Document:

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                                                                   EXHIBIT 10.1

                                  ADAPTEC, INC.
                       2000 NONSTATUTORY STOCK OPTION PLAN

     1.   PURPOSES OF THE PLAN. The purposes of this Nonstatutory Stock Option
Plan are:

          - to attract and to retain the best available personnel for positions
            of substantial responsibility,

          - to provide additional incentive to personnel of the Company, and

          - to promote the success of the Company's business.

          Options granted under the Plan will be Nonstatutory Stock Options.

     2.   DEFINITIONS. As used herein, the following definitions shall apply:

          (a) "ADMINISTRATOR" means the Board or any of its Committees as
shall be administering the Plan, in accordance with Section 4 of the Plan.

          (b) "APPLICABLE LAWS" means the requirements relating to the
administration of stock option plans under U.S. state corporate laws, U.S.
federal and state securities laws, the Code, any stock exchange or quotation
system on which the Common Stock is listed or quoted and the applicable laws of
any foreign country or jurisdiction where Options are, or will be, granted under
the Plan.

          (c) "BOARD" means the Board of Directors of the Company.

          (d) "CAUSE" shall have the meaning as set forth in Section 12(f)(i) of
the Plan.

          (e) "CHANGE OF CONTROL" shall have the meaning as set forth in Section
12(f)(ii) of the Plan.

          (f) "CODE" means the Internal Revenue Code of 1986, as amended.

          (g) "COMMITTEE" means a committee of Directors appointed by the Board
in accordance with Section 4 of the Plan.

          (h) "COMMON STOCK" means the Common Stock of the Company.

          (i) "COMPANY" means Adaptec, Inc., a Delaware corporation.

          (j) "CONSULTANT" means any person, including an advisor, engaged by
the Company or a Parent or Subsidiary to render services to such entity.

          (k) "DIRECTOR" means a member of the Board.

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          (l) "DISABILITY" means total and permanent disability as defined in
Section 22(e)(3) of the Code.

          (m) "EMPLOYEE" means any person, including Officers, employed by the
Company or any Parent or Subsidiary of the Company. A Service Provider shall not
cease to be an Employee in the case of (i) any leave of absence approved by the
Company or (ii) transfers between locations of the Company or between the
Company, its Parent, any Subsidiary, or any successor. Neither service as a
Director nor payment of a director's fee by the Company shall be sufficient to
constitute "employment" by the Company.

          (n) "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended.

          (o) "FAIR MARKET VALUE" means, as of any date, the value of Common
Stock determined as follows:

               (i) If the Common Stock is listed on any established stock
exchange or a national market system, including without limitation the Nasdaq
National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its
Fair Market Value shall be the closing sales price for such stock (or the
closing bid, if no sales were reported) as quoted on such exchange or system for
the last market trading day prior to the time of determination, as reported in
THE WALL STREET JOURNAL or such other source as the Administrator deems
reliable;

               (ii) If the Common Stock is regularly quoted by a recognized
securities dealer but selling prices are not reported, the Fair Market Value of
a Share of Common Stock shall be the mean between the high bid and low asked
prices for the Common Stock on the last market trading day prior to the day of
determination, as reported in THE WALL STREET JOURNAL or such other source as
the Administrator deems reliable;

               (iii) In the absence of an established market for the Common
Stock, the Fair Market Value shall be determined in good faith by the
Administrator.

          (p) "NOTICE OF GRANT" means a written or electronic notice evidencing
certain terms and conditions of an individual Option grant. The Notice of Grant
is part of the Option Agreement.

          (q) "OFFICER" means a person who is an officer of the Company within
the meaning of Section 16 of the Exchange Act and the rules and regulations
promulgated thereunder.

          (r) "OPTION" means a nonstatutory stock option granted pursuant to the
Plan, that is not intended to qualify as an incentive stock option within the
meaning of Section 422 of the Code and the regulations promulgated thereunder.

          (s) "OPTION AGREEMENT" means an agreement between the Company and an
Optionee evidencing the terms and conditions of an individual Option grant. The
Option Agreement is subject to the terms and conditions of the Plan.

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          (t) "OPTION EXCHANGE PROGRAM" means a program whereby outstanding
options are surrendered in exchange for options with a lower exercise price.

          (u) "OPTIONED STOCK" means the Common Stock subject to an Option.

          (v) "OPTIONEE" means the holder of an outstanding Option granted under
the Plan.

          (w) "PARENT" means a "parent corporation," whether now or hereafter
existing, as defined in Section 424(e) of the Code.

          (x) "PLAN" means this 1999 Nonstatutory Stock Option Plan.

          (y) "SERVICE PROVIDER" means an Employee including an Officer,
Consultant or Director.

          (z) "SHARE" means a share of the Common Stock, as adjusted in
accordance with Section 12 of the Plan.

          (aa) "SUBSIDIARY" means a "subsidiary corporation," whether now
or hereafter existing, as defined in Section 424(f) of the Code.

     3. STOCK SUBJECT TO THE PLAN. Subject to the provisions of Section 12 of
the Plan, the maximum aggregate number of Shares which may be optioned and sold
under the Plan is eight million (8,000,000) Shares. The Shares may be
authorized, but unissued, or reacquired Common Stock.

        If an Option expires or becomes unexercisable without having
been exercised in full, or is surrendered pursuant to an Option Exchange
Program, the unpurchased Shares which were subject thereto shall become
available for future grant or sale under the Plan (unless the Plan has
terminated).

     4. ADMINISTRATION OF THE PLAN.

          (a) ADMINISTRATION. The Plan shall be administered by (i) the Board or
(ii) a Committee, which committee shall be constituted to satisfy
Applicable Laws.

          (b) POWERS OF THE ADMINISTRATOR. Subject to the provisions of the
Plan, and in the case of a Committee, subject to the specific duties delegated
by the Board to such Committee, the Administrator shall have the authority, in
its discretion:

               (i) to determine the Fair Market Value of the Common Stock;

               (ii) to select the Service Providers to whom Options may be
granted hereunder;

               (iii) to determine whether and to what extent Options are granted
hereunder;

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               (iv) to determine the number of shares of Common Stock to be
covered by each Option granted hereunder;

               (v) to approve forms of agreement for use under the Plan;

               (vi) to determine the terms and conditions, not inconsistent with
the terms of the Plan, of any award granted hereunder. Such terms and conditions
include, but are not limited to, the exercise price, the time or times when
Options may be exercised (which may be based on performance criteria), any
vesting acceleration or waiver of forfeiture restrictions, and any restriction
or limitation regarding any Option or the shares of Common Stock relating
thereto, based in each case on such factors as the Administrator, in its sole
discretion, shall determine;

               (vii) to reduce the exercise price of any Option to the then
current Fair Market Value if the Fair Market Value of the Common Stock covered
by such Option shall have declined since the date the Option was granted;

               (viii) to institute an Option Exchange Program;

               (ix) to construe and interpret the terms of the Plan and awards
granted pursuant to the Plan;

               (x) to prescribe, amend and rescind rules and regulations
relating to the Plan, including rules and regulations relating to sub-plans
established for the purpose of qualifying for preferred tax treatment under
foreign tax laws;

               (xi) to modify or amend each Option (subject to Section 14(b) of
the Plan), including the discretionary authority to extend the post-termination
exercisability period of Options longer than is otherwise provided for in the
Plan;

               (xii) to authorize any person to execute on behalf of the Company
any instrument required to effect the grant of an Option previously granted by
the Administrator;

               (xiii) to determine the terms and restrictions applicable to
Options;

               (xiv) to allow Optionees to satisfy withholding tax obligations
by electing to have the Company withhold from the Shares to be issued upon
exercise of an Option that number of Shares having a Fair Market Value equal to
the amount required to be withheld. The Fair Market Value of the Shares to be
withheld shall be determined on the date that the amount of tax to be withheld
is to be determined. All elections by an Optionee to have Shares withheld for
this purpose shall be made in such form and under such conditions as the
Administrator may deem necessary or advisable; and

               (xv) to make all other determinations deemed necessary or
advisable for administering the Plan.

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          (c) EFFECT OF ADMINISTRATOR'S DECISION. The Administrator's
decisions, determinations and interpretations shall be final and binding on
all Optionees and any other holders of Options.

     5. ELIGIBILITY. Options may be granted to Service Providers; provided,
however, that notwithstanding anything to the contrary contained in the Plan,
Options may not be granted to Officers and Directors.

     6. LIMITATION. Neither the Plan nor any Option shall confer upon an
Optionee any right with respect to continuing the Optionee's relationship as a
Service Provider with the Company, nor shall they interfere in any way with the
Optionee's right or the Company's right to terminate such relationship at any
time, with or without cause.

     7. TERM OF PLAN. The Plan shall become effective upon its adoption by
the Board. It shall continue in effect for ten (10) years, unless sooner
terminated under Section 14 of the Plan.

     8. TERM OF OPTION. The term of each Option shall be stated in the Option
Agreement.

     9. OPTION EXERCISE PRICE AND CONSIDERATION.

          (a) EXERCISE PRICE. The per share exercise price for the Shares to
be issued pursuant to exercise of an Option shall be determined by the
Administrator.

          (b) WAITING PERIOD AND EXERCISE DATES. At the time an Option is
granted, the Administrator shall fix the period within which the Option may be
exercised and shall determine any conditions which must be satisfied before the
Option may be exercised.

          (c) FORM OF CONSIDERATION. The Administrator shall determine the
acceptable form of consideration for exercising an Option, including the
method of payment. Such consideration may consist entirely of:

               (i) cash;

               (ii) check;

               (iii) promissory note;

               (iv) other Shares which (A) in the case of Shares acquired upon
exercise of an option, have been owned by the Optionee for more than six months
on the date of surrender, and (B) have a Fair Market Value on the date of
surrender equal to the aggregate exercise price of the Shares as to which said
Option shall be exercised;

               (v) consideration received by the Company under a cashless
exercise program implemented by the Company in connection with the Plan;

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               (vi) a reduction in the amount of any Company liability to the
Optionee, including any liability attributable to the Optionee's participation
in any Company-sponsored deferred compensation program or arrangement;

               (vii) such other consideration and method of payment for the
issuance of Shares to the extent permitted by Applicable Laws; or

               (viii) any combination of the foregoing methods of payment.

