<PAGE>   1

                                                                     EXHIBIT 4.1


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


                             INTERPHASE CORPORATION

                                       and

                      COMPUTERSHARE INVESTOR SERVICES, LLC

                                  Rights Agent


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

                                RIGHTS AGREEMENT

                          Dated as of December 7, 2000


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


<PAGE>   2

                                TABLE OF CONTENTS


<TABLE>
<CAPTION>
SECTION                                                                                                        PAGE
-------                                                                                                        ----
<S>               <C>                                                                                          <C>
Section 1.        Certain Definitions.............................................................................1

Section 2.        Appointment of Rights Agent.....................................................................4

Section 3.        Issue of Rights Certificates....................................................................4

Section 4.        Form of Rights Certificates.....................................................................5

Section 5.        Countersignature and Registration...............................................................6

Section 6.        Transfer, Split Up, Combination and Exchange of Rights Certificates; Mutilated,
                  Destroyed, Lost or Stolen Rights Certificates...................................................7

Section 7.        Exercise of Rights; Purchase Price; Expiration Date of Rights...................................8

Section 8.        Cancellation and Destruction of Rights Certificates............................................10

Section 9.        Reservation and Availability of Common Stock...................................................10

Section 10.       Common Stock Record Date.......................................................................11

Section 11.       Adjustment of Purchase Price; Number and Kind of Shares or Number of Rights....................12

Section 12.       Certificate of Adjusted Purchase Price or Number of Shares.....................................19

Section 13.       Consolidation, Merger or Sale or Transfer of Assets or Earning Power...........................19

Section 14.       Fractional Rights and Fractional Shares........................................................22

Section 15.       Rights of Action...............................................................................23

Section 16.       Agreement of Rights Holders....................................................................24

Section 17.       Rights Certificate Holder Not Deemed a Stockholder.............................................24

Section 18.       Concerning the Rights Agent....................................................................25
</TABLE>



                                       -i-
<PAGE>   3

<TABLE>
<S>               <C>                                                                                          <C>
Section 19.       Merger or Consolidation or Change of Name of Rights Agent......................................25

Section 20.       Duties of Rights Agent.........................................................................26

Section 21.       Change of Rights Agent.........................................................................28

Section 22.       Issuance of New Rights Certificates............................................................29

Section 23.       Redemption and Termination.....................................................................29

Section 24.       Notice of Certain Events.......................................................................30

Section 25.       Notices........................................................................................30

Section 26.       Supplements and Amendments.....................................................................31

Section 27.       Successors.....................................................................................32

Section 28.       Determinations and Actions by the Board of Directors, etc......................................32

Section 29.       Benefits of this Agreement.....................................................................32

Section 30.       Severability...................................................................................33

Section 31.       Governing Law..................................................................................33

Section 32.       Counterparts...................................................................................33

Section 33.       Descriptive Headings...........................................................................33

Exhibit A         Form of Rights Certificate
</TABLE>



                                      -ii-
<PAGE>   4

                                RIGHTS AGREEMENT


         RIGHTS AGREEMENT, dated as of December 7, 2000 (the Agreement), between
Interphase Corporation, a Texas corporation (the Company), and Computershare
Investor Services, LLC, a limited liability company organized under the laws of
the State of Delaware (the Rights Agent).

                                   WITNESSETH:

         WHEREAS, on December 7, 2000, the Board of Directors of the Company
(the Board of Directors) authorized the distribution of one Right for each share
of Common Stock of the Company outstanding at the close of business on December
29, 2000 (the Record Date), each Right initially representing the right to
purchase one share of Common Stock of the Company upon the terms and subject to
the conditions hereinafter set forth (the Rights). At that time, the Board of
Directors further authorized and directed the issuance of one Right (subject to
adjustment as provided herein) with respect to each share of Common Stock of the
Company that becomes outstanding between the Record Date and the Distribution
Date (as hereinafter defined);

         NOW, THEREFORE, in consideration of the premises and the mutual
agreements herein set forth, the parties hereby agree as follows:

         Section 1. Certain Definitions. For purposes of this Agreement, the
following terms have the meanings indicated:

                  (a) Acquiring Person shall mean any Person who or which,
together with all Affiliates and Associates of such Person, shall be the
Beneficial Owner of 15% or more of the shares of Common Stock then outstanding,
but shall not include (i) the Company, (ii) any Subsidiary of the Company, (iii)
any employee benefit plan of the Company or of any Subsidiary of the Company, or
any Person or entity organized, appointed or established by the Company for or
pursuant to the terms of any such plan, or (iv) any Person who becomes an
Acquiring Person solely as a result of a reduction in the number of shares of
Common Stock outstanding due to the repurchase of shares of Common Stock by the
Company, unless and until such Person shall purchase or otherwise become the
Beneficial Owner of additional shares of Common Stock constituting 1% or more of
the then outstanding shares of Common Stock. Notwithstanding the foregoing, if
the Board of Directors determines in good faith that a Person who would
otherwise be an Acquiring Person has become such inadvertently, and such Person
divests as promptly as practicable a sufficient number of shares of Common Stock
so that such Person would no longer be an Acquiring Person, then such Person
shall not be deemed to be an Acquiring Person for any purposes of this
Agreement.

                  (b) Affiliate and Associate shall have the respective meanings
ascribed to such terms in Rule 12b-2 of the General Rules and Regulations under
the Securities Exchange Act of 1934, as amended and in effect on the date of
this Agreement (the Exchange Act).



<PAGE>   5

                  (c) A Person shall be deemed the Beneficial Owner of, and
shall be deemed to beneficially own, any securities:

                           (i) which such Person or any of such Person's
         Affiliates or Associates, directly or indirectly, has the right to
         acquire (whether such right is exercisable immediately or only after
         the passage of time) pursuant to any agreement, arrangement or
         understanding (whether or not in writing) or upon the exercise of
         conversion rights, exchange rights, rights, warrants or options, or
         otherwise; provided, however, that a Person shall not be deemed the
         Beneficial Owner of, or to beneficially own, (A) securities tendered
         pursuant to a tender or exchange offer made by such Person or any of
         such Person's Affiliates or Associates until such tendered securities
         are accepted for purchase or exchange, or (B) securities issuable upon
         exercise of Rights at any time prior to the occurrence of a Triggering
         Event, or (C) securities issuable upon exercise of Rights from and
         after the occurrence of a Triggering Event, which Rights were acquired
         by such Person or any of such Person's Affiliates or Associates prior
         to the Distribution Date (as defined hereinafter) or pursuant to
         Section 3(a) or Section 22 hereof (the Original Rights) or pursuant to
         Section 11(i) hereof in connection with an adjustment made with respect
         to any Original Rights;

                           (ii) which such Person or any of such Person's
         Affiliates or Associates, directly or indirectly, has the right to vote
         or dispose of or has beneficial ownership of (as determined pursuant to
         Rule 13d-3 of the General Rules and Regulations under the Exchange
         Act), including pursuant to any agreement, arrangement or
         understanding, whether or not in writing; provided, however, that a
         Person shall not be deemed the Beneficial Owner of, or to beneficially
         own, any security under this subparagraph (ii) as a result of an
         agreement, arrangement or understanding to vote such security if such
         agreement, arrangement or understanding: (A) arises solely from a
         revocable proxy or consent given in response to a public proxy or
         consent solicitation made pursuant to, and in accordance with, the
         applicable provisions of the General Rules and Regulations under the
         Exchange Act, and (B) is not also then reportable by such Person on
         Schedule 13D under the Exchange Act (or any comparable or successor
         report); or

                           (iii) which are beneficially owned, directly or
         indirectly, by any other Person (or any Affiliate or Associate thereof)
         with which such Person (or any of such Person's Affiliates or
         Associates) has any agreement, arrangement or understanding (whether or
         not in writing), for the purpose of acquiring, holding, voting (except
         pursuant to a revocable proxy as described in the proviso to
         subparagraph (ii) of this paragraph (c)) or disposing of any voting
         securities of the Company;



                                      -2-
<PAGE>   6

         provided, however, that nothing in this paragraph (c) shall cause a
         Person engaged in the business as an underwriter of securities to be
         deemed the Beneficial Owner of, or to beneficially own, any securities
         acquired through such Person's participation in good faith in a firm
         commitment underwriting until the expiration of forty (40) days after
         the date of such acquisition.

                  (d) Business Day shall mean any day other than a Saturday,
Sunday or a day on which banking institutions in the State of New York are
authorized or obligated by law or executive order to close.

                  (e) Close of Business on any given date shall mean 5:00 p.m.,
New York time, on such date; provided, however, that if such date is not a
Business Day it shall mean 5:00 p.m., New York time, on the next succeeding
Business Day.

                  (f) Common Stock shall mean, when used with reference to the
Company, the Common Stock, par value $0.10 per share, of the Company, and Common
Stock, when used with reference to any Person other than the Company, shall mean
the capital stock of such Person with the greatest voting power, or the equity
securities or other equity interest having power to control or direct the
management, of such Person.

                  (g) Person shall mean any individual, firm, corporation,
limited liability company, partnership or other entity, and shall include any
successor (by merger or otherwise) of such entity.

                  (h) Section 11(a)(ii) Event shall mean the event described in
Section 11(a)(ii) hereof.

                  (i) Section 13 Event shall mean any event described in clauses
(x), (y) or (z) of Section 13(a) hereof.

                  (j) Stock Acquisition Date shall mean the first date of public
announcement (which, for purposes of this definition, shall include, without
limitation, a report filed pursuant to Section 13(d) under the Exchange Act) by
the Company or an Acquiring Person that an Acquiring Person has become such.

                  (k) Subsidiary shall mean, with reference to any Person, any
Person of which an amount of voting securities sufficient to elect at least a
majority of the directors (or individuals exercising similar functions for
Persons other than corporations) of such Person is beneficially owned, directly
or indirectly, by such Person, or otherwise controlled by such Person.

                  (l) Triggering Event shall mean the Section 11(a)(ii) Event or
any Section 13 Event.



                                      -3-
<PAGE>   7

         Section 2. Appointment of Rights Agent. The Company hereby appoints the
Rights Agent to act as agent for the Company in accordance with the terms and
conditions hereof, and the Rights Agent hereby accepts such appointment. The
Company may from time to time appoint such Co-Rights Agents as it may deem
necessary or desirable. The Rights Agent shall have no duty to supervise, and in
no event shall be liable for, the acts or omissions of any such Co-Rights Agent.

         Section 3. Issue of Rights Certificates.

                  (a) Until the earlier of (i) the Close of Business on the
tenth Business Day after the Stock Acquisition Date or (ii) the Close of
Business on the tenth Business Day (or such later date as the Board of Directors
shall determine) after the date that a tender or exchange offer by any Person
(other than the Company, any Subsidiary of the Company, any employee benefit
plan of the Company or of any Subsidiary of the Company, or any Person or entity
organized, appointed or established by the Company for or pursuant to the terms
of any such plan) is first published or sent or given within the meaning of Rule
14d-2 of the General Rules and Regulations under the Exchange Act, if upon
consummation thereof, such Person would be the Beneficial Owner of 15% or more
of the shares of Common Stock then outstanding (the earlier of (i) and (ii)
being herein referred to as the Distribution Date), (x) the Rights will be
evidenced (subject to the provisions of paragraph (b) of this Section 3) by the
certificates for the Common Stock registered in the names of the holders of the
Common Stock (which certificates for Common Stock shall be deemed also to be
certificates for Rights) and not by separate certificates, and (y) the Rights
will be transferable only in connection with the transfer of the underlying
shares of Common Stock (including a transfer to the Company). As soon as
practicable after the Distribution Date, the Rights Agent, upon receipt of all
necessary information, will send by first-class, postage prepaid mail, to each
record holder of the Common Stock as of the Close of Business on the
Distribution Date, at the address of such holder shown on the records of the
Company, one or more right certificates, in substantially the form of Exhibit A
hereto (the Rights Certificates), evidencing one Right for each share of Common
Stock so held, subject to adjustment as provided herein. If an adjustment in the
number of Rights per share of Common Stock has been made pursuant to Section
11(p) hereof, at the time of distribution of the Rights Certificates, the
Company shall make the necessary and appropriate rounding adjustments (in
accordance with Section 14(a) hereof) so that Rights Certificates representing
only whole numbers of Rights are distributed and cash is paid in lieu of any
fractional Rights. As of and after the Distribution Date, the Rights will be
evidenced solely by such Rights Certificates.

                  (b) On the Record Date, or as soon as practicable thereafter,
the Company will send a copy of a summary of the Rights (the Summary of Rights),
by first-class, postage-prepaid mail, to each record holder of shares of Common
Stock as of the Close of Business on the Record Date, at the address of such
holder shown on the records of the Company. With respect to certificates for
shares of Common Stock outstanding as of the Record Date, until the Distribution
Date, the Rights will be evidenced by such certificates registered in the names
of the holders thereof together with a copy of the Summary of Rights. Until the
Distribution Date (or



                                      -4-
<PAGE>   8

the earlier of the Redemption Date (as defined hereinafter) or the Final
Expiration Date (as defined hereinafter)), the surrender for transfer of any
certificate for shares of Common Stock outstanding on the Record Date, with or
without a copy of the Summary of Rights, shall also constitute the transfer of
the Rights associated with the shares of Common Stock represented thereby.

