buildings in
      accordance with paragraph 20

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      (provided that Landlord alternatively may relocate Tenant's signage at
      Landlord's expense to a location mutually acceptable to Landlord and
      Tenant as may be agreed by the parties prior to such relocation); or (v)
      reconfigure the Common Area located within those certain areas surrounding
      the Buildings as highlighted in yellow on EXHIBIT A and designated as the
      "Protected Areas." No such subdivision, sale, exchange, disposition,
      transfer, or change to the configuration of all or any portion of the
      Common Area shall cause the Common Area to be increased or decreased
      unless and until Landlord has given Tenant written notice of such increase
      or decrease. Landlord shall have exclusive control of the Common Area and
      may at any time close any part thereof for periods not to exceed thirty
      (30) days (subject to delays due to causes beyond Landlord's control),
      exclude and restrain anyone from any part thereof, except the bonafide
      customers, employees and invitees of Tenant who use the Common Area in
      accordance with the reasonable rules and regulations as Landlord may from
      time to time promulgate. In exercising any such rights, Landlord shall not
      unreasonably disrupt Tenant's business.

      "C.2. Common Area Maintenance Expenses. The total of all costs and
      expenses paid or incurred by Landlord in connection with the operation,
      maintenance, ownership, repair and replacement of the Common Area, as
      calculated in accordance with generally accepted accounting principles,
      consistently applied. Without limiting the generality of the foregoing and
      subject to the exclusions set forth below, Common Area Maintenance
      Expenses include all costs of and expense for: (i) resurfacing, resealing,
      remarking, painting, repainting, striping or restriping the Parking Area
      (but excluding certain parking lot repairs to the Parking Area, cross
      hatched on EXHIBIT A and identified as the Phase III Parking Lot
      Resurfacing area, to be performed pursuant to the Second Amendment); (ii)
      maintenance, repair and replacement of sidewalks, curbs, paving, walkways,
      Parking Area, Property signs, landscaping, planting and irrigation
      systems, trash facilities, loading and delivery areas, lighting, drainage
      and common utility facilities associated with Parking Area lighting,
      signage and irrigation of landscaping, directional or other signs, markers
      and bumpers; (iii) wages, salaries, benefits, payroll burden fees and
      charges of non-executive personnel (but including Landlord's property
      manager to extent the manager is utilized, in lieu of retaining
      independent contractors, for the supervision of the maintenance or repair
      of the Common Area) employed by Landlord and the charges of all
      independent contractors retained by Landlord (to the extent on a
      percentage basis of time spent that such personnel and contractors are
      utilized by Landlord) for the maintenance or repair of the Common Area
      (but excluding the cost of any security services, except to the extent
      provided in paragraph 39); (iv) depreciation or amortization (or in lieu
      thereof, rental payments) on all tools, equipment and machinery used in
      the operation and maintenance of the Common Area; (v) premiums for
      Comprehensive General Liability Insurance or Commercial General Liability
      Insurance, casualty insurance, workers compensation insurance or other
      insurance on the Common Area, or any portion thereof or interest therein,
      and any deductibles (which deductible shall not exceed $15,000, increased
      annually by 3%) payable with respect to such insurance policies other than
      earthquake insurance for which the deductible shall not be included in
      Common Area Maintenance Expenses; (vi) cleaning, collection, storage and
      removal of trash, rubbish, dirt and debris, and sweeping and cleaning the
      Common Area; (vii) all personal property or real property taxes and
      assessments levied or assessed on the Property, or any portion thereof or
      interest therein, including without limitation the Real Property Taxes for
      the Premises, if applicable under paragraph 15.A; (viii) reasonable legal,
      accounting and other professional services for the operation of the Common
      Area, including reasonable costs, fees and expenses of contesting the
      validity or applicability of any law, ordinance, rule, regulation or order
      relating to the Buildings, and of contesting, appealing or otherwise
      attempting to reduce any Real Property Taxes assessed against the
      Property; (ix) any alterations, additions or improvements required to be
      made to the Common Area in order to reduce Common Area Maintenance
      Expenses or to protect the safety of occupants of the Property (provided
      in the latter case that such alterations, additions or improvements are
      not necessitated solely as a result of the use and occupancy of the Common
      Area by a new tenant of the Property or as a result of new tenant
      improvements to any building on the Property, other than in or on the
      Buildings, and further provided

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      in any case that the cost of any such alterations, additions, improvements
      or capital improvements, together with interest at the rate of ten percent
      (10%) per annum, or, if applicable, the rate paid by Landlord on funds
      borrowed for the purpose of constructing or installing such alterations,
      additions or improvements, shall be amortized over the useful life of the
      alteration, addition, improvement or capital improvement in question and
      included in Common Area Maintenance Expenses for each year over which such
      costs are amortized and that the annual amount of such amortized costs
      passed through as an expense shall not exceed the cost savings realized in
      such year); (x) all costs and expenses incurred in performing any
      alterations, additions or improvements required to be made to the Common
      Area in order to comply with applicable laws, ordinances, rules,
      regulations and orders enacted after the date hereof, provided that the
      cost of any such alterations, additions, improvements or capital
      improvements, together with interest at the rate of ten percent (10%) per
      annum, or, if applicable, the rate paid by Landlord on funds borrowed for
      the purpose of constructing or installing such alterations, additions or
      improvements, shall be amortized over the useful life of the alteration,
      addition, improvement or capital improvement in question and included in
      Common Area Maintenance Expenses for each year over which such costs are
      amortized; (xi) any and all payments due and owing on behalf of the
      Property or any portion thereof with respect to any CC&R's to the extent
      such payments are in lieu of or substitution for other Common Area
      Maintenance Expenses; and (xii) all costs and expenses related to the
      adoption and maintenance of a portion of Highway 101 (Tenant's Percentage
      Share of which shall not exceed $720 per year, increased annually by 3%).
      However, notwithstanding the foregoing or anything to the contrary in this
      Lease, Common Area Maintenance Expenses shall not include the cost of or
      expenses for the following: (A) leasing commissions, attorneys' fees or
      other costs or expenses incurred in connection with negotiations or
      disputes with other tenants of the Property or attorneys' fees incurred
      which must be capitalized for income tax purposes; (B) depreciation of
      buildings in the Property; (C) payments of principal, interest, late fees,
      prepayment fees or other charges on any debt secured by a mortgage
      covering the Property, or rental payments under any ground lease or
      underlying lease; (D) any penalties incurred due to Landlord's violation
      of any governmental rule or authority (but not excluding the cost of
      compliance therewith, if such cost is chargeable to Tenant pursuant to
      this Lease); (E) items for which Landlord is reimbursed by insurance; (F)
      all costs associated with the operation of the business of the entity
      which constitutes "Landlord", as distinguished from the costs of
      operations, including, but not limited to, costs of partnership accounting
      and legal matters, costs of defending any lawsuits with any mortgagee
      (except as the actions of Tenant may be in issue), costs of selling,
      syndicating, financing, mortgaging, or hypothecating any of the Landlord's
      interest in the Property and/or Common Area, or any portion thereof, costs
      of any disputes between Landlord and its employees, costs of disputes of
      Landlord with Building management or costs paid in connection with
      disputes with Tenant or any other tenants; (G) all costs (including
      permit, license and inspection fees) incurred in renovating or otherwise
      improving or decorating, painting or redecorating space for other tenants
      in the Property; (H) the creation of any reserves for equipment or capital
      replacement; (I) all costs arising from monitoring, cleaning up and
      otherwise remediating any release of Hazardous Materials at the Premises;
      (J) any Real Property Taxes or costs for which Landlord is separately and
      directly reimbursed by Tenant or any other tenant of the Property which
      are assessed against the Premises or the premises leased by such other
      tenant(s); (K) any costs for security services; (L) any costs of repairs
      for damage or destruction occasioned by fires or other casualty (except
      the deductible amount permitted under item (v) above); (M) any costs due
      to replacement or failure of Landlord's computer hardware or software or
      other equipment used in connection with the operation of the Common Area
      due to so called "Year 2000" issues relating to the inability to
      distinguish between dates before and after January 1, 2000; and (N) all
      capital expenditures not described in items (ix) and (x) above.

      "J. Parking Area. All Common Area on the Property (except sidewalks and
      service delivery facilities) now or hereafter designated by Landlord for
      the parking or access of motor vehicles, including roads, traffic lanes,
      vehicular parking spaces, landscaped areas and walkways, and including any
      parking structure constructed during the Term. Landlord and/or its
      successors may, by written notice to Tenant, elect in their sole
      discretion to increase and/or decrease the Parking Area from time

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      to time during the Term for any reason whatsoever (including without
      limitation an election by Landlord and/or its successors in their sole
      discretion to make changes to the buildings situated on the Property,
      and/or to subdivide, sell, exchange, dispose of, transfer, or change the
      configuration of all or any portion of the Parking Area from time to
      time), so long as such changes to the Parking Area do not reduce the
      number of parking spaces available for Tenant's use below the minimum
      requirements set forth in paragraph 37 for periods in excess of thirty
      (30) days (subject to delays due to causes beyond Landlord's control),
      materially impair access to or from the Buildings to and from the Parking
      Area or move the Parking Area materially farther from the Buildings. No
      such subdivision, sale, exchange, disposition, transfer, or change to the
      configuration of all or any portion of the Parking Area shall cause the
      Parking Area to be increased or decreased unless and until Landlord has
      given Tenant written notice of such increase or decrease.

      "K.1 Property. The real property shown on EXHIBIT A consisting of
      approximately nine and 31/100ths (9.31) acres and the buildings and
      permanent improvements located thereon, within which the Premises are
      located.

      "M.1 Rentable Area. The aggregate square footage in any one or more
      buildings on the Property, as appropriate, as reasonably determined by
      Landlord's architect in accordance with BOMA Standard (ANSI Z65.1 1980)
      for full floor office occupancy. The Rentable Area of Building 8 is 32,000
      square feet, the Rentable Area of Building 10 is 67,638 square feet and
      the Rentable Area of all of the buildings on the Property is 191,910
      square feet.

