EXHIBIT 10

                            MODIFICATION AGREEMENT

     This MODIFICATION AGREEMENT (this "Agreement") is entered into as of 
November 5, 1998, between DATA RACE, Inc., a Texas corporation (the "Company"); 
and Sovereign Partners L.P., Dominion Capital Fund, Ltd., and First Capital 
Group of Texas II, L.P. (the "Purchasers").

                                   RECITALS

     WHEREAS, pursuant to that certain Purchase Agreement, dated July 24, 1998, 
between the Company and the Purchasers (the "Purchase Agreement"), the Company 
issued to the Purchasers an aggregate of 2,250 shares of the Company's 
convertible preferred stock and common stock purchase warrants to purchase an 
aggregate of 480,248 shares of the Company's common stock;

     WHEREAS, pursuant to the Purchase Agreement, the Company agreed to issue, 
and the Purchasers agreed to purchase, subject to the satisfaction of certain 
conditions, an additional 1,750 shares of the Company's convertible preferred 
stock and additional common stock purchase warrants to purchase an aggregate of 
367,040 shares of the Company's common stock;

     WHEREAS, pursuant to the Purchase Agreement, the Company and the Purchasers
entered into that certain Registration Rights Agreement, dated July 24, 1998 
(the "Registration Rights Agreement"); and

     WHEREAS, the parties to this Agreement desire to modify and clarify certain
provisions of the Purchase Agreement, the Registration Rights Agreement and 
certain documents executed in connection therewith.

                                   AGREEMENT

     For good and valuable consideration, the sufficiency and receipt of which 
is hereby acknowledged by each party, the parties to this Agreement agree as 
follows:

     1.  Unless the context requires otherwise, capitalized terms used, but not
         defined herein, shall have the applicable meanings given to them in the
         Purchase Agreement, the Registration Rights Agreement and the
         Statements of Designation referred to in the Purchase Agreement (the
         "Statements of Designation").

     2.  The parties acknowledge that the Company does not intend to register
         under the Securities Act, prior to the closing of the Call, the shares
         of Common Stock underlying the Preferred Stock and Warrants to be
         issued upon the closing of the Call. Accordingly, the parties hereby
         waive the condition to the closing of the Call that a registration
         statement under the Securities Act be in effect with respect to such
         shares of Common Stock. The Company agrees that, notwithstanding
         Section 3(a) of the Registration Rights Agreement and without reducing
         the time


 
         periods set forth in Section 3(e) of the Registration Rights Agreement,
         the Company agrees to file with the SEC an additional registration
         statement under the Securities Act covering the resale by the Holders
         of the shares of Common Stock underlying the Preferred Stock and
         Warrants issued on the closing of the Call, within ten business days
         following the closing of the Call; and assuming the SEC determines not
         to review the registration statement, the Company agrees to use its
         best efforts to cause the registration statement to be declared
         effective within 20 business days following the closing of the Call.
         The term "Demand," as used in the Registration Rights Agreement, shall
         be deemed to have been given as of the date of the closing of the Call
         with respect to the registration of the shares of Common Stock
         underlying the Preferred Stock and Warrants issued in the closing of
         the Call, and any penalties provided for under Section 3(e) of the
         Registration Rights Agreement shall be determined based on such deemed
         date of Demand. In addition to the modifications described above, the
         Purchasers waive any default or damages attributable to the failure of
         the registration statement previously filed with SEC with respect to
         the shares of Common Stock underlying the outstanding Preferred Stock
         and Warrants to be declared effective within the period specified in
         the Registration Rights Agreement and the Statements of Designations;
         provided, however, that the penalties accruing under Section 3(e) of
         the Registration Rights Agreement with respect to the outstanding
         Preferred Stock and Warrants shall be deemed waived only if the
         registration statement covering the underlying securities is declared
         effective on or before November 13, 1998. The parties acknowledge that,
         except as specified herein, no other rights are waived or reduced with
         respect to the matters described in this paragraph.

     3.  The parties acknowledge that the Preferred Stock to be issued at the
         closing of the Call will not be included in the Company's net tangible
         assets (as defined by the Nasdaq National Market continued listing
         requirements) until the registration statement with respect to the
         underlying shares of Common Stock is declared effective by the SEC.
         Accordingly, the parties agree that the condition to the closing of the
         Call that the Company be in compliance with the Nasdaq National Market
         continued listing requirements requirement upon closing of the Call
         shall be determined assuming that the Preferred Stock issued at such
         closing were included in the Company's net tangible assets.

     4.  The parties agree that the legal opinion required to be delivered to 
         the Purchasers as a condition to the closing of the Call shall be
         appropriately modified as may be necessary to be rendered consistent
         with the matters addressed in or related to this Modification.

     5.  The parties agree that the condition to the closing of the Call that
         the representations and warranties of the Company made pursuant to the
         Purchase Agreement and Exhibits be true and correct as of the date of
         the Call shall, in all cases, be subject to the matters addressed in or
         related to this Agreement.