     10. EXERCISE OF OPTION.

          (a) PROCEDURE FOR EXERCISE; RIGHTS AS A SHAREHOLDER. Any Option
granted hereunder shall be exercisable according to the terms of the Plan and
at such times and under such conditions as determined by the Administrator
and set forth in the Option Agreement. An Option may not be exercised for a
fraction of a Share.

              An Option shall be deemed exercised when the Company receives:
(i) written or electronic notice of exercise (in accordance with the Option
Agreement) from the person entitled to exercise the Option, and (ii) full
payment for the Shares with respect to which the Option is exercised. Full
payment may consist of any consideration and method of payment authorized by
the Administrator and permitted by the Option Agreement and the Plan. Shares
issued upon exercise of an Option shall be issued in the name of the Optionee
or, if requested by the Optionee, in the name of the Optionee and his or her
spouse. Until the Shares are issued (as evidenced by the appropriate entry on
the books of the Company or of a duly authorized transfer agent of the
Company), no right to vote or receive dividends or any other rights as a
shareholder shall exist with respect to the Optioned Stock, notwithstanding
the exercise of the Option. The Company shall issue (or cause to be issued)
such Shares promptly after the Option is exercised. No adjustment will be
made for a dividend or other right for which the record date is prior to the
date the Shares are issued, except as provided in Section 12 of the Plan.

              Exercising an Option in any manner shall decrease the number
of Shares thereafter available, both for purposes of the Plan and for sale
under the Option, by the number of Shares as to which the Option is exercised.

          (b) TERMINATION OF RELATIONSHIP AS A SERVICE PROVIDER. If an Optionee
ceases to be a Service Provider, other than upon the Optionee's death or
Disability, the Optionee may exercise his or her Option, but only within such
period of time as is specified in the Option Agreement, and only to the extent
that the Option is vested on the date of termination (but in no event later than
the expiration of the term of such Option as set forth in the Option Agreement).
In the absence of a specified time in the Option Agreement, the Option shall
remain exercisable for three (3) months following the Optionee's termination.
If, on the date of termination, the Optionee is not vested as to his or her
entire Option, the Shares covered by the unvested portion of the Option shall
revert to the Plan. If, after termination, the Optionee does not exercise his or
her Option within the time specified by the Administrator, the Option shall
terminate, and the Shares covered by such Option shall revert to the Plan.

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          (c) DISABILITY OF OPTIONEE. If an Optionee ceases to be a Service
Provider as a result of the Optionee's Disability, the Optionee may exercise his
or her Option within such period of time as is specified in the Option
Agreement, to the extent the Option is vested on the date of termination (but in
no event later than the expiration of the term of such Option as set forth in
the Option Agreement). In the absence of a specified time in the Option
Agreement, the Option shall remain exercisable for six (6) months following the
Optionee's termination. If, on the date of termination, the Optionee is not
vested as to his or her entire Option, the Shares covered by the unvested
portion of the Option shall revert to the Plan. If, after termination, the
Optionee does not exercise his or her Option within the time specified herein,
the Option shall terminate, and the Shares covered by such Option shall revert
to the Plan.

          (d) DEATH OF OPTIONEE. In the event of the death of an Optionee while
a Service Provider, Options granted hereunder to such Optionee shall become
vested and exercisable, in addition to Shares as to which such Options would
otherwise be vested and exercisable, for the lesser of the full number of Shares
covered by the Options or an aggregate of 50,000 Shares. Each Option held by the
Optionee at the time of death may be exercised at any time within six (6) months
following the date of death by the Optionee's estate or by a person who acquired
the right to exercise the Option by bequest or inheritance. In no event shall an
Option be exercised later than the expiration of the term of the Option, as set
forth in the stock option agreement.

          (e) BUYOUT PROVISIONS. The Administrator may at any time offer to buy
out for a payment in cash or Shares, an Option previously granted based on such
terms and conditions as the Administrator shall establish and communicate to the
Optionee at the time that such offer is made.

     11. NON-TRANSFERABILITY OF OPTIONS. Unless determined otherwise by the
Administrator, an Option may not be sold, pledged, assigned, hypothecated,
transferred, or disposed of in any manner other than by will or by the laws of
descent or distribution and may be exercised, during the lifetime of the
Optionee, only by the Optionee. If the Administrator makes an Option
transferable, such Option shall contain such additional terms and conditions as
the Administrator deems appropriate.

     12. ADJUSTMENTS UPON CHANGES IN CAPITALIZATION, DISSOLUTION, MERGER OR
ASSET SALE.

          (a) CHANGES IN CAPITALIZATION. Subject to any required action by the
shareholders of the Company, the number of shares of Common Stock covered by
each outstanding Option, and the number of shares of Common Stock which have
been authorized for issuance under the Plan but as to which no Options have yet
been granted or which have been returned to the Plan upon cancellation or
expiration of an Option, as well as the price per share of Common Stock covered
by each such outstanding Option, shall be proportionately adjusted for any
increase or decrease in the number of issued shares of Common Stock resulting
from a stock split, reverse stock split, stock dividend, combination or
reclassification of the Common Stock, or any other increase or decrease in the
number of issued shares of Common Stock effected without receipt of
consideration by the Company; provided, however, that conversion of any
convertible securities of the Company shall not be deemed to have been "effected
without receipt of consideration." Such adjustment shall be made by the Board,
whose determination in that respect shall be final, binding and conclusive.
Except as expressly provided herein, no issuance by the Company of shares of
stock of any class, or securities

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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 of Common Stock subject to an Option.

          (b) DISSOLUTION OR LIQUIDATION. In the event of the proposed
dissolution or liquidation of the Company, the Administrator shall notify each
Optionee as soon as practicable prior to the effective date of such proposed
transaction. The Administrator in its discretion may provide for an Optionee to
have the right to exercise his or her Option until ten (10) days prior to such
transaction as to all of the Optioned Stock covered thereby, including Shares as
to which the Option would not otherwise be exercisable. In addition, the
Administrator may provide that any Company repurchase option applicable to any
Shares purchased upon exercise of an Option shall lapse as to all such Shares,
provided the proposed dissolution or liquidation takes place at the time and in
the manner contemplated. To the extent it has not been previously exercised, an
Option will terminate immediately prior to the consummation of such proposed
action.

          (c) MERGER OR ASSET SALE. In the event of a merger of the Company with
or into another corporation, or the sale of substantially all of the assets of
the Company, each outstanding Option shall be assumed or an equivalent option or
right substituted by the successor corporation or a Parent or Subsidiary of the
successor corporation. In the event that the successor corporation refuses to
assume or substitute for the Option, the Optionee shall fully vest in and have
the right to exercise the Option as to all of the Optioned Stock, including
Shares as to which it would not otherwise be vested or exercisable. If an Option
becomes fully vested and exercisable in lieu of assumption or substitution in
the event of a merger or sale of assets, the Administrator shall notify the
Optionee in writing or electronically that the Option shall be fully vested and
exercisable for a period of fifteen (15) days from the date of such notice, and
the Option shall terminate upon the expiration of such period. For the purposes
of this paragraph, the Option shall be considered assumed if, following the
merger or sale of assets, the option or right confers the right to purchase or
receive, for each Share of Optioned Stock, immediately prior to the merger or
sale of assets, the consideration (whether stock, cash, or other securities or
property) received in the merger or sale of assets by holders of Common Stock
for each Share held on the effective date of the transaction (and if holders
were offered a choice of consideration, the type of consideration chosen by the
holders of a majority of the outstanding Shares); provided, however, that if
such consideration received in the merger or sale of assets is not solely common
stock of the successor corporation or its Parent, the Administrator may, with
the consent of the successor corporation, provide for the consideration to be
received upon the exercise of the Option, for each Share of Optioned Stock to be
solely common stock of the successor corporation or its Parent equal in fair
market value to the per share consideration received by holders of Common Stock
in the merger or sale of assets.

          (d) ACCELERATION UPON A CHANGE OF CONTROL. In the event of a "Change
of Control" of the Company then any Options outstanding upon the date of such
Change of Control that are not yet exercisable and vested on such date shall
have their vesting accelerated as to an additional twenty-five percent (25%) of
the unvested Shares subject to such Options as of the date of such Change of
Control, and such Stock Options shall continue to otherwise vest, (subject to
(i) Optionee remaining in Continuous Status as an Employee or Consultant, and
(ii) accelerated vesting as provided for in Sections 12(c) or 12(e) of this
Plan) at the same rate and as to the same number of Shares per vesting period as
immediately prior to the Change of Control. For example, if an

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Optionee holds an Option that is fifty percent (50%) vested immediately prior
to the date of a Change of Control, which Option ordinarily vests so as to be
one hundred percent (100%) vested four years after the date of grant (subject
to Optionee maintaining his or her Continuous Status as an Employee or
Consultant), the Option would, upon the date of the Change of Control, become
vested as to an additional twelve and one-half percent (12.5%) of the total
number of Shares covered by the Option (that is, 25% of the 50% that remained
unvested as of the date of the Change of Control). The Option would resume
vesting (subject to (i) Optionee maintaining his or her Continuous Status as
an Employee or Consultant, and (ii) accelerated vesting as provided for in
Sections 12(c) or 12(e) of this Plan) so as to be one hundred percent (100%)
vested three and one-half years following the date of grant. On the twelve
month anniversary date (the "Anniversary Date") following the date of the
Change of Control each Service Provider who is an Optionee shall have 25% of
the unvested Shares subject to such Options as of the Anniversary Date
accelerated, provided, however, that such Optionee was a Service Provider on
the date the Change of Control occurred and is a Service Provider on the
Anniversary Date. For purposes of this section 12(d), any acceleration
applies only to options that have not expired.

