<Page>


                                                                    Exhibit 10.1


                               FIFTH AMENDMENT TO
                         SENIOR SECURED CREDIT AGREEMENT

                  This Fifth Amendment to Senior Secured Credit Agreement
(this "Amendment") is entered into as of June 11, 2001, 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
Syndication 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, the Administrative Agent and the Required
Lenders have agreed to amend the Credit Agreement as follows.

                                    AGREEMENT

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

                  (i) inserting the following definitions in appropriate
    alphabetical order:

                  ""AFRIPA" means Titan Wireless Afripa Holding, Inc., a
    Delaware corporation."

                  ""AFRIPA GROUP" means Afripa and each Subsidiary directly or
         indirectly owned by Afripa but not owned directly by Borrower or any
         Subsidiary of Borrower other than Afripa or a Subsidiary of Afripa."

                  (ii) amending the definition of "EBITDA" by inserting the
         words "(other than SureBeam Post IPO and Afripa)" after the words "U.S.
         Subsidiaries" in each place they appear;


<Page>


                  (iii) amending the definition of "Guarantor" by deleting the
         words "(other than Titan Capital Trust and Titan Africa, Inc.)" and
         replacing them with "(other than Titan Capital Trust, Titan Africa,
         Inc. and Afripa)";

                  (iv) amending the definition of "Net Income" by inserting the
         words "(other than SureBeam Post IPO and Afripa)" after the words "U.S.
         Subsidiaries"; and

                  (v) amending the definition of "Net Worth" by inserting the
         words "(other than SureBeam Post IPO and the Afripa Group)" after the
         word "Subsidiaries" in the first place it appears.

         (b) Section 7.7 of the Credit Agreement is hereby amended by deleting
the last paragraph thereof and replacing it with the following:

                  "Notwithstanding the foregoing, in no event shall (i) SureBeam
         Post IPO, Cayenta Post IPO, Titan Capital Trust or Titan Africa, Inc.
         be subject to the provisions of this SECTION 7.7 or be required to
         grant any Liens in favor of the Administrative Agent on behalf of the
         Secured Parties, (ii) the Borrower be required to grant any Lien on any
         Capital Stock of Titan Capital Trust or (iii) Afripa be required to
         execute a supplement to the Subsidiary Guaranty, the Subsidiary
         Security Agreement or the Subsidiary Pledge Agreement or grant any Lien
         on any Capital Stock of any of its Foreign Subsidiaries."

        (c) Section 8.2 of the Credit Agreement is hereby amended by deleting
the period at the end of such section and replacing it with the following:

                  "; and PROVIDED, FURTHER, that, notwithstanding any provision
         of this Section 8.2, neither the Borrower nor any of its Restricted
         Subsidiaries may incur any Indebtedness (including, without limitation,
         Contingent Liabilities) otherwise permitted hereunder with respect to
         any member of the Afripa Group or which will be utilized, directly or
         indirectly, to fund or support in any respect any obligation or
         commitment of or with respect to any member of the Afripa Group."

        (d) Section 8.4(a) of the Credit Agreement is hereby amended by deleting
such provision in its entirety and inserting the following in replacement
therefor:


                                       2
<Page>


                  "(a) TOTAL DEBT TO EBITDA RATIO. The Borrower will not permit
         the Total Debt to EBITDA Ratio as of the last day of any Fiscal Quarter
         to be greater than the ratio set forth opposite such date:

<Table>
<Caption>

--------------------------------------------------------------------------------
Date                                                  Total Debt to EBITDA Ratio
--------------------------------------------------------------------------------
<S>                                                   <C>
Closing Date and First Fiscal Quarter of
Fiscal Year 2000                                               3.50:1.00
Second Fiscal Quarter of Fiscal Year 2000                      3.50:1.00
Third Fiscal Quarter of Fiscal Year 2000                       3.50:1.00
Fourth Fiscal Quarter of Fiscal Year 2000                      3.50:1.00
--------------------------------------------------------------------------------
First Fiscal Quarter of Fiscal Year 2001                       3.25:1.00
Second Fiscal Quarter of Fiscal Year 2001                      3.75:1.00
Third Fiscal Quarter of Fiscal Year 2001                       3.75:1.00
Fourth Fiscal Quarter of Fiscal Year 2001                      3.50:1.00
--------------------------------------------------------------------------------
First Fiscal Quarter of Fiscal Year 2002                       3.25:1.00
Second Fiscal Quarter of Fiscal Year 2002                      3.25:1.00
Third Fiscal Quarter of Fiscal Year 2002                       3.25:1.00
Fourth Fiscal Quarter of Fiscal Year 2002                      3.25:1.00
--------------------------------------------------------------------------------
First Fiscal Quarter of Fiscal Year 2003
and each Fiscal Quarter thereafter                             2.50:1.00
--------------------------------------------------------------------------------

</Table>

        (e) Section 8.4(b)(ii) of the Credit Agreement is hereby amended by
deleting the following language at the end of such provision:

        "PLUS (aa) the product of 80% TIMES the net increase to the Borrower's
        shareholders' equity resulting from the initial public offering of
        SureBeam after the Closing Date, MINUS (bb) the net decrease to the
        Borrower's shareholders' equity resulting from the deferred
        compensation charge related to the employee, director, officer and
        consultant stock options of SureBeam."

        (f) Section 8.4(e) of the Credit Agreement is hereby amended by adding
the following sentence at the end of such provision:

        "Any calculation to determine compliance with CLAUSES (a), (b), (c) or
        (d) of this SECTION 8.4 for any period which includes the date of the


                                       3
<Page>


        initial public offering of SureBeam shall be on a PRO FORMA basis and
        calculated on the assumption that the initial public offering of
        SureBeam was consummated on the first day of the relevant period."

        (g) Section 8.5(j) of the Credit Agreement is hereby amended by deleting
such provision in its entirety and inserting the following in replacement
therefor:

                  "(j) after the Closing Date, Investments in the Afripa Group
         and non-U.S. Persons in an amount not to exceed $50,000,000 in the
         aggregate from the Closing Date through the remaining term of this
         Agreement; and"

        (h) Section 8.5(k) of the Credit Agreement is hereby amended by adding
the following proviso after the semi-colon at the end of such provision:

        "PROVIDED, that no Investments pursuant to this clause (k) may be made,
        directly or indirectly, by the Borrower or any of its Restricted
        Subsidiaries in (x) any member of the Afripa Group, (y) any Person that
        is not a Restricted Subsidiary which owns an Investment, directly or
        indirectly (whether through other Persons or otherwise), in any member
        of the Afripa Group or (z) any Person that any member of the Afripa
        Group owns an Investment in;"

        (i) Section 8.15 of the Credit Agreement is hereby amended by inserting
the words "(other than any Foreign Subsidiary which is a member of the Afripa
Group)" after the words "Foreign Subsidiaries" in the first place they appear.

                  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):

        (a) The Administrative Agent shall have received counterparts of this
Amendment, executed by the Borrower and the Required Lenders.

         (b) 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 are true and correct.


                                       4
<Page>


        (c) The Borrower shall have paid to the Administrative Agent for the
account of each of the Lenders that consents to this Amendment an amount equal
to the aggregate principal amount of such Lender's Commitments under the Credit
Agreement, multiplied by 0.25%.

               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 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
Document 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. COSTS AND EXPENSES. The Borrower shall pay on demand
all reasonable costs and expenses of the Administrative Agent (including the
reasonable fees, costs and expenses of counsel to the Administrative Agent)
incurred in connection with the preparation, execution and delivery of this
Amendment.


                                       5
<Page>


               Section 7. 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 8. 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 9. 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.


                                       6
<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: /s/ Mark Sopp
                                            ------------------------------------
                                            Name: Mark Sopp
                                            Title: CFO














                                 Fifth Amendment
<Page>



ACKNOWLEDGED AND AGREED TO BY EACH GUARANTOR:

                                      ACS Technologies Inc.
                                      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.
                                      Horizon Services Company, 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.
                                      System Resources Corporation


                                      All By: /s/ Mark Sopp
                                             -----------------------------------
                                      Name: Mark Sopp
                                      Title: CFO


                                 Fifth Amendment
<Page>


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


                                      All By: /s/ Mark Sopp
                                             -----------------------------------
                                      Name: Mark Sopp
                                      Title: CFO











                                 Fifth Amendment
<Page>


                                      LENDER:



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








                                 Fifth Amendment