                  (c) Rights shall be issued in respect of all shares of Common
Stock which are issued after the date of this Agreement but prior to the earlier
of the Distribution Date or the Expiration Date (as defined hereinafter).
Certificates representing such shares of Common Stock shall also be deemed to be
certificates for Rights, and such certificates issued after the date of this
Agreement shall bear the following legend:

                           This certificate also evidences and entitles the
                  holder hereof to certain Rights as set forth in the Rights
                  Agreement between Interphase Corporation and Computershare
                  Investor Services, LLC, dated as of December 7, 2000 (the
                  Rights Agreement), the terms of which are hereby incorporated
                  herein by reference and a copy of which is on file at the
                  principal offices of Interphase Corporation. Under certain
                  circumstances, as set forth in the Rights Agreement, such
                  Rights will be evidenced by separate certificates and will no
                  longer be evidenced by this certificate. Interphase
                  Corporation will mail to the holder of this certificate a copy
                  of the Rights Agreement, as in effect on the date of mailing,
                  without charge promptly after receipt of a written request
                  therefor. Under certain circumstances set forth in the Rights
                  Agreement, Rights issued to, or held by, any Person who is,
                  was or becomes an Acquiring Person or any Affiliate or
                  Associate thereof (as such terms are defined in the Rights
                  Agreement), whether currently held by or on behalf of such
                  Person or by any subsequent holder, may become null and void.

With respect to such certificates containing the foregoing legend, until the
earlier of (i) the Distribution Date or (ii) the Expiration Date, the Rights
associated with the Common Stock represented by such certificates shall be
evidenced by such certificates alone and registered holders of Common Stock
shall also be the registered holders of the associated Rights, and the transfer
of any of such certificates shall also constitute the transfer of the Rights
associated with the Common Stock represented by such certificates.

         Section 4. Form of Rights Certificates.

                  (a) The Rights Certificates (and the forms of election to
purchase and of assignment to be printed on the reverse thereof) shall each be
substantially in the form set forth in Exhibit A hereto and may have such marks
of identification or designation and such legends, summaries or endorsements
printed thereon as the Company may deem appropriate (but which



                                      -5-
<PAGE>   9

do not change or increase the rights, duties or obligations of the Rights Agent)
and as are not inconsistent with the provisions of this Agreement, or as may be
required to comply with any applicable law or with any rule or regulation made
pursuant thereto or with any rule or regulation of any stock exchange on which
the Rights may from time to time be listed, or to conform to usage. Subject to
the provisions of Section 11 and Section 22 hereof, the Rights Certificates,
whenever distributed, shall be dated as of the Record Date and on their face
shall entitle the holders thereof to purchase such number of shares of Common
Stock as shall be set forth therein at the price per share set forth therein
(the Purchase Price), but the number of such shares and the Purchase Price
thereof shall be subject to adjustment as provided herein.

                  (b) Any Rights Certificate issued pursuant to Section 3(a) or
Section 22 hereof that represents Rights beneficially owned by: (i) an Acquiring
Person or any Associate or Affiliate of an Acquiring Person, (ii) a transferee
of an Acquiring Person (or of any such Associate or Affiliate) who becomes a
transferee after the Acquiring Person becomes such, or (iii) a transferee of an
Acquiring Person (or of any such Associate or Affiliate) who becomes a
transferee prior to or concurrently with the Acquiring Person becoming such and
receives such Rights pursuant to either (A) a transfer (whether or not for
consideration) from the Acquiring Person to holders of equity interests in such
Acquiring Person or to any Person with whom such Acquiring Person has any
continuing agreement, arrangement or understanding regarding the transferred
Rights or (B) a transfer which the Board of Directors has determined is part of
a plan, arrangement or understanding which has as a primary purpose or effect
avoidance of Section 7(e) hereof, and any Rights Certificate issued pursuant to
Section 6 or Section 11 hereof upon transfer, exchange, replacement or
adjustment of any other Rights Certificate referred to in this sentence, shall
contain (to the extent feasible and to the extent the Rights Agent has knowledge
of the applicability of this Section) the following legend:

                  The Rights represented by this Rights Certificate are or were
                  beneficially owned by a Person who was or became an Acquiring
                  Person or an Affiliate or Associate of an Acquiring Person (as
                  such terms are defined in the Rights Agreement). Accordingly,
                  this Rights Certificate and the Rights represented hereby may
                  become null and void in the circumstances specified in Section
                  7(e) of such Agreement.

         The provisions of Section 7(e) hereof shall be operative whether or not
the foregoing legend is contained on any such Rights Certificate.

         Section 5. Countersignature and Registration.

                  (a) The Rights Certificates shall be executed on behalf of the
Company by its Chairman of the Board, its President or any Vice President,
either manually or by facsimile signature, and shall have affixed thereto the
Company's seal or a facsimile thereof which shall be attested by the Secretary
or an Assistant Secretary of the Company, either manually or by facsimile
signature. The Rights Certificates shall be countersigned by the Rights Agent,
either



                                      -6-
<PAGE>   10

manually or by facsimile signature, and shall not be valid for any purpose
unless so countersigned. In case any officer of the Company who shall have
signed any of the Rights Certificates shall cease to be such officer of the
Company before countersignature by the Rights Agent and issuance and delivery by
the Company, such Rights Certificates, nevertheless, may be countersigned by the
Rights Agent and issued and delivered by the Company with the same force and
effect as though the person who signed such Rights Certificates had not ceased
to be such officer of the Company and any Rights Certificates may be signed on
behalf of the Company by any person who, at the actual date of the execution of
such Rights Certificate, shall be a proper officer of the Company to sign such
Rights Certificate, although at the date of the execution of this Rights
Agreement any such person was not such an officer.

                  (b) Following the Distribution Date and the receipt by the
Rights Agent of all relevant information, the Rights Agent will keep or cause to
be kept, at its principal office or offices designated as the appropriate place
for surrender of Rights Certificates upon exercise or transfer, books for
registration and transfer of the Rights Certificates issued hereunder. Such
books shall show the names and addresses of the respective holders of the Rights
Certificates, the number of Rights evidenced on its face by each of the Rights
Certificates and the date of each of the Rights Certificates.

         Section 6. Transfer, Split Up, Combination and Exchange of Rights
Certificates; Mutilated, Destroyed, Lost or Stolen Rights Certificates. (a)
Subject to the provisions of Section 4(b), Section 7(e) and Section 14 hereof,
at any time after the Close of Business on the Distribution Date, and at or
prior to the Close of Business on the Expiration Date, any Rights Certificate or
Certificates may be transferred, split up, combined or exchanged for another
Rights Certificate or Certificates, entitling the registered holder to purchase
a like number of shares of Common Stock as the Rights Certificate or
Certificates surrendered then entitled such holder (or former holder in the case
of a transfer) to purchase. Any registered holder desiring to transfer, split
up, combine or exchange any Rights Certificate or Certificates shall make such
request in writing delivered to the Rights Agent, and shall surrender the Rights
Certificate or Certificates to be transferred, split up, combined or exchanged
at the principal office or offices of the Rights Agent designated for such
purpose. Neither the Rights Agent nor the Company shall be obligated to take any
action whatsoever with respect to the transfer of any such surrendered Rights
Certificate until the registered holder shall have completed and signed the
certificate contained in the form of assignment on the reverse side of such
Rights Certificate and shall have provided such additional evidence of the
identity of the Beneficial Owner (or former Beneficial Owner) or Affiliates or
Associates thereof as the Company or the Rights Agent shall reasonably request.
Thereupon the Rights Agent shall, subject to Section 4(b), Section 7(e) and
Section 14 hereof, countersign and deliver to the Person entitled thereto a
Rights Certificate or Rights Certificates, as the case may be, as so requested.
The Company may require payment of a sum sufficient to cover any tax or
governmental charge that may be imposed in connection with any transfer, split
up, combination or exchange of Rights Certificates. The Rights Agent shall have
no duty or obligation to take any action under any Section of this Agreement
which requires the payment by a Rights holder of applicable taxes and
governmental charges unless and until the Rights Agent is satisfied that all
such taxes and/or charges have been paid.



                                      -7-
<PAGE>   11

                  (b) Upon receipt by the Company and the Rights Agent of
evidence reasonably satisfactory to them of the loss, theft, destruction or
mutilation of a Rights Certificate, and, in case of loss, theft or destruction,
of indemnity or security satisfactory to them, and reimbursement to the Company
and the Rights Agent of all reasonable expenses incidental thereto, and upon
surrender to the Rights Agent and cancellation of the Rights Certificate if
mutilated, the Company will execute and deliver a new Rights Certificate of like
tenor to the Rights Agent for countersignature and delivery to the registered
owner in lieu of the Rights Certificate so lost, stolen, destroyed or mutilated.

         Section 7. Exercise of Rights; Purchase Price; Expiration Date of
Rights. (a) Subject to Section 7(e) hereof, the registered holder of any Rights
Certificate may exercise the Rights evidenced thereby (except as otherwise
provided herein including, without limitation, the restrictions on
exercisability set forth in Section 9(c), Section 11(a)(iii) and Section 23(a)
hereof) in whole or in part at any time after the Distribution Date upon
surrender of the Rights Certificate, with the form of election to purchase and
the certificate on the reverse side thereof duly executed, to the Rights Agent
at the principal office or offices of the Rights Agent designated for such
purpose, together with payment of the aggregate Purchase Price with respect to
the total number of shares of Common Stock as to which such surrendered Rights
are then exercised, at or prior to the earlier of (i) the Close of Business on
December 6, 2010 (the Final Expiration Date), or (ii) the time at which the
Rights are redeemed as provided in Section 23 hereof (the earlier of (i) and
(ii) being herein referred to as the Expiration Date).

                  (b) The Purchase Price for each share of Common Stock pursuant
to the exercise of a Right shall initially be $93.00, and shall be subject to
adjustment from time to time as provided in Sections 11 and 13(a) hereof and
shall be payable in accordance with paragraph (c) below.

                  (c) Upon receipt of a Rights Certificate representing
exercisable Rights, with the form of election to purchase and the certificate
duly executed, accompanied by payment, with respect to each Right so exercised,
of the Purchase Price for the shares to be purchased as set forth below and an
amount equal to any applicable tax or governmental charge, the Rights Agent
shall, subject to Section 20(k) hereof, thereupon promptly (i) (A) requisition
from any transfer agent of the Common Stock (or make available, if the Rights
Agent is the transfer agent for such shares) certificates for the number of
shares of Common Stock to be purchased and the Company hereby irrevocably
authorizes its transfer agent to comply with all such requests, or (B) if the
Company, in its sole discretion, shall have elected to deposit the total number
of shares of Common Stock issuable upon exercise of the Rights hereunder with a
depositary agent, requisition from the depositary agent depositary receipts
representing such number of shares of Common Stock as are to be purchased (in
which case certificates for the shares of Common Stock represented by such
receipts shall be deposited by the transfer agent with the depositary agent) and
the Company will direct the depositary agent to comply with such request, (ii)
when appropriate, requisition from the Company the amount of cash, if any, to be
paid in lieu of fractional shares in accordance with Section 14 hereof, (iii)
promptly after receipt of such



                                      -8-
<PAGE>   12

certificates or depositary receipts, cause the same to be delivered to, or upon
the order of, the registered holder of such Rights Certificate, registered in
such name or names as may be designated by such holder, and (iv) when
appropriate, after receipt thereof, promptly deliver such cash, if any, to, or
upon the order of, the registered holder of such Rights Certificate. The payment
of the Purchase Price (as such amount may be reduced pursuant to Section
11(a)(iii) hereof) may be made (x) in cash or by certified bank check or bank
draft payable to the order of the Company, or (y) by delivery of a certificate
or certificates (with appropriate stock powers executed in blank attached
thereto) evidencing a number of shares of Common Stock equal to the then
Purchase Price divided by the closing price (as determined pursuant to Section
11(d) hereof) per share of Common Stock on the Trading Day (as defined
hereinafter) immediately preceding the date of such exercise. If the Company is
obligated to issue other securities (including Common Stock) of the Company, pay
cash and/or distribute other property pursuant to Section 11(a) hereof, the
Company will make all arrangements necessary so that such other securities, cash
and/or other property are available for distribution by the Rights Agent, if and
when necessary to comply with this Agreement. The Company reserves the right to
require prior to the occurrence of a Triggering Event that, upon any exercise of
Rights, a number of Rights be exercised so that only whole shares of Common
Stock would be issued.

                  (d) In case the registered holder of any Rights Certificate
shall exercise less than all the Rights evidenced thereby, a new Rights
Certificate evidencing Rights equivalent to the Rights remaining unexercised
shall be issued by the Rights Agent and delivered to, or upon the order of, the
registered holder of such Rights Certificate, registered in such name or names
as may be designated by such holder, subject to the provisions of Section 6 and
Section 14 hereof.

