Document:

<PAGE>   1
                                                           EXHIBIT 4.(ii)(d)(8)

                                TABLE OF CONTENTS

                               GUARANTY AGREEMENT

<TABLE>
<CAPTION>
SECTION                                     HEADING                                               PAGE
<S>                                                                                               <C>
1. Definitions......................................................................................1
2. Guarantee........................................................................................2
3. Secretary's Rights...............................................................................3
4. Primary Liability................................................................................3
5. Representations and Warranties...................................................................3
6. Continuing Guarantee.............................................................................4
7. Default..........................................................................................4
8. Notices..........................................................................................4
9. Amendments and Supplements.......................................................................5
10.Governing Law....................................................................................5
11.Counterparts.....................................................................................5
</TABLE>

<PAGE>   2

                       GUARANTY AGREEMENT IN FAVOR OF THE
                            UNITED STATES OF AMERICA

         THIS GUARANTY (this "Guaranty Agreement"), dated this February 10,
2000, is by and between PROJECT AMERICA, INC., a Delaware corporation (the
"Guarantor") TO THE UNITED STATES OF AMERICA (the "United States"), represented
by the SECRETARY OF TRANSPORTATION, acting by and through the MARITIME
ADMINISTRATOR (the "Secretary").

                                   WITNESSETH:

         A. WHEREAS, the Guarantor is the parent of Project America Ship I,
Inc., a Delaware corporation (the "Shipowner");

         B. WHEREAS, the Shipowner, in connection with the financing of the cost
of construction of the Vessel on the date hereof borrowed certain funds and
created and authorized the issuance of obligations designated either "United
States Government Guaranteed Ship Financing Notes" or "United States Government
Guaranteed Ship Financing Bonds" in the aggregate principal amount of
$534,447,000 (the "Obligations") bearing interest at the rate specified therein;

         C. WHEREAS, the Shipowner, on the date hereof, accepted the Secretary's
Commitment to Guarantee Obligations (the "Commitment") pursuant to Title XI of
the Merchant Marine Act, 1936, as amended (the "Act"), whereby the Secretary
authorized a guarantee to be endorsed upon each of the Obligations (the
"Guarantees");

         D. WHEREAS, the Shipowner has, in consideration of the issuance of the
Guarantees by the Secretary of the payment of the unpaid interest on, and the
unpaid balance of the principal of the Obligations, pursuant to the terms and
provisions of the Security Agreement, Contract No. MA-13581, dated the date
hereof between the Shipowner and the Secretary (the "Security Agreement"),
issued and delivered to the Secretary a promissory note in the principal amount
of $534,447,000 (said promissory note, as originally executed and as the same
may hereafter be amended, modified, supplemented or endorsed, herein called the
"Secretary's Note");

         E. WHEREAS, the Secretary required this Guaranty Agreement from the
Guarantor as an integral part of the consideration offered by or on behalf of
the Shipowner as a condition of the Secretary entering into the Commitment and
issuing the Guarantees, and the Guarantor is entering into this Guaranty
Agreement for the purpose of guaranteeing the Shipowner's obligations to the
Secretary under the Secretary's Note.

         NOW, THEREFORE, in consideration of the premises and of other good and
valuable consideration, the receipt and adequacy of which are hereby
acknowledged, the Guarantor hereby agrees as follows:

         1. Definitions. Unless otherwise specifically defined herein, the
capitalized terms used herein are defined in Schedule X to the Security
Agreement and any reference therein to other instruments shall have the
respective meaning stated in Schedule X of the Security Agreement or such other
instruments.

<PAGE>   3

         2. Guarantee.

               (a) The Guarantor hereby absolutely, irrevocably, and
unconditionally guarantees the due and punctual payment of the principal and
interest on the Secretary's Note. The Guarantor shall be required to make said
payments under this Guaranty Agreement upon receipt of a written notice from the
Secretary which states that the Shipowner has not promptly, completely or
effectively made said payments. The failure of Guarantor to receive such a
written notice or the failure of the Secretary to send said notice shall not
relieve the Guarantor of its obligations under this Guaranty Agreement. This
Guaranty Agreement shall be enforceable and exercisable by the Secretary from
the first day of any failure by the Shipowner to make payment or mandatory
prepayment of the principal of and the interest on the Secretary's Note when the
same shall be due. The Guarantor shall immediately pay to the Secretary or its
designee in immediately available funds, such payments guaranteed herein.