      "R.1 Tenant's Percentage Share. The ratio (expressed as a percentage) of
      the total Rentable Area of the Premises to the total Rentable Area of all
      of the buildings located on the Property owned by Landlord from time to
      time, which as of the date hereof shall equal 51.92% (i.e., the Rentable
      Area of the Premises divided by the Rentable Area of the buildings located
      on the Property owned by Landlord as of the date hereof). Tenant's
      Percentage Share shall be recalculated each and every time that the amount
      of Rentable Area contained in Premises is adjusted, or the Premises is
      expanded, buildings are added to or removed from the Property, or there is
      a change in the total Rentable Area of those buildings located on the
      Property owned by Landlord, or Landlord sells, exchanges, or otherwise
      transfers any or all of the buildings located on the Property (including
      without limitation the Buildings). The parties acknowledge and agree that
      the total Rentable Area of all of the buildings located on the Property
      owned by Landlord may increase and/or decrease from time to time during
      the Term, since Landlord may elect in its sole discretion to sell a
      building or buildings or to make changes to the buildings it owns."

      6. Monthly Rent. Paragraph 5.A of the Lease is hereby amended to (a)
delete the last two lines of the first paragraph of paragraph 5.A. and (b) to
add the following paragraph as the second paragraph to the Lease:

      "Notwithstanding anything to the contrary contained in the previous
      paragraph, as of the Effective Date (as defined hereinafter), Tenant shall
      pay to Landlord, in lawful money of the United States, Monthly Rent in the
      amount of $87,223.07 per month, which amount represents the sum of
      $28,016.00 per month for the Building at 1228 Douglas and $59,217.07 per
      month for the Building at 550 Broadway and which amount shall be subject
      to adjustment on each Adjustment Date in accordance with paragraph 5.B.,
      the next Adjustment Date being November 1, 1998. If the Term of this Lease
      extends beyond the date which if ten (10) years from the Commencement
      Date, the Monthly Rent for the eleventh (11th) year of the Term shall be
      (i) 134% of initial Monthly Rent attributable to Building 8 and Building
      10 (i.e., $113,487.68 per month) if the cumulative increase in the Index
      from the Commencement Date through the tenth (10th) year of the Term
      exceeds thirty-four percent (34%), or (ii) the Monthly Rent payable during
      the last month of the tenth (10th) year of the Term, increased by the
      percentage increase in the Index over the twelve (12) month period

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      immediately preceding the commencement of the eleventh (11th) year of the
      Term (calculated as provided in paragraph 5.B.) if the cumulative increase
      in the Index during such 10-year period is thirty-four percent (34%) or
      less. At the commencement of the twelfth (12th) and thirteenth (13th)
      years of the Term (if applicable), the Monthly Rent shall be increased by
      the percentage increase in the Index, calculated as provided in paragraph
      5.B. over the previous 12-month period.

      7. Additional Rent. Paragraph 5.E of the Lease is hereby amended to add in
the second line thereof after the words "including, without limitation," the
words "Common Area Maintenance Expenses pursuant to paragraph 5.G.,".

      8. Common Area Maintenance Expenses. The following paragraph is added as a
new paragraph 5.G. of the Lease:

            "G. Common Area Maintenance Expenses.

                  (1) Estimated Payments. Commencing as of the Effective Date
            and continuing throughout the entire Term, Tenant shall pay Tenant's
            Percentage Share of all Common Area Maintenance Expenses paid or
            payable by Landlord in each year. On the Effective Date and during
            December of each calendar year or as soon thereafter as practicable,
            Landlord shall give Tenant notice of its estimate of amounts payable
            under this paragraph 5.G.(1) for the ensuing calendar year. Such
            notice shall show in reasonable detail the basis on which the
            estimate was determined. On or before the first day of each month
            during the ensuing calendar year, Tenant shall pay to Landlord
            one-twelfth (1/12th) of such estimated amounts, provided that if
            such notice is not given in December, Tenant shall continue to pay
            on the basis of the prior year's estimate until the month after such
            notice is given. If at any time or times it appears to Landlord, in
            its reasonable judgment, that the amounts payable under this
            paragraph 5.G.(1) for the current calendar year will vary from its
            then-current estimate by more than five percent (5%), Landlord may,
            by notice to Tenant, showing in reasonable detail the basis for such
            variance, revise its estimate for such year, in which case
            subsequent payments by Tenant for such year shall be based upon such
            revised estimate. Landlord's election not to give the notice
            described in the foregoing sentence shall not affect Landlord's
            ability to charge Tenant for, nor Tenant's liability to pay for, any
            shortfall in the estimated payments for such calendar year
            previously made by Tenant, as set forth in paragraph 5.G.(2).

                  "(2) Adjustment. Within one hundred twenty (120) days after
            the close of each calendar year or as soon after such 120-day period
            as reasonably practicable, Landlord shall deliver to Tenant a
            reasonably detailed statement of Common Area Maintenance Expenses
            for such calendar year, certified by Landlord or its property
            manager, subject to Tenant's right to audit as hereinafter provided.
            At that time, Landlord shall also deliver to Tenant a statement,
            certified as correct by Landlord, of the adjustments to be made
            pursuant to paragraph 5.G.(1) above. If Landlord's statement shows
            that Tenant owes an amount that is less than the estimated payments
            for such calendar year previously made by Tenant, Landlord may
            elect, in its sole discretion, to either refund such excess to
            Tenant within thirty (30) days after delivery of the statement, or
            offset such overpayment against Monthly Rent due or remaining due
            under this Lease; provided that if no Monthly Rent remains due,
            Landlord shall refund such excess to Tenant within thirty (30) days
            after delivery of the statement. If such statement shows that Tenant
            owes an amount that is more than the estimated payments for such
            calendar year previously made by Tenant, Tenant shall pay the
            deficiency to Landlord within thirty (30) days after delivery of the
            statement.

                  "(3) Last Lease Year. If this Lease shall terminate on a day
            other than the last day of a calendar year, the adjustment in
            Minimum Rent applicable to the calendar year in which such
            termination shall occur shall be prorated on the basis which the
            number of days from the commencement of such calendar year to and
            including such termination date bears to three hundred

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            sixty (360). The termination of this Lease shall not affect the
            obligations of Landlord and Tenant pursuant to paragraph 5.G.(2) to
            be performed after such termination."

      9. Security Deposit. Paragraph 7 of the Lease is hereby amended to add the
fallowing sentence to the end thereof: "Landlord and Tenant agree that as of the
Effective Date of the Third Amendment, the Security Deposit shall be further
reduced to Eighty-Seven Thousand Two Hundred Thirty-Three and 07/100
($87,233.07)."

      10. Real Property Taxes. Paragraph 15.A is hereby amended to delete the
first two sentences thereof and insert in place thereof the following:

            "Tenant shall pay the Real Property Taxes for the Premises. If
            billed directly, Tenant shall pay such Real Property Taxes directly
            to the San Mateo County assessor. If the Real Property Taxes for the
            Premises are billed to Landlord or included in bills to Landlord for
            Real Property Taxes covering the entire Property, then Tenant shall
            pay its share of Real Property Taxes as part of the Common Area
            Maintenance Expenses."

The following paragraph is added as a new paragraph 15.D:

            "D. Tax Parcels. If Landlord determines in its reasonable discretion
            that the configuration of tax parcels within the Property (including
            without limitation the tax parcel on which the Premises is situated)
            causes the allocation of Real Property Taxes between the affected
            tax parcels to be unfair or inequitable, Landlord reserves the right
            to internally reallocate the Real Property Taxes assessed against
            such affected tax parcels in a manner that reasonably addresses such
            unfairness or inequity. If Landlord effects any such reallocation,
            then the Real Property Taxes payable by Tenant under this Lease
            shall be those Real Property Taxes allocated to the Premises
            pursuant to this paragraph 15.D."

      11. Repairs and Maintenance. Paragraph 17.A of the Lease is hereby amended
by adding the words "Landlord shall repair, maintain and operate the Common Area
and" to the beginning thereof. Paragraph 17.B. is hereby amended by deleting
therefrom the third, fourth, fifth and sixth sentences regarding Tenant's
obligation to maintain the Outside Area.

      12. Parking Area. Paragraph 37 is hereby deleted and the following is
inserted in place thereof:

            "Tenant shall have the non-exclusive right, in common with any other
            tenants or occupants of the Property, to use up to 274 unassigned
            parking spaces, upon terms and conditions, as may from time to time
            be reasonably established by Landlord (provided that such terms and
            conditions shall not include an imposition by Landlord of a charge
            for parking). Should parking charges or surcharges of any kind be
            imposed on the parking facilities by a governmental agency, Tenant
            shall reimburse Landlord for such charges and/or surcharges or, if
            possible, shall pay such charges and/or surcharges directly to the
            governmental agency and, in such event, Tenant shall provide
            Landlord with proof that such charges and/or surcharges have been
            paid by Tenant."

      13. Security. The following paragraph is hereby added to the Lease as
paragraph 39:

            "39. Security. Tenant shall be solely responsible for providing such
            security services for the Premises and the Common Area surrounding
            or adjacent to the Premises as an owner or manager of such property
            would be obligated to provide. At the request of Tenant, Landlord
            shall not be responsible for providing such security services in
            connection with Landlord's operation of the Common Area. Tenant may
            later elect to have Landlord assume responsibility for the security
            of the Common Area surrounding or adjacent to the Premises and, upon
            such election by Tenant, Landlord's costs in providing such services
            shall be included in Common Area Maintenance Expenses
            notwithstanding anything to the contrary contained in paragraph
            3.C.2."

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      14. Exhibits. EXHIBIT A attached to the Lease is hereby deleted and
EXHIBIT A attached hereto is inserted in place thereof.

