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                                                                    EXHIBIT 10.1


                                    GUARANTY

                  This Guaranty ("Guaranty") is made as of the 29th day of
January, 2001 by Affiliated Computer Services, Inc. (the "Guarantor"), in favor
of Citicorp USA, Inc., a Delaware corporation ("Lender").

                                    RECITALS

                  WHEREAS, DDH Aviation, Inc., a Texas corporation, 448 Alliance
Corp. and Blue Sky Yacht Sales, Inc. (collectively, the "Borrowers"), have
entered into that certain Loan and Security Agreement with Lender dated as of
the date hereof (as amended or restated from time to time, the "Loan Agreement")
pursuant to which Lender has agreed to provide certain credit facilities to
Borrowers;

                  WHEREAS, Lender has required, as a condition, among others, to
executing the Loan Agreement, that Guarantor execute and deliver this Guaranty;
and

                  WHEREAS, the Borrowers are providing consideration to the
Guarantor for its agreement to execute and deliver this Guaranty.

                  NOW, THEREFORE, for and in consideration of the foregoing,
Guarantor and Lender agree as follows:

1. Defined Terms. Capitalized terms used herein, without definition shall have
the meanings given such terms in the Loan Agreement.

2. Guaranty.

         (a) The Guarantor unconditionally guarantees the full and prompt
payment , when due, whether upon maturity, by acceleration or otherwise, and at
all times thereafter of all sums which may now be or may hereafter become due
and owing by the Borrowers under and in connection with the Loan Agreement and
the other Loan Documents which include all of the Secured Obligations.
Notwithstanding the foregoing, Guarantor's liability hereunder with respect to
the Secured Obligations shall be limited to an amount (the "Guaranteed Amount"),
at any time of determination equal to the lesser of (i) $11,500,000 or (ii) the
sum of 24.5% of the outstanding Secured Obligations under the Equipment Purchase
Facility plus 41.1% of the outstanding Secured Obligations under the Deposit
Facility and the Working Capital Facility at such time. The Guarantor hereby
agrees that this Guaranty is an absolute guarantee of payment and is not a
guaranty of collection.

         (b) Notwithstanding anything contained herein to the contrary,
Guarantor's liability with respect to this Guaranty shall include all fees,
costs and expenses (including, without limitation, all court costs and
reasonable attorneys' fees and costs and expenses) paid or incurred by Lender
in: (i) endeavoring to collect all or any part of the Secured Obligations up to
the Guaranteed Amount from, or in prosecuting any action against, the Guarantor;
(ii) taking any action with respect to any security or collateral securing the
obligations of Guarantor under this Guaranty; and (iii) preserving, protecting
or defending the enforceability of this Guaranty or its


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rights hereunder (all such costs and expenses are referred to hereinafter
collectively as the "Expenses").

3. Payment of Obligations. At any time, and from time to time, if an Event of
Default (as defined in the Loan Agreement) shall occur and be continuing,
Guarantor shall pay to Lender, on demand and in immediately available funds, all
Secured Obligations, if any, then due, up to the Guaranteed Amount at such time,
after taking into account all amounts previously paid by Guarantor under this
Guaranty together with all Expenses (at any time of determination, the
"Guaranteed Obligations").

4. Obligations Unconditional.

         (a) The Guarantor hereby agrees that its obligations under this
Guaranty shall be unconditional, irrespective of:

                  (i) the validity or enforceability, avoidance or subordination
         of any of the Secured Obligations;

                  (ii) the absence of any attempt by, or on behalf of, Lender to
         collect, or take any other action to enforce, all or any part of the
         Secured Obligations from Borrowers or any of them, or from any other
         guarantor of all or any part or the Secured Obligations or any other
         person;

                  (iii) the election of any remedy by, or on behalf of, Lender
         with respect to all or any part of the Secured Obligations;

                  (iv) the waiver, consent, extension, forbearance or granting
         of any indulgence by, or on behalf of, Lender with respect to any
         provision of the Loan Documents;

                  (v) the failure of Lender to take any steps to perfect and
         maintain its security interest in, or to preserve its respective right
         to, any of the Collateral for all or any part of the Secured
         Obligations;

                  (vi) the election by, or on behalf of, Lender, in any
         proceeding instituted under the United States Bankruptcy Code (the
         "Bankruptcy Code") of the application of Section 1111 (b)(2) of the
         Bankruptcy Code;

                  (vii) any borrowing or grant of a security interest by the
         Borrowers, as debtor-in-possession, under Section 364 of the Bankruptcy
         Code, or the disallowance under Section 502 of the Bankruptcy Code of
         all or any portion of the claims of Lender for repayment of all or any
         part of the Secured Obligations or any Expenses relating thereto; or

                  (viii) any other circumstance other than payment in full which
         might otherwise constitute a legal or equitable discharge or defense of
         a guarantor or the Borrowers.

         (b) The Guarantor hereby waives any requirement of diligence,
presentment, demand of payment, filing of claims with a court in the event of
receivership or bankruptcy of any



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Borrower, protest or notice with respect to all or any part of the Secured
Obligations, and all demands whatsoever (and Guarantor shall not require that
the same be made on the Borrowers as a condition precedent to any of Guarantor's
obligations hereunder), and covenants that this Guaranty will not be discharged,
except by complete payment of all of the Secured Obligations or by payment to
Lender of the entire amount of Guarantor's liability hereunder.

5. Payment; Reinstatement. Upon Borrowers' failure to make payment of all or any
portion of the Secured Obligations when due whether upon maturity, by
acceleration or otherwise, Lender may proceed directly and at once, without
further notice, against the Guarantor to obtain performance of and to collect
and recover the amount, or any portion, of the Guaranteed Obligations without
Lender first proceeding against any Borrower, or any other guarantor or Person,
or any security or collateral for all or any part thereof. Payments and credits,
if any, from the Guarantor, any Borrower, any other guarantor of all or any
portion of the Secured Obligations or any other Person on account of the Secured
Obligations or of any other liability or obligation of the Guarantor to Lender,
shall be applied to the Guaranteed Obligations, and neither Guarantor, nor any
Borrower, nor any other guarantor of all nor any portion of the Guaranteed
Obligations nor any other Person shall have any further liability with respect
to any such payments and credits if such payments and credits have been made as
provided herein; provided, however, that if such payments or credits, or any
part thereof, are subsequently invalidated, declared to be fraudulent or
preferential, set aside and/or required to be repaid to the Guarantor, any
Borrower, any other guarantor or any other Person, or their respective estates,
trustees, receivers or any other party under any bankruptcy law, state or
federal law, common law or equitable cause, then, to the extent of such payment
or repayment, the Secured Obligations or other obligations or liabilities or any
part thereof which has been paid, reduced or satisfied by such amount shall be
reinstated and shall continue in full force and effect as of the time
immediately preceding the time such initial payment, credit, reduction or
satisfaction occurred.

6. Inability to Collect. The Guarantor agrees that, notwithstanding anything set
forth in this Guaranty to the contrary, if for whatever reason, Lender is
prevented by applicable law from exercising any of its rights to receive payment
from Borrowers, or any of them, of all or any part of the Secured Obligations,
to collect interest on all or any part of the Secured Obligations or to enforce
or exercise any other right or remedy with respect to all or any part of the
Secured Obligations, or is prevented from taking any action to realize on all or
any part of the Collateral securing the Secured Obligations or the liabilities
of any guarantor of the Secured Obligations, such Guarantor shall pay to Lender,
on demand therefor and in immediately available funds, the amount that would
otherwise have been due and payable had such rights and remedies been permitted
to be exercised by Lender up to the Guaranteed Amount, less any other amounts
previously paid under this Guaranty.

7. Lender's Actions.

         (a) Lender is hereby authorized, without notice or demand and without
affecting the liability of any Guarantor hereunder, from time to time (i) to
renew, extend, accelerate or otherwise change the time for payment of, or other
terms relating to, all or any part of the Secured Obligations or to otherwise
modify, amend or change the terms of the Loan Documents; (ii) to accept partial
payments on all or any part of the Secured Obligations; (iii) to take and hold
security or collateral for the payment of all or any part of the Secured
Obligations, this Guaranty, or any other guaranties of all or any part of the
Secured Obligations or other liabilities of any



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Borrower; (iv) to exchange, enforce, waive and release any such security or
collateral; (v) release any of the Secured Obligations or any portion thereof;
and (vi) to settle, release, compromise, collect or otherwise liquidate all or
any part of the Secured Obligations and exchange, enforce, release or waive any
security or collateral for all or any part of the Secured Obligations, and any
of the foregoing may be done in any manner, without affecting or impairing all
or any part of the obligations of Guarantor hereunder.

         (b) The Guarantor hereby assumes responsibility for keeping itself
informed of the financial condition of the Borrowers and any and all endorsers
and/or other guarantors of all or any part of the Secured Obligations, and of
all other circumstances bearing upon the risk of nonpayment of the Secured
Obligations, or any part thereof, that diligent inquiry would reveal, and the
Guarantor hereby agrees that Lender shall not have any duty to advise the
Guarantor of information known to it regarding such condition or any such
circumstances. The Guarantor hereby acknowledges that it has been furnished
copies of the Loan Documents and has had the opportunity to review any Loan
Documents relating thereto or financial information relevant thereto. The
Guarantor further acknowledges and agrees that in the event Lender, in its sole
discretion, undertakes at any time or from time to time to provide any such
information to such Guarantor, then the party providing such information shall
be under no obligation (i) to undertake any investigation not a part of its
regular business routine; (ii) to disclose any information which, pursuant to
accepted or reasonable banking or commercial finance practices, such party
wishes to maintain confidential; or (iii) to make any other or future
disclosures of such information or any other information to the Guarantor.

         (c) The Guarantor consents and agrees that Lender, or any Person acting
for or on behalf of Lender, shall not be under any obligation to marshal any
assets in favor of Guarantor or against or in payment of all or any part of the
Secured Obligations.

8. Representations and Warranties. The Guarantor represents and warrants as
follows (i) the Guarantor has full corporate power and authority to execute and
deliver this Guaranty and to perform and observe the provisions of this
Guaranty; (ii) the execution, delivery and performance by the Guarantor of this
Guaranty and any other Loan Documents to which it is a party have been duly
authorized by all necessary corporate action, and do not contravene the
Guarantor's charter or bylaws or any law or contractual restriction binding on
or affecting the Guarantor or any of the Guarantor's property; (iii) no
authorization or approval or other action by, and no notice to or filing with,
any governmental authority or regulatory body is required for the due execution,
delivery and performance by the Guarantor of this Guaranty; (iv) this Guaranty
is the legal, valid and binding obligation of the Guarantor enforceable against
the Guarantor in accordance with its terms, except as enforcement may be limited
by applicable bankruptcy, insolvency, reorganization, moratorium, or similar
laws generally affecting the rights of creditors and subject to general
equitable principles; and (v) except as otherwise disclosed in its latest Form
10-K or Form 10-Q, as applicable, filed with the Securities and Exchange
Commission, there is no pending or threatened investigation, litigation or
proceeding affecting the Guarantor that (A) could have a material adverse effect
on the financial condition or property of the Guarantor or the ability of the
Guarantor to perform the Guarantor's obligations under this Guaranty or (B)
purports to affect the legality, validity or enforceability of this Guaranty.



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9. Waivers.

         (a) The Guarantor waives any defense arising by reason of: (i) any
disability or other defense of any Borrower or any other person, including but
not limited to the insolvency or bankruptcy of any Borrower or any other person,
or any stay in connection with any such bankruptcy proceedings; (ii) the
cessation from any cause whatsoever, other than payment in full, of the Secured
Obligations; (iii) the application by any Borrower of the proceeds of any
Secured Obligation secured hereby for purposes other that the purposes
represented by the Borrowers to Lender or intended or understood by Lender or
the Guarantor; or (iv) any act or omission by Lender which directly or
indirectly results in or aids the discharge or release of the Borrowers, any
other person, any Secured Obligation, or any collateral, by operation of law or
otherwise.

         (b) The Guarantor waives all right which such Guarantor may have under:
(i) any law which may limit on the amount of a deficiency judgment based on any
Secured Obligation; (ii) any bar to deficiency judgments; (iii) any requirement
of law that Lender exhaust any security for the Secured Obligations before
proceeding against Guarantor; (iv) any law which may prohibit Lender from
enforcing its rights and remedies against any Borrower by both a private sale
and an action in court; or (v) any law which requires that a court action to
enforce Lender's rights be an action to foreclose any security instrument
securing the Secured Obligations.

         (c) The Guarantor agrees not to assert any right, claim or cause of
action including, without limitation, a claim for subrogation, reimbursement,
indemnification or otherwise against any Borrower arising out of or by reason of
this Guaranty or the obligations hereunder including, without limitation, the
payment or securing or purchasing of any of the Secured Obligations by the
Guarantor unless and until the Secured Obligations are paid in full and all
commitments to lend under the Loan Agreement are terminated. The Guarantor
agrees that any and all claims of the Guarantor against the Borrowers or any of
them, any endorser or any other guarantor of all or any part of the Secured
Obligations, or against any of their respective properties, shall be subordinate
and subject in right of payment to the prior payment, in full, of all principal
and interest, all reasonable costs of collection (including reasonable
attorneys' and paralegals' fees and expenses) and any other liabilities or
obligations owing to the Lender by the Borrowers or any of the Borrowers'
subsidiaries which may arise either with respect to or under the Loan Agreement
or any other Loan Documents. Notwithstanding any right of the Guarantor to ask,
demand, sue for, take or receive any payment from the Borrowers or any of the
Borrowers' subsidiaries, all rights, liens and security interests (if any) of
the Guarantor, whether now or hereafter arising or howsoever existing, in any
assets of any Borrower or any of a Borrower's subsidiaries (whether constituting
part of any security or collateral which may be given to the Lender to secure
payment of the Secured Obligations or otherwise) shall be and hereby are
subordinated to the rights of the Lender in those assets. The Guarantor shall
have no right to possession of any such asset or to foreclose upon any such
asset, whether by judicial action or otherwise, unless and until all of the
Secured Obligations shall have been fully paid and satisfied and all commitments
to lend under the Loan Agreement have been terminated. If all or any part of the
assets of any Borrower or any of a Borrower's subsidiaries, or the proceeds
thereof, are subject to any distribution, division or application to the
creditors of any Borrower or any of a Borrower's subsidiaries, whether partial,
complete, voluntary or involuntary and whether by reason of liquidation,
bankruptcy, arrangement, receivership, assignment for the benefit of creditors
or any other action or proceeding, or if the business of any Borrower or any of
a



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Borrower's subsidiaries is dissolved or if substantially all of the assets of
any Borrower or any of a Borrower's subsidiaries are sold, then, and in any such
event, any payment or distribution of any kind or character, either in cash,
securities or other property, which shall be payable or deliverable upon or with
respect to any indebtedness of any Borrower or any of a Borrower's subsidiaries
to the Guarantor shall be paid or delivered directly to the Lender for
application to the Secured Obligations due or to become due, until such Secured
Obligations shall have first been fully paid and satisfied.

         (d) The Guarantor warrants and agrees that each of the waivers set
forth above are made with the Guarantor's full knowledge of their significance
and consequences, with the understanding that events giving rise to any defense
waived may diminish, destroy or otherwise adversely affect rights which the
Guarantor otherwise may have against any Borrower, Lender or others, or against
collateral, and that under the circumstances existing in connection herewith,
the waivers are reasonable and not contrary to public policy or law. If any of
the waivers are determined to be contrary to any applicable law or public
policy, such waivers shall be effective to the maximum extent permitted by law.

         (e) No delay on the part of Lender in the exercise of any right or
remedy arising under this Guaranty, or any of the Loan Documents, or otherwise
with respect to all or any part of the Secured Obligations, any collateral
securing the Secured Obligations or any other guaranty of or security for all or
any part of the Secured Obligations shall operate as a waiver thereof, and no
single or partial exercise by any such person of any such right or remedy shall
preclude any further exercise thereof. No modification or waiver of any of the
provisions of this Guaranty shall be binding upon Lender except as expressly set
forth in a writing duly executed and delivered by Lender. Failure by Lender at
any time or times hereafter to require strict performance by any Borrower,
Guarantor, any other guarantor of all or any part of the Secured Obligations or
any other person of any of the provisions, warranties, terms and conditions
contained in the Loan Documents shall not waive, affect or diminish any right of
Lender at any time or times hereafter to demand strict performance thereof, and
such right shall not be deemed to have been modified or waived by any act or
knowledge of Lender, unless such waiver is contained in an instrument in
writing, and directed and delivered to Guarantor, specifying such waiver signed
by Lender. No waiver by Lender of any Event of Default or default under any of
the Loan Documents shall operate as a waiver of any other default or the same
default on a future occasion. Any final determination by a court of competent
jurisdiction of the amount of any principal and/or interest owing by any
Borrower to Lender, shall be conclusive and binding on the Guarantor
irrespective of whether the Guarantor was party to the suit or action in which
such determination was made.

         (f) This Guaranty shall continue in full force and effect and may not
be terminated or otherwise revoked until all obligations of Lender to extend
credit under the Facilities shall have been terminated and either (i) the
Secured Obligations shall have been fully paid or (ii) the Guaranteed Amount and
all Expenses, if any, have been paid to Lender under this Guaranty.

         (g) This Guaranty shall be binding upon Guarantor and upon its
representatives, successors and assigns and shall inure to the benefit of Lender
and its successors and assigns. All references herein to the Borrowers or
Guarantor shall be deemed to include their respective successors and assigns.
The successors and assigns of the Borrowers and the Guarantor shall include,
without limitation, a receiver, trustee or debtor-in-possession of or for any
such party. All references to the singular shall be deemed to include the plural
where the context so requires.



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10. Choice of Law, Jurisdiction, and Venue. This Guaranty shall be governed by
the internal laws of the State of New York. The Guarantor hereby acknowledges
that any dispute between the Guarantor and Lender arising out of, connected
with, related to, or incidental to the relationship established between them in
connection with this Guaranty or any other instrument, document or agreement
executed or delivered in connection herewith or the transactions related hereto,
and whether arising in contract, tort, equity, or otherwise, shall be resolved
in accordance with the internal laws and not the conflicts of law provisions of
the State of New York.

         IN ANY ACTION OR PROCEEDING ARISING UNDER OR RELATING TO THIS GUARANTY
OR ANY OTHER LOAN DOCUMENT OR ANY OF THE OBLIGATIONS (AS DEFINED HEREIN), EACH
OF LENDER AND GUARANTOR HEREBY IRREVOCABLY (A) CONSENTS AND SUBMITS TO THE
NONEXCLUSIVE JURISDICTION OF ANY STATE OR FEDERAL COURT SITTING IN THE BOROUGH
OF MANHATTAN IN NEW YORK, NEW YORK, AND (B) WAIVES ANY OBJECTION WHICH SUCH
PARTY MAY HAVE AT ANY TIME TO THE LAYING OF VENUE OF ANY SUCH PROCEEDINGS
BROUGHT IN ANY SUCH COURT, AND (C) WAIVES ANY CLAIM THAT SUCH PROCEEDINGS HAVE
BEEN BROUGHT IN AN INCONVENIENT FORUM AND (D) FURTHER WAIVES THE RIGHT TO OBJECT
WITH RESPECT TO SUCH PROCEEDINGS THAT SUCH COURT DOES NOT HAVE ANY JURISDICTION
OVER SUCH PARTY. THIS FORUM SELECTION AGREEMENT APPLIES NO MATTER WHAT THE FORM
OF ACTION, WHETHER IN REM, IN PERSONAM, OR ANY OTHER, OR WHETHER BASED ON ANY
STATUTE, RULE, OR REGULATION, NOW EXISTING OR HEREAFTER ENACTED.

         THE GUARANTOR HEREBY WAIVES PERSONAL SERVICE OF ANY AND ALL PROCESS
UPON IT AND CONSENTS THAT ALL SUCH SERVICE OF PROCESS MAY BE MADE AT THE OPTION
OF LENDER BY ANY ONE OF THE FOLLOWING (A) DELIVERY IN PERSON, (B) BY COURIER, OR
(C) CERTIFIED OR REGISTERED MAIL, POSTAGE PREPAID, TO THE GUARANTOR AT ITS
ADDRESS NOTED BELOW.

         ANY PROCESS SERVED BY MAIL SHALL BE COMPLETE ON THE DATE IT IS MAILED.
ANY PROCESS SERVED BY ANY OTHER MANNER AFOREMENTIONED SHALL BE COMPLETE ON THE
DATE IT IS DELIVERED. THE GUARANTOR CONSENTS TO SERVICE OF PROCESS AS AFORESAID.
THE GUARANTOR ALSO WAIVES ANY DEFECT IN SERVICE CAUSED BY ITS FAILURE TO NOTIFY
LENDER IN WRITING OF ANY CHANGE OF ADDRESS.

         NOTHING HEREIN SHALL AFFECT THE RIGHT OF LENDER TO SERVE LEGAL PROCESS
IN ANY OTHER MANNER PERMITTED BY LAW OR THE RIGHT OF LENDER TO BRING ANY ACTION
OR PROCEEDING AGAINST THE GUARANTOR OR ITS PROPERTY IN THE COURTS OF ANY OTHER
JURISDICTION.

11. WAIVER OF JURY TRIAL. THE GUARANTOR AND LENDER HEREBY IRREVOCABLY WAIVE
TRIAL BY JURY IN ANY ACTION OR PROCEEDING WITH RESPECT TO THIS GUARANTY.

12. Severability. Wherever possible, each provision of this Guaranty shall be
interpreted in such manner as to be effective and valid under applicable law,
but if any provision of this Guaranty shall be prohibited by or invalid under
such law, such provision shall be ineffective to



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the extent of such prohibition or invalidity without invalidating the remainder
of such provision or the remaining provisions of this Guaranty.

13. Notices. Any notice required or desired to be served, given or delivered
hereunder shall be in writing, and shall be delivered by (i) United States
registered mail, return receipt requested with proper postage prepaid, (ii)
facsimile with receipt confirmed, (iii) reputable overnight courier with all
charges prepaid, or (iv) by messenger, all of which shall be properly addressed
to the party to be notified and sent to the addresses set forth below their
names on the signature page hereto or to such other address as the parties
shall, from time to time, designate in writing.

14. Counterparts. This Guaranty may be executed in any number of counterparts,
all of which taken together shall constitute one agreement, and any of the
parties hereto may execute this Guaranty by signing any such counterpart. This
Guaranty shall be effective when it has been executed by the parties hereto.






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         IN WITNESS WHEREOF, this Guaranty has been duly executed as of the day
and year first set forth above.

                                         Affiliated Computer Services, Inc.

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

                                         Notice Address:
                                         2828 North Haskell Avenue
                                         Dallas, Texas 75214
                                         Attention:  General Counsel
                                         Fax:  214-823-5746



                                         CITICORP USA, INC.



                                         By:
                                             ----------------------------------
                                         Title:  Vice President

                                         Notice Address:

                                         Citicorp USA, Inc.
                                         500 West Madison Street
                                         Suite 400
                                         Chicago, IL  60661
                                         Attention: John Wayland
                                         Fax: (312) 627-5316

                                         with a copy to:

                                         Citicorp USA, Inc.
                                         425 Park Avenue
                                         New York, NY  10022
                                         Attention: Christopher Dee
                                         Fax: (212) 793-1152

                                         and a copy to:

                                         Victoria Gilbert, Esq.
                                         Sonnenschein Nath & Rosenthal
                                         8000 Sears Tower
                                         Chicago, IL  60606
                                         Fax: (312) 876-7934