               (b) The Guarantor hereby consents and agrees that its obligations
under this Guaranty Agreement will not be discharged by any act or omission to
act of any kind by the Secretary or any other person or any other circumstances
whatsoever (including, but not limited to, any extension, rearrangement, or
renewal with respect to any indebtedness or other obligation of the Shipowner
with or without notice to the Guarantor, any waiver of any right of the
Secretary under the terms of the Secretary's Note, the Security Agreement, the
Mortgage, or this Guaranty Agreement, any release of security, any transfer or
assignment of rights or obligations accruing to the Secretary under the
Secretary's Note, the Security Agreement, the Mortgage, or this Guaranty
Agreement, any corporate reorganization, dissolution, merger, acquisition of or
by or other alteration of the corporate existence or structure of the Shipowner
or the Guarantor, discharge of the Shipowner in bankruptcy, the invalidity,
illegality, or unenforceability of the Secretary's Note, the Security Agreement,
the Mortgage, or this Guaranty Agreement or the absence of any action to enforce
the obligations of the Shipowner) which might constitute a legal or equitable
discharge of the Guarantor; it being the intention of the Guarantor that this
Guaranty Agreement be absolute, continuing, and unconditional and the guarantee
hereunder shall only be discharged by the payment in full of all sums so
guaranteed hereunder.

               (c) The Guarantor hereby irrevocably and unconditionally waives:
(1) notice of any of the matters referred to in this Guaranty Agreement and any
action by the Secretary in reliance thereon; (2) all notices which may be
required by statute, rule of law, or otherwise to preserve any rights against
the Guarantor hereunder, including without limitations, any demand, protest,
proof of notice of non-payment of all sums payable under the Secretary's Note or
any notice of any failure on the part of the Shipowner to perform or comply with
any covenant, term, or obligations of any agreement to which it is a party; (3)
any requirement for the enforcement, assertion, or exercise of any right,
remedy, power, or privilege under or with respect to the Mortgage, the Security
Agreement, or the Secretary's Note; (4) any requirement of diligence; (5) any
requirement that the Shipowner be joined as a party to any proceedings for the
enforcement of any provision of this Guaranty Agreement, or that the Secretary
proceed against any other guarantor executing this Guaranty Agreement or any
other guaranty agreement; (6) any and all defenses to payment hereunder, except
the defense of payment already made, and agrees to confess without contesting
liability hereunder for any judgment entered hereon; (7) presentment, demand,
protest, notice of protest and dishonor, notice of intent to accelerate, and
notice of acceptance; or (8) the right to require the Secretary to pursue any
remedy in the Secretary's power whatsoever.

                                       2

<PAGE>   4

               (d) The Guarantor hereby agrees that this Guaranty Agreement
shall continue to be effective or shall be reinstated, as the case may be, if at
any time payment of any sum hereby guaranteed is rescinded or must be otherwise
restored or returned by the Secretary, upon the insolvency, bankruptcy, or
reorganization of the Shipowner, or otherwise, all as though such payment had
not been made. The Guarantor further agrees that if the maturity of any
obligations guaranteed herein be accelerated by bankruptcy or otherwise, such
maturity shall also be deemed accelerated for the purpose of this Guaranty
Agreement without demand or notice to the Guarantor.

               (e) Any amount payable hereunder shall not be subject to any
reduction by reason of any counterclaim, set-off, deduction, abatement, or
otherwise.

               (f) The Guarantor shall pay all reasonable costs and expenses
(including, without limitation, attorneys' fees and expenses) incurred in
connection with the enforcement of the obligations of the Guarantor under this
Guaranty Agreement.

               (g) The Secretary's Note may be amended, modified, or endorsed
without the consent of the Guarantor.

               (h) The Secretary may enforce the Guarantor's obligations
hereunder without in any way first pursuing or exhausting any other rights or
remedies which the Secretary may have against the Shipowner or any other person,
firm, or corporation or against any security the Secretary may hold.

         3. Secretary's Rights. The Guarantor authorizes the Secretary, without
notice or demand and without affecting the Guarantor's liability hereunder, to
take and hold security for the payment of this Guaranty Agreement and/or any of
the obligations guaranteed herein and exchange, enforce, waive, and release any
such security; and to apply such security and direct the order or manner of sale
thereof as the Secretary in his discretion may determine; and to obtain a
guarantee of any of the obligations guaranteed herein from any one or more
persons, corporations, or entities whomsoever and at any time or times to
enforce, waive, rearrange, modify, limit or release such other persons,
corporations, or entities from their obligations under such guarantees.

