FOURTH AMENDED AND RESTATED MASTER LINE OF CREDIT NOTE


         THIS  FOURTH  AMENDED  AND  RESTATED  MASTER  LINE OF CREDIT NOTE (this
"Agreement")  is entered  into as of this 21st day of August  1998,  by COMARCO,
INC., a corporation  organized  under the laws of the State of  California  (the
"Borrower") in favor of NATIONSBANK,  N.A., a national banking association,  its
successors and assigns (the "Lender").

                                    RECITALS
                                    --------
         A. The  Lender  made a  secured  revolving  loan (the  "Master  Line of
Credit")  to the  Borrower in the  original  maximum  principal  amount of Eight
Million Dollars  ($8,000,000),  which Master Line of Credit is evidenced by that
certain Master Line of Credit Note (the  "Original  Master Line of Credit Note")
dated  September  26,  1994  from the  Borrower  to the  Lender  in the  maximum
principal amount of Eight Million Dollars ($8,000,000),  as amended and restated
in its entirety  pursuant to the provisions of that certain Amended and Restated
Master Line of Credit Note dated  October 31, 1995 from the Borrower in favor of
the Lender in the maximum principal amount of Eight Million Dollars ($8,000,000)
(the "First Replacement Master Line of Credit Note"), and as further amended and
restated in its  entirety  pursuant to the  provisions  of that  certain  Second
Amended and  Restated  Master Line of Credit Note dated August 30, 1996 from the
Borrower in favor of the Lender in the maximum principal amount of Eight Million
Dollars  ($8,000,000) (the "Second Replacement Master Line of Credit Note"), and
which  Second  Replacement  Master Line of Credit  Note was further  amended and
restated  in its  entirety  pursuant to the  provisions  of that  certain  Third
Amended  and  Restated  Master Line of Credit Note date August 15, 1997 from the
Borrower in favor of the Lender in the maximum principal amount of Eight Million
Dollars ($8,000,000) (the "Third Replacement Master Line of Credit Note").

         B. The Master  Line of Credit is  governed  by the  provisions  of that
certain Loan Agreement of even date with the Original Master Line of Credit Note
by and among the  Borrower,  the  Guarantors  named  therein and the Lender (the
"Original  Loan  Agreement").  The Original  Loan  Agreement was amended by that
certain (i) First  Amendment to Loan Agreement  dated  September 26, 1995 by and
among the Borrower,  the  Guarantors  named therein and the Lender,  (ii) Second
Amendment to Loan  Agreement  dated August 30, 1996,  by and among the Borrower,
the guarantors  named therein and the Lender,  and (iii) Third Amendment to Loan
Agreement dated August 15, 1997 by and among the Borrower,  the guarantors named
therein and the Lender (the Original Loan Agreement as amended from time to time
is hereafter called the "Loan Agreement"). All capitalized terms used herein and
not otherwise  defined herein shall have the meanings given to such terms in the
Loan Agreement.

         C. The  Borrower  has  requested  that the Lender  increase the maximum
principal  amount of the  Master  Line of Credit and the Lender has agreed to on
the  condition,  among  others,  that the  Borrower  execute  and  deliver  this
Agreement.
         NOW,  THEREFORE,  in  consideration  of the premises and other good and
valuable  consideration,   the  receipt  and  sufficiency  of  which  is  hereby
acknowledged, the Lender and the Borrower covenant and agree as follows:
         1. The  Recitals.  The parties  hereto  acknowledge  and agree that the
above  Recitals  are  true and  correct  in all  respects  and that the same are
incorporated herein and made a part hereof by reference.
         2. The Master Line of Credit Note. The Third Replacement Master Line of
Credit Note is hereby amended and restated in its entirety as follows:


                           MASTER LINE OF CREDIT NOTE
                           --------------------------
         $10,000,000                                            McLean, Virginia
                FOR VALUE RECEIVED, COMARCO, INC., a corporation organized under
         the laws of the State of  California (the "Borrower")promises to pay to
         the  order of  NATIONSBANK, N.A., a national banking  association,  its
         successors and assigns (the "Lender"), the principal sum of TEN MILLION
         DOLLARS ($10,000,000) (the "Principal  Sum"), or so much thereof as has
         been or may be advanced or readvanced  to or for  the  account  of  the
         Borrower,  together  with   interest  thereon  at  the  rate  or  rates
         hereinafter  provided,  in accordance with the following:

                  1.  Interest.  Except as otherwise  expressly set forth below,
         amounts outstanding  hereunder shall bear interest at the Prime Rate or
         the Floating  LIBOR Rate. For purposes  hereof,  the "Prime Rate" means
         the fluctuating prime rate of interest  established and declared by the
         Lender from time to time. The Prime Rate does not necessarily represent
         the lowest rate of interest charged by the Lender to its borrowers. For
         purposes  hereof,  the  "Floating  LIBOR Rate" shall mean a fluctuating
         rate of  interest  equal to the one  month  rate of  interest  (rounded
         upwards, if necessary to the nearest 1/100 of 1%) appearing on Telerate
         Page 3750 (or any  successor  page) as the one month  London  interbank
         offered  rate for  deposits  in  Dollars  at  approximately  11:00 a.m.
         (London  time) on the second  preceding  business day as adjusted  from
         time to time in Lender's sole  discretion for then  applicable  reserve
         requirements,  deposit insurance  assessment rates and other regulatory
         costs.  If for any reason such rate is not  available,  the term "LIBOR
         Rate"  shall mean the  fluctuating  rate of  interest  equal to the one
         month rate of interest  (rounded  upwards,  if necessary to the nearest
         1/100 of 1%)  appearing  on Reuters  Screen  LIBO Page as the one month
         London interbank  offered rate for deposits in Dollars at approximately
         11:00 a.m.  (London  time) on the second  preceding  business  day,  as
         adjusted  from  time to time  in  Lender's  sole  discretion  for  then
         applicable reserve requirements, deposit insurance assessment rates and
         other regulatory  costs;  provided,  however,  if more than one rate is
         specified on Reuters Screen LIBO page, the applicable rate shall be the
         arithmetic  mean of all such  rates.  "Telerate  Page  3750"  means the
         British Bankers  Association  Libor Rates  (determined as of 11:00 a.m.
         London time) that are published by Dow Jones Telerate, Inc.

                  So long as no event of default or any act,  event or condition
         which,  with notice or the passage of time or both, would constitute an
         event  of  default   under  any  Loan  Document  has  occurred  and  is
         continuing,  the Borrower  shall have the right to elect that specified
         amounts  advanced under this Note, bear interest for specified  periods
         (each being herein  referred to as a "LIBOR Rate Funding  Period"),  at
         the LIBOR Rate,  plus one and one half  percent  (1.50%)(the  "Adjusted
         LIBOR Rate"). Election by the Borrower of a LIBOR Rate interest rate as
         herein provided shall be made in a writing  delivered to the Lender not
         less than  three  (3)  Banking  Days  prior to the date of on which the
         LIBOR Rate is to begin,  and shall specify (1) the Banking Day on which
         the LIBOR  Rate is to be  effective  and the period for which the LIBOR
         Rate shall be  applicable  (which  shall be only 30, 60, 90 or 180 days
         and the expiration of which may not be later than the "Maturity Date");
         and (2) the principal  amount of this Note which shall bear interest at
         the Adjusted LIBOR Rate (each being herein referred to as a "LIBOR Rate
         Funding  Segment").  The  Borrower  may not  revoke  any such  election
         without  the  Lender's  written  consent.  Upon  the  expiration  of an
         applicable  LIBOR  Rate  Funding  Period,  unless  notice of LIBOR Rate
         election  from the  Borrower,  the rate of interest  applicable  to any
         LIBOR  Rate  Funding  Segment  (after  the  expiration  thereof)  shall
         automatically  convert at the end of the applicable  LIBOR Rate Funding
         Period, to the Prime Rate.

         For purposes hereof,  the "LIBOR Rate" shall mean the per annum rate of
         interest, as determined by the Lender in its sole discretion,  at which
         deposits in United States Dollars in an amount  approximately  equal to
         the  amount  for  which  the  rate is to be fixed  and with  maturities
         comparable to the interest period  selected by the Borrower,  to be the
         averages  of rates per annum for 11:00  a.m.  (London,  time),  two (2)
         Banking Days prior to the first day of such LIBOR Rate  Funding  Period
         for delivery on the first such day of such LIBOR Rate  Funding  Period,
         in amounts comparable to the applicable LIBOR Rate Funding Segment,  as
         adjusted for Federal  Reserve  Board reserve  requirements  and similar
         assessments, if any, imposed upon the Lender.

                  All  interest  payable  under the terms of this Note  shall be
         calculated on the basis of a 360-day year and the actual number of days
         elapsed.

