<PAGE>


                                                                   Exhibit 10.46


                               FOURTH AMENDMENT TO
                         SENIOR SECURED CREDIT AGREEMENT

               This Fourth Amendment to Senior Secured Credit Agreement (this
"Amendment") is entered into as of November 20, 2000, by and among The Titan
Corporation (the "Borrower"), the financial institutions party hereto (the
"Lenders"), Credit Suisse First Boston, as Lead Arranger and as Administrative
Agent for the Lenders (the "Administrative Agent"), First Union Securities,
Inc., as Co-Arranger and as Syndication Agent (the "Syndication Agent"), and the
Bank of Nova Scotia, as the Documentation Agent (the "Documentation Agent").

                                    RECITALS

               A. The Borrower, the Lenders, the Administrative Agent, the Syndi
cation Agent and the Documentation Agent are parties to that certain Senior
Secured Credit Agreement dated as of February 23, 2000 (as amended to date, the
"Credit Agreement"). Capitalized terms used herein without definition have the
meanings ascribed to such terms in the Credit Agreement.

               B. The Borrower has requested that the Credit Agreement be
amended to add a senior secured multi-draw term loan facility in an aggregate
principal amount of up to $75 million (the "Rollover Delay-Draw Term Loan
Facility").

               C.  The Credit Agreement requires the consent of the Required
Lenders for any such amendment.

               D. The Borrower hereby requests the consent of the Required
Lenders to add the Rollover Delay-Draw Term Loan Facility to the Credit
Agreement and to amend the Credit Agreement as herein provided.


                                    AGREEMENT

                  Section 1. AMENDMENTS TO CREDIT AGREEMENT. (a) Section 1.1 of
the Credit Agreement is hereby amended by:

                  (i)      amending the definition of "Applicable Margin" by
         deleting the heading in the pricing performance grid contained therein
         which reads "Multi-Draw Term Loans and Revolving Loan" each


<PAGE>


         place such heading appears and inserting the following in replacement
         therefor:

                  "Multi-Draw Term Loans, Revolving Loans and Rollover
                  Delay-Draw Term Loans";

                  (ii)     amending the definition of "Commitment" by inserting
         the following after the text "Term C Loan Commitment,":

                  "Rollover Delay-Draw Term Loan Commitment,"

                  (iii)    amending the definition of "Net Proceeds" by
         inserting the following after the phrase "and the Revolving Loan
         Commitment Amount" in the last paragraph thereof:

                  ", Rollover Delay-Draw Term Loan Commitment Amount"

                  (iv)     deleting the definition of "Non-Utilization Fee" and
         replacing it with the following:

                           ""NON-UTILIZATION FEE" means a Usage-based fee equal
         to the percentage specified in the grid below of (i) prior to the
         Multi-Draw Term Loan Commitment Termination Date, the undrawn portion
         of each of the Revolving Loan Commitment Amount and the Multi-Draw Term
         Loan Commitment Amount, (ii) on and after the Multi-Draw Term Loan
         Commitment Termination Date until the Rollover Delay-Draw Term Loan
         Commitment Termination Date, the undrawn portion of each of the
         Revolving Loan Commitment Amount and the Rollover Delay-Draw Term Loan
         Commitment Amount, and (iii) after the Rollover Delay-Draw Term Loan
         Commitment Termination Date, the undrawn portion of the Revolving Loan
         Commitment Amount:

<TABLE>
<CAPTION>

                Usage                                            Non-Utilization Fee
        --------------------                                 -------------------------
<S>                                                              <C>
less than 30%                                                            1.00%
30% less than equal to Usage less than equal to 50%                      0.75%
greater than 50%                                                         0.50%"

</TABLE>


                                       2
<PAGE>


                  (v)      amending the definition of "Percentage" by

                           (1)      deleting the word "or" appearing directly
                                    after the phrase "Term B Loans or Term B
                                    Loan Commitments,";

                           (2)      inserting the following directly after the
                                    phrase "Term C Loans or Term C Loan
                                    Commitments":

                                    "or Rollover Delay-Draw Term Loans or
                                    Rollover Delay-Draw Term Loan Commitments,";
                                    and

                           (3)      inserting the following after the phrase
                                    "Term C Loans" in the last sentence thereof:

                                    "or Rollover Delay-Draw Term Loans";

                  (vi)     amending the definition of "Stated Maturity Date" by

                           (1)      deleting the word "and" from after the
                                    semicolon ";" at the end of clause (c);

                           (2)      replacing the period "." at the end of
                                    clause (d) with a semicolon ";" and
                                    inserting the word "and" thereafter; and

                           (3)      inserting the following new clause (e):

                                    "(e) the Rollover Delay-Draw Term Loans, the
                                    sixth anniversary of the Closing Date.";

                  (vii)    deleting the definition of "Term Loan" in its
         entirety and replacing it with the following:

                           ""TERM LOAN" means, as the context may require, a
                           Multi-Draw Term Loan, a Term B Loan, a Term C Loan,
                           and/or a Rollover Delay-Draw Term Loan."