         4. Primary Liability. It is expressly agreed that the liability of the
Guarantor for the payment of the obligations guaranteed herein shall be primary
and not secondary.

         5. Representations and Warranties. The Guarantor represents and
warrants as follows:

               (a) It is a corporation duly organized, validly existing, and in
good standing under the laws of the state of Delaware and has full power and
authority (corporate, legal and other) to execute, deliver, and carry out the
terms of this Guaranty Agreement;

               (b) This Guaranty Agreement has been duly authorized, executed,
and delivered by the Guarantor and constitutes the legal, valid, and binding
obligation of the Guarantor enforceable against the Guarantor in accordance with
its terms;

               (c) The execution, delivery, and performance by the Guarantor of
this Guaranty

                                       3
<PAGE>   5

Agreement does not require the approval or consent of its shareholders or of any
governmental authority and does not contravene the Guarantor's Articles of
Incorporation, or any mortgage, indenture, or other agreement binding upon it,
or any law, regulation, order, judgment, or decree applicable to the Guarantor;

               (d) The Guarantor's guarantee pursuant to this Guaranty Agreement
may be expected to benefit, directly or indirectly, the Guarantor; and

               (e) The Guarantor has fully adequate financial resources, funds,
and assets to satisfy its obligations under this Guaranty Agreement and the
Guarantor will in the future retain sufficient financial resources, funds, and
assets to fully satisfy its obligations under this Guaranty Agreement.

         6. Continuing Guarantee. This Guaranty Agreement is a continuing
guarantee of payment and collectability and shall:

               (a) Remain in full force and effect so long as any obligation of
the Shipowner to the Secretary referred to herein exists;

               (b) Be binding upon the Guarantor, its successors and assigns;

               (c) Be executed and issued for the sole and exclusive benefit of
the United States, and no other party shall be permitted to claim any benefit,
direct or indirect, therefrom. This Guaranty Agreement is nonassignable, any
assignment thereof shall be null and void and have no legal effect whatsoever;
and

               (d) Inure to the benefit of, and be enforceable by the Secretary,
his successors and assigns.

         7. Default. A default under the terms of this Guaranty Agreement shall
be deemed to occur if the Guarantor fails to make any payment guaranteed
hereunder.

         8. Notices. All communications may be made or delivered in person or by
certified or registered mail, postage prepaid, addressed to the Guarantor or the
Secretary as provided below or to such other address as the Guarantor or the
Secretary may hereafter specify in a written notice to the other and all notices
or other communications shall be in writing so addressed and shall be effective
upon receipt by the addressee thereof:

                                       4
<PAGE>   6

         Guarantor:                PROJECT AMERICA, INC.
                                   c/o American Classic Voyages Co.
                                   2 North Riverside Plaza
                                   Chicago, Illinois 60606
                                   Attn: Executive Vice President and
                                         General Counsel

         Secretary:                SECRETARY OF TRANSPORTATION
                                   c/o Maritime Administration
                                   Department of Transportation
                                   Washington, DC  20590
                                   Attn: Chief, Division of Ship
                                         Financing Contracts

         9. Amendments and Supplements. No agreement shall be effective to
change or modify, supplement, amend, or discharge in whole or in part this
Guaranty Agreement unless such agreement is in writing, signed by the Guarantor
and the Secretary.

         10. Governing Law. This Guaranty Agreement shall be governed by federal
law of the United States of America or in the absence of applicable federal law
by the laws of the State of Illinois.

         11. Counterparts. This Guaranty Agreement may be executed in one or
more counterparts. All such counterparts shall be deemed to be originals and
shall together constitute but one and the same instrument.

                                       5

<PAGE>   7

         IN WITNESS WHEREOF, this Guaranty Agreement has been executed by the
Guarantor as of the day and year first above written.

GUARANTOR:                                 PROJECT AMERICA, INC.