          (e) TERMINATION WITHOUT CAUSE. In the event an Optionee is
involuntarily terminated without Cause within twelve (12) months following a
"Change of Control" of the Company (as such terms are defined in Section 12(f)
below), then any unexpired Options outstanding upon the date of such Change of
Control that are not yet exercisable and vested on such date shall become one
hundred percent (100%) exercisable and vested. Notwithstanding the foregoing,
(unless Optionee is party to a duly authorized written agreement with the
Company providing otherwise) this Plan does not constitute a contract of
employment or impose on the Company any obligation to retain the Optionee, or to
change the Company's policies regarding termination of employment or other
provision of services. The employment of Optionees who are Employees is and
shall continue to be at-will, as defined under applicable law, and may be
terminated at any time, with or without cause.

          (f) DEFINITIONS.

               (i)  CHANGE OF CONTROL. For purposes of this Section, a
"Change of Control" means the occurrence of any of the following:

                    (A) When any "person," as such term is used in Sections
     13(d) and 14(d) of the Securities Exchange Act (other than the Company,
     a Subsidiary or a Company employee benefit plan, including any trustee
     of such plan acting as trustee) is or becomes the "beneficial owner" (as
     defined in Rule 13d-3 under the Exchange Act), directly or indirectly,
     of securities of the Company representing fifty percent (50%) or more of
     the combined voting power of the Company's then outstanding securities;
     or

                    (B) A change in the composition of the Board occurring
     within a two-year period, as a result of which fewer than a majority of
     the directors are Incumbent Directors. "Incumbent Directors" shall mean
     directors who either (I) are directors of the Company as of the date
     hereof, or (II) are elected, or nominated for election, to the Board
     with the affirmative votes of at least a majority of the Incumbent
     Directors at the time of such election or nomination (but shall not
     include an individual whose election or nomination is in

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     connection with an actual or threatened proxy contest relating to the
     election of directors to the Company);

                    (C) The consummation of a merger or consolidation of the
     Company with any other corporation, other than a merger or consolidation
     which would result in the voting securities of the Company outstanding
     immediately prior thereto continuing to represent (either by remaining
     outstanding or by being converted into voting securities of the
     surviving entity) at least fifty percent (50%) of the total voting power
     represented by the voting securities of the Company or such surviving
     entity outstanding immediately after such merger or consolidation; or

                    (D) The consummation of the sale or disposition by the
     Company of all or substantially all the Company's assets.

               (ii) CAUSE. For purposes of this Section, "Cause" shall mean
     (A) any act of personal dishonesty taken by the Optionee in connection
     with his responsibilities as a service provider to the Company and
     intended to result in substantial personal enrichment of the Optionee,
     (B) the Optionee's conviction of a felony, or (C) a willful act by the
     Optionee which constitutes gross misconduct and which is injurious to
     the Company, or (D) continued substantial violations by the Optionee of
     the Optionee's duties to the Company which are demonstrably willful and
     deliberate on the Optionee's part after there has been delivered to the
     Optionee a written demand for performance from the Company which
     specifically sets forth the factual basis for the Company's belief that
     the Optionee has committed continued substantial violations of his or
     her duties.

     13. DATE OF GRANT. The date of grant of an Option shall be, for all
purposes, the date on which the Administrator makes the determination granting
such Option, or such other later date as is determined by the Administrator.
Notice of the determination shall be provided to each Optionee within a
reasonable time after the date of such grant.

     14. AMENDMENT AND TERMINATION OF THE PLAN.

          (a) AMENDMENT AND TERMINATION. The Board may at any time amend, alter,
suspend or terminate the Plan.

          (b) EFFECT OF AMENDMENT OR TERMINATION. No amendment, alteration,
suspension or termination of the Plan shall impair the rights of any Optionee,
unless mutually agreed otherwise between the Optionee and the Administrator,
which agreement must be in writing and signed by the Optionee and the Company.
Termination of the Plan shall not affect the Administrator's ability to exercise
the powers granted to it hereunder with respect to options granted under the
Plan prior to the date of such termination.

     15. CONDITIONS UPON ISSUANCE OF SHARES.

          (a) LEGAL COMPLIANCE. Shares shall not be issued pursuant to the
exercise of an Option unless the exercise of such Option and the issuance and
delivery of such Shares shall comply

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with Applicable Laws and shall be further subject to the approval of counsel
for the Company with respect to such compliance.

          (b) INVESTMENT REPRESENTATIONS. As a condition to the exercise of an
Option the Company may require the person exercising such Option to represent
and warrant at the time of any such exercise that the Shares are being purchased
only for investment and without any present intention to sell or distribute such
Shares if, in the opinion of counsel for the Company, such a representation is
required.

     16. INABILITY TO OBTAIN AUTHORITY. The inability of the Company to obtain
authority from any regulatory body having jurisdiction, which authority is
deemed by the Company's counsel to be necessary to the lawful issuance and sale
of any Shares hereunder, shall relieve the Company of any liability in respect
of the failure to issue or sell such Shares as to which such requisite authority
shall not have been obtained.

     17. RESERVATION OF SHARES. The Company, during the term of this Plan, will
at all times reserve and keep available such number of Shares as shall be
sufficient to satisfy the requirements of the Plan.

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                                  ADAPTEC, INC.

                       2000 NONSTATUTORY STOCK OPTION PLAN

                             STOCK OPTION AGREEMENT

     Unless otherwise defined herein, the terms defined in the Plan shall
have the same defined meanings in this Option Agreement.

I.   NOTICE OF STOCK OPTION GRANT

     [OPTIONEE'S NAME AND ADDRESS]

     You have been granted an option to purchase Common Stock of the Company,
subject to the terms and conditions of the Plan and this Option Agreement, as
follows:

         Grant Number
                                              --------------------------------

         Date of Grant
                                              --------------------------------

         Vesting Commencement Date
                                              --------------------------------

         Exercise Price per Share             $
                                               -------------------------------

         Total Number of Shares Granted
                                              --------------------------------

         Total Exercise Price                 $
                                               -------------------------------

         Type of Option:                      Nonstatutory Stock Option

         Term/Expiration Date:
                                              --------------------------------

         VESTING SCHEDULE:

     Subject to the Optionee continuing to be a Service Provider on such dates,
this Option shall vest and become exercisable in accordance with the following
schedule:

     25% of the Shares subject to the Option shall vest six (6) months after
the Vesting Commencement Date, and 1/4 of the Shares subject to the Option
shall vest each 6-month thereafter on the same day of the month as the
Vesting Commencement Date.

         TERMINATION PERIOD:

     This Option may be exercised for three (3) months after Optionee ceases to
be a Service Provider. Upon the death or Disability of the Optionee, this Option
may be exercised for such longer

<PAGE>

period as provided in the Plan. In no event shall this Option be exercised
later than the Term/Expiration Date as provided above.

II.  AGREEMENT

     1. GRANT OF OPTION. The Plan Administrator of the Company hereby grants
to the Optionee named in the Notice of Grant attached as Part I of this
Agreement (the "Optionee") an option (the "Option") to purchase the number of
Shares, as set forth in the Notice of Grant, at the exercise price per share
set forth in the Notice of Grant (the "Exercise Price"), subject to the terms
and conditions of the Plan, which is incorporated herein by reference.
Subject to Section 14(b) of the Plan, in the event of a conflict between the
terms and conditions of the Plan and the terms and conditions of this Option
Agreement, the terms and conditions of the Plan shall prevail.

     2. EXERCISE OF OPTION.

          (a) RIGHT TO EXERCISE. This Option is exercisable during its term
in accordance with the Vesting Schedule set out in the Notice of Grant and
the applicable provisions of the Plan and this Option Agreement.

          (b) METHOD OF EXERCISE. This Option is exercisable by delivery of
an exercise notice, in the form attached as Exhibit A (the "Exercise
Notice"), which shall state the election to exercise the Option, the number
of Shares in respect of which the Option is being exercised (the "Exercised
Shares"), and such other representations and agreements as may be required by
the Company pursuant to the provisions of the Plan. The Exercise Notice shall
be completed by the Optionee and delivered to the Company's Stock Plan
Administrator. The Exercise Notice shall be accompanied by payment of the
aggregate Exercise Price as to all Exercised Shares. This Option shall be
deemed to be exercised upon receipt by the Company of such fully executed
Exercise Notice accompanied by such aggregate Exercise Price.

          No Shares shall be issued pursuant to the exercise of this Option
unless such issuance and exercise complies with Applicable Laws. Assuming such
compliance, for income tax purposes the Exercised Shares shall be considered
transferred to the Optionee on the date the Option is exercised with respect to
such Exercised Shares.

     3. METHOD OF PAYMENT. Payment of the aggregate Exercise Price shall be
by any of the following, or a combination thereof, at the election of the
Optionee:

          (a) cash;

          (b) check;

          (c) consideration received by the Company under a cashless exercise
program implemented by the Company in connection with the Plan; or

          (d) surrender of other Shares which (i) in the case of Shares acquired
upon exercise of an option, have been owned by the Optionee for more than six
(6) months on the date of

                                      -2-

<PAGE>

surrender, AND (ii) have a Fair Market Value on the date of surrender equal
to the aggregate Exercise Price of the Exercised Shares.

     4. NON-TRANSFERABILITY OF OPTION. This Option may not be transferred in any
manner otherwise than by will or by the laws of descent or distribution and may
be exercised during the lifetime of Optionee only by the Optionee. The terms of
the Plan and this Option Agreement shall be binding upon the executors,
administrators, heirs, successors and assigns of the Optionee.