                                       3
<PAGE>


                  (viii)   deleting the definition of "Term Loan Commitment" in
         its entirety and replacing it with the following:

                           ""TERM LOAN COMMITMENT" means, as the context may
                           require, a Term B Loan Commitment, a Term C Loan
                           Commit ment, a Multi-Draw Term Loan Commitment and/or
                           a Roll over Delay-Draw Term Loan Commitment."

                  (ix)     deleting the definition of "Term Loan Commitment
         Amount" in its entirety and replacing it with the following:

                           ""TERM LOAN COMMITMENT AMOUNT" means, as the context
                           may require, the Term B Loan Commitment Amount, the
                           Term C Loan Commitment Amount, the Multi-Draw Term
                           Loan Commitment Amount and/or the Rollover Delay-Draw
                           Term Loan Commitment Amount."

                  (x)      deleting the definition of "Term Loan Commitment
         Termination Date" in its entirety and replacing it with the following:

                           ""TERM LOAN COMMITMENT TERMINATION DATE" means, as
                           the context may require, the Term B Loan Commitment
                           Termination Date, the Term C Loan Commitment
                           Termination Date, the Multi-Draw Term Loan
                           Termination Date and/or the Rollover Delay-Draw Term
                           Loan Commitment Termination Date."

                  (xi)     deleting the definition of "Term Loan Lender" in its
         entirety and replacing it with the following:

                           ""TERM LOAN LENDER" means, as the context may
                           require, each Multi-Draw Term Loan Lender, each Term
                           B Loan Lender, each Term C Loan Lender and each
                           Rollover Delay-Draw Term Loan Lender."

                  (xii)    deleting the definition of "Term Note"in its entirety
         and replacing it with the following:


                                       4
<PAGE>


                           "TERM NOTE" means, as the context may require, a
                           Multi-Draw Term Note, a Term B Note, a Term C Note,
                           and/or a Rollover Delay-Draw Term Note."

                  (xiii)   deleting the definition of "Usage" in its entirety
         and replacing it with the following:

                           ""USAGE" means, (A) for each applicable Fiscal
                           Quarter or portion thereof ending prior to the
                           initial date that the Rollover Delay-Draw Term Loan
                           Commitment is in effect, a percentage equal to (1)
                           the daily average of the sum of (i) the aggregate
                           principal amount of all outstanding Revolving Loans
                           (including the aggregate principal amount of all
                           outstanding Swing Line Loans and the Letter of Credit
                           Outstandings but excluding Revolving Loans made for
                           the purpose of repaying any Refunded Swing Line Loans
                           or reimbursing the Issuers for any amount drawn under
                           any Letter of Credit but not yet so applied, to the
                           extent such amounts are included as outstanding
                           Swing Line Loans or Letter of Credit Outstandings)
                           PLUS (ii) the aggregate principal amount of all
                           outstanding Multi-Draw Term Loans, DIVIDED by (2) the
                           daily average of the sum of (i) the Revolving Loan
                           Commitment Amount and (ii) either (x) the Multi-Draw
                           Term Loan Commitment Amount (prior to the Multi-Draw
                           Term Loan Commitment Termination Date) or (y) the
                           aggregate principal amount of all outstanding
                           Multi-Draw Term Loans (subsequent to the Multi-Draw
                           Term Loan Commitment Date), for such Fiscal Quarter
                           or portion thereof, and (B) for each applicable
                           Fiscal Quarter or portion thereof ending on or after
                           the initial date the Rollover Delay-Draw Term Loan
                           Commitment is in effect a percentage equal to (1) the
                           daily average of the sum of (i) the aggregate
                           principal amount of all outstanding Revolving Loans
                           (including the aggregate principal amount of all
                           outstanding Swing Line Loans and the Letter of Credit
                           Outstandings but excluding Revolving Loans made for
                           the purpose of repaying any Refunded Swing Line Loans
                           or reimbursing the Issuers for any amount drawn under
                           any Letter of Credit but not yet so ap plied, to the
                           extent such amounts are included as outstanding Swing
                           Line Loans or Letter of Credit Outstandings) PLUS
                           (ii) the aggregate principal amount of all
                           outstanding Rollover