                  2. Payments and Maturity.  The unpaid Principal Sum,  together
         with interest  thereon at the rate or rates  provided  above,  shall be
         payable as follows:

                           (a) Except as otherwise  provided in this Note,  this
         Note shall be payable in successive monthly installments of accrued and
         unpaid interest only, on the last day of each month commencing July 31,
         1998, and on the last day of each month thereafter to maturity;

                           (b) Unless  sooner paid,  the unpaid  Principal  Sum,
         together with all accrued and unpaid interest  thereon shall be due and
         payable in full on June 30, 2000.

                           The fact that the balance hereunder may be reduced to
         zero from time to time pursuant to the Loan  Agreement  will not affect
         the  continuing  validity of this Note or the Loan  Agreement,  and the
         balance may be increased to the Principal Sum after any such  reduction
         to zero.

                  3.  Default  Interest.  Upon  the  occurrence  of an  Event of
         Default (as hereinafter  defined),  the unpaid Principal Sum shall bear
         interest  thereafter  at a rate two percent (2%) per annum in excess of
         the then highest current rate or rates of interest hereunder until such
         Event of Default is cured.

                  4.  Late  Charges.  If the  Borrower  shall  fail to make  any
         payment  under the terms of this Note  within  five (5) days  after the
         date such  payment  is due,  the  Borrower  shall pay to the  Lender on
         demand a late charge equal to five percent (5%) of such payment.

                  5. Application and Place of Payments.  All payments  hereunder
         shall be applied  first to the payment of any late charges and costs of
         collections  then due  hereunder,  second to the payment of accrued and
         unpaid interest then due hereunder, and the remainder, if any, shall be
         applied to the unpaid  Principal  Sum.  Notwithstanding  the foregoing,
         accrued and unpaid interest on amounts  outstanding  hereunder  bearing
         interest on a LIBOR Rate basis shall be due and payable on the last day
         of the applicable  LIBOR Rate Funding Period (as herein defined) and if
         such LIBOR Rate Funding  Period is longer than ninety (90) days, on the
         ninetieth (90th) day of each LIBOR Rate Funding Period. All payments on
         account of this Note shall be paid in lawful money of the United States
         of  America  in  immediately  available  funds on or before  11:00 a.m.
         (Washington,  D.C. time) at its principal office in McLean, Virginia or
         at such  other  times and places as the Lender may at any time and from
         time to time designate in writing to the Borrower.

                  6.  Prepayment.  The  Borrower  may  prepay  amounts  accruing
         interest  based on the  Prime  Rate,  in whole or in part,  at any time
         without notice to the Lender without premium or penalty.  No prepayment
         of any other amounts  outstanding  hereunder shall be permitted without
         the prior written consent of the Lender.

                  7. Loan Agreement and Other Loan  Documents.  This Note is the
         "Master Line of Credit Note"  described in a Loan Agreement dated as of
         September  26,  1994 by and among the  Borrower  and  Comarco  Wireless
         Technologies,  Inc.,  International Business Services,  Inc., Decisions
         and Designs,  Inc.,  LCTI,  Inc. (the  "Original  Guarantors")  and the
         Lender,  as  amended  by (i)  that  certain  First  Amendment  to  Loan
         Agreement  dated  September 26, 1995,  by and among the  Borrower,  the
         Original  Guarantors and the Lender, (ii) that certain Second Amendment
         to Loan Agreement dated August 30, 1996, by and among the Borrower, the
         Original Guarantors,  Manufacturing  Training Technology,  Center, Inc.
         ("MTTCI"),   Comarco  Staffing,   Inc.   (formerly  known  as  CoSource
         Solutions,  Inc.)  ("CSI") and the  Lender,  (iii) that  certain  Third
         Amendment  to Loan  Agreement  dated as of August 15, 1997 by and among
         the Borrower,  the Original  Guarantors,  MTTCI,  CSI, Comarco Systems,
         Inc.,  Comarco Wireless  International,  Inc. and the Lender,  and (iv)
         that certain  Fourth  Amendment to Loan Agreement of even date herewith
         by and among the Borrower, the Original Guarantors, MTTCI, CSI, Comarco
         Systems, Inc., Comarco Wireless International,  Inc. and the Lender (as
         amended, modified, restated,  substituted,  extended and renewed at any
         time and from time to time,  the "Loan  Agreement").  The  indebtedness
         evidenced  by this Note is  included  within  the  meaning  of the term
         "Obligations"  as  defined  in  the  Security   Agreement.   This  Note
         increases,  amends and  restates in its  entirety  that  certain  Third
         Amended and  Restated  Master Line of Credit Note dated August 15, 1997
         in the maximum  principal amount of Eight Million Dollars  ($8,000,000)
         from the Borrower in favor of the Lender.  The term "Loan Documents" as
         used in this Note shall mean  collectively  this Note, any  Acquisition
         Term Note, the Loan Agreement and any other instrument,  agreement,  or
         document   previously,   simultaneously,   or  hereafter  executed  and
         delivered by the  Borrower,  the  Guarantors  and/or any other  person,
         singularly  or jointly  with any other  person,  evidencing,  securing,
         guaranteeing, or in connection with the Principal Sum, this Note and/or
         the Loan Agreement. All capitalized terms used herein and not otherwise
         defined  shall  have  the  meanings  given  to such  terms  in the Loan
         Agreement.

