Exhibit 10.21

                          TAX INDEMNIFICATION AGREEMENT

      AGREEMENT made this 6th day of June, 1997, by and between Robocom Systems
Inc., a New York corporation (the "Company"), and the shareholders of the
Company named on the signature page hereto (each, a "Shareholder" and
collectively, the "Shareholders").

                               W I T N E S S E T H

      WHEREAS, since June 1990, the Company has elected to be taxed as an "S"
corporation under subchapter S of the Internal Revenue Code of 1986, as amended
(the "Code"), and under similar provisions of state and local tax laws;

      WHEREAS, the Company's election will be terminated on the date (the
"Termination Date") of its execution and delivery of an underwriting agreement
for the public offering and sale of its common stock;

      WHEREAS, for periods prior to the Termination Date (the "S Corporation
Period"), the Company's items of income, gain, loss, deduction and credit were
passed through to and reported on the individual tax returns of the Company's
shareholders;

      WHEREAS, in contemplation of the public offering and sale of the Company's
stock, the parties to this Agreement desire to set forth their rights and
obligations with respect to certain taxes and related liabilities that may be
imposed upon the Shareholders as a result of the conduct of the Company's
business during the S Corporation Period;

      NOW, THEREFORE, in consideration of the foregoing and of the mutual
promises, covenants and conditions hereinafter contained, the parties hereto
agree as follows:

      1. Indemnification. The Company agrees to indemnify, defend and hold
harmless each Shareholder from and against any and all losses, liabilities,
obligations, damages, impositions, assessments, fines, deficiencies, costs and
expenses, including without limitation reasonable attorneys' and accountants'
fees and expenses (a "Loss") with respect to any and all Federal, state or local
taxes of any kind whatsoever, including interest, penalties and additions to
taxes ("Taxes") imposed upon a Shareholder as a result of (i) any change which
results in an increase in an item of the Company's income or gain with respect
to one of the taxable years in the S Corporation Period and a corresponding
decrease in an item of the Company's income or gain with respect to another
taxable year that is not in the S 
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Corporation Period, or (ii) any change which results in a decrease in an item of
the Company's loss, deduction or credit with respect to one of the taxable years
in the S Corporation Period and a corresponding increase in an item of or loss,
deduction or credit with respect to another taxable year that is not in the S
Corporation Period.

      2. Notification of Proposed Adjustment. Each Shareholder shall notify the
Company within fifteen (15) days after receiving any notice of an intention of a
taxing authority to audit any return of such Shareholder that includes any item
of income, gain, loss, deduction or credit reported by the Company with respect
to the S Corporation Period. Each Shareholder shall notify the Company within
fifteen (15) days after receiving any notice from a taxing authority of any
proposed adjustment for which the Company may be required to indemnify such
Shareholder under this Agreement (a "Proposed Adjustment").

      3. Contest of Proposed Adjustment. Upon receipt of a notice of a Proposed
Adjustment, the Company may (i) decide not to contest the Proposed Adjustment,
(ii) require the affected Shareholder(s) to contest the Proposed Adjustment at
the Company's expense, or (iii) require the affected Shareholder(s) to permit
the Company and its representatives to contest the Proposed Adjustment at the
Company's expense. All costs of contesting the Proposed Adjustment in any forum,
including all administrative and judicial appeals, shall be borne by the
Company. If the Company requires any Shareholder to contest a Proposed
Adjustment, the Company shall pay to such Shareholder on demand all costs and
expenses (including attorneys' and accounting fees) that such Shareholder may
incur in contesting the Proposed Adjustment. No Shareholder shall make, accept
or enter into a settlement or other compromise with respect to any Proposed
Adjustment without the written consent of the Company, which consent shall not
be unreasonably withheld.

      4. Payment; Refund. Upon the final resolution of any proceeding to contest
a Proposed Adjustment, or if the Company decides not to contest or decides to
abandon its contest of a Proposed Adjustment, the Company shall pay to each
affected Shareholder, in cash, the amount of the Loss for Taxes with respect to
the Proposed Adjustment no later than 10 days prior to the due date of any
payment required to be made by such Shareholder with respect thereto. If any
portion of any Loss for Taxes paid to any Shareholder by the Company is
thereafter refunded or repaid to such Shareholder by any taxing authority, such
Shareholder shall repay to the Company the amount of such refund or repayment,
less any unreimbursed costs incurred by such Shareholder with respect to the
refund or repayment.