     6.  The parties agree that the condition to the closing of the Call that
         the Company shall have performed, satisfied and complied with all
         covenants, agreements and

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         conditions required pursuant to the Purchase Agreement and Exhibits to
         be performed, satisfied or complied with by the Company prior to the
         closing of the Call shall, in all cases, be subject to the matters
         addressed in or related to this Agreement.

     7.  The parties acknowledge that the minimum conversion price (and the
         maximum conversion price) with respect to the outstanding Series D
         Preferred Stock has been fixed in accordance with the Statement of
         Designation for Series D Preferred Stock. Accordingly, the parties
         agree that, with respect to the outstanding Preferred Stock and
         Warrants, the Company shall be required to register and keep reserved
         for issuance only that number of shares of Common Stock that is at any
         time issuable upon conversion of such Preferred Stock and Warrants, and
         the Purchase Agreement, the Registration Rights Agreement and the
         Statements of Designation for the Series D Preferred Stock and Series E
         Preferred Stock shall be deemed appropriately modified to such extent.
         In addition, with respect to the Series F Preferred Stock and the
         Warrants to be issued on the closing of the Call, the Company shall be
         required to register and keep reserved for issuance only that number of
         shares of Common Stock that is at any time issuable upon conversion of
         such Series F Preferred Stock and Warrants, and the Purchase Agreement,
         the Registration Rights Agreement and the Statement of Designation for
         the Series F Preferred shall be deemed appropriately modified to such
         extent.

     8.  The parties desire to clarify Section 4(e) of each of the Statements of
         Designation which provides that the failure to pay certain penalties
         constitutes a Triggering Event. The parties intended that the
         redemption obligations arising from such a Triggering event be in lieu
         of, rather than in addition to, the penalties described in Section
         4(e). The parties acknowledge and agree that a holder that elects to
         require the Company to redeem Preferred Shares upon the occurrence of a
         Triggering Event attributable to such failure to pay the penalties
         described in Section 4(e) shall be deemed to have waived its right to
         receive the penalties described in such Section.

     9.  Notwithstanding that the Purchase Agreement and the Registration Rights
         Agreement were executed on behalf of First Capital Group of Texas II,
         L.P. ("First Capital Group"), by First Capital Group Investment
         Partners, L.P., its General Partner, by Jeffrey P. Blanchard, "General
         Partner" of First Capital Group Management Company, "L.P."
         ("Management Company"), the parties acknowledge that they have been
         advised that Management Company is a Texas limited liability company
         (rather than a limited partnership as implied by the signature pages to
         the Purchase Agreement and the Registration Rights Agreement), and that
         Jeffrey P. Blanchard is an authorized officer of Management Company
         (rather than a partner of Management Company). The parties acknowledge
         and agree that any documents executed on behalf of First Capital Group
         in connection with the private placement pursuant to the Purchase
         Agreement are deemed modified accordingly as of their respective dates
         of execution.

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     10.  The parties acknowledge that, to the extent the Purchase Agreement,
          the Registration Rights Agreement or any of the Statements of
          Designation are inconsistent with the terms of this Agreement, the
          terms of this Agreement shall be deemed controlling and the other
          documents shall be deemed appropriately modified. Except as modified
          as provided herein, the Purchase Agreement, the Registration Rights
          Agreement and the Statements of Designation shall remain in full force
          and effect in accordance with their terms.

     11.  This Agreement sets forth the entire understanding between the parties
          hereto concerning the subject matter contained herein. Provisions of
          this Agreement may be amended or waived only by written instrument
          executed by the party against whom enforcement is sought. This
          Agreement shall be binding upon the parties and the respective
          successors and assigns. The parties agree to execute such additional
          documents and take such additional actions as may be reasonably
          necessary to give effect to the purposes and intent of this Agreement.
          This Agreement may be executed in one or more counterparts, any of
          which shall be deemed to be an original, all of which taken together
          shall constitute one and the same instrument.

                        [signatures on following page]

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        IN WITNESS WHEREOF, each party has duly executed this Modification 
Agreement as of the date first written above.


COMPANY                             PURCHASERS
- -------                             ----------

DATA RACE, INC.                     SOVEREIGN PARTNERS L.P.

By: /s/ Gregory T. Skalla           By:       /s/ Stephen Hicks
   ----------------------------        -----------------------------------------
   Gregory T. Skalla, Senior Vice      Name:  Stephen Hicks
   President-Finance and Chief              ------------------------------------
   Financial Officer                   Title: President: General Partner
                                             -----------------------------------

                                    DOMINION CAPITAL FUND, LTD.

                                    By: Inter Carribean Services (Bahamas) Ltd.

                                    By:       /s/ Carl O'Connell
                                              /s/ Nina Ray
                                       -----------------------------------------
                                       Name:  Carl O'Connell; Nina Ray
                                            ------------------------------------
                                       Title: Director and Attorney-in-Fact
                                             -----------------------------------

                                    FIRST CAPITAL GROUP OF TEXAS II, L.P.

                                    By: First Capital Group Investment Partners,
                                        L.P., its General Partner

                                    By: First Capital Group Management Company,
                                        L.C., its General Partner


                                    By: /s/ Jeffrey P. Blanchard
                                       -----------------------------------------
                                       Jeffrey P. Blanchard
                                       Authorized Officer



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