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                                                       REGISTRATION NO. 333-6087
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                     SECURITIES AND EXCHANGE COMMISSION
                           WASHINGTON, D.C.  20549

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                       POST-EFFECTIVE AMENDMENT NO. 1
                                     TO
                                  FORM S-4

           REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933

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                           CAYENNE SOFTWARE, INC.
                (FORMERLY BACHMAN INFORMATION SYSTEMS, INC.)
           (Exact name of registrant as specified in its charter)

      MASSACHUSETTS                                             04-2784044
(State or other jurisdiction of                                (IRS Employer
incorporation or organization)                              Identification No.)

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                        8 NEW ENGLAND EXECUTIVE PARK
                            BURLINGTON, MA  01803
                               (617) 273-9003
(Address, including zip code, and telephone number, including area code, of 
                  registrant's principal executive office)

                                PETER J. BONI
                    PRESIDENT AND CHIEF EXECUTIVE OFFICER
                           CAYENNE SOFTWARE, INC.
                        8 NEW ENGLAND EXECUTIVE PARK
                            BURLINGTON, MA  01803
                               (617) 273-9003
(Name, address, including zip code, and telephone number, including area code,
                            of agent for service)

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                                 COPIES TO:
                            David W. Walker, Esq.
                             Foley, Hoag & Eliot
                           One Post Office Square
                         Boston, Massachusetts 02109
                               (617) 832-1000

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             This filing contains 12 sequentially numbered pages
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         Registration Statement No. 333-6087 (the "Registration Statement")
covered 4,850,000 shares of Common Stock, par value $.01 per share ("Common
Stock"), of Cayenne Software, Inc. (formerly Bachman Information Systems,
Inc.), a Massachusetts corporation ("Cayenne"), to be issued to holders of
Common Stock of Cadre Technologies Inc. ("Cadre") in connection with the merger
into Cadre of a subsidiary of Cayenne (the "Merger"), pursuant to an Agreement
and Plan of Merger (the "Merger Agreement") that provided for the adjustment of
the amount of Cayeene shares to be issued and the exchange ratio.

         The Merger was consummated on July 18, 1996. Pursuant to the Merger
Agreement, the adjusted amount of Cayenne shares to be issued was determined to
be 4,808,167, and the exchange ratio was determined to be 0.3088 Cayenne share
for each outstanding share of Cadre.

         Pursuant to Rule 478 promulgated under the Securities Act of 1933, as
amended (the "Act") and the undertaking contained in the Registration Statement
pursuant to Item 512(a)(3) of Regulation S-K under the Act, Cayenne hereby
removes from registration the shares of Cayene Common Stock in excess of
4,808,167.

         At the Closing, tax opinions in the forms previously filed as Exhibits
8.1 and 8.2 to the Registration Statement were delivered. Copies of the executed
opinions are filed as Exhibits with this Amendment.


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                                   PART II

                   INFORMATION NOT REQUIRED IN PROSPECTUS

ITEM 21.                      EXHIBITS AND FINANCIAL STATEMENT SCHEDULES.



      (a)               EXHIBITS
       
      8.1 Tax opinion of Foley, Hoag & Eliot LLP, counsel to the Registrant, as
          delivered 
      8.2 Tax opinion of Testa, Hurwitz & Thibeault, counsel to Cadre, as 
          delivered




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                                  SIGNATURE

      Pursuant to the requirements of the Securities Act of 1933, as amended,
the Registrant has duly caused this Post-Effective Amendment No. 1 to the
Registration Statement to be signed on its behalf by the undersigned, thereunto
duly authorized, in the Town of Burlington, Massachusetts, on July 24, 1996.

                           CAYENNE SOFTWARE, INC.


                           By: Peter S. Boni, President
                                and Chief Executive Officer

                           By: /s/ Eugene J. DiDonato 
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                               Eugene J. DiDonato 
                               Vice President and General Counsel,
                                 Attorney-in-Fact


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