      15. Effective Date. The effective date of this Third Amendment shall be
the date which is the Effective Date under that certain Partial Termination of
Lease between Landlord and Tenant dated as of the date hereof and executed
simultaneously herewith.

      16. Interpretation of Amendment. This Third Amendment and Lease (as
previously amended) shall be construed as a whole in order to effectuate the
intent of the parties to amend the Lease in the manner specified in this Third
Amendment. All provisions of the Lease affected by this Third Amendment shall be
deemed amended regardless of whether so specified in this Third Amendment.
Subject to the foregoing, if any provision of the Lease conflicts with any
provision of this Third Amendment, the provision of this Third Amendment shall
control.

      17. No Further Amendment. Except as amended by this Third Amendment, the
Lease shall continue in full force and effect and in accordance with its terms.

      IN WITNESS WHEREOF, the parties have executed this Third Amendment as of
the date first hereinabove set forth.

LANDLORD: MARTIN/CAMPUS ASSOCIATES NO. 4, L.P.,
               a Delaware limited partnership

                By: MARTIN/REDWOOD PARTNERS, L.P.,
                    a California limited partnership
                    General Partner

                    By: TMG REDWOOD LLC,
                        a California limited liability company
                        General Partner

                        By: THE MARTIN GROUP OF COMPANIES, INC.
                            a California corporation
                            Managing Member
                            By:
                               ------------------------------------
                            Name: /s/ Cathy Greenwald
                                 ----------------------------------
                            Title: Vice President
                                  ---------------------------------

TENANT:         AMPEX CORPORATION
                a Delaware corporation

                By:
                   --------------------------------------
                Name: /s/ Richard Jacquet
                     ------------------------------------
                Title: Vice President
                      -----------------------------------

                By:
                   --------------------------------------
                Name:
                     ------------------------------------
                Title:
                      -----------------------------------

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                  SECOND PARTIAL TERMINATION OF LEASE AGREEMENT

THIS PARTIAL TERMINATION OF LEASE AGREEMENT ("Agreement") is made and entered
into as of the 19th day of November, 1999, by and between MARTIN/CAMPUS
ASSOCIATES NO. 4, L.P., a Delaware limited partnership ("Landlord"), and AMPEX
CORPORATION, a Delaware corporation ("Tenant")

                                    RECITALS

This Agreement is entered into on the basis of the following facts,
understandings and intentions of the parties:

      A. Martin/Campus Associates, L.P., a Delaware limited partnership
("Original Landlord"), and Tenant entered in to that certain Lease dated January
19, 1996 which demised those certain premises commonly known as 1228 Douglas
Avenue (Building 8), 1250 Douglas Avenue (Building 20) and 550 Broadway
(building 10), consisting of approximately 32,000 square feet, 32,512 square
feet, and 67,638 square feet, respectively, located in Redwood City, California
as more particularly described in the Lease (the "Premises"), which Lease has
been amended by a certain First Amendment to Lease dated December 20, 1996 (the
"First Amendment"), by a certain Amendment to Bay Road Lease and
Douglas/Broadway Lease dated June 22, 1998 (the "Second Amendment"), and by a
certain Third Amendment to Lease dated September 10, 1998 (the "Third
Amendment") (the Lease, the First Amendment, the Second Amendment, and the Third
Amendment are hereinafter collectively referred to as the "Lease").

      B. Original Landlord assigned all of its rights, title and interest as
landlord under the Lease to Landlord pursuant to that certain Assignment and
assumption of Tenant Leases dated as of September 22, 1997 (the "Assignment of
Lease").

      C. Landlord and Tenant terminated and canceled the Lease only with respect
to that portion of the Premises located at 1250 Douglas Avenue, consisting of
32,512 square feet and commonly referred to as Building 20 in the Partial
Termination of Lease Agreement dated September 10, 1998, and released each other
from their respective obligations under the Lease with respect to Building 20
after such date.

      D. Landlord and Tenant desire to terminate and cancel the Lease only with
respect to that portion of the Premises located at 550 Broadway, consisting of
67,638 square feet and commonly referred to as Building 10 (the "Released
Premises") upon the date Tenant vacates and surrenders the Released Premises and
to release each other from their respective obligations under the Lease with
respect to the Released Premises arising after such date.

      E. Except as expressly provided in this Agreement, all capitalized terms,
which are defined in the Lease, shall have the same meaning when used in this
Agreement.

NOW, THEREFORE, in good consideration of the mutual covenants set forth below
and other good and valuable consideration, the parties agree as follows:

      1. Termination of the Lease. The Lease is hereby terminated and canceled
with respect to the Released Premises on and as of the Effective Date. The
"Effective Date" shall be December 31, 1999. The rights of Tenant to occupy the
Released Premises, and the rights of Tenant under the Lease, shall automatically
and without further action on the part of Landlord terminate at 5:00 p.m. on the
Effective Date. Not later that 5:00 p.m. on the Effective Date, Tenant shall
surrender possession of the Released Premises, and shall deliver exclusive
possession and occupancy thereof and all keys thereto, to Landlord. The Released
Premises shall be surrendered in the condition existing on the Commencement
Date, normal wear and tear (as defined in Paragraph 14 of the Lease) and fire
and other casualty excepted, broom clean, with the plumbing and electrical
systems, lighting and HVAC equipment in good order and repair. On or before the
Effective Date, Tenant shall remove all of Tenant's Personal Property from the
Released

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 1
<PAGE>

Premises and repair and damage and perform any restoration work caused by the
removal of said Personal Property. Upon surrender of the Released Premises, as
provided in this Agreement, all rent and other amounts payable by Tenant under
the Lease attributable to the Released Premises, including, without limitation,
rent and Tenant's share of taxes, utility costs and other operating expenses,
shall be prorated through the Effective Date and paid by Tenant pursuant to the
terms of the Lease.

      2. Consideration. In consideration for the early termination of the Lease,
Landlord shall pay to Tenant Two Million Two Hundred Thousand and 00/100 Dollars
($2,200,000.00) (the "Termination Fee"), payable in two installments as follows:
(i) a nonrefundable payment of Two Hundred Thousand Dollars ($200,000) to be
provided on the earlier of either November 15, 1999 or the date this Agreement
is fully executed by both parties; and (ii) a second payment of Two Million
Dollars ($2,000,000) on or before December 20, 1999, provided that Tenant has
fully complied with the terms and conditions set forth in this Agreement as of
that date. If any payment is not received by Tenant within ten (10) days after
the date such payment is due, then Landlord shall pay Tenant a late charge of
five (5%) percent of the delinquent amount.

      3. Termination Documents from Tenant. During regular business hours, but
no later than the Effective Date, Landlord and Tenant shall conduct an
inspection of the Released Premises. If the condition of the Released Premised
is as required by Paragraph 1 above, then (a) Landlord and Tenant shall each
deliver to the other an executed Acknowledgement of Partial Termination and
Surrender of all of the right, title and interest of Tenant in and to the Lease
only with respect to the Released Premises, in the form attached to this
Agreement as Exhibit A; and (b) Tenant shall deliver to Landlord a Quitclaim
Deed of all of the right, title and interest of Tenant in and to the Released
Premises and the personal property remaining on the Released Premises, in the
form attached to this Agreement as Exhibit B.

      4. Tenant's Obligations. Nothing in this Agreement shall limit or reduce
Tenant's obligations to pay all rent and other amounts of every kind and nature
whatsoever payable by Tenant under the Lease and to comply with all of Tenant's
other obligations under the Lease with respect to the Released Premises through
the Effective Date and with respect to the balance of the Premises through the
Effective Date and continuing hereafter throughout the remaining term of the
Lease.

      5. Remedies. Tenant acknowledges that if Landlord is not able to obtain
exclusive possession of the Released Premises on or before the Effective Date,
the Landlord may incur substantial damages, costs and losses. Tenant understands
and agrees that Tenant's failure to deliver possession of the Released Premises
as provided in this agreement and to perform its other obligations under this
Agreement may cause Landlord to be unable to fulfill its obligations to certain
third parties, including its obligations to perform certain work to prepare the
Released Premises for new tenants, which failure would cause material damage to
the Landlord. In accordance with the foregoing understandings, as of the
Effective Date, Landlord shall have the right to prosecute any proceedings at
law and in equity, in the event of any default or breach of the obligations of
Tenant contained in this Agreement. If Tenant does not vacate the Release
Premises, terminate the Lease with respect to the Released Premises or perform
Tenant's obligations under the other terms of this Agreement of the Effective
Date, then in addition to all other rights and remedies of Landlord under
applicable law or in equity, Landlord shall be entitled to receive from Tenant
all damages resulting from or arising our of Tenant's failure to vacate the
Released Premises. All rights , privileges and elections of remedies set forth
in this Paragraph 5 are cumulative and not alternative to the extent permitted
by law or equity.

      6. Holding Over. If Tenant remains in possession of the Released Premises
after the Effective Date, with Landlord's consent, such possession by Tenant
shall be deemed to be a month-to-month tenancy with respect to the Released
Premises, and, solely for the first month of any hold over period, the monthly
rent shall be prorated on a daily basis. Tenant acknowledges that the Landlord's
cost of owning and carrying the Released Premises is substantially in excess of
the rent payable by Tenant under this Lease. Accordingly, during such
month-to-month tenancy, the Monthly Rent (as defined in the Lease for the
Premises payable pursuant to the terms of the Lease shall be One Hundred
Sixty-Four

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 2
<PAGE>

Thousand, Nine Hundred Sixty-Nine and 31/100 Dollars ($164,969.31) per month
which amount represents the sum of Twenty-Nine Thousand Six Hundred Ninety-Three
and 31/100 Dollars ($29,693.31) for 1228 Douglas Avenue (being the current
rental rate under the Lease) and One Hundred Thirty-Five Thousand, Two Hundred
Seventy-Six and 00/100 Dollars ($135,276.00) for the Released Premises (being a
hold-over rental rate per month). Tenant shall pay such Monthly Rent and all
other sums required to be paid under the Lease monthly on or before the first
day of each month. All other provisions of the Lease, except those pertaining to
the term, shall apply to the month-to-month tenancy for the Released Premises.