                  (e) Notwithstanding anything in this Agreement to the
contrary, from and after the occurrence of the Section 11(a)(ii) Event, any
Rights beneficially owned by (i) an Acquiring Person or an Associate or
Affiliate of an Acquiring Person, (ii) a transferee of an Acquiring Person (or
of any such Associate or Affiliate) who becomes a transferee after the Acquiring
Person becomes such, or (iii) a transferee of an Acquiring Person (or of any
such Associate or Affiliate) who becomes a transferee prior to or concurrently
with the Acquiring Person becoming such and receives such Rights pursuant to
either (A) a transfer (whether or not for consideration) from the Acquiring
Person to holders of equity interests in such Acquiring Person or to any Person
with whom the Acquiring Person has any continuing agreement, arrangement or
understanding regarding the transferred Rights or (B) a transfer which the Board
of Directors has determined is part of a plan, arrangement or understanding
which has as a primary purpose or effect the avoidance of this Section 7(e),
shall become null and void without any further action, and no holder of such
Rights shall have any rights whatsoever with respect to such Rights, whether
under any provision of this Agreement or otherwise. The Company shall notify the
Rights Agent when this Section 7(e) applies and shall use all reasonable efforts
to insure that the provisions of this Section 7(e) and Section 4(b) hereof are
complied with, but neither the Company nor the Rights Agent shall have any
liability to any holder of Rights Certificates or other Person as a result of
the Company's failure to make any determinations with respect to an Acquiring
Person or its Affiliates, Associates or transferees hereunder.



                                      -9-
<PAGE>   13

                  (f) Notwithstanding anything in this Agreement to the
contrary, neither the Rights Agent nor the Company shall be obligated to
undertake any action with respect to a registered holder upon the occurrence of
any purported exercise as set forth in this Section 7 unless such registered
holder shall have (i) properly completed and signed the certificate contained in
the form of election to purchase set forth on the reverse side of the Rights
Certificate surrendered for such exercise, and (ii) provided such additional
evidence of the identity of the Beneficial Owner (or former Beneficial Owner) or
Affiliates or Associates thereof as the Company or the Rights Agent shall
reasonably request.

         Section 8. Cancellation and Destruction of Rights Certificates. All
Rights Certificates surrendered for the purpose of exercise, transfer, split up,
combination or exchange shall, if surrendered to the Company or any of its
agents, be delivered to the Rights Agent for cancellation or in canceled form,
or, if surrendered to the Rights Agent, shall be canceled by it, and no Rights
Certificates shall be issued in lieu thereof except as expressly permitted by
any of the provisions of this Agreement. The Company shall deliver to the Rights
Agent for cancellation and retirement, and the Rights Agent shall so cancel and
retire, any other Rights Certificate purchased or acquired by the Company
otherwise than upon the exercise thereof. The Rights Agent shall deliver all
canceled Rights Certificates to the Company, or shall, at the written request of
the Company, destroy such canceled Rights Certificates, and in such case shall
deliver a certificate of destruction thereof to the Company.

         Section 9. Reservation and Availability of Common Stock. (a) The
Company covenants and agrees that, following the occurrence of a Triggering
Event, it will cause to be reserved and kept available out of its authorized and
unissued shares of Common Stock or out of its authorized and issued shares held
in its treasury, the number of shares of Common Stock that, as provided in this
Agreement, including Section 11(a)(iii) hereof, will be sufficient to permit the
exercise in full of all outstanding Rights.

                  (b) So long as the shares of Common Stock issuable and
deliverable upon the exercise of the Rights may be listed on any national
securities exchange, the Company shall use its best efforts to cause, from and
after such time as the Rights become exercisable, all shares reserved for such
issuance to be listed on such exchange upon official notice of issuance upon
such exercise.

                  (c) The Company shall use its best efforts (i) to file, as
soon as practicable following the Distribution Date, or as soon as is required
by law, a registration statement under the Securities Act of 1933, as amended
(the Act), with respect to the securities purchasable upon exercise of the
Rights on an appropriate form, (ii) to cause such registration statement to
become effective as soon as practicable after such filing, and (iii) to cause
such registration statement to remain effective (with a prospectus at all times
meeting the requirements of the Act) until the earlier of (A) the date as of
which the Rights are no longer exercisable for such securities, and (B) the
Expiration Date. The Company will also take such action as may be appropriate
under, or to ensure compliance with, the securities or blue sky laws of the
various states in connection with the exercisability of the Rights. The Company
may temporarily suspend, for a period of



                                      -10-
<PAGE>   14

time not to exceed ninety (90) days after the date set forth in clause (i) of
the first sentence of this Section 9(c), the exercisability of the Rights in
order to prepare and file such registration statement and permit it to become
effective. Upon any such suspension, the Company shall issue a public
announcement stating that the exercisability of the Rights has been temporarily
suspended, as well as a public announcement at such time as the suspension is no
longer in effect. The Company shall promptly provide the Rights Agent with
copies of such announcements. Notwithstanding any provision of this Agreement to
the contrary, the Rights shall not be exercisable in any jurisdiction if the
requisite qualification in such jurisdiction shall not have been obtained, the
exercise thereof shall not be permitted under applicable law or a registration
statement shall not have been declared effective.

                  (d) The Company covenants and agrees that it will take all
such action as may be necessary to ensure that all shares of Common Stock
delivered upon exercise of Rights shall, at the time of delivery of the
certificates for such shares (subject to payment of the Purchase Price), be duly
and validly authorized and issued and fully paid and nonassessable.

                  (e) The Company further covenants and agrees that it will pay
when due and payable any and all taxes and governmental charges which may be
payable in respect of the issuance or delivery of the Rights Certificates and of
any shares of Common Stock upon the exercise of Rights. The Company shall not,
however, be required to pay any tax or charge which may be payable in respect of
any transfer or delivery of Rights Certificates or the issuance or delivery of
certificates for Common Stock in a name other than that of the registered holder
of the Rights Certificates evidencing Rights surrendered for exercise or to
issue or deliver any certificates for shares of Common Stock in a name other
than that of the registered holder upon the exercise of any Rights until such
tax or charge shall have been paid (any such tax or charge being payable by the
holder of such Rights Certificate at the time of surrender) or until it has been
established to the Company's satisfaction that no such tax is due.

         Section 10. Common Stock Record Date. Each Person in whose name any
certificate for shares of Common Stock is issued upon the exercise of Rights
shall for all purposes be deemed to have become the holder of record of the
Common Stock represented thereby on, and such certificate shall be dated, the
date upon which the Rights Certificate evidencing such Rights was duly
surrendered and payment of the Purchase Price (and all applicable taxes or
charge) was made; provided, however, that if the date of such surrender and
payment is a date upon which the Common Stock transfer books of the Company are
closed, such Person shall be deemed to have become the record holder of such
shares on, and such certificate shall be dated, the next succeeding Business Day
on which the Common Stock transfer books of the Company are open. Prior to the
exercise of the Rights evidenced thereby, the holder of a Rights Certificate
shall not be entitled to any rights of a stockholder of the Company with respect
to shares for which the Rights shall be exercisable, including, without
limitation, the right to vote, to receive dividends or other distributions or to
exercise any preemptive rights, and shall not be entitled to receive any notice
of any proceedings of the Company, except as provided herein.



                                      -11-
<PAGE>   15

         Section 11. Adjustment of Purchase Price, Number and Kind of Shares or
Number of Rights. The Purchase Price, the number and kind of shares covered by
each Right and the number of Rights outstanding are subject to adjustment from
time to time as provided in this Section 11.

                           (a)(i) In the event the Company shall at any time
         after the date of the Record Date (A) declare a dividend on the Common
         Stock payable in shares of Common Stock, (B) subdivide the outstanding
         Common Stock, (C) combine the outstanding Common Stock into a smaller
         number of shares, or (D) issue any shares of its capital stock in a
         reclassification of the Common Stock (including any such
         reclassification in connection with a consolidation or merger in which
         the Company is the continuing or surviving corporation), except as
         otherwise provided in this Section 11(a) hereof, the Purchase Price in
         effect at the time of the record date for such dividend or of the
         effective date of such subdivision, combination or reclassification,
         and the number of shares of Common Stock or capital stock, as the case
         may be, issuable on such date, shall be proportionately adjusted so
         that the holder of any Right exercised after such time shall be
         entitled to receive, upon payment of the Purchase Price then in effect,
         the aggregate number and kind of shares of Common Stock or capital
         stock, as the case may be, which, if such Right had been exercised
         immediately prior to such date and at a time when the Common Stock
         transfer books of the Company were open, he would have owned upon such
         exercise and been entitled to receive by virtue of such dividend,
         subdivision, combination or reclassification. If an event occurs which
         would require an adjustment under both this Section 11(a)(i) and
         Section 11(a)(ii) hereof, the adjustment provided for in this Section
         11(a)(i) shall be in addition to, and shall be made prior to, any
         adjustment required pursuant to Section 11(a)(ii) hereof.

                           (ii) If any Person becomes an Acquiring Person,
         unless the event causing the 15% threshold to be crossed is a
         transaction set forth in Section 13(a) hereof, or is an acquisition of
         shares of Common Stock pursuant to a tender offer or an exchange offer
         for all outstanding shares of Common Stock at a price and on terms
         determined by at least a majority of the directors to be in the best
         interests of the Company and its stockholders (a Qualifying Offer),
         then, promptly following the occurrence of such event, proper provision
         shall be made so that each holder of a Right (except as provided below
         and in Section 7(e) hereof) shall thereafter have the right to receive,
         upon exercise thereof at the then current Purchase Price in accordance
         with the terms of this Agreement, such number of shares of Common Stock
         of the Company as shall equal the result obtained by (x) multiplying
         the then current Purchase Price by the then number of shares of Common
         Stock for which a Right was exercisable immediately prior to the
         occurrence of the Section 11(a)(ii) Event, and (y) dividing that
         product (which, following such occurrence, shall thereafter be referred
         to as the Purchase Price for each Right and for all purposes of this
         Agreement) by 50% of the current market



                                      -12-
<PAGE>   16

         price (determined pursuant to Section 11(d) hereof) per share of Common
         Stock on the date of such occurrence (such number of shares, the
         Adjustment Shares).

                           (iii) If the number of shares of Common Stock that
         are authorized by the Certificate of Incorporation but not outstanding
         or reserved for issuance for purposes other than upon exercise of the
         Rights are not sufficient to permit the exercise in full of the Rights
         in accordance with the foregoing subparagraph (ii) of this Section
         11(a), the Company shall: (A) determine the excess of (1) the value of
         the Adjustment Shares issuable upon the exercise of a Right (the
         Current Value) over (2) the Purchase Price (such excess, the Spread),
         and (B) with respect to each Right (subject to Section 7(e) hereof),
         make adequate provision to substitute for the Adjustment Shares, upon
         exercise of the Right and payment of the applicable Purchase Price, (1)
         cash, (2) a reduction in the Purchase Price, (3) other equity
         securities of the Company (including, without limitation, shares, or
         units of shares, of preferred stock which the Board of Directors has
         deemed to have the same value as shares of Common Stock (such shares of
         preferred stock, common stock equivalents)), (4) debt securities of the
         Company, (5) other assets, or (6) any combination of the foregoing,
         having an aggregate value equal to the Current Value, where such
         aggregate value has been determined by the Board of Directors based
         upon the advice of a nationally recognized investment banking firm
         selected by the Board of Directors; provided, however, if the Company
         shall not have made adequate provision to deliver the Current Value
         pursuant to clause (B) above within thirty (30) days following the
         later of (x) the occurrence of the Section 11(a)(ii) Event and (y) the
         date on which the Company's right of redemption pursuant to Section
         23(a) expires (the later of (x) and (y) being referred to herein as the
         Section 11(a)(ii) Trigger Date), then the Company shall be obligated to
         deliver, upon the surrender for exercise of a Right and without
         requiring payment of the Purchase Price, shares of Common Stock (to the
         extent available) and then, if necessary, cash, which shares and/or
         cash have an aggregate value equal to the Spread. If the Board of
         Directors shall determine in good faith that it is likely that
         sufficient additional shares of Common Stock could be authorized for
         issuance upon exercise in full of the Rights, the thirty (30) day
         period set forth above may be extended to the extent necessary, but not
         more than ninety (90) days after the Section 11(a)(ii) Trigger Date, in
         order that the Company may seek stockholder approval for the
         authorization of such additional shares (such period, as it may be
         extended, the Substitution Period). To the extent that the Company
         determines that some action need be taken pursuant to the first and/or
         second sentences of this Section 11(a)(iii), the Company (x) shall
         provide, subject to Section 7(e) hereof, that such action shall apply
         uniformly to all outstanding Rights, and (y) may suspend the
         exercisability of the Rights until the expiration of the Substitution
         Period in order to seek any authorization of additional shares and/or
         to decide the appropriate form of distribution to be made pursuant to
         such first sentence and to determine the value thereof. In the event of
         any such suspension, the Company



                                      -13-
<PAGE>   17

         shall issue a public announcement stating that the exercisability of
         the Rights has been temporarily suspended, as well as a public
         announcement at such time as the suspension is no longer in effect. The
         Company shall promptly provide the Rights Agent with copies of all such
         announcements. For purposes of this Section 11(a)(iii), the value of
         each Adjustment Share shall be the current market price (as determined
         pursuant to Section 11(d) hereof) per share of the Common Stock on the
         Section 11(a)(ii) Trigger Date and the per share or per unit value of
         any common stock equivalent shall be deemed to be equal to the current
         market price (as determined pursuant to Section 11(d) hereof) of the
         Common Stock on such date.

