<PAGE>


                                    AMENDMENT

          AMENDMENT,  dated as of January 15, 1996, among Zivi R. Nedivi,  Joram
D.  Rosenfeld  and  Yoav  Stern  (each a  "Stockholder"  and  collectively,  the
"Stockholders").

                              W I T N E S S E T H:
                              - - - - - - - - - -

          WHEREAS,  the  Stockholders  are parties to a  Stockholders  Agreement
dated  August 24,  1995 (the  "Stockholders  Agreement"),  pursuant to which the
Stockholders  agreed,  among other things,  to restrict the  disposition  of the
Shares owned by them (capitalized  terms used herein not otherwise defined shall
have the meanings given to them in the Stockholders Agreement);

          WHEREAS,  on the date  hereof,  the  Stockholders  have  formed  Helix
Capital Corporation, L.L.C., a Delaware limited liability company ("Helix");

          WHEREAS, the Stockholders desire to contribute capital to Helix in the
form of the  promissory  notes  attached  hereto as Exhibit A (the  "Notes") and
Helix is desirous of accepting such capital  contribution  on the condition that
the Shares are pledged as collateral for the Notes;

          WHEREAS,  in connection  therewith,  the  Stockholders  have agreed to
amend the Stockholders  Agreement pursuant to the terms and provisions contained
herein;

          NOW, THEREFORE,  for good and valuable consideration,  the receipt and
sufficiency of which are hereby acknowledged, the parties hereto hereby agree as
follows:

          1. Disposition of Shares.  Section 3(a) of the Stockholders  Agreement
is hereby amended by adding at the end thereof the following phrase:

          "and the issuance of, and in  accordance  with the terms of,
          the Secured  Non-Recourse  Promissory  Notes  issued by each
          Stockholder to Helix Capital Corporation, L.L.C. on the date
          hereof,  which Notes are secured by, among other things, the
          Shares."

          2.  Exercise by Helix.  The  Stockholders  agree that  notwithstanding
anything contained in the Stockholders  Agreement to the contrary,  any exercise
by Helix of the rights  granted to it pursuant to the Notes shall not constitute
a  violation  or  breach  of  the  Stockholders  Agreement,   including  without
limitation, the right to


<PAGE>

<PAGE>


purchase  the  Shares in  accordance  with the terms of the Notes and the right,
upon a default of the Notes, to exercise all ownership rights to the Shares.

          3. Stockholder  Capacity.  Each  Stockholder  executing this Amendment
does not make any  agreement  or  understanding  herein  in his  capacity  as an
officer  or  director  of the  Company.  Each  Stockholder  signs  solely in his
capacity as the record and beneficial  owner of, or the trustee of a trust whose
beneficiaries are the beneficial owners of, such Stockholder's Shares.

          4. Governing  Law. This Amendment  shall be governed by, and construed
in accordance with, the laws of the State of New York,  without giving effect to
the principles of conflicts of laws thereunder.

          5. Effect of  Amendment.  Except as expressly  set forth  herein,  the
amendments  contained  herein shall not  constitute a waiver or amendment of any
term or  provision  of the  Stockholders  Agreement,  and  all  such  terms  and
provisions  shall  remain in full force and effect and are hereby  ratified  and
confirmed in all respects.

          6.  Counterparts.  This  Amendment  may be  executed  in any number of
counterparts, each of which when so executed being deemed an original and all of
which taken together constituting one and the same agreement.

          7. Section Headings. The section headings contained herein are for the
purpose of convenience only and are not intended to define or limit the contents
thereof.

          IN WITNESS  WHEREOF,  the parties  have caused  this  Amendment  to be
executed as of the date first above written.


                                            ---------------------------------
                                            Zivi R. Nedivi

                                            ---------------------------------
                                            Joram D. Rosenfeld

                                            ---------------------------------
                                            Yoav Stern


                                       -2-





<PAGE>