      7. Amendment to Lease. This Agreement is and shall constitute an amendment
to the Lease and shall be effective as of the date of this Agreement. In
addition, as a condition precedent to the effectiveness of the termination of
this Lease with respect to the Released Premises, Landlord and Tenant shall,
upon execution of this Agreement, execute a further Fourth Amendment to the
Lease in the form attached hereto as Exhibit C.

      8. Representations and Warranties

            8.1. Of Tenant. As a material inducement to Landlord to enter into
this Agreement, Tenant represents and warrants to Landlord that, as of the date
of this Agreement:

                  8.1.1. No Defaults. That Lease is in full force and effect.
There are not defaults by Landlord or Tenant under the Lease, and no
circumstance has occurred which, but for the expiration of an applicable grace
period, would constitute an event of default by Landlord or Tenant under the
Lease. Tenant has no defenses or rights of offset under the Lease.

                  8.1.2. Authority. Tenant has full right, power and authority
to enter into this Agreement, and has obtained all necessary consents and
resolutions from its board of directors required under the documents governing
its affairs in order to consummate this transactions, and the persons executing
this Agreement have been duly authorized to do so. This Agreement and the Lease
are binding obligations of Tenant, enforceable in accordance with their terms.

                  8.1.3. No Assignments. Tenant is the sole lawful tenant of the
Released Premises under the Lease, and Tenant has not sublet, assigned,
conveyed, encumbered or otherwise transferred any of the right, title or
interest of Tenant under the Lease or arising from its use or occupancy of the
Released Premises, and no other person, partnership, corporation or other entity
has any right, title or interest in the Lease or the Released Premises, or the
right to occupy or use all or any part of the Released Premises.

            8.2 Of Landlord. As a material inducement to Tenant to enter into
this Agreement, Landlord represents and warrants to Tenant that, as of the date
of this Agreement:

                  8.2.1 No. Defaults. The Lease is in full force and effect.
There are not defaults by Tenant or Landlord under the Lease, and no
circumstance has occurred which, but for the expiration of an applicable grace
period, would constitute an event of default by Tenant or Landlord under the
Lease.

                  8.2.2 Authority. Landlord has full right, power and authority
to enter into this Agreement and has obtained all necessary consents and
resolutions required under the documents governing its affairs in order to
consummate this transaction, and the person executing this Agreement has been
duly authorized to do so. This Agreement and the Lease are binding obligations
of Landlord, enforceable in accordance with their terms.

                  8.2.3 No Assignments. Landlord is the sole lawful owner of the
Premises and no other party's consent to the execution of this Agreement is
required.

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 3
<PAGE>

      9. Attorneys' Fees. If either party should bring an action to enforce the
terms of this Agreement or declare rights under this Agreement, the prevailing
party in such action shall be entitled to reasonable attorneys' fees, costs and
expenses to be paid by the losing party in such action.

      10. Construction. Counsel for all parties have read and approved the
language of this Agreement. The provisions of this Agreement shall be construed
as a whole according to their common meaning and not strictly for or against
Tenant or Landlord.

      11. Miscellaneous. This Agreement shall inure to the benefit of, and shall
be binding upon, the parties hereto and their respective successors and
permitted assigns. This Agreement may not be amended, changed or waived except
by a writing signed by the parties hereto, and shall be construed and enforced
in accordance with the laws of the State of California. This Agreement
supersedes any prior oral agreements between the parties with respect to the
subject matter hereof, and the parties acknowledge that there are no oral
agreements between them with regard to such subject matter. This Agreement may
be executed in multiple counterparts, each of which shall be deemed a duplicate
original, but all of which taken together shall constitute one and the same
instrument.

      12. Effect of Lease on Remaining Premises. With respect to that portion of
the Premises commonly known as 1228 Douglas Avenue (Building 8), consisting of
approximately 32,000 square feet (the "Remaining Premises"), nothing contained
in this Agreement shall be deemed to constitute or cause a termination of the
Lease or the landlord/tenant relationship between Landlord and Tenant. The Lease
is hereby ratified and confirmed with respect to the Remaining Premises, subject
to the amendments and modifications provided in the lease amendment attached
hereto as Exhibit C. Notwithstanding any other provision of this Agreement,
there remains an outstanding issue regarding Landlord's obligation to repair and
repave Parking Lot G, which is part of the common area under the Lease and
nothing in this Agreement shall constitute a waiver of either party's rights and
obligations regarding said issue.

      13. Letter of Credit. Pursuant to Paragraph 7 of the Lease, Landlord holds
a letter of credit as a security deposit. At any time after the Effective Date,
Tenant may substitute a letter of credit otherwise meeting the requirements of
paragraph 7 of the Lease in the amount of $29,693.31.

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 4
<PAGE>

      IN WITNESS WHEREOF, the parties have duly executed this Agreement on the
date first written above.

LANDLORD: MARTIN/CAMPUS ASSOCIATES NO. 4, L.P.
               a Delaware limited partnership

               By: MARTIN/REDWOOD PARTNERS, L.P.,
                   a California limited partnership
                   General Partner

                   By: TMG REDWOOD LLC,
                       a California limited liability company
                       General Partner

                       By: THE MARTIN GROUP OF
                           COMPANIES, INC.
                           a California corporation
                           Managing Member

                           By:
                              --------------------------------------

                            Name: /s/ Cathy Greenwald
                                 -----------------------------------
                            Title: Vice President
                                  ----------------------------------

TENANT:        AMPEX CORPORATION
               a Delaware corporation

               By:
                  ----------------------------------

               Name:/s/ Richard Jacquet
                    --------------------------------

               Title: Vice President
                     -------------------------------

               By:
                  ----------------------------------

               Name:
                    --------------------------------

               Title:
                     -------------------------------

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 5
<PAGE>

                                    EXHIBIT A

              ACKNOWLEDGEMENT OF PARTIAL TERMIANTION AND SURRENDER

      The undersigned hereby acknowledges:

      1. The Lease dated January 19, 1996 between Martin/Campus Associates No.
4, L.P., a Delaware limited partnership and Ampex Corporation, as amended (the
"Lease") for the premises described therein (the "Premises"), is terminated with
respect only to those premises commonly known as 550 Broadway, Redwood City,
California (the "Released Premises") as of the date set forth below and is of no
further force or effect with respect to the Released Premises.

      2. The Released Premises have been surrendered as of the date set forth
below and exclusive occupancy thereof is hereunder delivered to Martin/Campus
Associates No. 4, L.P.

      3. This Acknowledgement of Partial Termination and Surrender is dated
_________, 1999.

         AMPEX CORPORATION,
         a Delaware corporation

         By:  /s/ Richard Jacquet
             ------------------------------------
         Its:  Vice President
             ------------------------------------

         By:
             ------------------------------------
         Its:
             ------------------------------------

         MARTIN/CAMPUS ASSOCIATES NO. 4, L.P.,
         a Delaware limited partnership

         By: MARTIN/REDWOOD PARTNERS, L.P.,
             a California limited partnership
             General Partner

             By: TMG REDWOOD LLC,
                 a California limited liability company
                 General Partner

                 By: THE MARTIN GROUP OF COMPANIES, INC.
                     a California corporation
                     Managing Member

                     By:
                        -----------------------------------
                     Name: /s/ Cathy Greenwald
                          ---------------------------------
                     Title: Vice President
                           --------------------------------

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 6
<PAGE>

                                    EXHIBIT B

Recorded at the request of:
Martin/Campus Associates No. 4, L.P.

And, when recorded, return to:
Mandel, Buder & Verges
101 Vallejo Street
San Francisco, CA  94111
Attention:  Scott C. Verges, Esq.
--------------------------------------------------------------------------------

                                 QUITCLAIM DEED

      For One Dollar ($1.00) and other valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, AMPEX CORPORATION, a Delaware
corporation ("Ampex") hereby quitclaims, demises and releases to MARTIN/CAMPUS
ASSOCIATES NO. 4, L.P., a Delaware limited partnership ("Grantee"), all of
Ampex's right, title and interest in and to or any right title and interest
claimed by, under or through Ampex to that certain improved real property or
premises therein and any personal property located thereon commonly known as 550
Broadway, Redwood City, California, more particularly described in Exhibit A
attached hereto and incorporated herein by this reference ("Property").

      IN WITNESS WHEREOF, Ampex has executed this Quitclaim Deed this ___ day of
________________, 1999.

                                        "Ampex"

                                        AMPEX CORPORATION,
                                        a Delaware corporation

                                        By: /s/ Richard Jacquet
                                            ------------------------------------
                                        Its:  Vice President
                                            ------------------------------------

                                        By:
                                           -------------------------------------
                                        Its:
                                            ------------------------------------

                           [Acknowledgements Required]
                         [Property Description Required]

--------------------------------------------------------------------------------
SECOND PARTIAL TERMINATION OF LEASE AGREEMENT - Rev. 3 (11/12/99)         Page 7
<PAGE>

                            FOURTH AMENDMENT TO LEASE

      THIS FOURTH AMENDMENT TO LEASE (the "Fourth Amendment") is made and
entered into as of this 19th of November 1999 by and between MARTIN/CAMPUS
ASSOCIATES NO. 4, L.P., a Delaware limited partnership ("Landlord") and Ampex
Corporation, a Delaware corporation ("Tenant").