     5. TERM OF OPTION. This Option may be exercised only within the term set
out in the Notice of Grant, and may be exercised during such term only in
accordance with the Plan and the terms of this Option Agreement.

     6. TAX CONSEQUENCES. Some of the federal tax consequences relating to
this Option, as of the date of this Option, are set forth below. THIS SUMMARY
IS NECESSARILY INCOMPLETE, AND THE TAX LAWS AND REGULATIONS ARE SUBJECT TO
CHANGE. THE OPTIONEE SHOULD CONSULT A TAX ADVISER BEFORE EXERCISING THIS
OPTION OR DISPOSING OF THE SHARES.

          (a) EXERCISING THE OPTION. The Optionee may incur regular federal
income tax liability upon exercise of an NSO. The Optionee will be treated as
having received compensation income (taxable at ordinary income tax rates)
equal to the excess, if any, of the Fair Market Value of the Exercised Shares
on the date of exercise over their aggregate Exercise Price. If the Optionee
is an Employee or a former Employee, the Company will be required to withhold
from his or her compensation or collect from Optionee and pay to the
applicable taxing authorities an amount in cash equal to a percentage of this
compensation income at the time of exercise, and may refuse to honor the
exercise and refuse to deliver Shares if such withholding amounts are not
delivered at the time of exercise.

          (b) DISPOSITION OF SHARES. If the Optionee holds NSO Shares for at
least one year, any gain realized on disposition of the Shares will be
treated as long-term capital gain for federal income tax purposes.

     7. ENTIRE AGREEMENT; GOVERNING LAW. The Plan is incorporated herein by
reference. The Plan and this Option Agreement constitute the entire agreement of
the parties with respect to the subject matter hereof and supersede in their
entirety all prior undertakings and agreements of the Company and Optionee with
respect to the subject matter hereof, and may not be modified adversely to the
Optionee's interest except by means of a writing signed by the Company and
Optionee. This agreement is governed by the internal substantive laws, but not
the choice of law rules, of California.

     8. NO GUARANTEE OF CONTINUED SERVICE. OPTIONEE ACKNOWLEDGES AND AGREES THAT
THE VESTING OF SHARES PURSUANT TO THE VESTING SCHEDULE HEREOF IS EARNED ONLY BY
CONTINUING AS A SERVICE PROVIDER AT THE WILL OF THE COMPANY (AND NOT THROUGH THE
ACT OF BEING HIRED, BEING GRANTED AN OPTION OR PURCHASING SHARES HEREUNDER).
OPTIONEE FURTHER ACKNOWLEDGES AND AGREES THAT THIS AGREEMENT, THE TRANSACTIONS

                                      -3-

<PAGE>

CONTEMPLATED HEREUNDER AND THE VESTING SCHEDULE SET FORTH HEREIN DO NOT
CONSTITUTE AN EXPRESS OR IMPLIED PROMISE OF CONTINUED ENGAGEMENT AS A SERVICE
PROVIDER FOR THE VESTING PERIOD, FOR ANY PERIOD, OR AT ALL, AND SHALL NOT
INTERFERE WITH OPTIONEE'S RIGHT OR THE COMPANY'S RIGHT TO TERMINATE OPTIONEE'S
RELATIONSHIP AS A SERVICE PROVIDER AT ANY TIME, WITH OR WITHOUT CAUSE.

     By your signature and the signature of the Company's representative below,
you and the Company agree that this Option is granted under and governed by the
terms and conditions of the Plan and this Option Agreement. Optionee has
reviewed the Plan and this Option Agreement in their entirety, has had an
opportunity to obtain the advice of counsel prior to executing this Option
Agreement and fully understands all provisions of the Plan and Option Agreement.
Optionee hereby agrees to accept as binding, conclusive and final all decisions
or interpretations of the Administrator upon any questions relating to the Plan
and Option Agreement. Optionee further agrees to notify the Company upon any
change in the residence address indicated below.

OPTIONEE                                ADAPTEC, INC.

----------------------------------      -------------------------------------
Signature                               By

----------------------------------      -------------------------------------
Print Name                              Title

----------------------------------
Residence Address

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

                                      -4-

<PAGE>

                                    EXHIBIT A

                                  ADAPTEC, INC.

                       2000 NONSTATUTORY STOCK OPTION PLAN

                                 EXERCISE NOTICE

Adaptec, Inc.
691 Milpitas Boulevard
Milpitas, CA  95035

Attention:  Stock Plan Administrator

     1. EXERCISE OF OPTION. Effective as of today, ________________, 20___, the
undersigned ("Purchaser") hereby elects to purchase ______________ shares (the
"Shares") of the Common Stock of Adaptec, Inc. (the "Company") under and
pursuant to the 2000 Nonstatutory Stock Option Plan (the "Plan") and the Stock
Option Agreement dated, _________, 20___ (the "Option Agreement"). The purchase
price for the Shares shall be $_______, as required by the Option Agreement.

     2. DELIVERY OF PAYMENT. Purchaser herewith delivers to the Company the
full purchase price for the Shares.

     3. REPRESENTATIONS OF PURCHASER. Purchaser acknowledges that Purchaser
has received, read and understood the Plan and the Option Agreement and
agrees to abide by and be bound by their terms and conditions.

     4. RIGHTS AS SHAREHOLDER. Until the issuance (as evidenced by the
appropriate entry on the books of the Company or of a duly authorized
transfer agent of the Company) of the Shares, no right to vote or receive
dividends or any other rights as a shareholder shall exist with respect to
the Optioned Stock, notwithstanding the exercise of the Option. The Shares so
acquired shall be issued to the Optionee as soon as practicable after
exercise of the Option. No adjustment will be made for a dividend or other
right for which the record date is prior to the date of issuance, except as
provided in Section 12 of the Plan.

     5. TAX CONSULTATION. Purchaser understands that Purchaser may suffer
adverse tax consequences as a result of Purchaser's purchase or disposition
of the Shares. Purchaser represents that Purchaser has consulted with any tax
consultants Purchaser deems advisable in connection with the purchase or
disposition of the Shares and that Purchaser is not relying on the Company
for any tax advice.

<PAGE>

     6. ENTIRE AGREEMENT; GOVERNING LAW. The Plan and Option Agreement are
incorporated herein by reference. This Agreement, the Plan and the Option
Agreement constitute the entire agreement of the parties with respect to the
subject matter hereof and supersede in their entirety all prior undertakings
and agreements of the Company and Purchaser with respect to the subject
matter hereof, and may not be modified adversely to the Purchaser's interest
except by means of a writing signed by the Company and Purchaser. This
agreement is governed by the internal substantive laws, but not the choice of
law rules, of California

Submitted by:                         Accepted by:

PURCHASER                             ADAPTEC, INC.

--------------------------------      -------------------------------------
Signature                             By

--------------------------------      -------------------------------------
Print Name                            Title

                                      -------------------------------------
                                      Date Received

ADDRESS:                              ADDRESS:   691 South Milpitas Boulevard
           ----------------------                Milpitas, CA  95035
           ---------------------

                                      -2-<PAGE>

                                                                     Exhibit 4.2

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

                             MACK-CALI REALTY, L.P.,

                                     ISSUER

                                       to

                            WILMINGTON TRUST COMPANY,

                                     TRUSTEE

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

                          Supplemental Indenture No. 3

                          Dated as of December 21, 2000

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

                                   $15,000,000
                                       of
                              7.835% Notes due 2010

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

<PAGE>

            SUPPLEMENTAL INDENTURE NO. 3, dated as of December 21, 2000 (the
"SUPPLEMENTAL INDENTURE"), between MACK-CALI REALTY, L.P., a limited partnership
duly organized and existing under the laws of the State of Delaware (herein
called the "ISSUER"), and WILMINGTON TRUST COMPANY, a Delaware banking
corporation duly organized and existing under the laws of the State of Delaware,
as Trustee (herein called the "TRUSTEE").

                             RECITALS OF THE ISSUER

            The Issuer and Mack-Cali Realty Corporation, a corporation duly
organized and existing under the laws of the State of Maryland (herein called
the "CORPORATION"), have heretofore delivered to the Trustee an Indenture dated
as of March 16, 1999 (the "ORIGINAL Indenture"), a form of which has been filed
with the Securities and Exchange Commission under the Securities Act of 1933, as
amended, as an exhibit to the Issuer's Registration Statement on Form S-3
(Registration No. 333-57103), providing for the issuance from time to time of
Debt Securities of the Issuer (the "SECURITIES").

            Section 301 of the Original Indenture provides for various matters
with respect to any series of Securities issued under the Original Indenture to
be established in an indenture supplemental to the Original Indenture.

            Section 901(7) of the Original Indenture provides for the Issuer and
the Trustee to enter into an indenture supplemental to the Original Indenture to
establish the form or terms of Securities of any series as provided by Sections
201 and 301 of the Original Indenture.

            The Board of Directors of the Corporation, the general partner of
the Issuer, has duly adopted resolutions authorizing the Issuer to execute and
deliver this Supplemental Indenture.

            All the conditions and requirements necessary to make this
Supplemental Indenture, when duly executed and delivered, a valid and binding
agreement in accordance with its terms and for the purposes herein expressed,
have been performed and fulfilled.

        NOW, THEREFORE, THIS SUPPLEMENTAL INDENTURE WITNESSETH:

            For and in consideration of the premises and the purchase of the
Securities provided for herein by the Holders thereof, it is mutually covenanted
and agreed, for the equal and proportionate benefit of all Holders of the Notes,
as follows:

<PAGE>

                                   ARTICLE ONE

                   RELATION TO ORIGINAL INDENTURE; DEFINITIONS

            Section 1.1  RELATION TO ORIGINAL INDENTURE.

            This Supplemental Indenture constitutes an integral part of the
Original Indenture.

            Section 1.2  DEFINITIONS.

