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                                  UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION

                             Washington, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT


     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934


                        Date of Report: February 15, 2005
                        (Date of earliest event reported)

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


                      TRANSACTION SYSTEMS ARCHITECTS, INC.
             (Exact name of registrant as specified in its charter)


          Delaware                   0-25346                     47-0772104
(State or other jurisdiction       (Commission                (I.R.S. Employer
      of incorporation)            File Number)              Identification No.)


                             224 South 108th Avenue,
                              Omaha, Nebraska 68154
          (Address of principal executive offices, including zip code)


                                 (402) 334-5101
              (Registrant's telephone number, including area code)

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


Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registrant under any of the
following provisions:

  [ ] Written communications pursuant to Rule 425 under the Securities Act
       (17 CFR 230.425)

  [ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act
       (17 CFR 240.14a-12)

  [ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the
       Exchange Act (17 CFR 240.14d-2(b))

  [ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the
       Exchange Act (17 CFR 240.13e-4(c))


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 Item 7.01.  Regulation FD Disclosure.

     On February 15, 2005, Transaction Systems Architects, Inc. issued a press
release responding to a public statement issued by JANA Partners LLC on February
14, 2005. A copy of this press release is attached hereto as Exhibit 99.1.

Item 9.01.  Financial Statements and Exhibits.

     Exhibit 99.1 -- Press Release dated February 15, 2005.












                                    SIGNATURE

     Pursuant to the requirements of the Securities Exchange Act of 1934, the
registrant has duly caused this report to be signed on its behalf by the
undersigned thereunto duly authorized.


                                          TRANSACTION SYSTEMS ARCHITECTS, INC.


 Date: February 15, 2005                  By:        /s/ Dennis P. Byrnes
                                             -----------------------------------
                                                       Dennis P. Byrnes
                                                    Senior Vice President,
                                                General Counsel and Secretary








                                  EXHIBIT INDEX

       Exhibit
       Number     Description
       -------    -----------
         99.1     Press Release dated February 15, 2005.