                  8. Events of Default. The occurrence of any one or more of the
         following events shall constitute an event of default (individually, an
         "Event of Default" and collectively, the "Events of Default") under the
         terms of this Note:

                           (a) The failure of the  Borrower to pay to the Lender
         within  five (5) days of when due any and all  amounts  payable  by the
         Borrower to the Lender under the terms of this Note; or

                           (b) The occurrence of an event of default (as defined
         therein)  under  the  terms and  conditions  of any of the  other  Loan
         Documents, including, but not limited to the Loan Agreement.

                  9. Remedies.  Upon the  occurrence of an Event of Default,  at
         the option of the Lender,  all amounts  payable by the  Borrower to the
         Lender  under the terms of this Note shall  immediately  become due and
         payable by the Borrower to the Lender  without  notice to the Borrower,
         or any other  person,  and the  Lender  shall  have all of the  rights,
         powers, and remedies available under the terms of this Note, any of the
         other  Loan  Documents  and all  applicable  laws.  The  Borrower,  the
         Guarantors and all endorsers, guarantors, and other parties who may now
         or in the future be primarily or secondarily  liable for the payment of
         the  indebtedness   evidenced  by  this  Note  hereby  severally  waive
         presentment,  protest and demand,  notice of protest,  notice of demand
         and of dishonor and  non-payment of this Note and expressly  agree that
         this Note or any payment  hereunder  may be extended  from time to time
         without in any way affecting  the  liability of the  Borrower,  and any
         guarantors and endorsers.

                  10.  Expenses.  The Borrower  promises to pay to the Lender on
         demand by the Lender all costs and  expenses  incurred by the Lender in
         connection with the collection and enforcement of this Note, including,
         without  limitation,  reasonable  attorneys'  fees and expenses and all
         court costs.

                  11.  Notices.  Any notice,  request,  or demand to or upon the
         Borrower or the Lender shall be deemed to have been  properly  given or
         made when delivered in accordance with the Loan Agreement.

                  12. Miscellaneous. Each right, power, and remedy of the Lender
         as provided for in this Note or any of the other Loan Documents, or now
         or hereafter  existing under any  applicable law or otherwise  shall be
         cumulative  and  concurrent  and shall be in  addition  to every  other
         right,  power,  or remedy provided for in this Note or any of the other
         Loan Documents or now or hereafter  existing under any applicable  law,
         and the  exercise or beginning of the exercise by the Lender of any one
         or more of such  rights,  powers,  or remedies  shall not  preclude the
         simultaneous  or later  exercise by the Lender of any or all such other
         rights,  powers,  or  remedies.  No  failure  or delay by the Lender to
         insist upon the strict performance of any term, condition, covenant, or
         agreement  of  this  Note or any of the  other  Loan  Documents,  or to
         exercise any right,  power, or remedy consequent upon a breach thereof,
         shall  constitute a waiver of any such term,  condition,  covenant,  or
         agreement or of any such breach, or preclude the Lender from exercising
         any such right, power, or remedy at a later time or times. By accepting
         payment  after the due date of any  amount  payable  under the terms of
         this Note,  the Lender shall not be deemed to waive the right either to
         require prompt payment when due of all other amounts  payable under the
         terms of this Note or to declare an Event of Default for the failure to
         effect  such  prompt  payment  of any such other  amount.  No course of
         dealing or conduct shall be effective to amend, modify, waive, release,
         or change any provisions of this Note.