            For all purposes of this Supplemental Indenture, except as otherwise
expressly provided for or unless the context otherwise requires:

            (1) Capitalized terms used but not defined herein shall have the
      respective meanings assigned to them in the Original Indenture; and

            (2) All references herein to Articles and Sections, unless otherwise
      specified, refer to the corresponding Articles and Sections of this
      Supplemental Indenture.

            "ACQUIRED INDEBTEDNESS" means Indebtedness of a Person (i) existing
at the time such Person becomes a Subsidiary or (ii) assumed in connection with
the acquisition of assets from such Person, in each case, other than
Indebtedness incurred in connection with, or in contemplation of, such Person
becoming a Subsidiary or such acquisition. Acquired Indebtedness shall be deemed
to be incurred on the date of the related acquisition of assets from any Person
or the date the acquired Person becomes a Subsidiary.

            "ANNUAL SERVICE CHARGE" for any period means the aggregate interest
expense for such period in respect of, and the amortization during such period
of any original issue discount of, Indebtedness of the Issuer and its
Subsidiaries.

            "BUSINESS DAY" means any day, other than a Saturday or Sunday, that
is neither a legal holiday nor a day on which banking institutions in the City
of New York or Delaware are authorized or required by law, regulation or
executive order to close.

            "CONSOLIDATED INCOME AVAILABLE FOR DEBT SERVICE" for any period
means Earnings from Operations of the Issuer and its Subsidiaries plus amounts
which have been deducted, and minus amounts which have been added, for the
following (without duplication): (i) interest on Indebtedness of the Issuer and
its Subsidiaries, (ii) provision for taxes of the Issuer and its Subsidiaries
based on income, (iii) amortization of debt discount and deferred financing
costs, (iv) provisions for gains and losses on properties and depreciation and
amortization, (v)

                                       2
<PAGE>

increases in deferred taxes and other non-cash items, (vi) depreciation and
amortization with respect to interests in joint venture and partially owned
entity investments, (vii) the effect of any charge resulting from a change in
accounting principles in determining Earnings from Operations for such period
and (viii) amortization of deferred charges.

            "CORPORATE TRUST OFFICE" means the office of the Trustee at which,
at any particular time, its corporate trust business shall be principally
administered, which office at the date hereof is located at Rodney Square North,
1100 North Market Street, Wilmington, Delaware 19890-0001, Attention: Corporate
Trust Administration and, for purposes of the Place of Payment provisions of
Sections 305 and 1002 of the Original Indenture, is located at Rodney Square
North, 1100 North Market Street, Wilmington, Delaware 19890-0001, Attention:
Corporate Trust Administration.

            "EARNINGS FROM OPERATIONS" for any period means net income excluding
provisions for gains and losses on sales of investments or joint ventures,
extraordinary and non-recurring items, and property valuation losses, as
reflected in the consolidated financial statements of the Issuer and its
Subsidiaries for such period determined in accordance with GAAP.

            "ENCUMBRANCE" means any mortgage, lien, charge, pledge or security
interest of any kind.

            "EXCHANGE ACT" means the Securities Exchange Act of 1934, as
amended, and the rules and regulations promulgated thereunder by the Commission.

            "GAAP" means generally accepted accounting principles as used in the
United States applied on a consistent basis as in effect from time to time;
provided that solely for purposes of any calculation required by the financial
covenants contained herein, "GAAP" shall mean generally accepted accounting
principles as used in the United States on the date hereof, applied on a
consistent basis.

            "INDEBTEDNESS" of the Issuer or any Subsidiary means, without
duplication, any indebtedness of the Issuer or any Subsidiary, whether or not
contingent, in respect of: (i) borrowed money evidenced by bonds, notes,
debentures or similar instruments whether or not such indebtedness is secured by
any Encumbrance existing on property owned by the Issuer or any Subsidiary, (ii)
indebtedness for borrowed money of a Person other than the Issuer or a
Subsidiary which is secured by any Encumbrance existing on property owned by the
Issuer or any Subsidiary, to the extent of the lesser of (x) the amount of
indebtedness so secured and (y) the fair market value of the property subject to
such Encumbrance, (iii) the reimbursement obligations, contingent or otherwise,
in connection with any letters of credit actually issued or amounts representing
the balance deferred and unpaid of the purchase price of any property or
services, except any such balance that

                                       3
<PAGE>

constitutes an accrued expense or trade payable, or (iv) any lease of property
by the Issuer or any Subsidiary as lessee which is reflected on the Issuer's
consolidated balance sheet as a capitalized lease in accordance with GAAP; and
also includes, to the extent not otherwise included, any obligation by the
Issuer or any Subsidiary to be liable for, or to pay, as obligor, guarantor or
otherwise (other than for purposes of collection in the ordinary course of
business), Indebtedness of another Person (other than the Issuer or any
Subsidiary; it being understood that Indebtedness shall be deemed to be incurred
by the Issuer or any Subsidiary whenever the Issuer or such Subsidiary shall
create, assume, guarantee or otherwise become liable in respect thereof;
Indebtedness of a Subsidiary of the Issuer existing prior to the time it became
a Subsidiary of the Issuer shall be deemed to be incurred upon such Subsidiary's
becoming a Subsidiary of the Issuer; and Indebtedness of a person existing prior
to a merger or consolidation of such person with the Issuer or any Subsidiary of
the Issuer in which such person is the successor to the Issuer or such
Subsidiary shall be deemed to be incurred upon the consummation of such merger
or consolidation; provided, however, the term "Indebtedness" shall not include
any such indebtedness that has been the subject of an "in substance" defeasance
in accordance with GAAP).

            "INTERCOMPANY INDEBTEDNESS" means Indebtedness to which the only
parties are the Issuer, the Corporation and any Subsidiary (but only so long as
such Indebtedness is held solely by any of the Issuer, the Corporation and any
Subsidiary) that is subordinate in right of payment to the Notes.

            "MAKE-WHOLE PREMIUM" means, in connection with any optional
redemption of any Notes, the excess, if any, of (i) the aggregate present value
as of the date of such redemption of each dollar of principal of such Notes
being redeemed and the amount of interest (exclusive of interest accrued to the
date of redemption) that would have been payable in respect of such dollar if
such redemption had not been made, determined by discounting, on a semi-annual
basis, such principal and interest at the Reinvestment Rate (determined on the
third Business Day preceding the date such notice of redemption is given) from
the respective dates on which such principal and interest would have been
payable if such redemption had not been made, over (ii) the aggregate principal
amount of such Notes being redeemed.

            "NOTES" has the meaning specified in Section 2.1 hereof.

            "REINVESTMENT RATE" means 0.25% (twenty-five one hundredths of one
percent) plus the arithmetic mean of the yields under the respective headings
"This Week" and "Last Week" published in the Statistical Release under the
caption "Treasury Constant Maturities" for the maturity (rounded to the nearest
month) corresponding to the remaining life to maturity of such Notes, as of the
payment date of the principal of such Notes being redeemed. If no maturity
exactly corresponds to such maturity, yields for the two published maturities
most closely corresponding to such maturity shall be calculated pursuant to the
immediately preceding sentence and the Reinvestment Rate shall be obtained by
linear interpolation, rounding in each of

                                       4
<PAGE>

such relevant periods to the nearest month. For such purposes of calculating the
Reinvestment Rate, the most recent Statistical Release published prior to the
date of determination of the Make-Whole Premium shall be used.

            "STATISTICAL RELEASE" means the statistical release designated
"H.15(519)" or any successor publication which is published weekly by the
Federal Reserve System and which establishes yields on actively traded United
States government securities adjusted to constant maturities or, if such
statistical release is not published at the time of any determination of the
Make-Whole Premium, then such other reasonably comparable index which shall be
designated by the Issuer.

            "SUBSIDIARY" means, with respect to any Person, any corporation or
other entity of which a majority of the voting power of the voting equity
securities or the outstanding equity interests of which are owned, directly or
indirectly, by such Person. For the purposes of this definition, "voting equity
securities" means equity securities having voting power for the election of
directors, whether at all times or only so long as no senior class of security
has such voting power by reason of any contingency.

            "TOTAL ASSETS" as of any date means the sum of (i) the Undepreciated
Real Estate Assets and (ii) all other assets of the Issuer and its Subsidiaries
determined in accordance with GAAP (but excluding accounts receivable and
intangibles).

            "TOTAL UNENCUMBERED ASSETS" means the sum of (i) those Undepreciated
Real Estate Assets not subject to an Encumbrance for borrowed money and (ii) all
other assets of the Issuer and its Subsidiaries not subject to an Encumbrance
for borrowed money, determined in accordance with GAAP (but excluding accounts
receivable and intangibles).

            "UNDEPRECIATED REAL ESTATE ASSETS" as of any date means the cost
(original cost plus capital improvements) of real estate assets of the Issuer
and its Subsidiaries on such date, before depreciation and amortization,
determined on a consolidated basis in accordance with GAAP.

            "UNSECURED INDEBTEDNESS" means Indebtedness which is not secured by
any Encumbrance upon any of the properties of the Issuer or any Subsidiary.

                                       5
<PAGE>

                                   ARTICLE TWO

                               THE SERIES OF NOTES

            Section 2.1 TITLE OF THE SECURITIES.

            There shall be a series of Securities designated the "7.835% Notes
due 2010" (the "NOTES").

            Section 2.2  LIMITATION ON AGGREGATE PRINCIPAL AMOUNT.

            The aggregate principal amount of the Notes shall be limited to
$15,000,000, and, except as provided in this Section and in Section 306 of the
Original Indenture, the Issuer shall not execute and the Trustee shall not
authenticate or deliver Notes in excess of such aggregate principal amount.

            Nothing contained in this Section 2.2 or elsewhere in this
Supplemental Indenture, or in the Notes, is intended to or shall limit execution
by the Issuer or authentication or delivery by the Trustee of Notes under the
circumstances contemplated by Sections 303, 304, 305, 306, 906, 1107 and 1305 of
the Original Indenture.