(SEAL)                                     By  /s/ Jordan B. Allen
                                              ---------------------------------
                                              Its Executive Vice President

ATTEST:

By  /s/ Pam Stringer
  -------------------------------
  Its Assistant Secretary

<PAGE>   8

ACKNOWLEDGED BY:

                                           UNITED STATES OF AMERICA,
                                           SECRETARY OF TRANSPORTATION

                                           MARITIME ADMINISTRATOR

(SEAL)                                     By  /s/ Joel C. Richard
                                              ---------------------------------
                                              Its Secretary

ATTEST:

By  /s/ Sarah J. Washington
   ----------------------------
   Its Assistant Secretary<PAGE>   1

Exhibit 10.1

                               FIRST AMENDMENT TO

                              AMENDED AND RESTATED

                           REVOLVING CREDIT AGREEMENT

                                      AMONG

                         AMERITRADE HOLDING CORPORATION,
                          FIRST NATIONAL BANK OF OMAHA,
                         HARRIS TRUST AND SAVINGS BANK,
                     LASALLE BANK NATIONAL ASSOCIATION, AND
                      MERCANTILE BANK NATIONAL ASSOCIATION

                          DATED AS OF JANUARY 25, 2000

                                 APRIL 28, 2000

<PAGE>   2

                     FIRST AMENDMENT TO AMENDED AND RESTATED
                           REVOLVING CREDIT AGREEMENT

     THIS FIRST AMENDMENT to AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT
(this "First Amendment") entered into as of this 28th day of April, 2000, is
intended to amend the terms of the Amended and Restated Revolving Credit
Agreement (the "Agreement") dated as of the 25th day of January, 2000, among
AMERITRADE HOLDING CORPORATION, a Delaware corporation having its principal
place of business at 4211 South 102nd Street, Omaha, Nebraska 68127 (the
"Borrower"); FIRST NATIONAL BANK OF OMAHA, a national banking association having
its principal place of business at One First National Center, Omaha, Nebraska
68102 ("Agent" or "FNB-O"); HARRIS TRUST AND SAVINGS BANK, an Illinois banking
corporation having its principal place of business at 111 W. Monroe Street,
Chicago, Illinois 60603 ("Harris"); LASALLE BANK NATIONAL ASSOCIATION, a
national banking association having its principal place of business at 135 South
LaSalle Street, Chicago, Illinois 60603 ("LaSalle"); and MERCANTILE BANK
NATIONAL ASSOCIATION, a national banking association having its principal place
of business at One Mercantile Center, 7th and Washington TRAM 12-3, St. Louis,
Missouri 63101 ("Mercantile"). All terms and conditions of the Agreement shall
remain in full force and effect except as expressly amended herein. All
capitalized terms used but not otherwise defined herein shall have the
respective meanings prescribed in the Agreement.

     WHEREAS, the Borrower has requested that it be permitted to pledge the NITE
Stock pursuant to the terms of a credit facility with one or more third parties
other than the Revolving Lenders; and

     WHEREAS, the Revolving Lenders have agreed to permit such additional
borrowing and pledge on the terms and conditions specified below;

     NOW, THEREFORE, the parties hereby agree that as of the Effective Date
specified below:

     1.   The definition of "Collateral" in Section I of the Agreement is hereby
          amended to add the words "(excluding NITE Stock other than the Pledged
          NITE Stock)" in clause (c) of such definition immediately after the
          word "securities." The definition of "Indebtedness" in Section I of
          the Agreement is hereby amended to add the words "and amounts
          outstanding under any Other Credit Facility" after the words
          "Subordinated Debt."

     2.   The following definition is hereby added to Section I of the
          Agreement:

          Other Credit Facility:  As defined in Section 4.25 hereof.

     3.   Section 2.1 of the Agreement is hereby amended to read as follows:

          2.1 Revolving Credit. Until December 31, 2001, the Revolving Lenders
          severally agree to advance funds for general corporate purposes not to
          exceed the amount shown below (the "Base Revolving Credit Facility")
          to the Borrower on a revolving credit basis.

<PAGE>   3

               Such Advances shall be made on a pro rata basis by the Revolving
          Lenders, based on the following maximum Advance limits and applicable
          percentages for each Revolving Lender: (i) as to FNB-O, $21,666,675
          (28.8889%); (ii) as to Harris, $16,666,650 (22.2222%); (iii) as to
          Mercantile, $20,000,000 (26.6667%); (iv) as to LaSalle, $16,666,650
          (22.2222%); provided, however, that each Revolving Lender's Commitment
          is several and not joint or joint and several. The Base Revolving
          Credit Facility shall be subject to reduction as specified in Section
          4.3 of the Pledge Agreement.

