1 EXHIBIT 4.2 [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.](2) 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 - ---------- (2) The portion of the legend in brackets shall be inserted only if applicable and shall replace the preceding sentence. 2 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. -2- 3 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 -3- 4 [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: -4- 5 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. -5- 6 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: -6- 7 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. -7-