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                                      AGREEMENT



    THIS AGREEMENT is made this 17th day of March 1997 between Zycad
Corporation ("Zycad") and Halifax Fund, L.P., Capital Ventures Intn'l, Heracles
Fund, Lewis A. Fraser and Joseph A. Umbach (collectively "Investors").


    WHEREAS, Investors participated in a $5 million Debenture financing with
Zycad in February 13, 1997, of which $3.5 million was funded on or about
February 14, 1997 and $1.5 million will be funded when the S-3 for the
underlying common stock is effective and registered with the SEC (the
"Debentures"), and


    WHEREAS, the Investors and Zycad are desirous of converting the Debentures
to Preferred Stock with essentially the same terms and conditions. 

    NOW, THEREFORE, it is mutually agreed as follows:

    1.   Zycad and the Investors agree to convert the Debentures into $5
         million Series A Preferred Stock of Zycad, convertible into Zycad
         Common Stock upon the same terms and conditions as the Debentures. 
         The Preferred Stock would have the same economic and financial terms
         as the Debentures and the other terms and conditions shall be
         essentially the same as the Debentures, and shall otherwise be
         acceptable to each subscriber and its representatives, in their sole
         discretion.
         
    2.   Zycad agrees not to issue any convertible instrument which would be
         senior to the Preferred Stock being issued under this Agreement.
         
    3.   In the event the Common Stock of the Company trades at a closing price
         below $1.25 for more than five (5) consecutive trading days, Zycad
         agrees to seek shareholder approval for additional shares of common
         stock to be reserved for conversion of the Preferred Stock.
         
    4.   Zycad agrees to have its counsel, Wilson, Sonsini, Goodrich and
         Rosati, draft the documents necessary to complete the conversion of
         the Debentures into Series A Preferred Stock and shall pay for the
         attorneys fees of the attorney(s) representing the Investors for the
         document.  Investors will use their best efforts minimize attorney's
         fees.
         
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    IN WITNESS WHEREOF, the parties have signed below as of the date first
above written.

--------------------------------       ------------------------------------
Halifax Fund, L.P.                     Capital Ventures International
By:  The Palladin Group, L.P.
Its:  Investment Advisor

By: /s/ Andrew Kaplan                  By: /s/ Andrew Frost
   ------------------------------         ---------------------------------
Name: Andrew Kaplan                    Name:  Andrew Frost
     ----------------------------           -------------------------------
Title: Vice President                  Title: Director
     ----------------------------            ------------------------------
Date: 5/15/97                          Date: /5/15/97
     ----------------------------           -------------------------------

                                                                
--------------------------------       ------------------------------------
Heracles Fund                          Joseph A. Umbach    
By: Promethean Investment Grp. L.L.C.  By: Promethean Investment Grp, L.L.C.
Its:  Investment Advisor               Its:  Investment Advisor

By: /s/ James F. O'Brien               By: /s/ James F. O'Brien
   ------------------------------         ---------------------------------
Name: James F. O'Brien                 Name: James F. O'Brien
     ----------------------------           -------------------------------
Title: President                       Title: President
     ----------------------------            ------------------------------
Date: 5/15/97                          Date: 5/15/97
     ----------------------------           -------------------------------
                                                                

--------------------------------       ------------------------------------
Lewis A. Fraser                        Zycad Corporation
By:  Promethean Investment Group,
     L.L.C.    
Its:  Investment Advisor                    

By: /s/ James F. O'Brien               By: /s/ Phillips W. Smith
   ------------------------------         ---------------------------------
Name: James F. O'Brien                 Name: Phillips W. Smith
     ----------------------------           -------------------------------
Title: President                       Title: President and Chief Executive 
                                                         Officer
     ----------------------------            ------------------------------
Date: 5/15/97                          Date: 5/15/97
     ----------------------------           -------------------------------


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