               The Borrower shall not be entitled to any Advance hereunder if,
          after the making of such Advance, the Principal Loan Amount would
          exceed the least of (x) the then current Base Revolving Credit
          Facility, or (y) the sum of $25,000,000 plus one and one-half (1 1/2)
          times the Borrower's Annualized Modified Cash Flow, or (z) the number
          of Core Retail Accounts times $200, determined in each case after
          giving effect to the requested Advance. Nor shall the Borrower be
          entitled to any further Advances hereunder after the occurrence and
          during the continuation of any Event of Default or any event which
          with the passage of time or the giving of notice or both would
          constitute an Event of Default, or if the Borrower's representations
          and warranties cease to be true and correct in all material respects
          at the time of the requested Advance. Advances shall be made, on the
          terms and conditions of this Agreement, upon the Borrower's request.
          Requests shall be made by 12:00 noon Omaha time on the Business Day
          prior to the requested date of the Advance. Requests shall be made by
          presentation to FNB-O of a drawing certificate in the form of Exhibit
          B. The Borrower's obligation to make payments of principal and
          interest on the foregoing revolving credit indebtedness shall be
          further evidenced by the Notes.

4.        Section 4.2 of the Agreement is hereby amended to read as follows:

          4.2  Corporate Structure and Assets.
               ------------------------------

               (a)  The Borrower shall not merge or consolidate with any other
               corporation or entity without the prior written consent of the
               Requisite Revolving Lenders, except as provided in clause (b)
               below.

               (b)  The foregoing restriction on mergers and consolidations
               shall not apply if: (i) in the case of a merger, the Borrower is
               the surviving entity and expressly reaffirms its obligations
               hereunder; (ii) in the case of a consolidation, the resulting
               corporation expressly assumes the obligations of the Borrower
               hereunder; (iii) the surviving or resulting corporation is
               organized under the laws of the United States or a jurisdiction
               thereof; (iv) after giving effect to such merger or
               consolidation, the surviving or resulting corporation will be
               engaged in substantially the same lines of business as are now
               engaged in by the Borrower and its Subsidiaries and businesses
               reasonably related thereto; and (v) immediately after giving
               effect to such merger or consolidation, no Event of Default will
               exist hereunder.

               (c)  The Borrower shall not sell any assets, other than in the
               ordinary course of business, in an aggregate amount greater than
               one million dollars ($1,000,000),

                                      -2-
<PAGE>   4

               except (i) items that are obsolete or no longer necessary for
               operation of the business, (ii) the Borrower's interest in
               Comprehensive Software Systems, Ltd. and (iii) the Borrower's
               interest in the NITE Stock (other than the Pledged NITE Stock).
               The Revolving Lenders shall be entitled to receive as a
               prepayment on the Notes the net cash proceeds of any sale of
               assets of the Borrower which are prohibited by the preceding
               sentence. Notwithstanding the foregoing prepayment requirements,
               any such prohibited sale shall remain a violation of this
               Agreement. Any net cash proceeds from the sale of the Borrower's
               interest in the NITE Stock (other than the Pledged NITE Stock)
               shall either (y) be reinvested solely in Permitted Investments or
               additional investments in Advance Clearing, or (z) subject to the
               provisions of the following sentence, paid to the Revolving
               Lenders as a prepayment on the Notes as specified below. To the
               extent the sold NITE Stock secured an Other Credit Facility and
               the net cash proceeds of the sale are required to be used to
               reduce the amount outstanding under the Other Credit Facility,
               the net cash proceeds shall be repaid first to reduce such Other
               Credit Facility as required thereby, and second, to the extent of
               any remaining net cash proceeds, pro rata in accordance with the
               next sentence. If the sold NITE Stock did not secure an Other
               Credit Facility, the net cash proceeds shall be applied pro rata
               (based on the amounts outstanding thereunder) to prepayment of
               the Other Credit Facility or Facilities and the prepayment of the
               Notes. For purposes of this Section 4.2 (c), "net cash proceeds"
               shall mean any proceeds shall mean the amount in cash or cash
               equivalents received from the sale after taxes and after payment
               of all costs and expenses incurred in connection with the sale,
               including brokerage or similar fees.

               (d)  In addition, the Borrower shall not engage in any business
               materially different from that in which it is presently engaged
               and businesses reasonably related thereto without the prior
               written consent of the Requisite Revolving Lenders, which consent
               shall not be unreasonably withheld.