                                       5
<PAGE>


                           Delay-Draw Term Loans, DIVIDED by (2) the daily
                           average of the sum of (i) the Revolving Loan
                           Commitment Amount and (ii) either (x) the Rollover
                           Delay-Draw Term Loan Commitment Amount (prior to the
                           Rollover Delay-Draw Term Loan Commitment Termination
                           Date) or (y) the aggregate principal amount of all
                           outstanding Rollover Delay-Draw Term Loans
                           (subsequent to the Rollover Delay-Draw Term Loan
                           Commit ment Date), for such Fiscal Quarter or portion
                           thereof."

                  (vi)     inserting the following definitions in Section 1.1 of
         the Credit Agreement in appropriate alphabetical order :

                           ""FOURTH AMENDMENT" means that Fourth Amendment to
                           Senior Secured Credit Agreement dated as of November
                           20, 2000 among the Borrower, the Lenders, the
                           Administrative Agent, the Syndication Agent and the
                           Documentation Agent."

                           ""ROLLOVER DELAY-DRAW TERM LOAN" is defined in
                           SECTION 2.3(d)."

                           ""ROLLOVER DELAY-DRAW TERM LOAN COMMITMENT" means,
                           relative to any Lender, such Lender's obligation (if
                           any) to make Rollover Delay-Draw Term Loans pursuant
                           to SECTION 2.3(d)."

                           ""ROLLOVER DELAY-DRAW TERM LOAN COMMITMENT AMOUNT"
                           means, on any date, $75,000,000, as such amount may
                           be reduced from time to time pursuant to SECTION
                           2.6."

                           ""ROLLOVER DELAY-DRAW TERM LOAN COMMITMENT
                           TERMINATION DATE" means the earliest of:

                             (a) November 23, 2001;

                             (b) the date on which the Rollover Delay-Draw Term
                             Loan Commitment Amount is terminated in full or
                             reduced to zero pursuant to SECTION 2.6; or

                             (c)  the date on which any Commitment Termination
                             Event occurs.


                                       6
<PAGE>


                           Upon the occurrence of any event described in CLAUSE
                           (a), (b), or (c), the Rollover Delay-Draw Term Loan
                           Commitments shall terminate automatically without any
                           further action."

                           ""ROLLOVER DELAY-DRAW TERM LOAN LENDER" means the
                           Lenders listed on SCHEDULE II (as supplemented) with
                           Rollover Delay-Draw Term Loan Commitments and Lenders
                           from time to time holding Rollover Delay-Draw Term
                           Loans and Roll over Delay-Draw Term Loan Commitments
                           after giving effect to any assignments permitted by
                           SECTION 11.11."

                           ""ROLLOVER DELAY-DRAW TERM NOTE" means a promissory
                           note of the Borrower payable to any Lender, in the
                           form of EXHIBIT A-6 hereto (as such promissory note
                           may be amended, endorsed or otherwise modified from
                           time to time), evidencing the aggregate Indebtedness
                           of the Borrower to such Lender resulting from
                           outstanding Rollover Delay-Draw Term Loans, and also
                           means all other promissory notes accepted from time
                           to time in substitution therefor or renewal thereof."

        (b) Section 2.3 of the Credit Agreement is hereby amended by adding the
following clause 2.3(d):

                  ""(d) ROLLOVER DELAY-DRAW TERM LOANS. From time to time on any
         Business Day occurring after November 23, 2000, but prior to the
         Rollover Delay-Draw Term Loan Commitment Termination Date, each
         Rollover Delay-Draw Term Loan Lender will make loans (relative to such
         Rollover Delay-Draw Term Loan Lender, its "ROLLOVER DELAY-DRAW TERM
         LOANS") to the Borrower equal to such Rollover Delay-Draw Term Loan
         Lender's Percentage of the aggregate amount of each Borrowing of the
         Rollover Delay-Draw Term Loans requested by the Borrower to be made on
         such day. No amounts paid or prepaid with respect to Rollover
         Delay-Draw Term Loans may be reborrowed."

