<PAGE>

                             AMENDMENT TO LEASE AGREEMENT
                                  DATED MAY 25, 1995


     THIS IS AN AMENDMENT to that Lease Agreement dated May 25, 1995 by and 
between Firouz D. Memarzadeh and Farah R. Memarzadeh, husband and wife dba 
PARS Asset Management Company and SBS Engineering, Inc. ("Tenant").

                                      WITNESSETH:

     WHEREAS, PARS Asset Management Company and SBS Engineering, Inc. entered 
into a Lease Agreement dated May 25, 1995 ("Agreement").

     WHEREAS, PARS Sorrento Valley Science Park I LLC, a California limited 
liability company ("Landlord") is the current owner of American Financial 
Center-5 and has been assigned all rights, title and interest in the Agreement;

     NOW, THEREFORE, in consideration of the mutual covenants contained 
herein, it is agreed that the Agreement is hereby modified, amplified, and 
amended in the following respects, effective September 1, 1996.

     The parties agree as follows:

     1. Tenant hereby expands its lease to occupy a portion of Suite 300
        ("Expansion Space") comprising 3,484 Rentable Square Feet ("RSF") as
        shown on attachment "A" for a one-year term.

     2. Commencement date of the Expansion Space shall be September 1, 1996.

     3. Termination date of the Expansion Space shall be August 31, 1997.

     4. The rental rate for the Expansion Space shall be as follows:

        9/1/96 - 8/31/97   $20/sf   3,484 sf   $5,806.67/mo.  $69,680 annual

     5. Landlord will provide Tenant with $7,839 allowance ("Allowance"). This
        Allowance shall be used for Tenant move-in and Tenant improvements.
        All Tenant improvements shall be approved by Landlord. Any unused
        portion of this Allowance will be paid to Tenant upon Tenant move in.

     6. The Expansion Space shall not be subject to any operating expense
        pass-through during the term of this Amendment to Lease.
     
     7. The Tenant understands and hereby agrees that Landlord is not
        responsible for payment of any commission to any real estate broker
        or agent in connection with this Amendment to Lease Agreement and the
        Lease Expansion.


                                         Initials  [illegible]               1


<PAGE>

     8.

     9. All other terms and conditions of the Agreement shall apply to the
        Expansion Space.

    10. Tenant has the option of extending the Amendment to Lease Agreement
        for a period of one year at a rate of 5% above the rental rate for
        Expansion Space as shown in Item 4 of this Amendment by giving six
        months written notice.


    IN WITNESS WHEREOF, the parties have executed this Amendment on the 21st 
day of September, 1996.


TENANT                                    LANDLORD

SBS ENGINEERING, INC.                     PARS SORRENTO VALLEY SCIENCE
                                          PARK I LLC

By:   [illegible]                         By:   [illegible]
   ---------------------------               ---------------------------
Its:  VICE PRESIDENT                      Its:  MANAGER LLC
    --------------------------                --------------------------
     FINANCE & ADMINISTRATION


                                         Initials  [illegible]               2


<PAGE>


[Floorplan]


The Usable Square Feet of the Premises has been established using the current 
Building Owners and Managers Association international ANSI 2 65.1 method of 
measurement. Copyright 1990 (the "BOMA" Method). The Rentable Square Feet of 
the Premises has been established using a Building efficiency factor of 
Eighty-Five Percent (85%). The indicated square footage is approximate and is 
not the governing factor in monetary consideration of the lease.



NOTES
-----

1. AREA CALCULATIONS INDICATE "RENTABLE" A AS PER "BOMA" STANDARDS.

2. ALL FIXTURES INDICATED ARE BUILT-IN.

3. ALL FLOOR COVERINGS ARE CARPET (UNLESS NOTED).

4. ALL EXTERIOR WINDOWS ARE FURNISHED WITH BLINDS.

    AREA CALCULATION
    ----------------
   
    SUITE 300    3184.41 SQ. FT.



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