     7. The following Section 4.25 is hereby added to the Agreement:

        4.25  Other Credit Agreements; NITE Stock.

               (a)  The Borrower shall not suffer to exist any security interest
               on the Pledged NITE Stock. The Borrower shall not suffer to exist
               any security interest or other encumbrance on any other portion
               of the NITE Stock owned by the Borrower and its Subsidiaries
               other than to secure indebtedness of the Borrower under any
               credit, margin stock, or put and/or call agreement secured by or
               covering such NITE Stock (an "Other Credit Facility").

               (b)  The Borrower shall not permit the Principal Loan Amount, at
               any time when there is indebtedness outstanding under any Other
               Credit Facility, to be less than the lesser of (i) one half of
               the aggregate principal amount outstanding under all Other Credit
               Facilities and (ii) the maximum amount permitted to be
               outstanding at such time under Section 2.1 of this Agreement.
               Notwithstanding anything to

                                      -3-
<PAGE>   5

               the contrary herein or in any other Operative Document, no
               Temporary Administrative Convenience Breach by the Borrower of
               this Section 4.25(b) shall be an Event of Default (or an event
               which with the passage of time or the giving of notice or both
               will constitute an Event of Default) nor create a default upon
               which Agent or any other Revolving Lender may exercise any remedy
               against any Collateral or exercise any right of set-off. For
               purposes of this Section 4.25(b), a "Temporary Administrative
               Convenience Breach" is a breach of this Section 4.25 (b) which
               (y) does not continue for more than two Business Days, or (z)
               does not result in the ratio of the aggregate amount outstanding
               under all Other Credit Facilities to the Principal Loan Amount to
               exceed 7:3 .

               (c) The Borrower shall not permit the aggregate principal amount
               outstanding under all Other Credit Facilities to exceed 70% of
               the fair market value of the NITE Stock (exclusive of the Pledged
               NITE Stock) owned by the Borrower and its Subsidiaries.

               (d) Prior to entering into any Other Credit Facility, the
               Borrower shall provide to Agent a copy of the final form of the
               operative agreements for the Other Credit Facility and such Other
               Credit Facility shall not, in the reasonable opinion of Agent,
               constitute an Event of Default hereunder or materially adversely
               affect the rights of the Revolving Lenders under this Agreement.

     9.  Section 6.1(f) of the Agreement is hereby amended by adding "Other
Credit Agreement," after the phrase "(including the Subordinated Debt)."

     10. Section 4.17 of the Agreement is hereby amended by inserting the
following at the end of the proviso to the first sentence "and (iv) Permitted
Investments."

                          CHANGE TO SECURITY AGREEMENT

     11. Section 5(a) of the Security Agreement is hereby amended by adding the
following at the end of the last sentence thereof "and other than Permitted
Liens."

                           CHANGE TO PLEDGE AGREEMENT

     12. Section 4.3 of the Pledge Agreement is hereby amended to read as
follows:

           Section 4.3  NITE Stock  Covenants. In connection with the NITE
           Stock, the Borrower agrees as follows:

                  (a)  Mark to Market. The Borrower represents and warrants that
                  the original Pledged NITE Stock has a market value of at least
                  $50,000,000. The Pledged NITE Stock shall be marked to market
                  weekly to determine the fair market value of such Collateral.
                  The Borrower shall provide to the Agent weekly a report
                  showing the current fair market value of the Pledged NITE
                  Stock.

                                      -4-
<PAGE>   6

                  (b)  Additional Pledged NITE Stock. In the event that the fair
                  market value of the Pledged NITE Stock at any time is less
                  than $36,000,000, the Borrower shall give notice of such
                  deficiency to the Agent and, within three Business Days after
                  the determination of the deficiency, deliver to the Agent, or
                  transfer into the Pledged Account, as applicable, additional
                  NITE Stock such that the fair market value of the Pledged NITE
                  Stock again shall be at least $50,000,000. Prior to the
                  provision of such additional Pledged NITE Stock, the Base
                  Revolving Credit Facility shall be reduced immediately to an
                  amount equal to the sum of (a) 1.5 times Annualized Modified
                  Cash Flow (but not to exceed $50,000,000), plus (b) 70% of the
                  fair market value of the Pledged NITE Stock (as to (a) and (b)
                  together, the "Maximum Loan Availability"). Failure to provide
                  such additional Pledged NITE Stock within three Business Days
                  shall constitute a default under this Stock Pledge Agreement
                  unless the total amount outstanding under the Notes does not
                  exceed the Maximum Loan Availability.