        (c) Section 2.4 of the Credit Agreement is hereby amended by inserting
the following clause 2.4(e):

                  "(e)     all Rollover Delay-Draw Term Loans


                                       7
<PAGE>


                           (i) of all Lenders made prior to the Rollover Delay-
                  Draw Term Loan Commitment Termination Date would ex ceed the
                  Rollover Delay-Draw Term Loan Commitment Amount; or

                           (ii) of such Lender with a Rollover Delay-Draw Term
                  Loan Commitment made prior to the Rollover Delay-Draw Term
                  Loan Commitment Termination Date would exceed such Lender's
                  Percentage of the Rollover Delay-Draw Term Loan Commitment
                  Amount."

        (d) Section 2.6(a) of the Credit Agreement is hereby amended by
inserting the following after the phrase "the Revolving Loan Commitment Amount"
in the first sentence thereof:

                  ", Rollover Delay-Draw Term Loan Commitment Amount,"

        (e) Section 2.6(b) of the Credit Agreement is hereby amended by deleting
such provision in its entirety and inserting the following in replacement
therefor:

                  "(b)     MANDATORY. (i) (A) On the Multi-Draw Term Loan
                           Commitment Termination Date, the Multi-Draw Term Loan
                           Commitment Amount shall automatically and without
                           the requirement of any action on the part of any
                           Person be permanently reduced to zero, and (B) on
                           the Rollover Delay-Draw Term Loan Commitment
                           Termination Date, the Rollover Delay-Draw Term Loan
                           Commitment Amount shall automatically and without the
                           requirement of any action on the part of any Person
                           be permanently reduced to zero, and (ii) on the date
                           the Borrower or any of its Restricted Subsidiaries
                           receives any Net Proceeds and after the expiration of
                           any period designated for the purchase of Qualified
                           Assets, if appropriate (in accordance with the
                           definition of "Net Proceeds"), (1) with respect to
                           any Net Proceeds not applied to reduce the
                           outstanding Term Loans in accordance with SECTION
                           3.1(c), the Multi-Draw Term Loan Commitment Amount
                           (prior to the Multi-Draw Term Loan Commitment
                           Termination Date) shall, and the Rollover Delay-Draw
                           Term Loan Commitment Amount (prior to the


                                       8
<PAGE>


                           Rollover Delay-Draw Term Loan Commitment Termination
                           Date) shall, be reduced by an amount equal to 100% of
                           Net Proceeds with respect to Net Proceeds described
                           in CLAUSES (b), (c), and (d) of the definition
                           thereof and 50% of such Net Proceeds with respect to
                           the Net Proceeds described in CLAUSE (a) of the
                           definition thereof, and (2) the Revolving Loan
                           Commitment Amount (after application of such Net
                           Proceeds pursuant to SECTION 3.2(b)) shall be reduced
                           by an amount equal to 100% of the remaining Net
                           Proceeds with respect to Net Proceeds described in
                           CLAUSES (b), (c), and (d) of the definition thereof
                           and 50% of such Net Proceeds with respect to the Net
                           Proceeds described in CLAUSE (a) of the definition
                           thereof.

        (f) Section 2.7 of the Credit Agreement is hereby amended by inserting
the phrase "or Rollover Delay-Draw Term Loans" in the first sentence thereof
immediately following the phrase "in the case of Multi-Draw Term Loans"
contained therein.

        (g) Section 3.1(d) of the Credit Agreement is hereby amended by adding
the following clause (iv):

                  "(iv) Rollover Delay-Draw Term Loans in installments on the
         dates set forth below (PROVIDED that if such date is not a Business
         Day, the installment shall be paid on the preceding Business Day),
         each such installment to be in an amount equal to the corresponding
         percentages set forth below of the principal amount of the Rollover
         Delay-Draw Term Loans outstanding as of the Rollover Delay-Draw Term
         Loan Commitment Termination Date:

<TABLE>
<CAPTION>

                                                SCHEDULED REPAYMENT
                 DATE                            OF ROLLOVER DELAY-
                                                  DRAW TERM LOANS
====================================== ======================================
<S>                                    <C>
December 31, 2001                                      2.50%
March 31, 2002                                         2.50%
-------------------------------------- --------------------------------------
June 30, 2002                                          3.75%
September 30, 2002                                     3.75%
December 31, 2002                                      3.75%
March 31, 2003                                         3.75%