                                R E C I T A L S:

      This Fourth Amendment is entered into upon the basis of, and with
reference to the following facts, understandings and intentions of the parties:

      A.         Martin/Campus Associates, L.P., a Delaware limited partnership
            ("Original Landlord"), and Tenant entered into that certain Lease
            dated January 19, 1996 which demised those certain premises located
            at 1228 Douglas Avenue (Building 8), 1250 Douglas Avenue (Building
            20) and 550 Broadway (Building 10), Redwood City, California as more
            particularly described in the Lease (the "Premises"), which Lease
            has been amended by a certain First Amendment Lease dated December
            20, 1996 (the "First Amendment"), by a certain Amendment to Bay Road
            Lease and Douglas/Broadway Lease dated June 22, 1998 (the "Second
            Amendment"), and by a certain Third Amendment Lease dated September
            10, 1998 (the "Third Amendment") (the Lease, the First Amendment,
            the Second Amendment, and the Third Amendment are hereinafter
            collectively referred to as the "Lease").

      B.         Original Landlord assigned all of its right, title and interest
            as landlord under the Lease to Landlord pursuant to that certain
            Assignment and Assumption of Tenant Leases dated as of September 22,
            1997 (the "Assignment of Lease").

      C.         Landlord and Tenant terminated and canceled the Lease only with
            respect to that portion of the Premises located at 1250 Douglas
            Avenue, consisting of 32,512 square feet and commonly referred to as
            Building 20 in the Third Amendment on September 10, 1998 and the
            Partial Termination of Lease Agreement of the same date, and
            released each other from their respective obligations under the
            Lease with respect to Building 20 after such date.

      D.         Landlord and Tenant desire to modify and amend the terms of the
            Lease (i) to provide for the surrender of that portion of the
            Premises located at 550 Broadway, consisting of 67,638 square feet
            and commonly referred to as Building 10 (the "Released Premises")
            (as defined in that certain Second Partial Termination of Lease
            Agreement of even date herewith) upon the date Tenant vacates and
            surrenders the Released Premises, and (ii) to release each other
            from their respective obligations under the Lease with respect to
            the Released Premises arising after December 31, 1999 (the
            "Effective Date")

NOW, THEREFORE, for good and valuable consideration, including the mutual
covenants contained in the Lease and in this Fourth Amendment, Landlord and
Tenant hereby agree as follows:

      1. Defined Terms. Except as expressly provided in this Fourth Amendment to
the contrary, terms that are defined in the Lease, shall have the same meaning
when used in this Fourth Amendment.

      2. Title Page. The last two lines of the Title Page of the Lease (as
modified by the Third Amendment) are hereby deleted and the following lines are
inserted in place thereof:

      For the approximately 32,000 SF Premises at 1228 Douglas Avenue, Redwood
City, CA 94063.

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 1
<PAGE>

      3. Lease Summary: The Building Addresses, the Total Building Square
Footage, the Monthly Rent and the Security Deposit terms contained in the Lease
Summary (as modified by the Third Amendment) are hereby deleted and the
following terms are inserted in place thereof:

      Building Address: 1228 Douglas Avenue
                        Redwood City, CA 94063

                        * * *

      Total Building Square Footage: 32,000 square feet

                        * * *

      Monthly Rent (net): $29,639.31

                        * * *

      Security Deposit: $29,639.31

      4. Premises. Paragraph 2 of the Lease (as amended by the Third Amendment)
is hereby deleted in its entirety and the following Paragraph is inserted in
place thereof:

            Landlord hereby leases to Tenant and Tenant hereby leases from
            Landlord those certain premises consisting of a total area of
            approximately 32,000 square feet in that certain building, commonly
            known as 1228 Douglas Avenue (Building 8), consisting of
            approximately 32,000 square feet (the "Building") in the City of
            Redwood City, County of San Mateo, State of California, as more
            particularly shown on EXHIBIT A (collectively, the "Premises"). The
            Premises also include the appurtenant right to use in common with
            other tenants of the Property the Common Area of the Property owned
            by Landlord.

      5. Definitions. Paragraph 3 of the Lease (as amended by the Third
Amendment) is hereby amended to replace the existing definition of each of the
following terms with the following new definitions:

            M.1 Rentable Area. The aggregate square footage in any one or more
            buildings on the Property, as appropriate, as reasonably determined
            by Landlord's" architect in accordance with BOMA Standard (ANSI
            Z65.1 1980) for full floor office occupancy. The Rentable Area of
            Building 8 is 32,000 square feet, and the Rentable Area of all of
            the buildings on the Property is 191,910 square feet.

            R. 1 Tenant's Percentage Share. The ratio (expressed as a
            percentage) of the total Rentable Area of the Premises to the total
            Rentable Area of all of the buildings located on the Property owned
            by Landlord from time to time, which as of the date hereof shall
            equal 16.67% (i.e., the Rentable Area of the Premises divided by the
            Rentable Area of the buildings located on the Property owned by
            Landlord as of the date hereof). Tenant's Percentage Share shall be
            recalculated each and every time that the amount of Rentable Area
            contained in Premises is adjusted, or the Premises is expanded,
            buildings are added to or removed from the Property, or there is a
            change in the total Rentable Area of those buildings located on the
            Property owned by Landlord, or Landlord sells, exchanges, or
            otherwise transfers any or all of the buildings located on the
            Property (including without limitation the Buildings). The

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 2
<PAGE>

            parties acknowledge and agree that the total Rentable Area of all of
            the buildings located on the Property owned by Landlord may increase
            and/or decrease from time to time during the Term, since Landlord
            may elect in its sole discretion to sell a building or buildings or
            to make changes to the buildings it owns.

      6. Monthly Rent. Paragraph 5. A of the Lease (as modified by the Third
Amendment) is hereby amended to (a) delete the last two lines of the first
paragraph of paragraph 5.A. and (b) to add the following paragraph as the second
paragraph to the Lease:

            Notwithstanding anything to the contrary contained in the previous
            paragraph, as of the Effective Date (as defined hereinafter), Tenant
            shall pay to Landlord, in lawful money of the United States, Monthly
            Rent in the amount of $29,664.00 per month, which amount represents
            the sum of $29,664.00 per month for the Building at 1228 Douglas,
            and which amount shall be subject to adjustment on each Adjustment
            Date in accordance with paragraph 5.B., the next Adjustment Date
            being November 1, 2000. If the Term of this Lease extends beyond the
            date which if ten (10) years from the Commencement Date, the Monthly
            Rent for the eleventh (11th) year of the Term shall be (i) 134% of
            initial Monthly Rent attributable to Building 8 (i.e. $36,448.00 per
            month) if the cumulative increase in the Index from the Commencement
            Date through the tenth (10th) year of the Term exceeds thirty-four
            percent (34%), or (ii) the Monthly Rent payable during the last
            month of the tenth (10th) year of the Term, increased by the
            percentage increase in the Index over the twelve (12) month period
            immediately preceding the commencement of the eleventh (11th) year
            of the Term (calculated as provided in a paragraph 5.B.) if the
            cumulative increase in the Index during such 10-year period is
            thirty-four percent (34%) or less. At the commencement of the
            twelfth (12th) and thirteenth (13) years of the Term (if
            applicable), the Monthly Rent shall be increased by the percentage
            increase in the Index, calculate as provided in paragraph 5.B. over
            the previous 12-month period.

      7. Security Deposit. Paragraph 7 of the Lease is hereby amended to replace
the last sentence thereof (as modified by the Third Amendment) with the
following: "Landlord and Tenant agree that as of the Effective Date of the
Fourth Amendment, the Security Deposit shall be further reduced to Twenty-Nine
Thousand Six Hundred Sixty-Four and 00/100 ($29,664.00)."

      8. Parking Area. Paragraph 37 (as modified by the Third Amendment) is
hereby deleted and the following is inserted in place thereof:

            Tenant shall have the non-exclusive right, in common with any other
            tenants or occupants of the Property, to use up to 70 unassigned
            parking spaces, upon terms and conditions, as may from time to time
            be reasonably established by Landlord (provided that such terms and
            conditions shall not include an imposition by Landlord of a charge
            for parking). Should parking charges or surcharges of any kind be
            imposed on the parking facilities by a governmental agency, Tenant
            shall reimburse Landlord for such charges and/or surcharges or, if
            possible, shall pay such charges and/or surcharges directly to the
            governmental agency and, in such event, Tenant shall provide
            Landlord with proof that such charges and/or surcharges have been
            paid by Tenant.

      9. Exhibits. EXHIBT A attached to the Lease is hereby deleted and EXHIBIT
A attached hereto is inserted in place thereof.

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 3
<PAGE>

      10. Effective Date. The effective date of this Fourth Amendment shall be
December 31, 1999, the date which is the Effective Date under that certain
Second Partial Termination of Lease between Landlord and Tenant dated as of the
date hereof and executed simultaneously herewith.

      11. Interpretation of Amendment. This Fourth Amendment and the Lease (as
previously amended) shall be construed as a whole in order to effectuate the
intent of the parties to amend the Lease in the manner specified in this Fourth
Amendment. All provisions of the Lease affected by this Fourth Amendment shall
be deemed amended regardless of whether so specified in this Fourth Amendment.
This Fourth Amendment shall constitute a complete release between the parties
regarding their respective obligations under the Lease regarding Building 10.
Subject to the foregoing, if any provision of the Lease conflicts with any
provision of this Fourth Amendment, the provision of this Fourth Amendment shall
control.

      12. No Further Amendment. Except as amended by this Fourth Amendment, the
Lease shall continue in full force and effect and in accordance with its terms.

                         [SIGNATURES ON FOLLOWING PAGE]

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 4
<PAGE>

      IN WITNESS WHEREOF, the parties have executed this Fourth Amendment as the
date first hereinabove set forth.

LANDLORD:  MARTIN/CAMPUS ASSOCIATES NO. 4, L.P.
                a Delaware limited partnership

                By: MARTIN/REDWOOD PARTNERS, L.P.,
                    a California limited partnership
                    General Partner

                    By: TMG REDWOOD LLC,
                        a California limited liability company
                        General Partner

                        By: THE MARTIN GROUP OF
                            COMPANIES, INC.
                            a  California corporation
                            Managing Member

                            By:
                               -------------------------------
                            Name: /s/ Cathy Greenwald
                                 -----------------------------

                            Title: Vice President
                                  ----------------------------

TENANT:    AMPEX CORPORATION
           a Delaware corporation

           By:
              --------------------------------
           Name: /s/ Richard Jacquet
                ------------------------------
           Title: Vice President
                 -----------------------------

           By:
              --------------------------------
           Name:
                ------------------------------
           Title:
                 -----------------------------

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 5
<PAGE>

                                    EXHIBIT A

                      [MAP OF THE PREMISES TO BE INSERTED.]

--------------------------------------------------------------------------------
FOURTH AMENDMENT TO LEASE - Rev. 3 (11/12/99)                             Page 6<PAGE>

                                                                     EXHIBIT 4.5

                              PAKNETX CORPORATION

                                1997 STOCK PLAN
                                ---------------

     1.  Purpose.  The purpose of the PakNetX Corporation 1997 Stock Plan (the
         -------
"Plan") is to encourage key employees of PakNetX Corporation, a Delaware
corporation (the "Company"), and of any present or future parent or subsidiary
of the Company (collectively, "Related Corporations") and other individuals who
render services to the Company or a Related Corporation, by providing
opportunities to participate in the ownership of the Company and its future
growth through (a) the grant of options which qualify as "incentive stock
options" ("ISOs") under Section 422(b) of the Internal Revenue Code of 1986, as
amended (the "Code"); (b) the grant of options which do not qualify as ISOs
("Non-Qualified Options"); (c) awards of stock in the Company ("Awards"); and
(d) opportunities to make direct purchases of stock in the Company
("Purchases").  Both ISOs and Non-Qualified Options are referred to hereafter
individually as an "Option" and collectively as "Options."  Options, Awards and
authorizations to make Purchases are referred to hereafter collectively as
"Stock Rights."  As used herein, the terms "parent" and "subsidiary" mean
"parent corporation" and "subsidiary corporation," respectively, as those terms
are defined in Section 424 of the Code.

     2.  Administration of the Plan.
         ---------------------------

               A.  Board or Committee Administration.  The Plan shall (be
                   ---------------------------------
          administered by the Board of Directors of the Company (the "Board")
          or, subject to paragraph 2(D) (relating to compliance with Section
          162(m) of the Code), by a committee appointed by the Board (the
          "Committee").   Hereinafter, all references in this Plan to the
          "Committee" shall mean the Board if no Committee has been appointed.
          Subject to ratification of the grant or authorization of each Stock
          Right by the Board (if so required by applicable state law), and
          subject to the terms of the Plan, the Committee shall have the
          authority to (i) determine to whom (from among the class of employees
          eligible under paragraph 3 to receive ISOs) ISOs shall be granted, and
          to whom (from among the class of individuals and entities eligible
          under paragraph 3 to receive Non-Qualified Options and Awards and to
          make Purchases) Non-Qualified Options, Awards and authorizations to
          make Purchases may be granted; (ii) determine the time or times at
          which Options or Awards shall be granted or Purchases made; (iii)
          determine the purchase price of shares subject to each Option or
          Purchase, which prices shall not be less than the minimum price
          specified in paragraph 6; (iv) determine whether each Option granted
          shall be an ISO or a Non-Qualified Option; (v) determine (subject to
          paragraph 7) the time or times when each Option shall become
          exercisable and the duration of the exercise period; (vi) extend the
          period during which outstanding Options may be exercised; (vii)
          determine whether restrictions such as repurchase options are to be
          imposed on shares subject to Options, Awards and Purchases and the
          nature of such restrictions, if any, and (viii) interpret the Plan and
          prescribe and rescind rules and regulations relating to it.  If the
          Committee determines to issue a Non-Qualified Option, it shall take
          whatever actions it
<PAGE>

                                      -2-

          deems necessary, under Section 422 of the Code and the regulations
          promulgated thereunder, to ensure that such Option is not treated as
          an ISO. The interpretation and construction by the Committee of any
          provisions of the Plan or of any Stock Right granted under it shall be
          final unless otherwise determined by the Board. The Committee may from
          time to time adopt such rules and regulations for carrying out the
          Plan as it may deem advisable. No member of the Board or the Committee
          shall be liable for any action or determination made in good faith
          with respect to the Plan or any Stock Right granted under it.

               B.  Committee Actions.  The Committee may select one of its
                   -----------------
          members as its chairman, and shall hold meetings at such time and
          places as it may determine.  A majority of the Committee shall
          constitute a quorum and acts of a majority of the members of the
          Committee at a meeting at which a quorum is present, or acts reduced
          to or approved in writing by all the members of the Committee (if
          consistent with applicable state law), shall be the valid acts of the
          Committee.  From time to time the Board may increase the size of the
          Committee and appoint additional members thereof, remove members (with
          or without cause) and appoint new members in substitution therefor,
          fill vacancies however caused, or remove all members of the Committee
          and thereafter directly administer the Plan.

               C.  Grant of Stock Rights to Board Members.  Stock Rights may be
                   --------------------------------------
          granted to members of the Board.  All grants of Stock Rights to
          members of the Board shall in all respects be made in accordance with
          the provisions of this Plan applicable to other eligible persons.
          Members of the Board who either (i) are eligible to receive grants of
          Stock Rights pursuant to the Plan or (ii) have been granted Stock
          Rights may vote on any matters affecting the administration of the
          Plan or the grant of any Stock Rights pursuant to the Plan, except
          that no such member shall act upon the granting to himself or herself
          of Stock Rights, but any such member may be counted in determining the
          existence of a quorum at any meeting of the Board during which action
          is taken with respect to the granting to such member of Stock Rights.

               D.  Performance-Based Compensation.  The Board, in its
                   ------------------------------
          discretion, may take such action as may be necessary to ensure that
          Stock Rights granted under the Plan qualify as "qualified performance-
          based compensation" within the meaning of Section 162(m) of the Code
          and applicable regulations promulgated thereunder ("Performance-Based
          Compensation").  Such action may include, in the Board's discretion,
          some or all of the following (i) if the Board determines that Stock
          Rights granted under the Plan generally shall constitute Performance-
          Based Compensation,  the Plan shall be administered, to the extent
          required for such Stock Rights to constitute Performance-Based
          Compensation, by a Committee consisting solely of two or more "outside
          directors" (as defined in applicable regulations promulgated under
          Section 162(m) of the Code), (ii) if any Non-Qualified Options with an
          exercise price less than the fair market value per
<PAGE>

                                      -3-

         share of Common Stock are granted under the Plan and the Board
         determines that such Options should constitute Performance-Based
         Compensation, such options shall be made exercisable only upon the
         attainment of a pre-established, objective performance goal established
         by the Committee, and such grant shall be submitted for, and shall be
         contingent upon shareholder approval and (iii) Stock Rights granted
         under the Plan may be subject to such other terms and conditions as are
         necessary for compensation recognized in connection with the exercise
         or disposition of such Stock Right or the disposition of Common Stock
         acquired pursuant to such Stock Right, to constitute Performance-Based
         Compensation.

     3.  Eligible Employees and Others.  ISOs may be granted only to employees
         -----------------------------
of the Company or any Related Corporation.  Non-Qualified Options, Awards and
authorizations to make Purchases may be granted to any employee, officer or
director (whether or not also an employee) or consultant of the Company or any
Related Corporation.  The Committee may take into consideration a recipient's
individual circumstances in determining whether to grant a Stock Right.  The
granting of any Stock Right to any individual or entity shall neither entitle
that individual or entity to, nor disqualify such individual or entity from,
participation in any other grant of Stock Rights.

     4.  Stock.  The stock subject to Stock Rights shall be authorized but
         -----
unissued shares of Common Stock of the Company, par value $.0001 per share (the
"Common Stock"), or shares of Common Stock reacquired by the Company in any
manner.  The aggregate number of shares which may be issued pursuant to the Plan
is 4,311,774 subject to adjustment as provided in paragraph 13.  If any Option
granted under the Plan shall expire or terminate for any reason without having
been exercised in full or shall cease for any reason to be exercisable in whole
or in part or shall be repurchased by the Company, the unpurchased shares of
Common Stock subject to such Option shall again be available for grants of Stock
Rights under the Plan.

     No employee of the Company or any Related Corporation may be granted
Options to acquire, in the aggregate, more than 1,898,102 shares of Common Stock
under the Plan during any fiscal year of the Company.  If any Option granted
under the Plan shall expire or terminate for any reason without having been
exercised in full or shall cease for any reason to be exercisable in whole or in
part or shall be repurchased by the Company, the shares subject to such Option
shall be included in the determination of the aggregate number of shares of
Common Stock deemed to have been granted to such employee under the Plan.

     5.  Granting of Stock Rights.  Stock Rights may be granted under the Plan
         ------------------------
at any time on or after October 3, 1997 and prior to October 3, 2007.  The date
of grant of a Stock Right under the Plan will be the date specified by the
Committee at the time it grants the Stock Right; provided, however, that such
date shall not be prior to the date on which the Committee acts to approve the
grant.
<PAGE>

                                      -4-

     6.   Minimum Option Price; ISO Limitations.
          -------------------------------------

               A.  Price for Non-Qualified Options, Awards and Purchases.
                   -----------------------------------------------------
          Subject to paragraph 2(D) (relating to compliance with Section 162(m)
          of the Code), the exercise price per share specified in the agreement
          relating to each Non-Qualified Option granted, and the purchase price
          per share of stock granted in any Award or authorized as a Purchase,
          under the Plan may be less than the fair market value of the Common
          Stock of the Company on the date of grant; provided that, in no event
          shall such exercise price or such purchase price be less than the
          minimum legal consideration required therefor under the laws of any
          jurisdiction in which the Company or its successors in interest may be
          organized.

