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                                                                    EXHIBIT 10.2

                 FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED
                     SECURED ADVANCE FACILITY LOAN AGREEMENT

         This FOURTH AMENDMENT TO SECOND AMENDED AND RESTATED SECURED ADVANCE
FACILITY LOAN AGREEMENT (the "Amendment") is entered into effective as of June
19, 2000 by and between Azul Holdings Inc., a Delaware corporation with its
principal place of business at 2362 Spotswood Place, Boulder, Colorado 80304
(the "Borrower"), and Jeffrey L. Neuman as trustee of the Tudor Trust u/d/t
December 12, 1997, with an address of 450 Roxbury Drive, 4th Floor, Beverly
Hills, California 90210 (the "Lender").

         WHEREAS, the Borrower and the Lender are parties to that Second Amended
and Restated Secured Advance Facility Loan Agreement dated as of July 1, 1998,
as amended by that First Amendment to Second Amended and Restated Secured
Advance Facility Loan Agreement dated as of December 31, 1998, that Second
Amendment to Second Amended and Restated Secured Advance Facility Loan Agreement
dated as of December 7, 1999 and that Third Amendment to Second Amended and
Restated Secured Advance Facility Loan Agreement dated as of March 31, 2000 (as
amended, the "Agreement");

         WHEREAS, the Borrower plans to make additional investments principally
in emerging and early-stage companies within technology sectors such as the
e-commerce and biotechnology industries, as approved from time to time by the
Borrower's board of directors;

         WHEREAS, the Lender has agreed to loan to the Borrower up to an
additional $5,000,000 under this Agreement for the purpose of funding such
planned investments by the Borrower, and in connection therewith has agreed to
increase the Maximum Loan Amount under the Agreement from $12,500,000 to
$17,500,000; and

         WHEREAS, as a result of the foregoing the Borrower and the Lender
desire to amend and modify the Agreement as set forth herein, with all
capitalized terms used but not defined herein having the meanings given them
under the Agreement;

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


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         1. Amendments to Agreement.

               (a) Section 1.19 of the Agreement is amended and restated in its
          entirety as follows:

                    "1.19. Maximum Loan Amount. Seventeen Million Five Hundred
                    Thousand Dollars ($17,500,000.00)."

               (b) Section 1.25 of the Agreement is amended and restated in its
          entirety as follows:

                    "1.25 Secured Promissory Note. The amended and restated
                    secured promissory note in the amount of Seventeen Million
                    Five Hundred Thousand Dollars ($17,500,000.00) executed by
                    the Borrower and delivered to the Lender."

               (c) Section 3.7 of the Agreement is amended and restated in its
          entirety as follows:

                    "3.7 Conversion of Liabilities.

                    (a) Optional Conversion into Series C Stock. At any time
                    from and after June 1, 1999, the Lender may, at its written
                    election, convert up to $5,000,000 of the unpaid principal
                    balance of the Liabilities resulting from Advances under the
                    Maximum Loan Amount of $12,500,000 under the Agreement
                    immediately prior to June 19, 2000 (the "Series C
                    Convertible Liabilities") into the Borrower's Series C Stock
                    at a conversion rate of $10.00 per share (the "Series C
                    Conversion Price").

                    (b) Optional Conversion into Common Stock. With respect to
                    any Liabilities resulting from Advances made on or after
                    June 19, 2000 pursuant to the increase in the Maximum Loan
                    Amount under this Agreement by $5,000,000 from $12,500,000
                    to $17,500,000 effective as of June 19, 2000, the Lender
                    may, at its written election, convert up to $5,000,000 of
                    the unpaid principal balance of such

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                    Liabilities (the "Common Stock Convertible Liabilities")
                    into shares of the Borrower's Common Stock at a conversion
                    rate of $3.25 per share (the "Common Stock Conversion
                    Price").

                    (c) Adjustment for Dividends, Subdivisions, Stock Splits and
                    Combinations. In case the Borrower shall: (i) declare a
                    dividend of stock (into which Lender may convert Liabilities
                    under this Section 3.7) on such stock, (ii) subdivide such
                    outstanding stock into which Lender may convert Liabilities
                    under this Section 3.7 into a larger number of shares of
                    such stock by reclassification, stock split or otherwise, or
                    (iii) combine outstanding shares of such stock into a
                    smaller number of shares of such stock by reclassification
                    or otherwise, the number of shares of stock issuable upon
                    conversion of the Series C Convertible Liabilities or the
                    Common Stock Convertible Liabilities immediately prior to
                    any such event shall be adjusted proportionately so that
                    thereafter the Lender shall be entitled to receive upon
                    conversion of the Series C Convertible Liabilities or the
                    Common Stock Convertible Liabilities the number of shares of
                    Series C Stock or Common Stock which the Lender would have
                    owned after the happening of any of the events described
                    above had the Series C Convertible Liabilities or Common
                    Stock Convertible Liabilities been converted immediately
                    prior to the happening of such event, provided that the
                    Series C Conversion Price and Common Stock Conversion Price
                    shall in no event be reduced to less than the par value of
                    the shares issuable upon conversion. An adjustment made
                    pursuant to this Section 3.7 shall become effective
                    immediately after the record date in the case of a dividend
                    and shall become effective immediately after the effective
                    date in the case of a subdivision of combination. If after
                    June 1, 1999 the Borrower shall at any time consolidate or
                    merge with another corporation (other than a merger or
                    consolidation in which the Borrower is the surviving
                    corporation), the Lender will thereafter be entitled to
                    receive, upon the conversion of the Series C Convertible
                    Liabilities or Common Stock Convertible Liabilities, the
                    securities or property to which a holder of the number of
                    shares of Series C Stock or Common Stock then deliverable
                    upon the