</TABLE>


                                       9
<PAGE>


<TABLE>
<CAPTION>

                                                SCHEDULED REPAYMENT
                 DATE                            OF ROLLOVER DELAY-
                                                  DRAW TERM LOANS
====================================== ======================================
<S>                                    <C>
June 30, 2003                                          5.00%
September 30, 2003                                     5.00%
December 31, 2003                                      5.00%
March 31, 2004                                         5.00%
June 30, 2004                                          6.25%
September 30, 2004                                     6.25%
December 31, 2004                                      6.25%
March 31, 2005                                         6.25%
June 30, 2005                                          7.50%
September 30, 2005                                     7.50%
December 31, 2005                                      10.00%
Sixth Anniversary                                      10.00%
of the Closing Date
====================================== ======================================

</TABLE>

        ; PROVIDED that the scheduled installments of principal of the Rollover
        Delay-Draw Term Loans set forth above shall be reduced on a PRO RATA
        basis in connection with any voluntary or mandatory prepayments of the
        Rollover Delay-Draw Term Loans in accordance with SECTION 3.1; and
        PROVIDED, FURTHER that the final installment specified above for the
        repayment by the Borrower of the Rollover Delay-Draw Term Loans shall be
        in an amount, if such amount is different from that specified above,
        sufficient to repay all amounts owing by the Borrower under this
        Agreement with respect to the Rollover Delay-Draw Term Loans."

        (h) Section 3.2(b) of the Credit Agreement is hereby amended by deleting
clauses (x) and (y) of the proviso to clause (i) thereof and inserting the
following in replacement thereof:

               "(x) 100% of any prepayment so refused shall be applied PRO RATA
        to the Multi-Draw Term Loans and the Rollover Delay-Draw Term Loans
        until the Multi-Draw Term Loans and the Rollover Delay-Draw Term Loans
        have been paid in full and (y) after all Multi-Draw Term Loans and
        Rollover Delay-Draw Term Loans have been repaid in full and the
        Multi-Draw Term Loan Commitment and the Rollover Delay-Draw Term Loan
        Commitment have terminated, any remaining amount of the prepayment
        refused by the


                                       10
<PAGE>


         Term B Lenders and the Term C Lenders shall be applied PRO RATA to the
         Term B Loans and the Term C Loans"

        (i) Section 3.3 of the Credit Agreement is hereby amended by adding the
following clause (d):

                  "(d)     Notwithstanding the foregoing, the Rollover
                           Delay-Draw Term Loans shall initially bear interest
                           at the Alternate Base Rate plus the Applicable
                           Margin. Commencing on the earlier to occur of (i) the
                           date syndication of Rollover Delay-Draw Term Loans is
                           deemed closed by the Agent and (ii) December 23,
                           2000, such interest rates will be, at the Borrower's
                           option, either the Alternate Base Rate or the LIBO
                           Rate (Reserve Adjusted) plus, in each case, the
                           Applicable Margin."

        (j) Section 3.6(a) of the Credit Agreement is hereby amended by deleting
such section in its entirety and inserting the following in replacement
therefor:

                  "(a) NON-UTILIZATION FEE. The Borrower agrees to pay to the
         Administrative Agent for the account of each Lender, in accordance with
         such Lender's Percentage of the sum of (i) the Revolving Loan
         Commitment Amount, (ii) the Multi-Draw Term Loan Commitment Amount (on
         and prior to the Multi-Draw Term Loan Commitment Termination Date) or
         the outstanding Multi-Draw Term Loans (subsequent to the Multi-Draw
         Term Loan Commitment Termination Date), and (iii) the Rollover
         Delay-Draw Term Loan Commitment Amount (commencing on the initial date
         the Rollover Delay-Draw Term Loan Commitment is effective until and
         including the Rollover Delay-Draw Term Loan Commitment Termination
         Date) or the outstanding Rollover Delay-Draw Term Loans (subsequent to
         the Rollover Delay-Draw Term Loan Commitment Termination Date) for the
         period (including any portion thereof when any of its Commitments are
         suspended by reason of the Borrower's inability to satisfy any
         condition of ARTICLE V) commencing on the Closing Date and continuing
         through the Revolving Loan Commitment Termination Date, the
         Non-Utilization Fee. The Non-Utilization Fee payable pursuant to this
         Section shall be calculated on a year comprised of 360 days and
         payable by the Borrower in arrears on each Quarterly Payment Date,
         commencing with the first Quarterly Payment Date following the Closing
         Date, for the period ending on (and including) the last day of the
         immediately preceding December, March, June or September, respectively,
         on the Multi-Draw Term Loan Commitment Termination Date, the Rollover


                                       11
<PAGE>


         Delay-Draw Term Loan Commitment Termination Date and on the Revolving
         Loan Commitment Termination Date."