                  13.  Partial  Invalidity.  In the event any  provision of this
         Note (or any  part of any  provision)  is held by a court of  competent
         jurisdiction to be invalid,  illegal,  or unenforceable in any respect,
         such invalidity,  illegality,  or unenforceability shall not affect any
         other  provision (or remaining part of the affected  provision) of this
         Note; but this Note shall be construed as if such invalid,  illegal, or
         unenforceable  provision  (or part  thereof) had not been  contained in
         this  Note,  but  only  to  the  extent  it  is  invalid,  illegal,  or
         unenforceable.

                  14.   Captions.   The  captions   herein  set  forth  are  for
         convenience only and shall not be deemed to define,  limit, or describe
         the scope or intent of this Note.

                  15. Applicable Law. The Borrower  acknowledges and agrees that
         this  Note  shall  be  governed  by the  laws  of the  Commonwealth  of
         Virginia,  even  though for the  convenience  and at the request of the
         Borrower, this Note may be executed elsewhere.

                  16. Arbitration. Any controversy or claim between or among the
         parties  hereto  including  but not limited to those  arising out of or
         relating  to  this  Agreement  or any of the  other  Loan  Documents  ,
         including any claim based on or arising from any alleged tort, shall be
         determined  by  binding  arbitration  in  accordance  with the  Federal
         Arbitration Act (or if not applicable,  the applicable  state law), the
         rules of practice  and  procedure  for the  arbitration  of  commercial
         disputes  of  Judicial   Arbitration  and  Mediation   Services,   Inc.
         (J.A.M.S.) and the "special rules" set forth below. In the event of any
         inconsistency,  the special  rules  shall  control.  Judgment  upon any
         arbitration award may be entered in any court having jurisdiction.  Any
         party to this  agreement  may bring an action,  including  a summary or
         expedited proceeding, to compel arbitration of any controversy or claim
         to which this Agreement  applies in any court having  jurisdiction over
         such action.

                           (a) Special Rules. The arbitration shall be conducted
         in the  city of the  Borrower's  domicile  at time of this  Agreement's
         execution and administered by J.A.M.S.  who will appoint an arbitrator;
         if  J.A.M.S.  is unable or legally  precluded  from  administering  the
         arbitration,  then the American Arbitration Association will serve. All
         arbitration hearings will be commenced within 90 days of the demand for
         arbitration;  further,  the  arbitrator  shall only,  upon a showing of
         cause,  be permitted to extend the  commencement of such hearing for up
         to an additional 60 days.

                           (b) Reservation of Rights.  Nothing in this Agreement
         shall  be  deemed  to (i)  limit  the  applicability  of any  otherwise
         applicable  statutes of limitation or repose and any waivers  contained
         in this  Note  or (ii) be a  waiver  by the  Lender  of the  protection
         afforded to it by 12 U.S.C. Section 91 or any substantially  equivalent
         state law; or (iii) limit the right of the Lender (a) to exercise  self
         help remedies such as (but not limited to) setoff,  or (b) to foreclose
         against any real or personal property collateral, or (c) to obtain from
         a court provisional or ancillary  remedies such as (but not limited to)
         injunctive relief, writ of possession or the appointment of a receiver.
         Lender  may  exercise  such self  help  rights,  foreclosure  upon such
         property,  or obtain such  provisional  or ancillary  remedies  before,
         during or after the  pendency  of any  arbitration  proceeding  brought
         pursuant to this Agreement.  Neither the exercise of self help remedies
         nor the  institution  or  maintenance  of an action for  foreclosure or
         provisional  or  ancillary  remedies  shall  constitute a waiver of the
         right of any party,  including  the  claimant  in any such  action,  to
         arbitrate the merits of the controversy or claim occasioning  resort to
         such remedies.


         3.  Governing  Law,  Etc.  This  Agreement  shall  be  governed  by and
construed in accordance with the laws of the  Commonwealth of Virginia and shall
be deemed to be an instrument under seal pursuant to said law. The headings used
in this  Agreement are for the  convenience of the parties and shall not be used
to interpret or construe the provisions hereof.
         4. Not A  Novation.  It is  expressly  understood  and agreed  that the
indebtedness  evidenced by the Third Replacement  Master Line of Credit Note has
not been  extinguished or discharged  hereby.  The Borrower and the Lender agree
that the  execution  of this  Agreement  is not  intended and shall not cause or
result in a novation with regard to the Third Replacement  Master Line of Credit
Note.
         WITNESS the signature  and seal of the Borrower by its duly  authorized
officer as of the day and year first above written.
WITNESS/ATTEST:                                      COMARCO, INC.


______________________________            By:_____________________________(SEAL)
                                             Name:
                                             Title: