THIS FOURTEENTH  AMENDMENT TO CREDIT  AGREEMENT  (this  "Amendment") is
made and  entered  into as of the 4th day of August  1995,  by and  among  Telos
Corporation,  a Maryland  corporation  (formerly  known as C3,  Inc., a Maryland
corporation),   Telos  Corporation,   a  California  corporation   (individually
"Borrower" and collectively  "Borrowers") and  NationsBank,  N.A.,  successor by
merger to American Security Bank, N.A. (the "Bank" or "Agent").

                                   WITNESSETH:

         A.  Borrowers,  the  Bank  and the  Agent  entered  into  that  certain
Revolving and Reducing Senior Facility Credit Agreement, dated as of January 14,
1992 (the "Original Credit Agreement").

         B.  Borrowers,  the Bank and the Agent  entered into an  Agreement  and
Waiver dated as of July 20, 1992,  an Amendment  dated as of October 1, 1992, an
Amendment  dated as of January 15, 1993, an Amendment dated as of June 30, 1993,
an Amendment  dated as of August 31, 1993,  an Amendment  dated as of October 5,
1993, an Amendment dated as of December 31, 1993, an Amendment dated as of April
11,  1994,  an  Amendment  dated as of June 8, 1994,  an  Amendment  dated as of
October 7, 1994, an Amendment dated as of January 5, 1995, an Amendment dated as
of January  12, 1995 and an  Amendment  and Waiver  dated as of April 17,  1995,
whereby Borrowers,  the Agent and the Bank agreed,  among other things, to amend
certain  provisions  of the  Original  Credit  Agreement  (the  Original  Credit
Agreement,  as so  amended,  shall be  hereinafter  referred  to as the  "Credit
Agreement").

         C.  Borrowers,  the  Agent and the Bank  further  desire,  pursuant  to
Section 11.1 of the Credit Agreement,  to amend certain provisions of the Credit
Agreement  to enable the Bank,  upon  request  of  Borrowers,  to issue  standby
letters of credit, all on the terms and conditions set forth below.

         NOW  THEREFORE,  for good and valuable  consideration,  the receipt and
sufficiency  of which are hereby  acknowledged,  the  parties,  intending  to be
legally bound, hereby agree as follows:

         Section  1.  Definitions.  All  terms  used in this  Amendment  and not
otherwise  defined shall have the meanings  ascribed to such terms in the Credit
Agreement.

         Section  2.  Amendment  to  Definitions.  Section  1.2  of  the  Credit
Agreement is hereby  amended by the addition of the following  definition in the
appropriate places in such section:



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         "Application:  The meaning specified in Section 2A(a).

               Issuance Effective Date:  The meaning specified in Section 2A(b).

               Letter of Credit:  The meaning specified in Section 2A(a).

               Periodic LC Fee:  The meaning specified in Section 2A(b).

         Section 3. Letters of Credit. The Credit Agreement is hereby amended by
adding an Article IIA to the Credit Agreement after Article II, which shall read
as follows:

                                  "ARTICLE IIA

                                LETTERS OF CREDIT

         (a) Issuance. Borrowers and the Bank acknowledge that from time to time
Borrowers may request that the Bank issue a standby  letter or letters of credit
(each being herein  referred to as a "Letter of  Credit"),  in  connection  with
Borrowers' business  operations.  Any such request by Borrowers shall be made by
Borrowers submitting to the Bank an Application and Agreement for Standby Letter
of Credit  (each being  herein  referred to as an  "Application")  on the Bank's
standard form,  which  Application  shall be executed by authorized  officers of
each Borrower,  and be accompanied by such other  supporting  documentation  and
information,  borrowing and other corporate  resolutions and opinions of counsel
as the Bank may from time to time request.  Each Application  shall be deemed to
govern  the  terms  of  issuance  of the  subject  Letter  of  Credit;  it being
understood, however, that the fees for issuance thereof shall be as set forth in
Section 2A(b).

         (b)  Fees.  In  addition  to the  payment  of all fees as set  forth in
Section 2.6,  Borrowers  shall pay to the Bank the  following for each Letter of
Credit  issued  by the  Bank  for  the  benefit  of  Borrowers:  (i) a  one-time
origination fee in the amount of Three Hundred Dollars  ($300.00),  payable upon
the  issuance of each such  Letter of Credit,  and (ii) for each three (3) month
period (or partial  three (3) month  period)  during which such Letter of Credit
remains outstanding, a fee (the "Periodic LC Fee") in the amount of 1/2 of 1% of
the original  face amount of such Letter of Credit,  with the first  Periodic LC
Fee payment being payable on the date of issuance of such Letter of Credit,  and
each  subsequent  Periodic LC Fee payment  being payable in advance on the first
Banking Day of each and every  successive  third (3rd)  calendar month after the
Issuance Effective Date until such Letter of Credit is canceled or expires.  For
purposes of this Section 2A(b), the "Issuance Effective Date" shall be deemed to
be the  first  day of the  calendar  month in which a Letter of Credit is issued
(irrespective of the actual date of issuance). Notwithstanding the foregoing, it
is expressly  understood and agreed that the Bank shall not issue any Letters of
Credit having an expiration date beyond the Maturity Date.


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         (c) Other  Matters.  In the  event the Bank  issues  any  Letter(s)  of
Credit, (i) the maximum amount of credit available under the Commitment shall be
reduced by the face  amount of each  Letter of Credit (so long as such Letter of
Credit  remains  outstanding),  and (ii) any  amounts  drawn under any Letter of
Credit  shall be deemed a Loan and shall be  deemed to be an  advance  under the
Note,  shall bear  interest and be payable in  accordance  with the terms of the
Note and shall be secured by the Security  Documents  (in the same manner as all
other sums advanced under the Note). It is expressly  understood and agreed that
all  obligations and liabilities of Borrowers to the Bank in connection with any
such Letter(s) of Credit shall be deemed to be  Obligations,  and the Bank shall
have no obligation to release its rights under the Security  Documents until the
Note and all other sums due to the Bank in  connection  with the Loans have been
paid and satisfied in full,  all Letters of Credit have been canceled or expired
(i.e.,  none  are  outstanding),  and the  Bank  has no  further  obligation  or
responsibility  to make additional Loans or issue additional  Letters of Credit.
Furthermore,  in no event whatsoever shall the Bank have any obligation to issue
any Letter of Credit  which would cause the face amount of all then  outstanding
Letters of Credit issued by the Bank for the benefit of Borrowers to exceed,  in
the aggregate, Three Hundred Thousand Dollars ($300,000.00)."

         Section 4. Conditions  Precedent to this  Amendment.  The provisions of
this Amendment are  conditioned  upon, and shall not become  effective until the
occurrence of, each of the following:

         (a)      Borrowers   shall  have  delivered  to  the  Agent   certified
                  corporate  resolutions  approving  the  transaction  described
                  herein,  which shall be  satisfactory to the Agent in its sole
                  and absolute discretion.

         (b)      No litigation,  proceeding or any other action shall have been
                  filed,   or  threatened  to  be  filed,  by  any  party  which
                  challenges, seeks to enjoin, restrain or prohibit or to obtain
                  damages in respect of or which is related to the  transactions
                  contemplated by this Amendment.

         Section 5. No Waiver.  Notwithstanding  execution of this Amendment and
the  extension  of  Loans  by the  Bank to  Borrowers  in  accordance  with  the
provisions hereof,  neither the Bank nor the Agent is waiving,  and shall not be
deemed to have waived,  any of their  respective  rights under any provisions of
the Credit Agreement, the Note or the other Revolving Loan Documents. The Bank's
or the  Agent's  failure  to insist  upon the  strict  performance  of any term,
condition,  or other  provision of the Credit  Agreement,  the Note or the other
Revolving  Loan  Documents  or to  exercise  any  right or remedy  hereunder  or
thereunder  shall not  constitute  a waiver by the Bank or the Agent of any such
term,  condition or other provision or default or Event of 

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Default in connection therewith.

         Section 9. Continued Effect of Credit Agreement. Except as specifically
amended herein,  the Credit  Agreement is and shall continue to be in full force
and effect and is hereby ratified and confirmed in all respects.

         Section 10. Counterparts. This Amendment may be executed in one or more
counterparts,  all of which shall be considered one and the same Amendment,  and
shall  become  effective  when one or more of the same  counterparts  have  been
signed by each of the parties to this  Amendment  and delivered (by facsimile or
otherwise) to the other parties,  it being  understood  that each party need not
sign the same counterpart.

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         IN WITNESS  WHEREOF,  the Bank,  the  Agent,  and  Borrowers  have each
executed this Amendment as of the date first written above.

                                      NATIONSBANK, N.A.

                                      By:  /s/  Catherine S. Grimm
                                         -----------------------------
                                      Name:  Catherine S. Grimm
                                           ---------------------------
                                      Title:            VP
                                            --------------------------
                                      NATIONSBANK, N.A., as the Agent

                                      By:  /s/  Catherine S. Grimm
                                         -----------------------------
                                      Name:  Catherine S. Grimm
                                           ---------------------------
                                      Title:            VP
                                            --------------------------

                                      TELOS CORPORATION, formerly known as
                                      C3, Inc.

                                      By:  /s/  Gerald D. Calhoun
                                         -----------------------------
                                      Name:   Gerald D. Calhoun
                                           ---------------------------
                                      Title:Vice President Corporate Secretary
                                            -----------------------------------

                                      TELOS CORPORATION

                                      By:  /s/  Gerald D. Calhoun
                                         -----------------------------
                                      Name:   Gerald D. Calhoun
                                           ---------------------------
                                      Title:Vice President Corporate Secretary
                                            -----------------------------------



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