        (k)   A new Section 5.4 is hereby added to the Credit Agreement:

               "Section 5.4. ROLLOVER DELAY-DRAW TERM LOANS. In addition to the
conditions set forth in SECTION 5.2, no Rollover Delay-Draw Term Loans shall be
made until the following conditions precedent are satisfied:

               (a) The Administrative Agent shall have received resolutions of
the board of directors of the Borrower, certified by its Secretary or Assistant
Secretary, which authorize the execution, delivery and performance by the
Borrower of the Fourth Amendment.

               (b) The Administrative Agent shall have received the opinion of
Morgan, Lewis & Bockius LLP in form and substance reasonably satisfactory to the
Administrative Agent.

               (c) The Administrative Agent shall have received a certificate
from an Authorized Officer of the Borrower stating that the representations and
warranties set forth in Section 3(a)(x) of the Fourth Amendment are true and
correct.

               (d) The Administrative Agent shall have received, for the account
of each Rollover Delay-Draw Term Loan Lender, such Lender's Rollover Delay-Draw
Term Note, in an amount equal to the Rollover Delay-Draw Term Loan Commitment of
such Rollover Delay-Draw Term Loan Lender."

        (l) Schedule II to the Credit Agreement is hereby amended by adding
thereto a supplement set forth on Exhibit A hereto, reflecting the respective
Percent ages of the Rollover Delay-Draw Term Loan Lenders as of the effective
date of this Amendment.

        (m) The Credit Agreement is hereby amended by adding a new Exhibit A-6,
Form of Rollover Delay-Draw Term Note, attached hereto as Exhibit B.

                  Section 2. AMENDMENT EFFECTIVE DATE. This Amendment shall
become effective on the date on which all of the conditions set forth below have
been satisfied (or waived by the Required Lenders):


                                       12
<PAGE>


        (1) The Administrative Agent shall have received counterparts of this
Amendment, executed by the Borrower, the Required Lenders and all of the
Rollover Delay-Draw Term Loan Lenders.

        (2) The Administrative Agent shall have received a certificate from an
Authorized Officer of the Borrower stating that immediately before and after
giving effect to this Amendment, no Default shall have occurred and be
continuing or would result therefrom and that the representations and warranties
set forth in the Credit Agreement and in this Amendment (except as set forth in
Section 3(a)(x) of this Amendment) are true and correct.

        (3) The Multi-Draw Term Loan Commitment shall have terminated and no
Multi-Draw Term Loans shall have been borrowed.

        (4) The Borrower shall have paid to the Administrative Agent for the
account of the Lenders the following consent fees:

               (1) with respect to each Multi-Draw Term Loan Lender that becomes
        a Rollover Delay-Draw Term Loan Lender, an amount equal to such Lender's
        Rollover Delay-Draw Term Loan Commit ment multiplied by 0.05%; and

               (2) with respect to each Lender that consents to this Amendment,
        an amount equal to the aggregate principal amount of such Lender's
        Commitments under the Credit Agreement, multiplied by 0.05%.

               Section 3. REPRESENTATIONS AND WARRANTIES. The Borrower hereby
represents and warrants to the Administrative Agent and the Lenders that, as of
the date of and after giving effect to this Amendment and on the effective date
of this Amendment, (a) the execution, delivery and performance of this Amendment
and any and all other documents executed and/or delivered in connection herewith
(x) have been authorized by all requisite corporate action on the part of the
Borrower and (y) will not violate the Borrower's articles of incorporation or
bylaws, (b) all representations and warranties set forth in the Credit
Agreement and in any other Loan Document are true and correct as if made again
on and as of such date (except those, if any, which by their terms specifically
relate only to a different date), (c) no Default or Event of Default has
occurred and is continuing, and (d) the Credit Agreement (as


                                       13
<PAGE>


amended by this Amendment) and all other Loan Documents are and remain legal,
valid, binding and enforceable obligations in accordance with the terms thereof.

               Section 4. SURVIVAL OF REPRESENTATIONS AND WARRANTIES. All
representations and warranties made in this Amendment or any other Loan Docu
ment shall survive the execution and delivery of this Amendment and the other
Loan Documents, and no investigation by any of the Credit Agents or the Lenders,
or any closing, shall affect the representations and warranties or the right of
the Credit Agents and the Lenders to rely upon them.

               Section 5. REFERENCE TO AGREEMENT. Each of the Loan Documents,
including the Credit Agreement, and any and all other agreements, documents or
instruments now or hereafter executed and/or delivered pursuant to the terms
hereof or pursuant to the terms of the Credit Agreement as amended hereby, are
hereby amended so that any reference in such Loan Documents to the Credit
Agreement, whether direct or indirect, shall mean a reference to the Credit
Agreement as amended hereby.

               Section 6. GOVERNING LAW. THIS AMENDMENT SHALL BE DEEMED TO BE A
CONTRACT MADE UNDER AND GOVERNED BY THE INTERNAL LAWS OF THE STATE OF NEW YORK
(INCLUDING FOR SUCH PURPOSE SECTIONS 5-1401 AND 5-1402 OF THE GENERAL
OBLIGATIONS LAW OF THE STATE OF NEW YORK).

               Section 7. EXECUTION.  This Amendment may be executed in
counterparts, each of which shall be an original and all of which, collectively,
shall constitute one instrument.

               Section 8. LIMITED EFFECT. This Amendment relates only to the
specific matters covered herein, shall not be considered to be a waiver of any
rights the Lenders may have under the Credit Agreement, and shall not be
considered to create a course of dealing or to otherwise obligate the Lenders to
execute any amendments or grant any waivers or consents under the same or
similar circumstances in the future.


                                       14
<PAGE>


               IN WITNESS WHEREOF, the parties hereto have caused this Amendment
to be executed by their respective officers thereunto duly authorized as of the
day and year first above written.


                                      THE TITAN CORPORATION


                                      By:
                                         ---------------------------------------
                                         Name:
                                         Title:


                                       15
<PAGE>


                  ACKNOWLEDGED AND AGREED TO BY EACH GUARANTOR:


                           Advanced Communication Services, Inc.
                           Advanced Management Incorporated
                           Assist Cornerstone Technologies, Inc.
                           Atlantic Aerospace Electronics Corporation
                           AverStar, Inc.
                           Cayenta Operating Company
                           Cayenta, Inc.
                           Computer Based Systems, Inc.
                           DBA Systems, Inc.
                           Delfin Systems
                           Diversified Control Systems, Inc.
                           Eldyne, Inc.
                           Horizons Technology, Inc.
                           Integrated Control Systems, Inc.
                           Intermetrics International, Inc.
                           Intermetrics Securities, Inc.
                           J.B. Systems, Inc.
                           LinCom Corporation
                           LinCom Wireless, Inc.
                           Linkabit Wireless, Inc.
                           Mergeco, Inc.
                           MJR Associates, Inc.
                           Program Support Associates, Inc.
                           Pulse Engineering, Inc.
                           Pulse Sciences, Inc.
                           RF Microsystems, Inc.
                           SemCor, Inc.
                           SenCom, Inc.
                           SureBeam Corporation
                           System Resources Corporation


                           All By:
                                  ----------------------------------------------
                           Name:
                           Title:


                                       16
<PAGE>


                           Titan Food Pasteurization Corp.
                           Titan Medical Sterilization Corp.
                           Titan SureBeam Brazil, Inc.
                           Titan Systems Corporation
                           Titan Unidyne Corporation
                           Titan Wireless, Inc.
                           Tomotherapeutics, Inc.
                           Validity Corporation
                           VisiCom Laboratories, Inc.
                           Microlithics Corporation


                           All By:
                                  ----------------------------------------------
                           Name:
                           Title:


<PAGE>


                           LENDER:



                           By:
                              --------------------------------------------------
                              Name:
                              Title:



<PAGE>


                                                                       EXHIBIT A


                   SUPPLEMENT TO CREDIT AGREEMENT SCHEDULE II
                ROLLOVER DELAY-DRAW TERM LOAN LENDER PERCENTAGES

<TABLE>
<CAPTION>

                                                        ROLLOVER
                                                       DELAY-DRAW
                                                       TERM LOAN
           NAME AND NOTICE                             COMMITMENT
          ADDRESS OF LENDER                            PERCENTAGE
          -----------------                            ----------
<S>                                                    <C>
Credit Suisse First Boston                             14.85714285