                  (b) If the Company shall fix a record date for the issuance of
rights (other than the Rights), options or warrants to all holders of Common
Stock entitling them to subscribe for or purchase (for a period expiring within
forty-five (45) calendar days after such record date) shares of Common Stock (or
shares having the same rights, privileges and preferences as the shares of
Common Stock (equivalent common stock)) or securities convertible into Common
Stock or equivalent common stock at a price per share of Common Stock or per
share of equivalent common stock (or having a conversion price per share, if a
security convertible into Common Stock or equivalent common stock) less than the
current market price (as determined pursuant to Section 11(d) hereof) per share
of Common Stock on such record date, the Purchase Price to be in effect after
such record date shall be determined by multiplying the Purchase Price in effect
immediately prior to such record date by a fraction, the numerator of which
shall be the number of shares of Common Stock outstanding on such record date,
plus the number of shares of Common Stock which the aggregate offering price of
the total number of shares of Common Stock and/or equivalent common stock so to
be offered (and/or the aggregate initial conversion price of the convertible
securities so to be offered) would purchase at such current market price, and
the denominator of which shall be the number of shares of Common Stock
outstanding on such record date, plus the number of additional shares of Common
Stock and/or equivalent common stock to be offered for subscription or purchase
(or into which the convertible securities so to be offered are initially
convertible). In case such subscription price may be paid by delivery of
consideration part or all of which may be in a form other than cash, the value
of such consideration shall be as determined in good faith by the Board of
Directors, whose determination shall be described in a statement filed with the
Rights Agent and shall be binding on the Rights Agent and the holders of the
Rights. Shares of Common Stock owned by or held for the account of the Company
shall not be deemed outstanding for the purpose of any such computation. Such
adjustment shall be made successively whenever such a record date is fixed, and
in the event that such rights or warrants are not so issued, the Purchase Price
shall be adjusted to be the Purchase Price which would then be in effect if such
record date had not been fixed.

                  (c) If the Company shall fix a record date for a distribution
to all holders of Common Stock (including any such distribution made in
connection with a consolidation or merger in which the Company is the continuing
corporation) of evidences of indebtedness, cash (other than a regular quarterly
cash dividend out of the earnings or retained earnings of the



                                      -14-
<PAGE>   18

Company), assets (other than a dividend payable in Common Stock) or subscription
rights or warrants (excluding those referred to in Section 11(b) hereof), the
Purchase Price to be in effect after such record date shall be determined by
multiplying the Purchase Price in effect immediately prior to such record date
by a fraction, the numerator of which shall be the current market price (as
determined pursuant to Section 11(d) hereof) per share of Common Stock on such
record date, less the fair market value (as determined in good faith by the
Board of Directors, whose determination shall be described in a statement filed
with the Rights Agent) of the portion of the cash, assets or evidences of
indebtedness so to be distributed or of such subscription rights or warrants
applicable to a share of Common Stock and the denominator of which shall be such
current market price (as determined pursuant to Section 11(d) hereof) per share
of Common Stock. Such adjustments shall be made successively whenever such a
record date is fixed, and in the event that such distribution is not so made,
the Purchase Price shall be adjusted to be the Purchase Price which would have
been in effect if such record date had not been fixed.

                  (d) For the purpose of any computation hereunder, other than
computations made pursuant to Section 11(a)(iii) hereof, the current market
price per share of Common Stock on any date shall be deemed to be the average of
the daily closing prices per share of such Common Stock for the thirty (30)
consecutive Trading Days (as such term is hereinafter defined) immediately prior
to but not including such date, and for purposes of computations made pursuant
to Section 11(a)(iii) hereof, the current market price per share of Common Stock
on any date shall be deemed to be the average of the daily closing prices per
share of such Common Stock for the ten (10) consecutive Trading Days immediately
following but not including such date; provided, however, that if that the
current market price per share of the Common Stock is determined during a period
following the announcement by the issuer of such Common Stock of (A) a dividend
or distribution on such Common Stock payable in shares of such Common Stock or
securities convertible into shares of such Common Stock (other than the Rights)
or (B) any subdivision, combination or reclassification of such Common Stock,
and the ex-dividend date for such dividend or distribution, or the record date
for such subdivision, combination or reclassification shall not have occurred
prior to the commencement of the requisite thirty (30) Trading Day or ten (10)
Trading Day period, as set forth above, then, and in each such case, the current
market price shall be properly adjusted to take into account ex-dividend
trading. The closing price for each day shall be the last sale price, regular
way, or, in case no such sale takes place on such day, the average of the
closing bid and asked prices, regular way, in either case as reported in the
principal consolidated transaction reporting system with respect to securities
listed or admitted to trading on The Nasdaq Stock Market's National Market
System or, if the shares of Common Stock are not listed or admitted to trading
on The Nasdaq Stock Market's National Market System, as reported in the
principal consolidated transaction reporting system with respect to securities
listed on the principal national securities exchange on which the shares of
Common Stock are listed or admitted to trading or, if the shares of Common Stock
are not listed or admitted to trading on any national securities exchange, the
last quoted price or, if not so quoted, the average of the high bid and low
asked prices in the over-the-counter market, as reported by the National
Association of Securities Dealers, Inc. Automated Quotation System (NASDAQ) or
such other system then in use, or, if on any such date the shares of Common



                                      -15-
<PAGE>   19

Stock are not quoted by any such organization, the average of the closing bid
and asked prices as furnished by a professional market maker making a market in
the Common Stock selected by the Board of Directors. If on any such date no
market maker is making a market in the Common Stock, the fair value of such
shares on such date as determined in good faith by the Board of Directors shall
be used. The term Trading Day shall mean a day on which the principal national
securities exchange on which the shares of Common Stock are listed or admitted
to trading is open for the transaction of business or, if the shares of Common
Stock are not listed or admitted to trading on any national securities exchange,
a Business Day. If the Common Stock is not publicly held or not so listed or
traded, current market price per share shall mean the fair value per share as
determined in good faith by the Board of Directors, whose determination shall be
described in a statement filed with the Rights Agent and shall be conclusive for
all purposes.

                  (e) Anything herein to the contrary notwithstanding, no
adjustment in the Purchase Price shall be required unless such adjustment would
require an increase or decrease of at least one percent (1%) in the Purchase
Price; provided, however, that any adjustments which by reason of this Section
11(e) are not required to be made shall be carried forward and taken into
account in any subsequent adjustment. All calculations under this Section 11
shall be made to the nearest cent or to the nearest one ten-thousandth of a
share, as the case may be. Notwithstanding the first sentence of this Section
11(e), any adjustment required by this Section 11 shall be made no later than
the earlier of (i) three years from the date of the transaction which mandates
such adjustment or (ii) the Expiration Date.

                  (f) If as a result of an adjustment made pursuant to Section
11(a)(ii) or Section 13(a) hereof, the holder of any Right thereafter exercised
shall become entitled to receive any shares of capital stock other than Common
Stock, thereafter the number of such other shares so receivable upon exercise of
any Right and the Purchase Price thereof shall be subject to adjustment from
time to time in a manner and on terms as nearly equivalent as practicable to the
provisions with respect to the Common Stock contained in Sections 11(a), (b),
(c), (e), (g), (h), (i), (j), (k) and (m), and the provisions of Sections 7, 9,
10, 13 and 14 hereof with respect to the Common Stock shall apply on like terms
to any such other shares.

                  (g) All Rights originally issued by the Company subsequent to
any adjustment made to the Purchase Price hereunder shall evidence the right to
purchase, at the adjusted Purchase Price, the number of shares of Common Stock
purchasable from time to time hereunder upon exercise of the Rights, all subject
to further adjustment as provided herein.

                  (h) Unless the Company shall have exercised its election as
provided in Section 11(i), upon each adjustment of the Purchase Price as a
result of the calculations made in Sections 11(b) and (c), each Right
outstanding immediately prior to the making of such adjustment shall thereafter
evidence the right to purchase, at the adjusted Purchase Price, that number of
shares of Common Stock (calculated to the nearest one ten-thousandth) obtained
by (i) multiplying (x) the number of shares covered by a Right immediately prior
to this adjustment, by (y) the Purchase Price in effect immediately prior to
such adjustment of the Purchase Price,



                                      -16-
<PAGE>   20

and (ii) dividing the product so obtained by the Purchase Price in effect
immediately after such adjustment of the Purchase Price.

                  (i) The Company may elect on or after the date of any
adjustment of the Purchase Price to adjust the number of Rights, in lieu of any
adjustment in the number of shares of Common Stock purchasable upon the exercise
of a Right. Each of the Rights outstanding after the adjustment in the number of
Rights shall be exercisable for the number of shares of Common Stock for which a
Right was exercisable immediately prior to such adjustment. Each Right held of
record prior to such adjustment of the number of Rights shall become that number
of Rights (calculated to the nearest one ten-thousandth) obtained by dividing
the Purchase Price in effect immediately prior to adjustment of the Purchase
Price by the Purchase Price in effect immediately after adjustment of the
Purchase Price. The Company shall make a public announcement of its election
(with prompt written notice thereof to the Rights Agent) to adjust the number of
Rights, indicating the record date for the adjustment, and, if known at the
time, the amount of the adjustment to be made. This record date may be the date
on which the Purchase Price is adjusted or any day thereafter, but, if the
Rights Certificates have been issued, shall be at least ten (10) days later than
the date of the public announcement. If Rights Certificates have been issued,
upon each adjustment of the number of Rights pursuant to this Section 11 (i),
the Company shall, as promptly as practicable, cause to be distributed to
holders of record of Rights Certificates on such record date Rights Certificates
evidencing, subject to Section 14 hereof, the additional Rights to which such
holders shall be entitled as a result of such adjustment, or, at the option of
the Company, shall cause to be distributed to such holders of record in
substitution and replacement for the Rights Certificates held by such holders
prior to the date of adjustment, and upon surrender thereof, if required by the
Company, new Rights Certificates evidencing all the Rights to which such holders
shall be entitled after such adjustment. Rights Certificates so to be
distributed shall be issued, executed and countersigned in the manner provided
for herein (and may bear, at the option of the Company, the adjusted Purchase
Price) and shall be registered in the names of the holders of record of Rights
Certificates on the record date specified in the public announcement.

                  (j) Irrespective of any adjustment or change in the Purchase
Price or the number of shares of Common Stock issuable upon the exercise of the
Rights, the Rights Certificates theretofore and thereafter issued may continue
to express the Purchase Price per share and the number of shares which were
expressed in the initial Rights Certificates issued hereunder.

                  (k) Before taking any action that would cause an adjustment
reducing the Purchase Price below the then stated value, if any, of the number
of shares of Common Stock issuable upon exercise of the Rights, the Company
shall take any corporate action which may, in the opinion of its counsel, be
necessary in order that the Company may validly and legally issue fully paid and
nonassessable such number of shares of Common Stock at such adjusted Purchase
Price.



                                      -17-
<PAGE>   21

                  (l) In any case in which this Section 11 shall require that an
adjustment in the Purchase Price be made effective as of a record date for a
specified event, the Company may elect to defer (and shall promptly provide the
Rights Agent with written notice thereof) until the occurrence of such event the
issuance to the holder of any Right exercised after such record date the number
of shares of Common Stock and other capital stock or securities of the Company,
if any, issuable upon such exercise over and above the number of shares of
Common Stock and other capital stock or securities of the Company, if any,
issuable upon such exercise on the basis of the Purchase Price in effect prior
to such adjustment; provided, however, that the Company shall deliver to such
holder a due bill or other appropriate instrument evidencing such holder's right
to receive such additional shares (fractional or otherwise) or securities upon
the occurrence of the event requiring such adjustment.

                  (m) Anything in this Section 11 to the contrary
notwithstanding, the Company shall be entitled to make such reductions in the
Purchase Price, in addition to those adjustments expressly required by this
Section 11, as and to the extent that in their good faith judgment the Board of
Directors shall determine to be advisable in order that any (i) consolidation or
subdivision of the Common Stock, (ii) issuance wholly for cash of any shares of
Common Stock at less than the current market price, (iii) issuance wholly for
cash of shares of Common Stock or securities which by their terms are
convertible into or exchangeable for shares of Common Stock, (iv) stock
dividends, or (v) issuance of rights, options or warrants referred to in this
Section 11, hereafter made by the Company to holders of its Common Stock shall
not be taxable to such stockholders.

                  (n) The Company covenants and agrees that it shall not, at any
time after the Distribution Date, (i) consolidate with any other Person (other
than a Subsidiary of the Company in a transaction which complies with Section
11(o) hereof), (ii) merge with or into any other Person (other than a Subsidiary
of the Company in a transaction which complies with Section 11(o) hereof), or
(iii) sell or transfer (or permit any Subsidiary to sell or transfer), in one
transaction, or a series of related transactions, assets or earning power
aggregating more than 50% of the assets or earning power of the Company and its
Subsidiaries (taken as a whole) to any other Person or Persons (other than the
Company and/or any of its Subsidiaries in one or more transactions each of which
complies with Section 11(o) hereof), if (x) at the time of or immediately after
such consolidation, merger or sale there are any rights, warrants or other
instruments or securities outstanding or agreements in effect which would
substantially diminish or otherwise eliminate the benefits intended to be
afforded by the Rights or (y) prior to, simultaneously with or immediately after
such consolidation, merger or sale, the stockholders of the Person who
constitutes, or would constitute, the Principal Party for purposes of Section
13(a) hereof shall have received a distribution of Rights previously owned by
such Person or any of its Affiliates and Associates.



                                      -18-
<PAGE>   22

                  (o) The Company covenants and agrees that, after the
Distribution Date, it will not, except as permitted by Section 23 or Section 26
hereof, take (or permit any Subsidiary to take) any action if at the time such
action is taken it is reasonably foreseeable that such action will diminish
substantially or otherwise eliminate the benefits intended to be afforded by the
Rights.

                  (p) Anything in this Agreement to the contrary
notwithstanding, in the event that the Company shall at any time after the
Record Date and prior to the Distribution Date (i) declare a dividend on the
outstanding shares of Common Stock payable in shares of Common Stock, (ii)
subdivide the outstanding shares of Common Stock, or (iii) combine the
outstanding shares of Common Stock into a smaller number of shares, the number
of Rights associated with each share of Common Stock then outstanding, or issued
or delivered thereafter but prior to the Distribution Date, shall be
proportionately adjusted so that the number of Rights thereafter associated with
each share of Common Stock following any such event shall equal the result
obtained by multiplying the number of Rights associated with each share of
Common Stock immediately prior to such event by a fraction the numerator of
which shall be the total number of shares of Common Stock outstanding
immediately prior to the occurrence of the event and the denominator of which
shall be the total number of shares of Common Stock outstanding immediately
following the occurrence of such event.

         Section 12. Certificate of Adjusted Purchase Price or Number of Shares.
Whenever an adjustment is made as provided in Section 11 or Section 13 hereof,
the Company shall (a) promptly prepare a certificate setting forth such
adjustment and a brief statement of the facts and computations accounting for
such adjustment, (b) promptly file with the Rights Agent, and with each transfer
agent for the Common Stock, a copy of such certificate, and (c) mail or cause
the Rights Agent to mail a brief summary thereof to each holder of a Rights
Certificate (or, if prior to the Distribution Date, to each holder of a
certificate representing shares of Common Stock) in accordance with Section 25
hereof. The Rights Agent shall be fully protected in relying on any such
certificate and on any adjustment therein contained and shall have no duty with
respect to and shall not be deemed to have knowledge of any adjustment unless
and until it shall have received such a certificate.

         Section 13. Consolidation, Merger or Sale or Transfer of Assets or
Earning Power.

                  (a) If, following the Stock Acquisition Date, directly or
indirectly, (x) the Company shall consolidate with, or merge with and into, any
other Person (other than a Subsidiary of the Company in a transaction which
complies with Section 11(o) hereof), and the Company shall not be the continuing
or surviving corporation of such consolidation or merger, (y) any Person (other
than a Subsidiary of the Company in a transaction which complies with Section
11(o) hereof) shall consolidate with, or merge with or into, the Company, and
the Company shall be the continuing or surviving corporation of such
consolidation or merger and, in connection with such consolidation or merger,
all or part of the outstanding shares of Common Stock shall be changed into or
exchanged for stock or other securities of any other Person or cash or any other
property, or (z) the Company shall sell or otherwise transfer (or one or more of
its



                                      -19-
<PAGE>   23

Subsidiaries shall sell or otherwise transfer), in one transaction or a series
of related transactions, assets or earning power aggregating more than 50% of
the assets or earning power of the Company and its Subsidiaries (taken as a
whole) to any Person or Persons (other than the Company or any Subsidiary of the
Company in one or more transactions each of which complies with Section 11(o)
hereof), then, and in each such case (except as may be contemplated by Section
13(d) hereof), proper provision shall be made so that: (i) each holder of a
Right, except as provided in Section 7(e) hereof, shall thereafter have the
right to receive, upon the exercise thereof at the then current Purchase Price
in accordance with the terms of this Agreement, such number of validly
authorized and issued, fully paid, nonassessable and freely tradeable shares of
Common Stock of the Principal Party (as such term is hereinafter defined), not
subject to any liens, encumbrances, rights of first refusal or other adverse
claims, as shall be equal to the result obtained by (1) multiplying the then
current Purchase Price by the number of shares of Common Stock for which a Right
is exercisable immediately prior to the first occurrence of a Section 13 Event
(or, if the Section 11(a)(ii) Event has occurred prior to the first occurrence
of a Section 13 Event, multiplying the number of such shares for which a Right
was exercisable immediately prior to the occurrence of the Section 11(a)(ii)
Event by the Purchase Price in effect immediately prior to such first
occurrence), and dividing that product (which, following the first occurrence of
a Section 13 Event, shall be referred to as the Purchase Price for each Right
and for all purposes of this Agreement) by (2) 50% of the current market price
(determined pursuant to Section 11(d)(i) hereof) per share of the Common Stock
of such Principal Party on the date of consummation of such Section 13 Event,
(ii) such Principal Party shall thereafter be liable for, and shall assume, by
virtue of such Section 13 Event, all the obligations and duties of the Company
pursuant to this Agreement; (iii) the term Company shall thereafter be deemed to
refer to such Principal Party, it being specifically intended that the
provisions of Section 11 hereof shall apply only to such Principal Party
following the first occurrence of a Section 13 Event; (iv) such Principal Party
shall take such steps (including, but not limited to, the reservation of a
sufficient number of shares of its Common Stock) in connection with the
consummation of any such transaction as may be necessary to assure that the
provisions hereof shall thereafter be applicable, as nearly as reasonably may
be, in relation to its shares of Common Stock thereafter deliverable upon the
exercise of the Rights; and (v) the provisions of Section 11(a)(ii) hereof shall
be of no effect following the first occurrence of any Section 13 Event.

                  (b) Principal Party shall mean

                           (i) in the case of any transaction described in
         clause (x) or (y) of the first sentence of Section 13(a), the Person
         that is the issuer of any securities into which shares of Common Stock
         of the Company are converted in such merger or consolidation, and if no
         securities are so issued, the Person that is the other party to such
         merger or consolidation; and



                                      -20-
<PAGE>   24

                           (ii) in the case of any transaction described in
         clause (z) of the first sentence of Section 13(a), the Person that is
         the party receiving the greatest portion of the assets or earning power
         transferred pursuant to such transaction or transactions;

provided, however, that in any such case, (1) if the Common Stock of such Person
is not at such time and has not been continuously over the preceding twelve (12)
month period registered under Section 12 of the Exchange Act, and such Person is
a direct or indirect Subsidiary of another Person the Common Stock of which is
and has been so registered, Principal Party shall refer to such other Person;
(2) in case such Person is a Subsidiary, directly or indirectly, of more than
one Person, the Common Stocks of two or more of which are and have been so
registered, Principal Party shall refer to whichever of such Persons is the
issuer of the Common Stock having the greatest aggregate market value; and (3)
in case such Person is owned, directly or indirectly, by a joint venture formed
by two or more Persons that are not owned, directly or indirectly, by the same
Person, the rules set forth in (1) and (2) above shall apply to each of the
chains of ownership having an interest in such joint ventures as if such party
were a Subsidiary of both or all of such joint ventures and the Principal
Parties in each such chain shall bear the obligations set forth in this Section
13 in the same ratio as their direct or indirect interests in such Person bear
to the total of such interests.

                  (c) The Company shall not consummate any such consolidation,
merger, sale or transfer unless the Principal Party shall have a sufficient
number of authorized shares of its Common Stock which have not been issued or
reserved for issuance to permit the exercise in full of the Rights in accordance
with this Section 13 and unless prior thereto the Company and such Principal
Party shall have executed and delivered to the Rights Agent a supplemental
agreement providing for the terms set forth in paragraphs (a) and (b) of this
Section 13 and further providing that, as soon as practicable after the date of
any such consolidation, merger sale or transfer, the Principal Party will

                           (i) prepare and file a registration statement under
         the Act, with respect to the Rights and the securities purchasable upon
         exercise of the Rights on an appropriate form, and will use its best
         efforts to cause such registration statement to (A) become effective as
         soon as practicable after such filing and (B) remain effective (with a
         prospectus at all times meeting the requirements of the Act) until the
         Expiration Date; and

                           (ii) deliver to holders of the Rights historical
         financial statements for the Principal Party and each of its Affiliates
         which comply in all respects with the requirements for registration on
         Form 10 under the Exchange Act.



                                      -21-
<PAGE>   25

The provisions of this Section 13 shall similarly apply to successive mergers,
consolidations, sales or other transfers. If a Section 13 Event shall occur at
any time after the occurrence of the Section 11(a)(ii) Event, the Rights which
have not theretofore been exercised shall thereafter become exercisable in the
manner described in Section 13(a).

                  (d) Notwithstanding anything in this Agreement to the
contrary, Section 13 shall not be applicable to a transaction described in
subparagraphs (x) and (y) of Section 13(a) if (i) such transaction is
consummated with a Person or Persons who acquired shares of Common Stock
pursuant to a Qualifying Offer (or a wholly owned subsidiary of such Person or
Persons), (ii) the price per share of Common Stock offered in such transaction
is not less than the price per share of Common Stock paid to all holders of
shares of Common Stock whose shares were purchased pursuant to such Qualifying
Offer, and (iii) the form of consideration being offered to the remaining
holders of shares of Common Stock pursuant to such transaction is the same as
the form of consideration paid pursuant to such Qualifying Offer. Upon
consummation of any such transaction contemplated by this Section 13(d), all
rights hereunder shall expire.

                  (e) The Company covenants and agrees that, following the
Distribution Date, it shall not consummate any of the transactions described in
clauses (i), (ii) and (iii) of the first sentence of Section 13(a) if at the
time of or after such consummation there would be any charter or by-law
provisions or any rights, warrants or other instruments or securities
outstanding or agreements in effect or any other action taken which would
diminish or eliminate the benefits intended to be afforded by the Rights, unless
prior thereto the Principal Party shall have amended or repealed such charter or
by-law provisions, instruments or securities, agreements or actions or otherwise
protected the holders of the Rights from such diminution or elimination of
benefits, and the Company and the Principal Party shall have executed and
delivered to the Rights Agent a legally valid, binding and enforceable
supplemental agreement providing for such amendment, repeal or other protection.

         Section 14. Fractional Rights and Fractional Shares.

                  (a) The Company shall not be required to issue fractions of
Rights, except prior to the Distribution Date as provided in Section 11(p)
hereof, or to distribute Rights Certificates which evidence fractional Rights.
In lieu of such fractional Rights, there shall be paid to the registered holders
of the Rights Certificates with regard to which such fractional Rights would
otherwise be issuable, an amount in cash equal to the same fraction of the
current market value of a whole Right. For purposes of this Section 14(a), the
current market value of a whole Right shall be the closing price of the Rights
for the Trading Day immediately prior to the date on which such fractional
Rights would have been otherwise issuable. The closing price of the Rights for
any day shall be the last sale price, regular way, or, in case no such sale
takes place on such day, the average of the closing bid and asked prices,
regular way, in either case as reported in the principal consolidated
transaction reporting system with respect to



                                      -22-
<PAGE>   26

securities listed or admitted to trading on The Nasdaq Stock Market's National
Market System or, if the Rights are not listed or admitted to trading on The
Nasdaq Stock Market's National Market System, as reported in the principal
consolidated transaction reporting system with respect to securities listed on
the principal national securities exchange on which the Rights are listed or
admitted to trading, or if the Rights are not listed or admitted to trading on
any national securities exchange, the last quoted price or, if not so quoted,
the average of the high bid and low asked prices in the over-the-counter market,
as reported by NASDAQ or such other system then in use or, if on any such date
the Rights are not quoted by any such organization, the average of the closing
bid and asked prices as furnished by a professional market maker making a market
in the Rights selected by the Board of Directors. If on any such date no such
market maker is making a market in the Rights the fair value of the Rights on
such date as determined in good faith by the Board of Directors shall be used.

                  (b) The Company shall not be required to issue fractions of a
share of Common Stock upon exercise of the Rights, or to distribute certificates
which evidence fractional shares of such securities. Fractions of a share of
Common Stock may, at the election of the Company, be evidenced by depository
receipts, pursuant to an appropriate agreement between the Company and a
depositary selected by it; provided that such agreement shall provide that the
holders of such depositary receipts shall have the rights, privileges and
preferences to which they are entitled as beneficial owners of the Common Stock
represented by such depositary receipts. In lieu of fractional shares of Common
Stock or depositary receipts, the Company may pay to the registered holders of
Right Certificates at the time such Rights are exercised as herein provided an
amount in cash equal to the same fraction of the current market value of one
share of Common Stock. For the purposes of this Section 14(b), the current
market value of one share of Common Stock shall be the closing price of one
share of Common Stock (as determined pursuant to the second sentence of Section
11(d) hereof) for the Trading Day immediately prior to the date of such
exercise.

                  (c) The holder of a Right by the acceptance of the Rights
expressly waives his right to receive any fractional Rights or any fractional
shares upon exercise of a Right, except as permitted by this Section 14.

                  (d) The Rights Agent shall have no duty or obligation with
respect to this Section 14 and any other Section of this Agreement relating to
fractional shares unless and until it has received specific instructions (and
sufficient cash, if required) from the Company with respect to its duties and
obligations under such Sections.

         Section 15. Rights of Action. All rights of action in respect of this
Agreement are vested in the respective registered holders of the Rights
Certificates (and, prior to the Distribution Date, the registered holders of the
Common Stock); and any registered holder of any Rights Certificate (or, prior to
the Distribution Date, of the Common Stock), without the consent of the Rights
Agent or of the holder of any other Rights Certificate (or, prior to the
Distribution Date, of the Common Stock), may, in his own behalf and for his own
benefit, enforce, and may institute and maintain any suit, action or proceeding
against the Company to enforce, or otherwise act in respect of, his right to
exercise the Rights evidenced by such Rights Certificate in the manner provided
in such Rights Certificate and in this Agreement. Without limiting the foregoing
or any remedies available to the holders of Rights, it is specifically
acknowledged that



                                      -23-
<PAGE>   27

the holders of Rights would not have an adequate remedy at law for any breach of
this Agreement and shall be entitled to specific performance of the obligations
hereunder and injunctive relief against actual or threatened violations of the
obligations hereunder of any Person subject to this Agreement.

         Section 16. Agreement of Rights Holders. Every holder of a Right by
accepting the same consents and agrees with the Company and the Rights Agent and
with every other holder of a Right that:

                  (a) prior to the Distribution Date, the Rights will be
transferable only in connection with the transfer of Common Stock;

                  (b) after the Distribution Date, the Rights Certificates are
transferable only on the registry books of the Rights Agent if surrendered at
the principal office or offices of the Rights Agent designated for such
purposes, duly endorsed or accompanied by a proper instrument of transfer and
with the appropriate forms and certificates fully executed;

                  (c) subject to Section 6(a) and Section 7(f) hereof, the
Company and the Rights Agent may deem and treat the Person in whose name a
Rights Certificate (or, prior to the Distribution Date, the associated Common
Stock certificate) is registered as the absolute owner thereof and of the Rights
evidenced thereby (notwithstanding any notations of ownership or writing on the
Rights Certificates or the associated Common Stock certificate made by anyone
other than the Company or the Rights Agent) for all purposes whatsoever, and
neither the Company nor the Rights Agent, subject to the last sentence of
Section 7(e) hereof, shall be required to be affected by any notice to the
contrary; and

                  (d) notwithstanding anything in this Agreement to the
contrary, neither the Company nor the Rights Agent shall have any liability to
any holder of a Right or other Person as a result of its inability to perform
any of its obligations under this Agreement by reason of any preliminary or
permanent injunction or other order, decree, judgment or ruling issued by a
court of competent jurisdiction or by a governmental, regulatory or
administrative agency or commission, or any statute, rule, regulation or
executive order promulgated or enacted by any governmental authority,
prohibiting or otherwise restraining performance of such obligation; provided,
however, the Company must use its best efforts to have any such order, decree,
judgment or ruling lifted or otherwise overturned as soon as possible.

         Section 17. Rights Certificate Holder Not Deemed a Stockholder. No
holder, as such, of any Rights Certificate shall be entitled to vote, receive
dividends or be deemed for any purpose the holder of Common Stock or any other
securities of the Company which may at any time be issuable on the exercise of
the Rights represented thereby, nor shall anything contained herein or in any
Rights Certificate be construed to confer upon the holder of any Rights
Certificate, as such, any of the rights of a stockholder of the Company or any
right to vote for the election of directors or upon any matter submitted to
stockholders at any meeting thereof, or to give or withhold consent to any
corporate action, or to receive notice of meetings or other actions



                                      -24-
<PAGE>   28

affecting stockholders (except as provided in Section 24 hereof), or to receive
dividends or subscription rights, or otherwise, until the Right or Rights
evidenced by such Rights Certificate shall have been exercised in accordance
with the provisions hereof.

         Section 18. Concerning the Rights Agent.

                  (a) The Company agrees to pay to the Rights Agent reasonable
compensation for all services rendered by it hereunder and, from time to time,
on demand of the Rights Agent, its reasonable expenses and counsel fees and
disbursements and other disbursements incurred in the preparation, execution,
delivery, amendment and administration of this Agreement and the exercise and
performance of its duties hereunder. The Company shall indemnify the Rights
Agent for, and hold it harmless against, any loss, liability, damage, judgment,
fine, penalty, claim, demand, settlement, cost or expense (Loss) arising out of
or in connection with its acceptance and administration of this Agreement,
including, without limitation, the costs and expenses of defending itself
against any Loss, unless such Loss shall have been determined by a court of
competent jurisdiction to be a result of the Right Agent's gross negligence, bad
faith or intentional misconduct. The costs and expenses incurred in enforcing
this right of indemnification shall be paid by the Company. Any liability of the
Rights Agent under this Agreement will be limited to the amount of fees paid by
the Company to the Rights Agent. The obligations of the Company under this
Section 18(a) shall survive the termination of this Agreement and the Rights.

                  (b) The Rights Agent shall be authorized and protected and
shall incur no liability for or in respect of any action taken, suffered or
omitted by it in connection with its acceptance and administration of this
Agreement in reliance upon any Rights Certificate or certificate for Common
Stock or for other securities of the Company, instrument of assignment or
transfer, power of attorney, endorsement, affidavit, letter, notice, direction,
consent, certificate, statement or other paper or document believed by it to be
genuine and to be signed, executed and, where necessary, verified or
acknowledged, by the proper Person or Persons.

         Section 19. Merger or Consolidation or Change of Name of Rights Agent.

                  (a) Any Person into which the Rights Agent or any successor
Rights Agent may be merged or with which it may be consolidated, or any Person
resulting from any merger or consolidation to which the Rights Agent or any
successor Rights Agent shall be a party, or any Person succeeding to the
business of the Rights Agent or any successor Rights Agent, shall be the
successor to the Rights Agent under this Agreement without the execution or
filing of any paper or an further act on the part of any of the parties hereto;
provided, however, that such Person would be eligible for appointment as a
successor Rights Agent under the provisions of Section 21 hereof. In case at the
time such successor Rights Agent shall succeed to the agency created by this
Agreement, any of the Rights Certificates shall have been countersigned but not
delivered, any such successor Rights Agent may adopt the countersignature of a
predecessor Rights Agent and deliver such Rights Certificates so countersigned;
and in case at that time any of the Rights Certificates shall not have been
countersigned, any successor Rights Agent may



                                      -25-
<PAGE>   29

countersign such Rights Certificates either in the name of the predecessor or in
the name of the successor Rights Agent; and in all such cases such Rights
Certificates shall have the full force provided in the Rights Certificates and
in this Agreement.

                  (b) If at any time the name of the Rights Agent shall be
changed and at such time any of the Rights Certificates shall have been
countersigned but not delivered, the Rights Agent may adopt the countersignature
under its prior name and deliver Rights Certificates so countersigned; and in
case at that time any of the Rights Certificates shall not have been
countersigned, the Rights Agent may countersign such Rights Certificates either
in its prior name or in its changed name; and in all such cases such Rights
Certificates shall have the full force provided in the Rights Certificates and
in this Agreement.

         Section 20. Duties of Rights Agent. The Rights Agent undertakes only
the duties and obligations expressly imposed by this Agreement upon the
following terms and conditions, by all of which the Company and the holders of
Rights Certificates, by their acceptance thereof, shall be bound:

                  (a) The Rights Agent may consult with legal counsel (who may
be legal counsel for the Company), and the advice or opinion of such counsel
shall be full and complete authorization and protection to the Rights Agent and
the Rights Agent shall incur no liability for or in respect of any action taken,
suffered or omitted by it in good faith and in accordance with such advice or
opinion.

                  (b) Whenever in the performance of its duties under this
Agreement the Rights Agent shall deem it necessary or desirable that any fact or
matter (including, without limitation, the identity of any Acquiring Person and
the determination of current market price) be proved or established by the
Company prior to taking, suffering or omitting to take any action hereunder,
such fact or matter (unless other evidence in respect thereof be herein
specifically prescribed) may be deemed to be conclusively proved and established
by a certificate signed by the Chairman of the Board, the President, any Vice
President, the Treasurer, any Assistant Treasurer, the Secretary or any
Assistant Secretary of the Company and delivered to the Rights Agent; and such
certificate shall be full authorization and protection to the Rights Agent, and
the Rights Agent shall incur no liability for or in respect of any action taken,
suffered or omitted to be taken in good faith by it under the provisions of this
Agreement in reliance upon such certificate.

                  (c) The Rights Agent shall be liable hereunder only for its
own gross negligence, bad faith or intentional misconduct. In no case, however,
will the Rights Agent be liable for special, indirect, punitive, incidental or
consequential losses or damages of any kind whatsoever (including but not
limited to lost profits), even if the Rights Agent has been advised of the
possibility of such damages.

                  (d) The Rights Agent shall not be liable for or by reason of
any of the statements of fact or recitals contained in this Agreement or in the
Rights Certificates or be



                                      -26-
<PAGE>   30

required to verify the same (except as to its countersignature on such Rights
Certificates), but all such statements and recitals are and shall be deemed to
have been made by the Company only.

                  (e) The Rights Agent shall not have any liability for or be
under any responsibility in respect of the validity of this Agreement or the
execution and delivery hereof (except the due execution hereof by the Rights
Agent) or in respect of the validity or execution of any Rights Certificate
(except its countersignature thereof); nor shall it be responsible for any
breach by the Company of any covenant or condition contained in this Agreement
or in any Rights Certificate; nor shall it be responsible for any adjustment
required under the provisions of Section 11 or Section 13 hereof or responsible
for the manner, method or amount of any such adjustment or the ascertaining of
the existence of facts that would require any such adjustment (except with
respect to the exercise of Rights evidenced by Rights Certificates after actual
notice of any such adjustment); nor shall it by any act hereunder be deemed to
make any representation or warranty as to the authorization or reservation of
any shares of Common Stock to be issued pursuant to this Agreement or any Rights
Certificate or as to whether any shares of Common Stock will, when so issued, be
validly authorized and issued, fully paid and nonassessable.

                  (f) The Company shall perform, execute, acknowledge and
deliver or cause to be performed, executed, acknowledged and delivered all such
further and other acts, instruments and assurances as may reasonably be required
by the Rights Agent for the carrying out or performing by the Rights Agent of
the provisions of this Agreement.

                  (g) The Rights Agent is hereby authorized and directed to
accept instructions with respect to the performance of its duties hereunder from
the Chairman of the Board, the President, the Chief Financial Officer, the
Secretary or any Assistant Secretary of the Company, and to apply to such
officers for advice or instructions in connection with its duties, and it shall
be full authorization to the Rights Agent and the Rights Agent shall not be
liable for any action taken, suffered or omitted to be taken by it in good faith
in accordance with instructions of any such officer.

                  (h) The Rights Agent and any stockholder, affiliate, director,
officer or employee of the Rights Agent may buy, sell or deal in any of the
Rights or other securities of the Company or become pecuniarily interested in
any transaction in which the Company may be interested, or contract with or lend
money to the Company or otherwise act as fully and freely as though it were not
Rights Agent under this Agreement. Nothing herein shall preclude the Rights
Agent from acting in any other capacity for the Company or for any other Person.

                  (i) The Rights Agent may execute and exercise any of the
rights or powers hereby vested in it or perform any duty hereunder either itself
or by or through its attorneys or agents, and the Rights Agent shall not be
answerable or accountable for any act, default, neglect or misconduct of any
such attorneys or agents or for any loss to the Company or any other Person
resulting from any such act, default, neglect or misconduct; provided, however,
reasonable care was exercised in the selection and continued employment thereof.



                                      -27-
<PAGE>   31

                  (j) No provision of this Agreement shall require the Rights
Agent to expend or risk its own funds or otherwise incur any financial liability
in the performance of any of its duties hereunder or in the exercise of its
rights if it believes that repayment of such funds or adequate indemnification
against such risk or liability is not reasonably assured to it.

                  (k) If, with respect to any Right Certificate surrendered to
the Rights Agent for exercise or transfer, the certificate attached to the form
of assignment or form of election to purchase, as the case may be, has either
not been completed or indicates an affirmative response to clause 1 and/or 2
thereof, the Rights Agent shall not take any further action with respect to such
requested exercise of transfer without first consulting with the Company.

         Section 21. Change of Rights Agent. The Rights Agent or any successor
Rights Agent may resign and be discharged from its duties under this Agreement
upon thirty (30) days' notice in writing mailed to the Company, and to each
transfer agent of the Common Stock, by registered or certified mail, and to the
holders of the Rights Certificates by first-class mail. The Company may remove
the Rights Agent or any successor Rights Agent upon thirty (30) days' notice in
writing, mailed to the Rights Agent or successor Rights Agent, as the case may
be, and to each transfer agent of the Common Stock, by registered or certified
mail, and to the holders of the Rights Certificates by first-class mail. If the
Rights Agent shall resign or be removed or shall otherwise become incapable of
acting, the Company shall appoint a successor to the Rights Agent. If the
Company shall fail to make such appointment within a period of thirty (30) days
after giving notice of such removal or after it has been notified in writing of
such resignation or incapacity by the resigning or incapacitated Rights Agent or
by the holder of a Rights Certificate (who shall, with such notice, submit his
Rights Certificate for inspection by the Company), then any registered holder of
any Rights Certificate may apply to any court of competent jurisdiction for the
appointment of a new Rights Agent. Any successor Rights Agent, whether appointed
by the Company or by such a court, shall be either (a) a Person organized and
doing business under the laws of the United States or of any state of the United
States, in good standing, which is authorized under such laws to exercise stock
transfer powers and is subject to supervision or examination by federal or state
authority and which either has or is an affiliate of a Person which has at the
time of its appointment as Rights Agent a combined capital and surplus of at
least $25,000,000, or (b) an affiliate of such a Person. After appointment, the
successor Rights Agent shall be vested with the same powers, rights, duties and
responsibilities as if it had been originally named as Rights Agent without
further act or deed; but the predecessor Rights Agent shall deliver and transfer
to the successor Rights Agent any property at the time held by it hereunder, and
execute and deliver any further assurance, conveyance, act or deed necessary for
the purpose. Not later than the effective date of any such appointment, the
Company shall file notice thereof in writing with the predecessor Rights Agent
and each transfer agent of the Common Stock, and mail a notice thereof in
writing to the registered holders of the Rights Certificates. Failure to give
any notice provided for in this Section 21, however, or any defect therein,
shall not affect the legality or validity of the resignation or removal of the
Rights Agent or the appointment of the successor Rights Agent, as the case may
be.



                                      -28-
<PAGE>   32

         Section 22. Issuance of New Rights Certificates. Notwithstanding any of
the provisions of this Agreement or of the Rights to the contrary, the Company
may, at its option, issue new Rights Certificates evidencing Rights in such form
as may be approved by its Board of Directors to reflect any adjustment or change
in the Purchase Price or the number or kind or class of shares or other
securities or property purchasable under the Rights Certificates made in
accordance with the provisions of this Agreement. In addition, in connection
with the issuance or sale of shares of Common Stock following the Distribution
Date and prior to the redemption or expiration of the Rights, the Company (a)
shall, with respect to shares of Common Stock so issued or sold pursuant to the
exercise of stock options or under any employee plan or arrangement, granted or
awarded as of the Distribution Date, or upon the exercise, conversion or
exchange of securities hereinafter issued by the Company, and (b) may, in any
other case, if deemed necessary or appropriate by the Board of Directors, issue
Rights Certificates representing the appropriate number of Rights in connection
with such issuance or sale; provided, however, that (i) no such Rights
Certificate shall be issued if, and to the extent that, the Company shall be
advised by counsel that such issuance would create a significant risk of
material adverse tax consequences to the Company or the Person to whom such
Rights Certificate would be issued, and (ii) no such Rights Certificate shall be
issued if, and to the extent that, appropriate adjustment shall otherwise have
been made in lieu of the issuance thereof.

         Section 23. Redemption and Termination.

                  (a) The Board of Directors may, at its option, at any time
prior to the earlier of (i) the Close of Business on the tenth Business Day
following the Stock Acquisition Date or (ii) the Close of Business on the Final
Expiration Date, redeem all but not less than all of the then outstanding Rights
at a redemption price of $0.01 per Right, as such amount may be appropriately
adjusted to reflect any stock split, stock dividend or similar transaction
occurring after the date hereof (such redemption price being hereinafter
referred to as the Redemption Price). Such redemption of the Rights by the
Company may be made effective at such time, on such basis and with such
conditions as the Board of Directors, in its sole discretion, may establish.
Notwithstanding anything contained in this Agreement to the contrary, the Rights
shall not be exercisable after the occurrence of the Section 11(a)(ii) Event
until such time as the Company's right of redemption hereunder has expired. The
Company may, at its option, pay the Redemption Price in cash, shares of Common
Stock (based on the current market price, as defined in Section 11(d)(i) hereof,
of the Common Stock at the time of redemption) or any other form of
consideration deemed appropriate by the Board of Directors.

                  (b) Immediately upon the action of the Board of Directors
ordering the redemption of the Rights, evidence of which shall have been filed
with the Rights Agent and without any further action and without any notice, the
right to exercise the Rights will terminate and the only right thereafter of the
holders of Rights shall be to receive the Redemption Price for each Right so
held. Promptly after the action of the Board of Directors ordering the
redemption of the Rights, the Company shall give notice of such redemption to
the Rights Agent and the holders of the then outstanding Rights by mailing such
notice to all such holders at each holder's



                                      -29-
<PAGE>   33

last address as it appears upon the registry books of the Rights Agent or, prior
to the Distribution Date, on the registry books of the transfer agent for the
Common Stock. Any notice which is mailed in the manner herein provided shall be
deemed given, whether or not the holder receives the notice. Each such notice of
redemption will state the method by which the payment of the Redemption Price
will be made.

         Section 24. Notice of Certain Events.

                  (a) In case the Company shall propose, at any time after the
Distribution Date, (i) to pay any dividend payable in stock of any class to the
holders of its Common Stock or to make any other distribution to the holders of
Common Stock (other than a regular quarterly cash dividend out of earnings or
retained earnings of the Company), (ii) to offer to the holders of Common Stock
rights or warrants to subscribe for or to purchase any additional shares of
Common Stock or shares of stock of any class or any other securities, rights or
options, (iii) to effect any reclassification of its Common Stock (other than a
reclassification involving only the subdivision of outstanding shares of Common
Stock), (iv) to effect any consolidation or merger into or with any other Person
(other than a Subsidiary of the Company in a transaction which complies with
Section 11(o) hereof), or to effect any sale or other transfer (or to permit one
or more of its Subsidiaries to effect any sale or other transfer), in one
transaction or a series of related transactions, of more than 50% of the assets
or earning power of the Company and its Subsidiaries (taken as a whole) to any
other Person or Persons (other than the Company and/or any of its Subsidiaries
in one or more transactions each of which complies with Section 11(o) hereof),
or (v) to effect the liquidation, dissolution or winding up of the Company,
then, in each such case, the Company shall give to each holder of a Rights
Certificate, to the extent feasible and in accordance with Section 25 hereof,
and to the Rights Agent, notice of such proposed action, which notice shall
specify the record date for the purposes of such stock dividend or distribution
of rights or warrants, or the date on which such reclassification,
consolidation, merger, sale, transfer, liquidation, dissolution, or winding up
is to take place and the date of participation therein by the holders of the
shares of Common Stock, if any such date is to be fixed, and such notice shall
be so given in the case of any action covered by clause (i) or (ii) above at
least twenty (20) days prior to the record date for determining holders of the
shares of Common Stock for purposes of such action, and in the case of any such
other action, at least twenty (20) days prior to the date of the taking of such
proposed action or the date of participation therein by the holders of the
shares of Common Stock whichever shall be the earlier.

                  (b) If the Section 11(a)(ii) Event shall occur, the Company
shall as soon as practicable thereafter give to each holder of a Rights
Certificate, to the extent feasible and in accordance with Section 25 hereof,
and to the Rights Agent, a notice of the occurrence thereof, which notice shall
specify the Section 11(a)(ii) Event and the consequences of the Section
11(a)(ii) Event to holders of Rights under Section 11(a)(ii) hereof.

         Section 25. Notices. Notices or demands authorized by this Agreement to
be given or made by the Rights Agent or by the holder of any Rights Certificate
to or on the Company shall



                                      -30-
<PAGE>   34

be sufficiently given or made if sent by first-class mail, postage prepaid,
addressed (until another address is filed in writing with the Rights Agent) as
follows:

                           Interphase Corporation
                           13800 Senlac
                           Dallas, Texas 75234
                           Attention: Corporate Secretary

Subject to the provisions of Section 21, any notice or demand authorized by this
Agreement to be given or made by the Company or by the holder of any Rights
Certificate to or on the Rights Agent shall be sufficiently given or made if
sent by first-class mail, postage prepaid, addressed (until another address is
filed in writing with the Company) as follows:

                           Computershare Investor Services, LLC
                           2 North LaSalle Street
                           Chicago, Illinois 60602

Notices or demands authorized by this Agreement to be given or made by the
Company or the Rights Agent to the holder of any Rights Certificate (or, if
prior to the Distribution Date, to the holder of certificates representing
shares of Common Stock) shall be sufficiently given or made if sent by
first-class mail, postage prepaid, addressed to such holder at the last address
of such holder as it appears upon the registry books of the Rights Agent or,
prior to the Distribution Date, on the registry books of the transfer agent for
the Common Stock.

         Section 26. Supplements and Amendments. Prior to the Distribution Date
and subject to the penultimate sentence of this Section 26, the Company and the
Rights Agent shall, if the Company so directs, supplement or amend any provision
of this Agreement without the approval of any holders of certificates
representing shares of Common Stock. From and after the Distribution Date and
subject to the penultimate sentence of this Section 26, the Company and the
Rights Agent shall, if the Company so directs, supplement or amend this
Agreement without the approval of any holders of Rights Certificates in order to
(i) cure any ambiguity, (ii) correct or supplement any provision contained
herein which may be defective or inconsistent with any other provisions herein,
(iii) shorten or lengthen any time period hereunder, or (iv) change or
supplement the provisions hereunder in any manner which the Company may deem
necessary or desirable and which shall not adversely affect the interests of the
holders of Rights Certificates (other than an Acquiring Person or an Affiliate
or Associate of an Acquiring Person); provided that, this Agreement may not be
supplemented or amended to lengthen, pursuant to clause (iii) of this sentence,
(A) a time period relating to when the Rights may be redeemed at such time as
the Rights are not then redeemable, or (B) any other time period unless such
lengthening is for the purpose of protecting, enhancing or clarifying the rights
of, and/or the benefits to, the holders of Rights. Upon the delivery of a
certificate from an officer of the Company which states that the proposed
supplement or amendment is in compliance with the terms of this Section 26, and
provided that such amendment or supplement does not change or increase the
Rights Agent's duties, liabilities or obligations, the Rights Agent shall
execute such supplement or amendment.



                                      -31-
<PAGE>   35

Notwithstanding anything contained in this Agreement to the contrary, no
supplement or amendment shall be made which changes the Redemption Price, the
Final Expiration Date, the Purchase Price or the number of shares of Common
Stock for which a Right is exercisable; provided, however, that at any time
prior to (i) the Stock Acquisition Date or (ii) the date that a tender or
exchange offer by any Person (other than the Company, any Subsidiary of the
Company, any employee benefit plan of the Company or any Subsidiary of the
Company, or any Person or entity organized, appointed or established by the
Company for or pursuant to the terms of any such plan) is first published or
sent or given within the meaning of Rule 14d-2(a) of the General Rules and
Regulations under the Exchange Act, if upon consummation thereof, such Person
would be the Beneficial Owner of __% or more of the shares of Common Stock then
outstanding and if at the time of any amendment or supplement such tender or
exchange offer has not expired or been terminated, the Board of Directors may
amend this Agreement to increase the Purchase Price or extend the Final
Expiration Date. Prior to the Distribution Date, the interests of the holders of
Rights shall be deemed coincident with the interests of the holders of Common
Stock.

         Section 27. Successors. All the covenants and provisions of this
Agreement by or for the benefit of the Company or the Rights Agent shall bind
and inure to the benefit of their respective successors and assigns hereunder.

         Section 28. Determinations and Actions by the Board of Directors, etc.
For all purposes of this Agreement, any calculation of the number of shares of
Common Stock outstanding at any particular time, including for purposes of
determining the particular percentage of such outstanding shares of Common Stock
of which any Person is the Beneficial Owner, shall be made in accordance with
the last sentence of Rule 13d-3(d)(1)(i) of the General Rules and Regulations
under the Exchange Act. The Board of Directors shall have the exclusive power
and authority to administer this Agreement and to exercise all rights and powers
specifically granted to the Board of Directors or to the Company, or as may be
necessary or advisable in the administration of this Agreement, including,
without limitation, the right and power to (i) interpret the provisions of this
Agreement and (ii) make all determinations deemed necessary or advisable for the
administration of this Agreement (including a determination to redeem or not
redeem the Rights or to amend this Agreement). All actions, calculations,
valuations, interpretations and determinations (including, for purposes of
clause (y) below, all omissions with respect to the foregoing) which are done or
made by the Board of Directors in good faith, shall (x) be final, conclusive and
binding on the Company, the Rights Agent, the holders of the Rights and all
other Persons, and (y) not subject the Board of Directors to any liability to
the holders of the Rights. The Rights Agent shall always be entitled to assume
that the Company's Board of Directors acted in good faith and shall be fully
protected and incur no liability in reliance thereon.

         Section 29. Benefits of this Agreement. Nothing in this Agreement shall
be construed to give to any Person other than the Company, the Rights Agent and
the registered holders of the Rights Certificates (and, prior to the
Distribution Date, registered holders of the Common Stock) any legal or
equitable right, remedy or claim under this Agreement; but this Agreement shall
be



                                      -32-
<PAGE>   36

for the sole and exclusive benefit of the Company, the Rights Agent and the
registered holders of the Rights Certificates (and, prior to the Distribution
Date, registered holders of the Common Stock).

         Section 30. Severability. If any term, provision, covenant or
restriction of this Agreement is held by a court of competent jurisdiction or
other authority to be invalid, void or unenforceable, the remainder of the
terms, provisions, covenants and restrictions of this Agreement shall remain in
full force and effect and shall in no way be affected, impaired or invalidated;
provided, however, that notwithstanding anything in this Agreement to the
contrary, if any such term, provision, covenant or restriction is held by such
court or authority to be invalid, void or unenforceable and the Board of
Directors determines in its good faith judgment that severing the invalid
language from this Agreement would adversely affect the purpose or effect of
this Agreement, the right of redemption set forth in Section 23 hereof, if then
expired, shall be reinstated and shall not expire until the Close of Business on
the tenth Business Day following the date of such determination by the Board of
Directors. The Company shall promptly provide the Rights Agent with written
notice of such determination.

         Section 31. Governing Law. This Agreement, each Right and each Rights
Certificate issued hereunder and all provisions regarding the rights, duties and
obligations of the Rights Agent shall be deemed to be a contract made under the
laws of the State of Texas and for all purposes shall be governed by and
construed in accordance with the laws of such State applicable to contracts made
and to be performed entirely within such State.

         Section 32. Counterparts. This Agreement may be executed in any number
of counterparts and each of such counterparts shall be deemed for all purposes
to be an original, and all such counterparts shall together constitute but one
and the same instrument.

         Section 33. Descriptive Headings. Descriptive headings of the several
Sections of this Agreement are inserted for convenience only and shall not
control or affect the meaning or construction of any of the provisions hereof.



                                      -33-
<PAGE>   37

         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed and their respective corporate seals to be hereunto affixed and
attested, all as of the day and year first above written.


Attest:                                INTERPHASE CORPORATION


By:                                    By: /s/ Steven P. Kovac
   -------------------------------        --------------------------------------

Name:                                  Name: Steven P. Kovac
     -----------------------------          ------------------------------------

Title:                                 Title: Vice President of Finance and CFO
      ----------------------------           -----------------------------------


Attest:                                COMPUTERSHARE INVESTOR SERVICES, LLC

By:                                    By: /s/ Rozlynne R. Orr
   -------------------------------        --------------------------------------

Name:                                  Name: Rozlynne R. Orr
     -----------------------------          ------------------------------------

Title:                                 Title: Relationship Manager
      ----------------------------           -----------------------------------



                                      -34-
<PAGE>   38

                                                                       EXHIBIT A

                          [Form of Rights Certificate]


Certificate No. R-                                             __________ Rights


         NOT EXERCISABLE AFTER DECEMBER 6, 2010 OR EARLIER IF REDEEMED BY THE
         COMPANY. THE RIGHTS ARE SUBJECT TO REDEMPTION, AT THE OPTION OF THE
         COMPANY, AT $0.01 PER RIGHT ON THE TERMS SET FORTH IN THE RIGHTS
         AGREEMENT. UNDER CERTAIN CIRCUMSTANCES, RIGHTS BENEFICIALLY OWNED BY AN
         ACQUIRING PERSON (AS SUCH TERM IS DEFINED IN THE RIGHTS AGREEMENT) AND
         ANY SUBSEQUENT HOLDER OF SUCH RIGHTS MAY BECOME NULL AND VOID. [THE
         RIGHTS REPRESENTED BY THIS RIGHTS CERTIFICATE ARE OR WERE BENEFICIALLY
         OWNED BY A PERSON WHO WAS OR BECAME AN ACQUIRING PERSON OR AN AFFILIATE
         OR ASSOCIATE OF AN ACQUIRING PERSON (AS SUCH TERMS ARE DEFINED IN THE
         RIGHTS AGREEMENT). ACCORDINGLY, THIS RIGHTS CERTIFICATE AND THE RIGHTS
         REPRESENTED HEREBY MAY BECOME NULL AND VOID IN THE CIRCUMSTANCES
         SPECIFIED IN SECTION 7(e) OF SUCH AGREEMENT.](1)


                               Rights Certificate

                             INTERPHASE CORPORATION


         This certifies that                 , or registered assigns, is the
registered owner of the number of Rights set forth above, each of which entitles
the owner thereof, subject to the terms, provisions and conditions of the Rights
Agreement, dated as of December 7, 2000 (the "Rights Agreement"), between
Interphase Corporation, a Texas corporation (the "Company"), and Computershare
Investor Services, LLC, a limited liability company organized under the laws of
the State of Delaware (the "Rights Agent"), to purchase from the Company at any
time prior to 5:00 P.M. (New York City time) on December 6, 2010 at the office
or offices of the Rights Agent designated for such purpose, or its successors as
Rights Agent, one fully paid, nonassessable share of Common Stock (the "Common
Stock") of the Company, at a purchase price of $93.00 per share (the "Purchase
Price"), upon presentation and surrender of this Rights Certificate with the
Form of Election to Purchase and related Certificate duly executed. The

----------

         (1) The portion of the legend in brackets shall be inserted only if
applicable and shall replace the preceding sentence.



                                      A-1
<PAGE>   39

Purchase Price shall be paid, at the election of the holder, in cash or shares
of Common Stock of the Company having an equivalent value. The number of Rights
evidenced by this Rights Certificate (and the number of shares which may be
purchased upon exercise thereof) set forth above, and the Purchase Price per
share set forth above, are the number and Purchase Price as of December 7, 2000,
based on the Common Stock as constituted at such date.

         Upon the occurrence of the Section 11(a)(ii) Event (as such term is
defined in the Rights Agreement), if the Rights evidenced by this Rights
Certificate are beneficially owned by (i) an Acquiring Person or an Affiliate or
Associate of any such Acquiring Person (as such terms are defined in the Rights
Agreement), (ii) a transferee of any such Acquiring Person, Associate or
Affiliate, or (iii) under certain circumstances specified in the Rights
Agreement, a transferee of a person who, after such transfer, became an
Acquiring Person, or an Affiliate or Associate of an Acquiring Person, such
Rights shall become null and void and no holder hereof shall have any right with
respect to such Rights from and after the occurrence of the Section 11(a)(ii)
Event.

         As provided in the Rights Agreement, the Purchase Price and the number
and kind of shares of Common Stock or other securities, which may be purchased
upon the exercise of the Rights evidenced by this Rights Certificate are subject
to modification and adjustment upon the happening of certain events, including
Triggering Events.

         This Rights Certificate is subject to all of the terms, provisions and
conditions of the Rights Agreement, which terms, provisions and conditions are
hereby incorporated herein by reference and made a part hereof and to which
Rights Agreement reference is hereby made for a full description of the rights,
limitations of rights, obligations, duties and immunities hereunder of the
Rights Agent, which limitations of rights include the temporary suspension of
the exercisability of such Rights under the specific circumstances set forth in
the Rights Agreement. Copies of the Rights Agreement are on file at the
above-mentioned office of the Rights Agent and are also available upon written
request to the Rights Agent.

         This Rights Certificate, with or without other Rights Certificates,
upon surrender at the principal office or offices of the Rights Agent designated
for such purpose, may be exchanged for another Rights Certificate or Rights
Certificates of like tenor and date evidencing Rights entitling the holder to
purchase a like aggregate number of Common Stock as the Rights evidenced by the
Rights Certificate or Rights Certificates surrendered shall have entitled such
holder to purchase. If this Rights Certificate shall be exercised in part, the
holder shall be entitled to receive upon surrender hereof another Rights
Certificate or Rights Certificates for the number of whole Rights not exercised.

         Subject to the provisions of the Rights Agreement, the Rights evidenced
by this Certificate may be redeemed by the Company at its option at a redemption
price of $0.01 per Right at any time prior to the earlier of the close of
business on (i) the tenth Business Day following the Stock Acquisition Date (as
such time period may be extended pursuant to the Rights Agreement), and (ii) the
Final Expiration Date.



                                      A-2
<PAGE>   40

         The Company is not required to issue fractional shares of Common Stock
upon the exercise of any Right or Rights evidenced hereby (other than fractions
which are integral multiples of one share of Common Stock, which may, at the
election of the Company, be evidenced by depositary receipts), but in lieu
thereof a cash payment may be made, as provided in the Rights Agreement.

         No holder of this Rights Certificate shall be entitled to vote or
receive dividends or be deemed for any purpose the holder of shares of Common
Stock or of any other securities of the Company which may at any time be
issuable on the exercise hereof, nor shall anything contained in the Rights
Agreement or herein be construed to confer upon the holder hereof, as such, any
of the rights of a stockholder of the Company or any right to vote for the
election of directors or upon any matter submitted to stockholders at any
meeting thereof, or to give or withhold consent to any corporate action, or to
receive notice of meetings or other actions affecting stockholders (except as
provided in the Rights Agreement), or to receive dividends or subscription
rights, or otherwise, until the Right or Rights evidenced by this Rights
Certificate shall have been exercised as provided in the Rights Agreement.

         This Rights Certificate shall not be valid or obligatory for any
purpose until it shall have been countersigned by the Rights Agent.

         WITNESS the facsimile signature of the proper officers of the Company
and its corporate seal.


Dated as of                 ,
            ----------------  -----


Attest:                                INTERPHASE CORPORATION


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

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

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



Countersigned:

COMPUTERSHARE INVESTOR SERVICES, LLC


By:
   -------------------------------
        Authorized Signature



                                      A-3
<PAGE>   41

                  [Form of Reverse Side of Rights Certificate]



                               FORM OF ASSIGNMENT

                (To be executed by the registered holder if such
               holder desires to transfer the Rights Certificate.)


FOR VALUE RECEIVED _____________________________________________________________
hereby sells, assigns and transfers unto________________________________________

--------------------------------------------------------------------------------
                  (Please print name and address of transferee)


--------------------------------------------------------------------------------
this Rights Certificate, together with all right, title and interest therein,
and does hereby irrevocably constitute and appoint __________________ Attorney,
to transfer the within Rights Certificate on the books of the within-named
Company, with full power of substitution.


Date:                     ,
     ---------------------  ------


                                       -----------------------------------------
                                                       Signature


Signature Guaranteed:



                                      A-4
<PAGE>   42

                                   CERTIFICATE


         The undersigned hereby certifies by checking the appropriate boxes
that:

                  (1) this Rights Certificate [ ] is [ ] is not being sold,
assigned and transferred by or on behalf of a Person who is or was an Acquiring
Person or an Affiliate or Associate of any such Acquiring Person (as such terms
are defined in the Rights Agreement); and

                  (2) after due inquiry and to the best knowledge of the
undersigned, it [ ] did [ ]did not acquire the Rights evidenced by this Rights
Certificate from any Person who is, was or subsequently became an Acquiring
Person or an Affiliate or Associate of an Acquiring Person.


Dated:               ,
      ---------------  ----                 -----------------------------
                                                      Signature

Signature Guaranteed:


                                     NOTICE


                  The signature to the foregoing Assignment and Certificate must
correspond to the name as written upon the face of this Rights Certificate in
every particular, without alteration or enlargement or any change whatsoever.



                                      A-5
<PAGE>   43

                          FORM OF ELECTION TO PURCHASE

     (To be executed if holder desires to exercise Rights represented by the
                              Rights Certificate.)


To: INTERPHASE CORPORATION

         The undersigned hereby irrevocably elects to exercise ____________
Rights represented by this Rights Certificate to purchase the shares of Common
Stock issuable upon the exercise of the Rights (or such other securities of the
Company or of any other person which may be issuable upon the exercise of the
Rights) and requests that certificates for such shares be issued in the name of
and delivered to:

Please insert social security
or other identifying number
                           ----------------------------

--------------------------------------------------------------------------------
                         (Please print name and address)

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


         If such number of Rights shall not be all the Rights evidenced by this
Rights Certificate, a new Rights Certificate for the balance of such Rights
shall be registered in the name of and delivered to:


Please insert social security
or other identifying number
                           ----------------------------


--------------------------------------------------------------------------------
                         (Please print name and address)

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

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

Dated:                     ,
      ---------------------  -----
                                       -----------------------------------------
                                                       Signature

Signature Guaranteed:



                                      A-6
<PAGE>   44

                                   CERTIFICATE


         The undersigned hereby certifies by checking the appropriate boxes
that:

         (1) the Rights evidenced by this Rights Certificate [ ] are [ ] are not
being exercised by or on behalf of a Person who is or was an Acquiring Person or
an Affiliate or Associate of any such Acquiring Person (as such terms are
defined in the Rights Agreement); and

         (2) after due inquiry and to the best knowledge of the undersigned, it
[ ] did [ ] did not acquire the Rights evidenced by this Rights Certificate from
any Person who is, was or became an Acquiring Person or an Affiliate or
Associate of an Acquiring Person.


Dated:                ,
      ----------------  ----        --------------------------------------------
                                                     Signature


Signature Guaranteed:

                                     NOTICE

                  The signature to the foregoing Election to Purchase and
Certificate must correspond to the name as written upon the face of this Rights
Certificate in every particular, without alteration or enlargement or any change
whatsoever.



                                      A-7