                  (c)  Release of Pledged NITE Stock. The Agent shall release
                  the Pledged NITE Stock and return all interest therein to
                  the Borrower upon satisfaction of all of the following
                  conditions:

                       (i)   the Base Revolving Credit Facility is reduced to
                       $50,000,000.00 or less;

                       (ii)  the aggregate amounts outstanding under the Notes
                       and the Revolving Credit Agreement do not exceed the
                       product of l.5 times Annualized Modified Cash Flow; and

                       (iii) no Event of Default nor any event or occurrence
                       which with the passage of time, or notice, or both, would
                       constitute an Event of Default, has occurred and is
                       continuing.

     13. This First Amendment may be executed in several counterparts and such
counterparts together shall constitute one and the same instrument.

     14. Except as expressly agreed herein, all terms of the Agreement, the
Security Agreement and the Pledge Agreement shall remain in full force and
effect.

     15. This First Amendment shall be effective as of April 28, 2000 (the
"Effective Date").

                                      -5-
<PAGE>   7

         IN WITNESS WHEREOF, the Borrower and the Revolving Lenders have caused
this First Amendment to Amended and Restated Revolving Credit Agreement to be
executed by their duly authorized corporate officers as of the day and year
first above written.

                                    AMERITRADE HOLDING CORPORATION

                                    By:       /s/ John R. MacDonald
                                       ------------------------------------
                                     Title:       Chief Financial Officer
                                                  John R. MacDonald

                                    FIRST NATIONAL BANK OF OMAHA

                                    By:      /s/ J. P. Bonham
                                       ------------------------------------
                                     Title:  Vice President

NOTICE: A credit agreement must be in writing to be enforceable under Nebraska
law. To protect you and us from any misunderstandings or disappointments, any
contract, promise, undertaking, or offer to forebear repayment of money or to
make any other financial accommodation in connection with this loan of money or
grant or extension of credit, or any amendment of, cancellation of, waiver of,
or substitution for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                    INITIALED: /s/ JRM
                                               ----------------------------
                                                    Borrower

                                      -6-
<PAGE>   8

                                    HARRIS TRUST AND SAVINGS BANK

                                    By: /s/ Gary R. Shafer
                                        --------------------------------
                                       Title:    Vice President

NOTICE: A credit agreement must be in writing to be enforceable under Nebraska
law. To protect you and us from any misunderstandings or disappointments, any
contract, promise, undertaking, or offer to forebear repayment of money or to
make any other financial accommodation in connection with this loan of money or
grant or extension of credit, or any amendment of, cancellation of, waiver of,
or substitution for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                        INITIALED:

                                        /s/ JRM
                                        ------------------
                                        Borrower

<PAGE>   9

                                    MERCANTILE BANK NATIONAL ASSOCIATION

                                    By:    /s/ Joseph L. Sooter, Jr.
                                       --------------------------
                                       Title:   Vice President

NOTICE: A credit agreement must be in writing to be enforceable under Nebraska
law. To protect you and us from any misunderstandings or disappointments, any
contract, promise, undertaking, or offer to forebear repayment of money or to
make any other financial accommodation in connection with this loan of money or
grant or extension of credit, or any amendment of, cancellation of, waiver of,
or substitution for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                        INITIALED:

                                        /s/ JRM
                                        -------
                                        Borrower

<PAGE>   10

                                    LASALLE BANK NATIONAL ASSOCIATION

                                    By:       /s/ Darren Lemkau

                                       Title:  FVP
                                             ----------------------------

NOTICE: A credit agreement must be in writing to be enforceable under Nebraska
law. To protect you and us from any misunderstandings or disappointments, any
contract, promise, undertaking, or offer to forebear repayment of money or to
make any other financial accommodation in connection with this loan of money or
grant or extension of credit, or any amendment of, cancellation of, waiver of,
or substitution for any or all of the terms or provisions of any instrument or
document executed in connection with this loan of money or grant or extension of
credit, must be in writing to be effective.

                                        INITIALED:

                                        /s/ JRM
                                        -------
                                        Borrower

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00013-of-00352.parquet"}]]