               B.  Price for ISOs.  The exercise price per share specified in
                   --------------
          the agreement relating to each ISO granted under the Plan shall not be
          less than the fair market value per share of Common Stock on the date
          of such grant.  In the case of an ISO to be granted to an employee
          owning stock possessing more than ten percent (10%) of the total
          combined voting power of all classes of stock of the Company or any
          Related Corporation, the price per share specified in the agreement
          relating to such ISO shall not be less than one hundred ten percent
          (110%) of the fair market value per share of Common Stock on the date
          of grant.  For purposes of determining stock ownership under this
          paragraph, the rules of Section 424(d) of the Code shall apply.

               C.  $100,000 Annual Limitation on ISO Vesting.  Each eligible
                   -----------------------------------------
          employee may be granted Options treated as ISOs only to the extent
          that, in the aggregate under this Plan and all incentive stock option
          plans of the Company and any Related Corporation, ISOs do not become
          exercisable for the first time by such employee during any calendar
          year with respect to stock having a fair market value (determined at
          the time the ISOs were granted) in excess of $100,000.  The Company
          intends to designate any Options granted in excess of such limitation
          as Non-Qualified Options, and the Company shall issue separate
          certificates to the optionee with respect to Options that are Non-
          Qualified Options and Options that are ISOs.

               D.  Determination of Fair Market Value.  If, at the time an
                   ----------------------------------
          Option is granted under the Plan, the Company's Common Stock is
          publicly traded, "fair market value" shall be determined as of the
          date of grant or, if the prices or quotes discussed in this sentence
          are unavailable for such date, the last business day for which such
          prices or quotes are available prior to the date of grant and shall
          mean (i) the average (on that date) of the high and low prices of the
          Common Stock on the principal national securities exchange on which
          the Common Stock is traded, if the Common Stock is then traded on a
          national securities exchange; or (ii) the last reported sale price (on
          that date) of the Common Stock on the Nasdaq National Market, if the
          Common Stock is not then traded on a national securities exchange; or
          (iii) the closing bid price (or average of bid prices) last quoted (on

<PAGE>

                                      -5-

          that date) by an established quotation service for over-the-counter
          securities, if the Common Stock is not reported on the Nasdaq National
          Market.  If the Common Stock is not publicly traded at the time an
          Option is granted under the Plan, "fair market value" shall mean the
          fair value of the Common Stock as determined by the Committee after
          taking into consideration all factors which it deems appropriate,
          including, without limitation, recent sale and offer prices of the
          Common Stock in private transactions negotiated at arm's length.

     7.   Option Duration.  Subject to earlier termination as provided in
          ---------------
paragraphs 9 and 10 or in the agreement relating to such Option, each Option
shall expire on the date specified by the Committee, but not more than (i) ten
years from the date of grant in the case of Options generally and (ii) five
years from the date of grant in the case of ISOs granted to an employee owning
stock possessing more than ten percent (10%) of the total combined voting power
of all classes of stock of the Company or any Related Corporation, as determined
under paragraph 6(B).  Subject to earlier termination as provided in paragraphs
9 and 10, the term of each ISO shall be the term set forth in the original
instrument granting such ISO, except with respect to any part of such ISO that
is converted into a Non-Qualified Option pursuant to paragraph 16.

     8.   Exercise of Option.  Subject to the provisions of paragraphs 9 through
          ------------------
12, each Option granted under the Plan shall be exercisable as follows:

               A.  Vesting.  The Option shall either be fully exercisable on the
                   -------
          date of grant or shall become exercisable thereafter in such
          installments as the Committee may specify.

               B.  Full Vesting of Installments.  Once an installment becomes
                   ----------------------------
          exercisable, it shall remain exercisable until expiration or
          termination of the Option, unless otherwise specified by the
          Committee.

               C.  Partial Exercise.  Each Option or installment may be
                   ----------------
          exercised at any time or from time to time, in whole or in part, for
          up to the total number of shares with respect to which it is then
          exercisable.

               D.  Acceleration of Vesting.  The Committee shall have the right
                   -----------------------
          to accelerate the date that any installment of any Option becomes
          exercisable; provided that the Committee shall not, without the
          consent of an optionee, accelerate the permitted exercise date of any
          installment of any Option granted to any employee as an ISO (and not
          previously converted into a Non-Qualified Option pursuant to paragraph
          16) if such acceleration would violate the annual vesting limitation
          contained in Section 422(d) of the Code, as described in paragraph
          6(C).

     9.   Termination of Employment. Unless otherwise specified in the agreement
          -------------------------
relating to such ISO, if an ISO optionee ceases to be employed by the Company
and all Related
<PAGE>

                                      -6-

Corporations other than by reason of death or disability as defined in paragraph
10, no further installments of his or her ISOs shall become exercisable, and his
or her ISOs shall terminate on the earlier of (a) three months after the date of
termination of his or her employment, or (b) their specified expiration dates,
except to the extent that such ISOs (or unexercised installments thereof) have
been converted into Non-Qualified Options pursuant to paragraph 16. For purposes
of this paragraph 9, employment shall be considered as continuing uninterrupted
during any bona fide leave of absence (such as those attributable to illness,
military obligations or governmental service) provided that the period of such
leave does not exceed 90 days or, if longer, any period during which such
optionee's right to reemployment is guaranteed by statute or by contract. A bona
fide leave of absence with the written approval of the Committee shall not be
considered an interruption of employment under this paragraph 9, provided that
such written approval contractually obligates the Company or any Related
Corporation to continue the employment of the optionee after the approved period
of absence. ISOs granted under the Plan shall not be affected by any change of
employment within or among the Company and Related Corporations, so long as the
optionee continues to be an employee of the Company or any Related Corporation.
Nothing in the Plan shall be deemed to give any grantee of any Stock Right the
right to be retained in employment or other service by the Company or any
Related Corporation for any period of time.

     10.  Death; Disability.
          -----------------

               A.  Death.  If an ISO optionee ceases to be employed by the
                   -----
          Company and all Related Corporations by reason of his or her death,
          any ISO owned by such optionee may be exercised, to the extent
          otherwise exercisable on the date of death, by the estate, personal
          representative or beneficiary who has acquired the ISO by will or by
          the laws of descent and distribution, until the earlier of (i) the
          specified expiration date of the ISO or (ii) the one year anniversary
          of the date of the optionee's death.

               B.  Disability.  If an ISO optionee ceases to be employed by the
                   ----------
          Company and all Related Corporations by reason of his or her
          disability, such optionee shall have the right to exercise any ISO
          held by him or her on the date of termination of employment, for the
          number of shares for which he or she could have exercised it on that
          date, until the earlier of (i) the specified expiration date of the
          ISO or (ii) the one year anniversary of the date of the termination of
          the optionee's employment.  For the purposes of the Plan, the term
          "disability" shall mean "permanent and total disability" as defined in
          Section 22(e)(3) of the Code or any successor statute.

     11.  Assignability.  No ISO shall be assignable or transferable by the
          -------------
optionee except by will or by the laws of descent and distribution, and during
the lifetime of the optionee shall be exercisable only by such optionee.  Stock
Rights other than ISOs shall be transferable to the extent set forth in the
agreement relating to such Stock Right.
<PAGE>

                                      -7-

     12.  Terms and Conditions of Options.  Options shall be evidenced by
          -------------------------------
instruments (which need not be identical) in such forms as the Committee may
from time to time approve.  Such instruments shall conform to the terms and
conditions set forth in paragraphs 6 through 11 hereof and may contain such
other provisions as the Committee deems advisable which are not inconsistent
with the Plan, including restrictions applicable to shares of Common Stock
issuable upon exercise of Options.  The Committee may specify that any Non-
Qualified Option shall be subject to the restrictions set forth herein with
respect to ISOs, or to such other termination and cancellation provisions as the
Committee may determine.  The Committee may from time to time confer authority
and responsibility on one or more of its own members and/or one or more officers
of the Company to execute and deliver such instruments.  The proper officers of
the Company are authorized and directed to take any and all action necessary or
advisable from time to time to carry out the terms of such instruments.

     13.  Adjustments.  Upon the occurrence of any of the following events, an
          -----------
optionee's rights with respect to Options granted to such optionee hereunder
shall be adjusted as hereinafter provided, unless otherwise specifically
provided in the written agreement between the optionee and the Company relating
to such Option:

               A.  Stock Dividends and Stock Splits.  If the shares of Common
                   --------------------------------
          Stock shall be subdivided or combined into a greater or smaller number
          of shares or if the Company shall issue any shares of Common Stock as
          a stock dividend on its outstanding Common Stock, the number of shares
          of Common Stock deliverable upon the exercise of Options shall be
          appropriately increased or decreased proportionately, and appropriate
          adjustments shall be made in the purchase price per share to reflect
          such subdivision, combination or stock dividend.

               B.  Consolidations or Mergers.  If the Company is to be
                   -------------------------
          consolidated with or acquired by another entity in a merger or other
          reorganization in which the holders of the outstanding voting stock of
          the Company immediately preceding the consummation of such event,
          shall, immediately following such event, hold, as a group, less than a
          majority of the voting securities of the surviving or successor
          entity, or in the event of a sale of all or substantially all of the
          Company's assets or otherwise (each, an "Acquisition"), the Committee
          or the board of directors of any entity assuming the obligations of
          the Company hereunder (the "Successor Board"), shall, as to
          outstanding Options, either (i) make appropriate provision for the
          continuation of such Options by substituting on an equitable basis for
          the shares then subject to such Options either (a) the consideration
          payable with respect to the outstanding shares of Common Stock in
          connection with the Acquisition, (b) shares of stock of the surviving
          or successor corporation or (c) such other securities as the Successor
          Board deems appropriate, the fair market value of which shall not
          materially exceed the fair market value of the shares of Common Stock
          subject to such Options immediately preceding the Acquisition; or (ii)
          upon written notice to the optionees, provide that all Options must be
          exercised, to the extent then exercisable or to be
<PAGE>

                                      -8-

          exercisable as a result of the Acquisition, within a specified number
          of days of the date of such notice, at the end of which period the
          Options shall terminate; or (iii) terminate all Options in exchange
          for a cash payment equal to the excess of the fair market value of the
          shares subject to such Options (to the extent then exercisable or to
          be exercisable as a result of the Acquisition) over the exercise price
          thereof.

