
                          
                           TRIMBLE NAVIGATION LIMITED

                                 FIRST AMENDMENT
                                       to
                           REVOLVING CREDIT AGREEMENT


         This FIRST AMENDMENT (the "Amendment"),  dated as of April 30, 1996, is
among Trimble  Navigation  Limited (the "Borrower"),  The First National Bank of
Boston  ("FNBB"),  Mellon  Bank,  N.A.  ("Mellon"  and together  with FNBB,  the
"Banks"),  and The First  National  Bank of Boston as agent for  itself  and the
other Banks (the "Agent").

         WHEREAS,  the  Borrower,  the Banks and the Agent are  parties  to that
certain  Revolving  Credit  Agreement,  dated as of August 4, 1995 (the  "Credit
Agreement"),  pursuant to which the Banks,  upon certain  terms and  conditions,
have  made  loans to and may issue  letters  of credit  for the  benefit  of the
Borrower; and

         WHEREAS, the Borrower had requested that the Banks agree, and the Banks
have agreed,  on the terms and subject to the  conditions  set forth herein,  to
make certain changes to the Credit Agreement;

         NOW, THEREFORE, the parties hereto hereby agree as follows:

         P 1. Defined  Terms.  Capitalized  terms  which are used  herein  
without  definition  and which are  defined in the Credit Agreement shall 
have the same meanings herein as in the Credit Agreement.

         P 2. Amendment of Credit  Agreement.  Section 9.1 of the Credit 
Agreement is hereby amended by deleting from clause (i) of such P 9.1
the parenthetical "(treated as a single accounting period)".

         P 3.  Affirmation and Acknowledgment of the Borrower.  The Borrower
hereby  ratifies and confirms all of its  Obligations  to the Banks,  including,
without limitation,  the Revolving Credit Loans, and the Borrower hereby affirms
its absolute and unconditional  promise to pay to the Banks the Revolving Credit
Loans and all other amounts due under the Credit Agreement as amended hereby.

         P 4. Representations and Warranties.  The Borrower hereby represents 
and warrants to the Banks as follows:

                  (a)  The  execution  and  delivery  by the  Borrower  of  this
         Amendment and the  performance by the Borrower of its  obligations  and
         agreements  under this  Amendment  and the Credit  Agreement as amended
         hereby, are within the corporate  authority of the Borrower,  have been
         authorized  by all  necessary  corporate  proceedings  on behalf of the
         Borrower,  and do not and will not  contravene  any provision of law or
         any of the Borrower's charter,  other incorporation papers,  by-laws or
         any stock  provision  or any  amendment  thereof  or of any  indenture,
         agreement, instrument or undertaking binding upon the Borrower.

                                      (19)
<PAGE>


                  (b) This Amendment and the Credit  Agreement as amended hereby
         constitute  legal,  valid  and  binding  obligations  of the  Borrower,
         enforceable  in  accordance  with  their  respective  terms,  except as
         limited  by  bankruptcy,  insolvency,  reorganization,   moratorium  or
         similar laws  relating to or affecting  generally  the  enforcement  of
         creditors' rights.

                  (c)  No  approval  or  consent   of,  or  filing   with,   any
         governmental  agency or authority is required to make valid and legally
         binding the execution,  delivery or performance by the Borrower of this
         Amendment  or  the  Credit   Agreement  as  amended   hereby,   or  the
         consummation  by the  Borrower  of the  transactions  among the parties
         contemplated hereby and thereby or referred to herein.

                  (d) The representations and warranties contained in P 6 of
         the Credit Agreement were correct at and as of the date made. Except to
         the  extent  that  the  facts  upon  which  such   representations  and
         warranties  were based have changed in the ordinary  course of business
         (which  changes,  either  singly  or in the  aggregate,  have  not been
         materially  adverse) and after giving effect to the provisions  hereof,
         such  representations  and warranties also are correct at and as of the
         date hereof.

                  (e) The Borrower has  performed  and complied in all materials
         respects with all terms and conditions  herein required to be performed
         or complied  with by it prior to or at the time  hereof,  and as of the
         date hereof, after giving effect to the provisions hereof, there exists
         no Event of Default or Default.

       P 6. Effectiveness.  The  effectiveness  of this  Amendment  shall be
subject to the  satisfaction  of the following condition:

                  (a) Delivery.  Each of the  Borrower,  the Banks and the 
Agent  shall have  executed  and  delivered  this Amendment.

         P 7.  Miscellaneous  Provisions.  (a) Except as otherwise expressly
provided by this Amendment,  all of the terms,  conditions and provisions of the
Credit Agreement shall remain the same. It is declared and agreed by each of the
parties hereto that the Credit Agreement,  as amended hereby,  shall continue in
full force and effect, and that this Amendment and the Credit Agreement shall be
read and construed as one instrument.

                  (b) THIS  AMENDMENT IS INTENDED TO TAKE EFFECT AS AN AGREEMENT
         UNDER SEAL AND SHALL BE CONSTRUED ACCORDING TO AND GOVERNED BY THE LAWS
         OF THE COMMONWEALTH OF MASSACHUSETTS.

                  (c)  This   Amendment   may  be  executed  in  any  number  of
         counterparts,  but all such counterparts shall together  constitute but
         one  instrument.  In  making  proof of this  Amendment  it shall not be
         necessary to produce or account for more than one counterpart signed by
         each party hereto by and against which enforcement hereof is sought.

                                      (20)
<PAGE>


                  (d) Pursuant to P 15 of the Credit Agreement, the Borrower
         hereby  agrees  to  pay to the  Agent,  on  demand  by the  Agent,  all
         reasonable  out-of-pocket  costs and expenses  incurred or sustained by
         the  Agent  in  connection  with  the  preparation  of  this  Amendment
         (including reasonable legal fees).

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

                           TRIMBLE NAVIGATION LIMITED



                             By: /s/ John H. Barnet
                                Executive Vice President and
                                Chief Financial Officer

                           THE FIRST NATIONAL BANK OF
                           BOSTON, Individually, and as Agent



                            By: /s/ Lee A. Merkle
                                Vice President

                            MELLON BANK, N.A.



                            By: /s/ Jane R. Westrich
                                Vice President



                                      (21)
<PAGE>