      5. Gross-up. If any Shareholder notifies the Company that such Shareholder
is required to include any payment received pursuant to this Agreement in
computing such Shareholder's gross income in a tax return, other than (i) any
payment received prior 


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to the expiration of the "post-termination transition period" defined in section
1377(b) of the Code, or (ii) any payment for which such Shareholder failed to
give the Company timely notice to allow the Company to make such payment prior
to the expiration of the post-termination transition period, then, in addition
to all other payments made under this Agreement, the Company shall also pay to
such Shareholder an amount which, when added to the payment so included, will
place such Shareholder in the same net after-tax position that such Shareholder
would have been in if the payment had not been so included.

      6. Tax Matters. Each Shareholder agrees to prepare all tax returns
consistent with the manner in which each item of income, gain, loss, deduction
and credit of the Company is reported to such Shareholder. Irwin Balaban is the
"tax matters person" of the Company for the S Corporation Period.

      7. Notices. Any notice requested or permitted to be given under this
Agreement shall be sufficient if in writing and either delivered in person or
sent by first class certified or registered mail, postage prepaid, if to the
Company, at the Company's principal place of business, and if to a Shareholder,
at such Shareholder's address set forth on the signature page hereto, or to such
other address or addresses as any party shall have designated in writing to the
other parties hereto.

      8. Survivability. The covenants and agreements of the parties set forth in
this Agreement shall survive indefinitely, and shall inure to the benefit of and
be binding upon the parties hereto and their respective successors and assigns.

      9. Entire Agreement. This Agreement constitutes the entire agreement of
the parties with respect to the subject matter hereof and supersedes all prior
agreements and understandings, oral or written, between the parties with respect
to the subject matter hereof.

      10. Modification. No provision of this Agreement may be amended, waived,
or otherwise modified without the written consent of the parties.

      11. Governing Law. This Agreement shall be governed by and construed in
accordance with the laws of the State of New York.

      IN WITNESS WHEREOF, this Agreement has been duly executed as of the day
and year first above written.

                                          ROBOCOM SYSTEMS INC.


                                          By: /s/ Irwin Balaban
                                              --------------------------
                                              Irwin Balaban
                                              President and Chief
                                                Executive Officer


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<PAGE>

                                          SHAREHOLDERS:


                                           /s/ Irwin Balaban          
                                          ------------------------------
                                          Irwin Balaban

                                          Address: 511 Ocean Avenue 
                                                   Massapequa,NY    


                                           /s/ Herbert Goldman        
                                          ------------------------------
                                          Herbert Goldman

                                          Address: 511 Ocean Avenue
                                                   Massapequa, NY  


                                           /s/ Lawrence Klein         
                                          ------------------------------
                                          Lawrence Klein

                                          Address: 511 Ocean Avenue 
                                                   Massapequa, NY   


                                           /s/ Steven Kuhl            
                                          ------------------------------
                                          Steven Kuhl

                                          Address: 511 Ocean Avenue 
                                                   Massapequa, NY   


                                           /s/ Robert O'Connor        
                                          ------------------------------
                                          Robert O'Connor

                                          Address: 511 Ocean Avenue 
                                                   Massapequa, NY   


                                           /s/ Chung-Hsin Lee         
                                          ------------------------------
                                          Chung-Hsin Lee

                                          Address: 511 Ocean Avenue
                                                   Massapequa, NY  


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<PAGE>

                                            /s/ Judy Frenkel          
                                          ------------------------------
                                          Judy Frenkel

                                          Address: 511 Ocean Avenue 
                                                   Massapequa, NY   


                                           /s/ Max Kurland            
                                          ------------------------------
                                          Max Kurland

                                          Address: 511 Ocean Avenue 
                                                   Massapequa, NY   


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