Purchase And Sale Agreement

Purchase and Sale Agreement

by Unidyne Corp
September 13th, 1996

                                                                    EXHIBIT 10.2

                              SECOND AMENDMENT TO
                          PURCHASE AND SALE AGREEMENT

         This Second Amendment to the Purchase and Sale Agreement (the
"Agreement") is entered into this 2nd day of September, 1996 by and between
Blue Jay Enterprises, Inc., a Delaware corporation ("Blue Jay"), Robert M.
Bernstein ("Bernstein"), and the following shareholders of United Dynamatics
Inc., a Delaware corporation ("UDI"); Darnley Holdings, Ltd., a Bahamian
corporation ("Darnley"); Capital Idea, Inc., a Colorado corporation; and EETC,
Ltd., a Delaware corporation, Frank B. Holze and David M. Barrett (hereinafter
the foregoing shareholders collectively are referred to as "Shareholders" and
individually referred to as a "Shareholder").


         WHEREAS, the parties hereto, except Darnley, entered into a Purchase
and Sale Agreement as of May 17, 1996, as amended by a July 31, 1996 First
Amended Purchase and Sale Agreement (collectively, the "Amended Agreements");

         WHEREAS, the parties desires to further amend the Amended Agreements
as hereinafter set forth.

         NOW, THEREFORE, the parties hereby further amend the Amended
Agreements as follows:

         1.      Section 2.1 of the Amended Agreements is hereby deleted in its
                 entirety and replaced with the following:

                 2.1      Consideration.   The consideration to be paid by Blue
                 Jay for the UDI Shares shall be in the form of shares of Blue
                 Jay Common Stock in the ratio of 3826.59 shares of newly
                 issued Blue Jay Common Stock for each outstanding share of UDI
                 Common Stock, or an aggregate 4,086,794 shares of Blue Jay
                 Common Stock (the "Blue Jay Shares").

         2.      Schedule 2.4 to the Amended Agreements is deleted in its
entirety and replaced with Schedule 2.4 to this Agreement.

         3.      Except as expressly stated herein, the terms and conditions of
the Amended Agreements shall remain in full force and effect unchanged, and the
same are hereby ratified, confirmed and reaffirmed in all respects and Lender
shall not be deemed to have waived any of its rights thereunder.

         4.      This Agreement may be executed in any number of counterparts,
each of which shall be deemed to be an original,

but all of which together shall constitute one and the same instrument.

         5.      The validity and effect of this Agreement shall be governed by
and construed and enforced in accordance with the laws of the Commonwealth of

         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
date first written above.

                                  BLUE JAY ENTERPRISES, INC.

                                  By:  /s/ ROBERT M. BERNSTEIN 
                                           Robert M. Bernstein 

                                       /s/ ROBERT M. BERNSTEIN 
                                           Robert M. Bernstein

                                  DARNLEY HOLDINGS, LTD.

                                  By:  /s/ FRANK HOLZE           

                                  E.E.T.C., Ltd.

                                  By:  /s/ FRANK HOLZE
                                           Frank B. Holze

                                       /s/ FRANK HOLZE
                                           Frank B. Holze

                                  CAPITAL IDEA, INC.

                                  By:  /s/ C. EUGENE HUTCHESON
                                           C. Eugene Hutcheson

                                       /s/ CHARLOTTE E. DOREMUS
                                           Charlotte E. Doremus

                                       /s/ DAVID M. BARRETT 
                                           David M. Barrett

                                     - 2 -
                                                                    Schedule 2.4

Blue Jay common stock to be received by each shareholder:

Capital Idea 2,174,123 Darnley 500,000 Holze 688,805 Barrett 723,866 --------- Total 4,086,794