            Section 2.3  INTEREST AND INTEREST RATES; MATURITY DATE OF NOTES.

            The Notes will bear interest at a rate of 7.835% per annum from
December 21, 2000 or from the immediately preceding Interest Payment Date to
which interest has been paid or duly provided for, payable semi-annually in
arrears on June 15 and December 15 of each year, commencing on June 15, 2001
(each, an "INTEREST PAYMENT DATE"), to the Person in whose name such Note is
registered at the close of business on June 1 or December 1 (whether or not a
Business Day), as the case may be, next preceding such Interest Payment Date
(each, a "REGULAR RECORD Date"). Interest will be computed on the basis of a
360-day year comprised of twelve 30-day months. The interest so payable on any
Note which is not punctually paid or duly provided for on any Interest Payment
Date shall forthwith cease to be payable to the Person in whose name such Note
is registered on the relevant Regular Record Date, and such defaulted interest
shall instead be payable to the Person in whose name such Note is registered on
the Special Record Date or other specified date determined in accordance with
the Original Indenture.

            If any Interest Payment Date or Maturity falls on a day that is not
a Business Day, the required payment shall be made on the next Business Day as
if it were made on the date such payment was due and no interest shall accrue on
the amount so payable for the period from and after such Interest Payment Date
or Maturity, as the case may be.

            The Notes will mature on December 15, 2010.

                                       6
<PAGE>

            Section 2.4  LIMITATIONS ON INCURRENCE OF INDEBTEDNESS.

            (a) The Issuer will not, and will not permit any Subsidiary to,
incur any Indebtedness, other than Intercompany Indebtedness, if, immediately
after giving effect to the incurrence of such additional Indebtedness and the
application of the proceeds thereof, the aggregate principal amount of all
outstanding Indebtedness of the Issuer and its Subsidiaries on a consolidated
basis determined in accordance with GAAP is greater than 60% of the sum of
(without duplication) (i) the Total Assets of the Issuer and its Subsidiaries as
of the end of the calendar quarter covered in the Issuer's Annual Report on Form
10-K or Quarterly Report on Form 10-Q, as the case may be, most recently filed
with the Commission (or, if such filing is not permitted under the Exchange Act,
with the Trustee) prior to the incurrence of such additional Indebtedness and
(ii) the purchase price of any assets included in the definition of Total Assets
acquired, and the amount of any securities offering proceeds received (to the
extent such proceeds were not used to acquire items included in the definition
of Total Assets or used to reduce indebtedness), by the Issuer or any Subsidiary
since the end of such calendar quarter, including those proceeds obtained in
connection with the incurrence of such additional Indebtedness.

            (b) In addition to the limitation set forth in subsection (a) of
this Section 2.4, the Issuer will not, and will not permit any Subsidiary to,
incur any Indebtedness if the ratio of Consolidated Income Available for Debt
Service to the Annual Service Charge for the four consecutive fiscal quarters
most recently ended prior to the date on which such additional Indebtedness is
to be incurred shall have been less than 1.5:1, on a PRO FORMA basis after
giving effect thereto and to the application of the proceeds therefrom, and
calculated on the assumption that (i) such Indebtedness and any other
Indebtedness incurred by the Issuer and its Subsidiaries since the first day of
such four-quarter period and the application of the proceeds therefrom,
including to refinance other Indebtedness, had occurred at the beginning of such
period; (ii) the repayment or retirement of any other Indebtedness by the Issuer
and its Subsidiaries since the first day of such four-quarter period had been
repaid or retired at the beginning of such period (except that, in making such
computation, the amount of Indebtedness under any revolving credit facility
shall be computed based upon the average daily balance of such Indebtedness
during such period); (iii) in the case of Acquired Indebtedness or Indebtedness
incurred in connection with any acquisition since the first day of such
four-quarter period, the related acquisition had occurred as of the first day of
such period with the appropriate adjustments with respect to such acquisition
being included in such PRO FORMA calculation; and (iv) in the case of any
acquisition or disposition by the Issuer or its Subsidiaries of any asset or
group of assets since the first day of such four-quarter period, whether by
merger, stock purchase or sale, or asset purchase or sale, such acquisition or
disposition or any related repayment of Indebtedness had occurred as of the
first day of such period with the appropriate adjustments with respect to such
acquisition or disposition being included in such PRO FORMA calculation.

                                       7
<PAGE>

            (c) In addition to the limitations set forth in subsections (a) and
(b) of this Section 2.4, the Issuer will not, and will not permit any Subsidiary
to, incur any Indebtedness secured by any Encumbrance upon any of the property
of the Issuer or any Subsidiary, whether owned at the date of the Indenture or
thereafter acquired, if, immediately after giving effect to the incurrence of
such additional Indebtedness secured by an Encumbrance and the application of
the proceeds thereof, the aggregate principal amount of all outstanding
Indebtedness of the Issuer and its Subsidiaries on a consolidated basis which is
secured by any Encumbrance on property of the Issuer or any Subsidiary is
greater than 40% of the sum of (without duplication) (i) the Total Assets of the
Issuer and its Subsidiaries as of the end of the calendar quarter covered in the
Issuer's Annual Report on Form 10-K or Quarterly Report on Form 10-Q, as the
case may be, most recently filed with the Commission (or, if such filing is not
permitted under the Exchange Act, with the Trustee) prior to the incurrence of
such additional Indebtedness and (ii) the purchase price of any assets included
in the definition of Total Assets acquired, and the amount of any securities
offering proceeds received (to the extent such proceeds were not used to acquire
items included in the definition of Total Assets or used to reduce
Indebtedness), by the Issuer or any Subsidiary since the end of such calendar
quarter, including those proceeds obtained in connection with the incurrence of
such additional Indebtedness.

            (d) The Issuer and its Subsidiaries may not at any time own Total
Unencumbered Assets equal to less than 150% of the aggregate outstanding
principal amount of the Unsecured Indebtedness of the Issuer and its
Subsidiaries on a consolidated basis.

            (e) For purposes of this Section 2.4, Indebtedness shall be deemed
to be "incurred" by the Issuer or a Subsidiary whenever the Issuer or such
Subsidiary shall create, assume, guarantee or otherwise become liable in respect
thereof.

            Section 2.5  REDEMPTION.

            The Notes may be redeemed at any time at the option of the Issuer,
in whole or in part, at a redemption price equal to the sum of (i) the principal
amount of the Notes being redeemed plus accrued and unpaid interest thereon up
to but not including the Redemption Date and (ii) the Make-Whole Premium, if
any, with respect to such Notes (the "REDEMPTION PRICE").

            Section 2.6  PLACES OF PAYMENT.

            The Places of Payment where the Notes may be presented or
surrendered for payment, where the Notes may be surrendered for registration of
transfer or exchange and where notices and demands to and upon the Issuer in
respect of the Notes and the Original Indenture may be served shall be in
Wilmington, Delaware,

                                       8
<PAGE>

and the office or agency for such purpose shall initially be located at the
Corporate Trust Office.

            Section 2.7  METHOD OF PAYMENT.

            Payment of the principal of and interest on the Notes will be made
at the office or agency of the Issuer maintained for that purpose in Wilmington,
Delaware (which shall initially be an office or agency of the Trustee), in such
coin or currency of the United States of America as at the time of payment is
legal tender for payment of public and private debts; PROVIDED, HOWEVER, that at
the option of the Issuer, payments of principal and interest on the Notes (other
than payments of principal and interest due at Maturity) may be made (i) by
check mailed to the address of the Person entitled thereto as such address shall
appear in the Security Register or (ii) by wire transfer to an account
maintained by the Person entitled thereto located within the United States.

            Section 2.8  CURRENCY.

            Principal and interest on the Notes shall be payable in Dollars.

            Section 2.9  REGISTERED SECURITIES; GLOBAL FORM.

            The Notes shall be issuable and transferable in fully registered
form as Registered Securities, without coupons. The Notes shall each be issued
in the form of one or more permanent Global Securities. The depository for the
Notes shall be The Depository Trust Company ("DTC"). The Notes shall not be
issuable in definitive form except as provided in Section 305 of the Original
Indenture.

            Section 2.10  FORM OF NOTES.

            The Notes shall be substantially in the form attached as EXHIBIT A
hereto.

            Section 2.11  REGISTRAR AND PAYING AGENT.

            The Trustee shall initially serve as Security Registrar and Paying
Agent for the Notes.

            Section 2.12  DEFEASANCE.

             The provisions of Sections 1402 and 1403 of the Original Indenture,
together with the other provisions of Article Fourteen of the Original
Indenture, shall be applicable to the Notes. The provisions of Section 1403 of
the Original Indenture shall apply to the covenants set forth in Sections 2.4
and 2.15 of this Supplemental Indenture and to those covenants specified in
Section 1403 of the Original Indenture.

                                       9
<PAGE>

            Section 2.13  EVENTS OF DEFAULT

            The provisions of clause (5) of Section 501 of the Original
Indenture as applicable with respect to the Notes shall be deemed to be amended
and restated in their entirety to read as follows:

            (5) default under any bond, debenture, note, mortgage, indenture or
instrument under which there may be issued or by which there may be secured or
evidenced any indebtedness (other than non-recourse indebtedness) for money
borrowed by the Issuer (or by any Subsidiary, the repayment of which the Issuer
has guaranteed or for which the Issuer is directly responsible or liable as
obligor or guarantor), having an aggregate principal amount outstanding of at
least $10,000,000, whether such recourse indebtedness now exists or shall
hereafter be created, which default shall have resulted in such indebtedness
becoming or being declared due and payable prior to the date on which it would
otherwise have become due and payable, without such indebtedness having been
discharged, or such acceleration having been rescinded or annulled, within a
period of 10 days after there shall have been given written notice, by
registered or certified mail, to the Issuer by the Trustee or to the Issuer and
the Trustee by the Holders of at least a majority in principal amount of the
Outstanding Securities of that series specifying such default and requiring the
Issuer to cause such indebtedness to be discharged or cause such acceleration to
be rescinded or annulled and stating that such notice is a "Notice of Default"
hereunder; or

            Section  2.14  ACCELERATION OF MATURITY; RESCISSION AND ANNULMENT.

            The provisions of the first paragraph of Section 502 of the Original
Indenture as applicable with respect to the Notes shall be deemed to be amended
and restated in their entirety to read as follows:

            If an Event of Default with respect to Securities of any series at
the time Outstanding occurs and is continuing, then in every such case the
Trustee or the Holders of not less than a majority in principal amount of the
Outstanding Securities of that series may declare the principal (or, if any
Securities are Original Issue Discount Securities

                                       10
<PAGE>

or Indexed Securities, such portion of the principal as may be specified in the
terms thereof) of all the Securities of that series to be due and payable
immediately, by a notice in writing to the Issuer (and to the Trustee if given
by the Holders), and upon any such declaration such principal or specified
portion thereof shall become immediately due and payable. If an Event of Default
with respect to the Securities of any series set forth in Section 501(6) or (7)
of the Original Indenture occurs and is continuing, then in every such case all
the Securities of that series shall become immediately due and payable, without
notice to the Issuer, at the principal amount thereof (or, if any Securities are
Original Issue Discount Securities or Indexed Securities, such portion of the
principal as may be specified in the terms thereof) plus accrued interest to the
date the Securities of that series are paid plus the Make-Whole Premium, if any,
on the Securities of that series.

            Section 2.15  PROVISION OF FINANCIAL INFORMATION.

            Whether or not the Issuer is subject to Section 13 or 15(d) of the
Exchange Act, the Issuer will, to the extent permitted under the Exchange Act,
file with the Commission the annual reports, quarterly reports and other
documents which the Issuer would have been required to file with the Commission
pursuant to such Section 13 or 15(d) if the Issuer were so subject, such
documents to be filed with the Commission on or prior to the respective dates
(the "Required Filing Dates") by which the Issuer would have been required so to
file such documents if the Issuer were so subject.

            The Issuer will also in any event (x) within 15 days of each
Required Filing Date (i) if the Issuer is not then subject to Section 13 or
15(d) of the Exchange Act, transmit by mail to all Holders, as their names and
addresses appear in the Security Register, without cost to such Holders, copies
of the annual reports and quarterly reports which the Issuer would have been
required to file with the Commission pursuant to Section 13 or 15(d) of the
Exchange Act if the Issuer were subject to such Sections, and (ii) file with the
Trustee copies of annual reports, quarterly reports and other documents which
the Issuer would have been required to file with the Commission pursuant to
Section 13 or 15(d) of the Exchange Act if the Issuer were subject to such
Sections and (y) if filing such documents by the Issuer with the Commission is
not permitted under the Exchange Act, promptly upon written request and payment
of the reasonable cost of duplication and delivery, supply copies of such
documents to any prospective Holder.

            Section 2.16  WAIVER OF CERTAIN COVENANTS.

            Notwithstanding the provisions of Section 1010 of the Original
Indenture, the Issuer may omit in any particular instance to comply with any
term, provision or condition set forth in the Original Indenture and in this
Supplemental Indenture and with any other term, provision or condition with
respect to the Notes (except any such term, provision or condition which could
not be amended without the consent of all Holders of the Notes), if before or
after the time for such compliance the Holders of at least a majority in
principal amount of all Outstanding Notes by Act of such Holders, either waive
such compliance in such instance or generally waive compliance with such
covenant or condition. Except to the extent so expressly waived, and until such
waiver shall become effective, the obligations of the Issuer and the duties of
the Trustee in respect of any such term, provision or condition shall remain in
full force and effect.

                                       11
<PAGE>

            Section 2.17  NO GUARANTY BY THE CORPORATION.

            The Guarantee set forth in Article Sixteen of the Original Indenture
shall not be in effect with respect to the Notes.

                                  ARTICLE THREE

                            MISCELLANEOUS PROVISIONS

            SECTION 3.1.  RATIFICATION OF ORIGINAL INDENTURE.

            Except as expressly modified or amended hereby, the Original
Indenture continues in full force and effect and is in all respects confirmed
and preserved.

            SECTION 3.2.  GOVERNING LAW.

            This Supplemental Indenture and each Note shall be governed by and
construed in accordance with the laws of the State of New York. This
Supplemental Indenture is subject to the provisions of the Trust Indenture Act
of 1939, as amended, and shall, to the extent applicable, be governed by such
provisions.

            SECTION 3.3.  COUNTERPARTS.

            This Supplemental Indenture may be executed in any number of
counterparts, each of which so executed shall be deemed to be an original, but
all such counterparts shall together constitute but one and the same instrument.

            SECTION 3.4.  CERTAIN RIGHTS OF TRUSTEE.

            Except as otherwise expressly provided herein, no duties,
responsibilities or liabilities are assumed, or shall be construed to be
assumed, by the Trustee by reason of this Supplemental Indenture. This
Supplemental Indenture is executed and accepted by the Trustee subject to all
the terms and conditions set forth in the Original Indenture with the same force
and effect as if those terms and conditions were repeated at length herein and
made applicable to the Trustee with respect hereto.

            SECTION 3.5.  TRUSTEE NOT RESPONSIBLE.

            The Trustee shall not be responsible in any manner for or in respect
of the validity or sufficiency of this Supplemental Indenture.

                                       12
<PAGE>

            IN WITNESS WHEREOF, the parties hereto have caused this Supplemental
Indenture to be duly executed by their respective officers hereunto duly
authorized, all as of the day and year first written above.

                                   MACK-CALI REALTY, L.P.

                                   By:  Mack-Cali Realty Corporation, its
                                        General Partner

                                   By: /s/ Roger W. Thomas
                                       --------------------------
                                       Name: Roger W. Thomas
                                       Title: Executive Vice President
                                              and General Counsel

Attest: /s/ Daniel J. Wagner
        --------------------
Name: Daniel J. Wagner
Title: Assistant Secretary

                                    WILMINGTON TRUST COMPANY,
                                    as Trustee

                                     By: /s/ James D. Nesci
                                        ---------------------------
                                         Name: James D. Nesci
                                         Title: Authorized Signer

                                       13
<PAGE>

                                                          EXHIBIT A TO
                                                          SUPPLEMENTAL INDENTURE

UNLESS THIS SECURITY IS PRESENTED BY AN AUTHORIZED REPRESENTATIVE OF THE
DEPOSITORY TRUST COMPANY, A NEW YORK CORPORATION ("DTC"), 55 WATER STREET, NEW
YORK, NEW YORK, TO THE ISSUER (AS DEFINED BELOW) OR ITS AGENT FOR REGISTRATION
OF TRANSFER, EXCHANGE OR PAYMENT, AND ANY CERTIFICATE ISSUED IS REGISTERED IN
THE NAME OF CEDE & CO. OR IN SUCH OTHER NAME AS IS REQUESTED BY AN AUTHORIZED
REPRESENTATIVE OF DTC (AND ANY PAYMENT IS MADE TO CEDE & CO. OR TO SUCH OTHER
ENTITY AS IS REQUESTED BY AN AUTHORIZED REPRESENTATIVE OF DTC), ANY TRANSFER,
PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS
WRONGFUL INASMUCH AS THE REGISTERED OWNER HEREOF, CEDE & CO., HAS AN INTEREST
HEREIN.

THIS SECURITY IS A GLOBAL SECURITY WITHIN THE MEANING SET FORTH IN THE INDENTURE
HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF DTC OR A NOMINEE OF
DTC. THIS SECURITY IS EXCHANGEABLE FOR SECURITIES REGISTERED IN THE NAME OF A
PERSON OTHER THAN DTC OR ITS NOMINEE ONLY IN THE LIMITED CIRCUMSTANCES DESCRIBED
IN THE INDENTURE, AND MAY NOT BE TRANSFERRED EXCEPT AS A WHOLE BY DTC TO A
NOMINEE OF DTC OR ANOTHER NOMINEE OF DTC OR BY DTC OR ITS NOMINEE TO A SUCCESSOR
DEPOSITORY OR ITS NOMINEE.

Registered No. 1                                PRINCIPAL AMOUNT
CUSIP No.: 55448Q AD 8                          $15,000,000

                        MACK-CALI REALTY, L.P.

                         7.835% NOTE DUE 2010

            MACK-CALI REALTY, L.P., a limited partnership duly organized and
existing under the laws of the State of Delaware (herein referred to as the
"ISSUER" which term shall include any Successor Person under the Indenture
hereinafter referred to), for value received, hereby promises to pay to CEDE &
CO., or registered assigns, upon presentation, the principal sum of 15,000,000
DOLLARS on December 15, 2010, and to pay interest on the outstanding principal
amount thereon from December 21, 2000, or from the immediately preceding
Interest Payment Date to which interest has been paid or duly provided for,
semi-annually in arrears on June 15 and December 15 in each year, commencing
June 15, 2001, at the rate of 7.835% per annum, until the entire principal
hereof is paid or made available for payment. The interest so payable and
punctually paid or duly provided for on any Interest Payment Date will, as
provided in the Indenture, be paid to the Person in whose name this Security is
registered at the close of business on the Regular Record Date for such interest
which shall be the June 1 or December 1 (whether or not a Business Day), as the
case may be, next preceding such Interest Payment Date. Any such interest not so

                                       A-1
<PAGE>

punctually paid or duly provided for shall forthwith cease to be payable to the
Holder on such Regular Record Date, and may either be paid to the Person in
whose name this Security is registered at the close of business on a Special
Record Date for the payment of such Defaulted Interest to be fixed by the
Trustee, notice whereof shall be given to Holders of the Securities not more
than 15 days and not less than 10 days prior to such Special Record Date, or may
be paid at any time in any other lawful manner not inconsistent with the
requirements of any securities exchange on which the Securities may be listed,
and upon such notice as may be required by such exchange, all as more fully
provided in the Indenture. Payment of the principal of and interest on this
Security will be made at the office or agency maintained for that purpose in the
City of Wilmington, Delaware or elsewhere as provided in the Indenture, in such
coin or currency of the United States of America as at the time of payment is
legal tender for payment of public and private debts; PROVIDED, HOWEVER, that at
the option of the Issuer payments of principal and interest on the Notes (other
than payments of principal and interest due at Maturity) may be made (i) by
check mailed to the address of the Person entitled thereto as such address shall
appear in the Security Register or (ii) by wire transfer to an account of the
Person entitled thereto located within the United States.

            Securities of this series are one of a duly authorized issue of
securities of the Issuer (herein called the "SECURITIES"), issued and to be
issued in one or more series under an Indenture, dated as of March 16, 1999,
among the Issuer, Mack-Cali Realty Corporation and Wilmington Trust Company,
(herein called the "TRUSTEE", which term includes any successor trustee under
the Indenture), as supplemented by Supplemental Indenture No. 1, dated as of
March 16, 1999, as further supplemented by Supplemental Indenture No. 2, dated
as of August 2, 1999, and as further supplemented by Supplemental Indenture No.
3, dated as of December 21, 2000 (as so supplemented, herein called the
"INDENTURE"), between the Issuer and the Trustee to which Indenture and all
indentures supplemental thereto reference is hereby made for a statement of the
respective rights, limitations of rights, duties and immunities thereunder of
the Issuer, the Trustee and the Holders of the Securities and of the terms upon
which the Securities are authenticated and delivered. This Security is one of
the series designated in the first page thereof, limited in aggregate principal
amount to $15,000,000.

            Securities of this series may be redeemed at any time at the option
of the Issuer, in whole or in part, upon notice of not more than 60 nor less
than 30 days prior to the Redemption Date, at a redemption price equal to the
sum of (i) the principal amount of the Securities being redeemed plus accrued
and unpaid interest thereon up to but not including the Redemption Date and (ii)
the Make-Whole Premium, if any, with respect to such Securities.

            The Indenture contains provisions for defeasance at any time of (a)
the entire indebtedness of the Issuer on this Security and (b) certain
restrictive covenants and the related defaults and Events of Default applicable
to the Issuer, in each case,

                                      A-2
<PAGE>

upon compliance by the Issuer with certain conditions set forth in the
Indenture, which provisions apply to this Security.

            If an Event of Default with respect to the Securities shall occur
and be continuing, the principal of the Securities may be declared due and
payable in the manner and with the effect provided in the Indenture.

            As provided in and subject to the provisions of the Indenture, the
Holder of this Security shall not have the right to institute any proceeding
with respect to the Indenture or for the appointment of a receiver or trustee or
for any other remedy thereunder, unless such Holder shall have previously given
written notice to the Trustee of a continuing Event of Default with respect to
the Securities, the Holders of not less than a majority in principal amount of
the Securities of this series at the time Outstanding shall have made written
request to the Trustee to institute proceedings in respect of such Event of
Default as Trustee and offered the Trustee reasonable indemnity and the Trustee
shall not have received from the Holders of a majority in principal amount of
Securities of this series at the time Outstanding a direction inconsistent with
such request, and shall have failed to institute any such proceeding, for 60
days after receipt of such notice, request and offer of indemnity. The foregoing
shall not apply to any suit instituted by the Holder of this Security for the
enforcement of any payment of principal hereof or any interest on or after the
respective due dates expressed herein.

            The Indenture permits, with certain exceptions as therein provided,
the amendment thereof and the modification of the rights and obligations of the
Issuer and the rights of the Holders of the Securities of each series to be
affected under the Indenture at any time by the Issuer and the Trustee with the
consent of the Holders of not less than a majority in principal amount of the
Outstanding Securities of each series of Securities then Outstanding affected
thereby. The Indenture also contains provisions permitting the Holders of
specified percentages in principal amount of the Securities of each series at
the time Outstanding, on behalf of the Holders of all Securities of such series,
to waive compliance by the Issuer with certain provisions of the Indenture and
certain past defaults under the Indenture and their consequences. Any such
consent or waiver by the Holder of this Security shall be conclusive and binding
upon such Holder and upon all future Holders of this Security and of any
Security issued upon the registration of transfer hereof or in exchange herefor
or in lieu hereof, whether or not notation of such consent or waiver is made
upon this Security.

            No reference herein to the Indenture and no provision of this
Security or of the Indenture shall alter or impair the obligation of the Issuer,
which is absolute and unconditional, to pay the principal of (and Make-Whole
Premium, if any) and interest on this Security at the times, place and rate, and
in the coin or currency, herein prescribed.

                                      A-3
<PAGE>

            As provided in the Indenture and subject to certain limitations
therein set forth, the transfer of this Security is registrable in the Security
Register, upon surrender of this Security for registration of transfer at the
office or agency of the Issuer in any Place of Payment where the principal of
(and Make-Whole Premium, if any) and interest on this Security are payable, duly
endorsed by, or accompanied by a written instrument of transfer in form
satisfactory to the Issuer and the Security Registrar duly executed by the
Holder hereof or his attorney duly authorized in writing, and thereupon one or
more new Securities of this series, of authorized denominations and for the same
aggregate principal amount, will be issued to the designated transferee or
transferees.

            Except as set forth in Section 302 of the Indenture, the Securities
of this series are issuable only in registered form without coupons in
denominations of $1,000 and any integral multiple thereof. As provided in the
Indenture and subject to certain limitations therein set forth, Securities of
this series are exchangeable for a like aggregate principal amount of Securities
of this series of a different authorized denomination, as requested by the
Holder surrendering the same.

            No service charge shall be made for any such registration of
transfer or exchange, but the Issuer may require payment of a sum sufficient to
cover any tax or other governmental charge payable in connection therewith.

            Prior to due presentment of this Security for registration of
transfer, the Issuer, the Trustee and any agent of the Issuer or the Trustee may
treat the Person in whose name this Security is registered as the owner hereof
for all purposes, whether or not this Security be overdue, and neither the
Issuer, the Trustee nor any such agent shall be affected by notice to the
contrary.

            No recourse under or upon any obligation, covenant or agreement
contained in the Indenture or in this Security, or because of any indebtedness
evidenced hereby or thereby, shall be had against any promoter, as such, or
against any past, present or future shareholder, officer or director, as such,
of the Issuer or of any successor, either directly or through the Issuer or any
successor, under any rule of law, statute or constitutional provision or by the
enforcement of any assessment or by any legal or equitable proceeding or
otherwise, all such liability being expressly waived and released by the
acceptance of this Security by the Holder thereof and as part of the
consideration for the issue of the Securities of this series.

            All capitalized terms used in this Security which are defined in the
Indenture shall have the meanings assigned to them in the Indenture.

            THE INDENTURE AND THE SECURITIES, INCLUDING THIS SECURITY, SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

                                      A-4
<PAGE>

            Pursuant to a recommendation promulgated by the Committee on Uniform
Security Identification Procedures, the Issuer has caused "CUSIP" numbers to be
printed on the Securities of this series as a convenience to the Holders of such
Securities. No representation is made as to the correctness or accuracy of such
CUSIP numbers as printed on the Securities, and reliance may be placed only on
the other identification numbers printed hereon.

            Unless the certificate of authentication hereon has been executed by
or on behalf of the Trustee by manual signature, this Security shall not be
entitled to any benefit under the Indenture or be valid or obligatory for any
purpose.

      [REMAINDER OF PAGE INTENTIONALLY BLANK; SIGNATURE PAGE FOLLOWS]

                                      A-5
<PAGE>

            IN WITNESS WHEREOF, MACK-CALI REALTY, L.P. has caused this
instrument to be duly executed.

Dated: December 21, 2000

                                    MACK-CALI REALTY, L.P.

                                    By:  Mack-Cali Realty Corporation, its
                                         General Partner

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

Name:
Title:

TRUSTEE'S CERTIFICATE OF AUTHENTICATION:

            This is one of the Securities of the series designated therein
referred to in the within-mentioned Indenture.

                                    WILMINGTON TRUST COMPANY,
                                       as Trustee

                                       By:
                                          --------------------------------------
                                          Authorized Signatory

                                      A-6
<PAGE>

================================================================================

                                 ASSIGNMENT FORM

                   FOR VALUE RECEIVED, the undersigned hereby
                        sells, assigns and transfers unto

  PLEASE INSERT SOCIAL
  SECURITY OR OTHER IDENTIFYING
  NUMBER OF ASSIGNEE
------------------------------------
                                     ................................
------------------------------------

 .....................................................................
         (Please Print or Typewrite Name and Address including
                         Zip Code of Assignee)

 .....................................................................
the within Security of Mack-Cali Realty, L.P. and hereby does irrevocably
constitute and appoint

 ............................................................ Attorney
to transfer said Security on the books of the within-named Issuer with
full power of substitution in the premises.

Dated:  ..............  .............................................

                        .............................................

NOTICE: The signature to this assignment must correspond with the name as it
appears on the first page of the within Security in every particular, without
alteration or enlargement or any change whatever.

                        Signature(s) must be guaranteed by an institution which
                        is a member of one of the following recognized signature
                        Guarantee Programs: (i) The Securities Transfer Agent
                        Medallion Program (STAMP); (ii) The New York Stock
                        Exchange Medallion Program (MNSP); (iii) The Stock
                        Exchange Medallion Program (SEMP); or (iv) another
                        guarantee program acceptable to the Trustee.

                              -------------------------------
                               Signature Guarantee

================================================================================

                                      A-7

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