The Bank of Nova Scotia                                8.57142857

First Union National Bank                              8.57142857

Comerica Bank                                          9.14285715

Transamerica Business Credit Corp.                     8.57142857

Erste Bank                                             5.71428572

Fleet Boston Financial                                     8.0

KeyBank National Association                               8.0

IBM Credit Corporation                                 11.42857143

Imperial Bank                                          8.57142857

Bank Austria Creditanstalt Corporate Finance, Inc.     5.71428569

Fuji Bank LTD                                          2.85714287

</TABLE>


                                       19
<PAGE>


                                    EXHIBIT B

                                                                     EXHIBIT A-6


                          ROLLOVER DELAY-DRAW TERM NOTE


$_________                                                     November 23, 2000


         FOR VALUE RECEIVED, the undersigned, THE TITAN CORPORATION, a
Delaware corporation (the "BORROWER"), promises to pay to the order of [Name of
Lender] and its registered assigns (the "ROLLOVER DELAY-DRAW TERM LOAN LENDER")
on the Stated Maturity Date for all Rollover Delay-Draw Term Loans, the
principal sum of [_______________] DOLLARS ($_________) or, if less, the
aggregate unpaid principal amount of all Rollover Delay-Draw Term Loans made by
the Rollover Delay-Draw Term Loan Lender pursuant to that certain Senior Secured
Credit Agreement, dated as of February 23, 2000 (as amended, restated,
supplemented or otherwise modified from time to time, the "CREDIT AGREEMENT"),
among the Borrower, the various financial institutions (including the Rollover
Delay-Draw Term Loan Lender) as are or may become parties thereto (collectively,
the "LENDERS"), Credit Suisse First Boston, as administrative agent for the
Lenders (the "ADMINISTRATIVE AGENT"), First Union Securities, Inc., as
Syndication Agent, and The Bank of Nova Scotia, as Documentation Agent. Terms
used herein have the meanings provided in the Credit Agreement.

         The Borrower also promises to pay interest on the unpaid principal
amount hereof from time to time outstanding from the date hereof until maturity
(whether by acceleration or otherwise) and, after maturity, until paid, at the
rates per annum and on the dates specified in the Credit Agreement. Payments of
both principal and interest are to be made in lawful money of the United States
of America in same day or immediately available funds to the account designated
by the Administrative Agent pursuant to the Credit Agreement.

         This Rollover Delay-Draw Term Note is one of the Rollover Delay-Draw
Term Notes referred to in, and evidences Obligations incurred under, the Credit
Agreement, to which reference is made for a description of the security for this
Rollover Delay-Draw Term Note and for a statement of the terms and conditions on
which the Borrower is permitted and required to make prepayments and repayments
of principal of the Obligations evidenced by this Rollover Delay-Draw Term Note
and on which such Obligations may be declared to be immediately due and payable.

         The Borrower hereby irrevocably authorizes the Rollover Delay-Draw Term
Loan Lender to make (or cause to be made) appropriate notations on the grid
attached hereto (or on any continuation of such grid), which notations, if made,
shall evidence, INTER ALIA, the date of and the outstanding principal of, the
Rollover Delay-Draw Term Loans evidenced hereby. Such notations shall be
rebuttable presumptive evidence of the accuracy of the information so set forth;
PROVIDED,

                                       20
<PAGE>


HOWEVER, that the failure of the Rollover Delay-Draw Term Loan Lender to make
any such notations shall not limit or otherwise affect any Obligations of the
Borrower.

         Any assignment or transfer of this Rollover Delay-Draw Term Note shall
be effective solely by registration thereof in the Register pursuant to the
Credit Agreement.

         All parties hereto, whether as makers, endorsers, or otherwise,
severally waive presentment for payment, demand, protest and notice of dishonor.

         THIS ROLLOVER DELAY-DRAW TERM NOTE SHALL BE DEEMED TO BE A CONTRACT
MADE UNDER AND GOVERNED BY THE INTERNAL LAWS OF THE STATE OF NEW YORK (INCLUDING
FOR SUCH PURPOSES SECTIONS 5-1401 AND 5-1402 OF THE GENERAL OBLIGATIONS LAW OF
THE STATE OF NEW YORK).


                                         THE TITAN CORPORATION


                                         By
                                           -------------------------------------
                                           Name:
                                           Title:


                                       21
<PAGE>


            ROLLOVER DELAY-DRAW TERM LOAN AND PRINCIPAL PAYMENTS

<TABLE>
<CAPTION>

                Amount of
           Rollover Delay-Draw                            Amount of Principal         Unpaid Principal
              Term Loan Made                                      Repaid                   Balance
        --------------------------     Interest         -----------------------     ---------------------
         Alternate        LIBO          Period          Alternate          LIBO     Alternate        LIBO               Notation
Date     Base Rate        Rate      (If Applicable)     Base Rate          Rate     Base Rate        Rate      Total     Made By
====================================================================================================================================
<S>      <C>              <C>       <C>                 <C>                <C>      <C>              <C>       <C>      <C>












</TABLE>


                                       22