EXHIBIT 10.1

                                 April 14, 1998


DATA RACE, Inc.
12400 Network Boulevard
San Antonio, Texas 78249-3341

Attention:  Gregory T. Skalla

     Re:  Series C Convertible Participating Preferred Stock and Warrants

Dear Mr. Skalla:

     We refer to the Securities Purchase Agreement, dated November 7, 1997, as
amended by the letter agreement (the "Letter Agreement") dated January 30, 1998,
(the "Purchase Agreement"), by and among DATA RACE, Inc. (the "Company") and the
buyers named therein (the "Buyers") relating to the sale by the Company of
shares of Series C Convertible Participating Preferred Stock (the "Preferred
Stock") and the related warrants (the "Warrants") of the Company to the Buyers.
Pursuant to the terms of the Purchase Agreement, on November 12, 1997 the
Company sold 5,000 shares of Preferred Stock and 139,861 Warrants to the Buyers.
Subject to the terms and conditions set forth in the Purchase Agreement, the
Company will sell an aggregate of an additional 3,000 shares of Preferred Stock
(the "Additional Preferred Shares") and the related Warrants to the Buyers.

     The Company and the Buyers have agreed to the following change to the
Purchase Agreement, including the Letter Agreement:

          Section 1(c) of the Purchase Agreement is amended to define the
          "Additional Closing Date" as "June 1, 1998 (or such later date as is
          mutually agreed to by the Company and the Buyers)" rather than the
          Additional Closing Date currently set forth in Section 1(c) of the
          Purchase Agreement.  Each of the Buyers acknowledges it has received
          the Additional Share Notice.

     Except as modified herein, the Purchase Agreement, including the Letter
Agreement, remain in full force and effect in accordance with its terms.
Pursuant to Section 2(b)(ii) of the Statement of Designations, Preferences and
Rights of Series C Convertible Participating Preferred Stock of DATA RACE, Inc.
(the "Statement of Designations"), any Additional Preferred Shares issued on
June 1, 1998 will have an initial Fixed Conversion Price equal to 120% of the
Market Price (as defined in the Statement of Designations) of the Common Stock
on June 1, 1998.

     The Company agrees that, on or before April 15, 1998, the Company shall
publicly disclose the terms of this letter agreement.

 
     This letter agreement is effective April 14, 1998 and shall be binding upon
the parties and their successors and assigns and may be amended or terminated
only by a writing signed by all the parties hereto.

     Please indicate your agreement to the above by signing in the space
provided below and faxing a signed copy to each of the Buyers listed below.

BUYERS:

NELSON PARTNERS


By: /s/ ANNE DUPUY
   -------------------------------------
   Name:    Anne Dupuy
   Title:   Officer


OLYMPUS SECURITIES, LTD.


By: /s/ ANNE DUPUY
   -------------------------------------
   Name:    Anne Dupuy
   Its:     Director


CC INVESTMENTS, LDC


By: /s/ JOHN D. ZIEGELMAN
   -------------------------------------
   Name:    John D. Ziegelman
   Title:   Director


CAPITAL VENTURES INTERNATIONAL
   By:      Heights Capital Management
   Its:     Authorized Agent


By: /s/ MICHAEL SPOLAN
   -------------------------------------
   Name: Michael Spolan
   Its:  Secretary and General Counsel


                                 Accepted and agreed to this
                                 14th day of April, 1998:


                                 DATA RACE, INC.


                                 By: /s/ GREGORY T. SKALLA
                                    -------------------------------------
                                    Gregory T. Skalla
                                    Vice President and Chief Financial Officer