               C.  Recapitalization or Reorganization.  In the event of a
                   ----------------------------------
          recapitalization or reorganization of the Company (other than a
          transaction described in subparagraph B above) pursuant to which
          securities of the Company or of another corporation are issued with
          respect to the outstanding shares of Common Stock, an optionee upon
          exercising an Option shall be entitled to receive for the purchase
          price paid upon such exercise the securities he or she would have
          received if he or she had exercised such Option prior to such
          recapitalization or reorganization.

               D.  Modification of ISOs.  Notwithstanding the foregoing, any
                   --------------------
          adjustments made pursuant to subparagraphs A, B or C with respect to
          ISOs shall be made only after the Committee, after consulting with
          counsel for the Company, determines whether such adjustments would
          constitute a "modification" of such ISOs (as that term is defined in
          Section 424 of the Code) or would cause any adverse tax consequences
          for the holders of such ISOs.  If the Committee determines that such
          adjustments made with respect to ISOs would constitute a modification
          of such ISOs or would cause adverse tax consequences to the holders,
          it may refrain from making such adjustments.

               E.  Dissolution or Liquidation.  In the event of the proposed
                   --------------------------
          dissolution or liquidation of the Company, each Option will terminate
          immediately prior to the consummation of such proposed action or at
          such other time and subject to such other conditions as shall be
          determined by the Committee.

               F.  Issuances of Securities.  Except as expressly provided
                   -----------------------
          herein, no issuance by the Company of shares of stock of any class, or
          securities convertible into shares of stock of any class, shall
          affect, and no adjustment by reason thereof shall be made with respect
          to, the number or price of shares subject to Options.  No adjustments
          shall be made for dividends paid in cash or in property other than
          securities of the Company.

               G.  Fractional Shares.  No fractional shares shall be issued
                   -----------------
          under the Plan and the optionee shall receive from the Company cash in
          lieu of such fractional shares.

               H.  Adjustments.  Upon the happening of any of the events
                   -----------
          described in subparagraphs A, B or C above, the class and aggregate
          number of shares set
<PAGE>

                                      -9-

          forth in paragraph 4 hereof that are subject to Stock Rights which
          previously have been or subsequently may be granted under the Plan
          shall also be appropriately adjusted to reflect the events described
          in such subparagraphs. The Committee or the Successor Board shall
          determine the specific adjustments to be made under this paragraph 13
          and, subject to paragraph 2, its determination shall be conclusive.

     14.  Means of Exercising Options.  An Option (or any part or installment
          ---------------------------
thereof) shall be exercised by giving written notice to the Company at its
principal office address, or to such transfer agent as the Company shall
designate. Such notice shall identify the Option being exercised and specify the
number of shares as to which such Option is being exercised, accompanied by full
payment of the purchase price therefor either (a) in United States dollars in
cash or by check, (b) at the discretion of the Committee, through delivery of
shares of Common Stock having a fair market value equal as of the date of the
exercise to the cash exercise price of the Option, (c) at the discretion of the
Committee, by delivery of the grantee's personal recourse note bearing interest
payable not less than annually at no less than 100% of the lowest applicable
Federal rate, as defined in Section 1274(d) of the Code, (d) at the discretion
of the Committee and consistent with applicable law, through the delivery of an
assignment to the Company of a sufficient amount of the proceeds from the sale
of the Common Stock acquired upon exercise of the Option and an authorization to
the broker or selling agent to pay that amount to the Company, which sale shall
be at the participant's direction at the time of exercise, or (e) at the
discretion of the Committee, by any combination of (a), (b), (c) and (d) above.
If the Committee exercises its discretion to permit payment of the exercise
price of an ISO by means of the methods set forth in clauses (b), (c), (d) or
(e) of the preceding sentence, such discretion shall be exercised in writing at
the time of the grant of the ISO in question. The holder of an Option shall not
have the rights of a shareholder with respect to the shares covered by such
Option until the date of issuance of a stock certificate to such holder for such
shares. Except as expressly provided above in paragraph 13 with respect to
changes in capitalization and stock dividends, no adjustment shall be made for
dividends or similar rights for which the record date is before the date such
stock certificate is issued.

     15.  Term and Amendment of Plan.  This Plan was adopted by the Board on
          --------------------------
October 3, 1997, subject, with respect to the validation of ISOs granted under
the Plan, to approval of the Plan by the stockholders of the Company at the next
Meeting of Stockholders or, in lieu thereof, by written consent.  The Plan shall
expire at the end of the day on October 2, 2007 (except as to Options
outstanding on that date).  Subject to the provisions of paragraph 5 above,
Options may be granted under the Plan prior to the date of stockholder approval
of the Plan.  The Board may terminate or amend the Plan in any respect at any
time, except that, without the approval of the stockholders obtained within 12
months before or after the Board adopts a resolution authorizing any of the
following actions: (a) the total number of shares that may be issued under the
Plan may not be increased (except by adjustment pursuant to paragraph 13); (b)
the provisions of paragraph 3 regarding eligibility for grants of ISOs may not
be modified; (c) the provisions of paragraph 6(B) regarding the exercise price
at which shares may be offered pursuant to ISOs may not be modified (except by
adjustment pursuant to paragraph 13); and (d) the expiration date of the Plan
may not be extended.   Except as otherwise provided in this paragraph 15, in no
event
<PAGE>

                                     -10-

may action of the Board or stockholders alter or impair the rights of a
grantee, without such grantee's consent, under any Stock Right previously
granted to such grantee.

     16.  Modifications of ISOs; Conversion of ISOs into Non-Qualified Options.
          --------------------------------------------------------------------
Subject to paragraph 13(D), without the prior written consent of the holder of
an ISO, the Committee shall not alter the terms of such ISO (including the means
of exercising such ISO) if such alteration would constitute a modification
(within the meaning of Section 424(h)(3) of the Code).  The Committee, at the
written request or with the written consent of any optionee, may in its
discretion take such actions as may be necessary to convert such optionee's ISOs
(or any installments or portions of installments thereof) that have not been
exercised on the date of conversion into Non-Qualified Options at any time prior
to the expiration of such ISOs, regardless of whether the optionee is an
employee of the Company or a Related Corporation at the time of such conversion.
Such actions may include, but shall not be limited to, extending the exercise
period or reducing the exercise price of the appropriate installments of such
ISOs.  At the time of such conversion, the Committee (with the consent of the
optionee) may impose such conditions on the exercise of the resulting Non-
Qualified Options as the Committee in its discretion may determine, provided
that such conditions shall not be inconsistent with this Plan.  Nothing in the
Plan shall be deemed to give any optionee the right to have such optionee's ISOs
converted into Non-Qualified Options, and no such conversion shall occur until
and unless the Committee takes appropriate action.  Upon the taking of such
action, the Company shall issue separate certificates to the optionee with
respect to Options that are Non-Qualified Options and Options that are ISOs.

     17.  Application Of Funds.  The proceeds received by the Company from the
          --------------------
sale of shares pursuant to Options granted and Purchases authorized under the
Plan shall be used for general corporate purposes.

     18.  Notice to Company of Disqualifying Disposition.  By accepting an ISO
          ----------------------------------------------
granted under the Plan, each optionee agrees to notify the Company in writing
immediately after such optionee makes a Disqualifying Disposition (as described
in Sections 421, 422 and 424 of the Code and regulations thereunder) of any
stock acquired pursuant to the exercise of ISOs granted under the Plan.  A
Disqualifying Disposition is generally any disposition occurring on or before
the later of (a) the date two years following the date the ISO was granted or
(b) the date one year following the date the ISO was exercised.

     19.  Withholding of Additional Income Taxes.  Upon the exercise of a Non-
          --------------------------------------
Qualified Option, the transfer of a Non-Qualified Stock Option pursuant to an
arm's-length transaction, the grant of an Award, the making of a Purchase of
Common Stock for less than its fair market value, the making of a Disqualifying
Disposition (as defined in paragraph 18), the vesting or transfer of restricted
stock or securities acquired on the exercise of an Option hereunder, or the
making of a distribution or other payment with respect to such stock or
securities, the Company may withhold taxes in respect of amounts that constitute
compensation includible in gross income.  The Committee in its discretion may
condition (i) the exercise of an Option, (ii) the transfer of a Non-Qualified
Stock Option, (iii) the grant of an Award, (iv) the making of a Purchase of
Common Stock for less than its fair market value, or (v) the vesting or
<PAGE>

                                     -11-

transferability of restricted stock or securities acquired by exercising an
Option, on the grantee's making satisfactory arrangement for such withholding.
Such arrangement may include payment by the grantee in cash or by check of the
amount of the withholding taxes or, at the discretion of the Committee, by the
grantee's delivery of previously held shares of Common Stock or the withholding
from the shares of Common Stock otherwise deliverable upon exercise of a Option
shares having an aggregate fair market value equal to the amount of such
withholding taxes.

     20.  Governmental Regulation.  The Company's obligation to sell and deliver
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shares of the Common Stock under this Plan is subject to the approval of any
governmental authority required in connection with the authorization, issuance
or sale of such shares.

     Government regulations may impose reporting or other obligations on the
Company with respect to the Plan.  For example, the Company may be required to
send tax information statements to employees and former employees that exercise
ISOs under the Plan, and the Company may be required to file tax information
returns reporting the income received by grantees of Options in connection with
the Plan.

     21.  Governing Law.  The validity and construction of the Plan and the
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instruments evidencing Stock Rights shall be governed by the laws of Delaware,
or the laws of any jurisdiction in which the Company or its successors in
interest may be organized.

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