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                    conversion of the Series C Convertible Liabilities or Common
                    Stock Convertible Liabilities would have been entitled upon
                    such consolidation or merger, and the Borrower shall take
                    such steps in connection with such consolidation or merger
                    as may be necessary to ensure that the provisions hereof
                    shall thereafter be applicable, as nearly as reasonably may
                    be, in relation to any securities or property thereafter
                    deliverable upon the conversion of the Series C Convertible
                    Liabilities or Common Stock Convertible Liabilities."

               (d) Section 5.1 of the Agreement is amended and restated in its
          entirety as follows:

                    "5.1 Ordinary Course of Business. The Borrower agrees that
                    the Advances will be used in the ordinary course of the
                    Borrower's business. With respect to any Advances made on or
                    after June 19, 2000 pursuant to the increase under this
                    Agreement of the Maximum Loan Amount by $5,000,000 from
                    $12,500,000 to $17,500,000 effective as of June 19, 2000,
                    such Advances will be used to make additional investments
                    principally in emerging and early-stage technological
                    companies, as approved from time to time by the Borrower's
                    board of directors.

               (e) Section 11.2 of the Agreement is amended and restated in its
          entirety as follows:

                    "11.2 Loans. The Borrower will not make any loans or
                    advances to any individual, firm or corporation, including
                    without limitation its officers and employees; provided,
                    however, that it may make advances to its employees,
                    including its officers, with respect to reasonable business
                    expenses incurred by such employees which expenses are
                    reimbursable by it, and provided further that with respect
                    to any Advances made on or after June 19, 2000 pursuant to
                    the increase under this Agreement of the Maximum Loan Amount
                    by $5,000,000 from $12,500,000 to $17,500,000 effective as
                    of June 19, 2000, such Advances may be used to make loan
                    investments

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                    principally in emerging and early-stage technological
                    companies, as approved from time to time by the Borrower's
                    board of directors.

               (f) Section 11.3 of the Agreement is amended and restated in its
          entirety as follows:

                    "11.3 Purchase of Securities. The Borrower will not invest
                    in or purchase any stock or securities of any individual,
                    firm or corporation other than U.S. Government obligations
                    with a maturity not greater than one (1) year on
                    certificates of deposits with banks having a principal
                    office within the United States; provided, however, that
                    with respect to any Advances made on or after June 19, 2000
                    pursuant to the increase under this Agreement of the Maximum
                    Loan Amount by $5,000,000 from $12,500,000 to $17,500,000
                    effective as of June 19, 2000, such Advances may be used to
                    purchase securities to make investments principally in
                    emerging and early-stage technological companies, as
                    approved from time to time by the Borrower's board of
                    directors.

               (d) The Amended and Restated Secured Promissory Note attached as
          Exhibit 7.1 to the Agreement is amended and restated in its entirety
          in the form attached hereto as Exhibit A (the "Restated Note"). The
          Borrower shall execute the Restated Note and deliver the
          originally-executed Restated Note to the Lender. A condition to the
          Borrower's obligation to execute and deliver the Restated Note to the
          Lender hereunder shall be the Lender's obligation to deliver to the
          Borrower for cancellation the originally-executed Amended and Restated
          Secured Promissory Note dated May, 2000 in the principal amount of
          $12,357,150 (the "Prior Note"). The Prior Note shall be marked
          "CANCELED" and stored at the Borrower's executive offices.

         2. Effect on Agreement. Except as amended by this Amendment, the
Agreement shall remain in full force and effect. After the date of this
Amendment, every reference in the Agreement to "this Agreement" shall mean the
Agreement as amended by this Amendment.

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         3. Miscellaneous.

               (a) Successors and Assigns. The obligations of the Borrower
          hereunder shall be binding upon its successors and assigns (but such
          reference is not intended as a consent to any assignment not
          specifically permitted by the Lender) and shall inure to the benefit
          of the successors and assigns of the Lender.

               (b) Counterparts and Facsimile Signatures. This Amendment may be
          executed in two or more counterparts, each of which shall be deemed an
          original but all of which together shall constitute one and the same
          instrument. This Amendment may be executed by facsimile signature.

               (c) Headings. The section headings contained in this Amendment
          are inserted for convenience only and shall not affect in any way the
          meaning or interpretation of this Amendment.

               (d) Governing Law. This Amendment shall be governed by and
          construed in accordance with the laws of the Commonwealth of
          Massachusetts and shall constitute an agreement under seal.

               (e) Expenses. The Borrower will pay the reasonable legal fees and
          out-of-pocket expenses of the Lender's counsel incurred in connection
          with the preparation, execution and delivery of this Amendment.


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         IN WITNESS WHEREOF, the parties have executed this Amendment as of the
date first written above.

BORROWER:

AZUL HOLDINGS INC.,
a Delaware corporation

By: /s/ Jeffrey L. Neuman
   ------------------------------------
        Jeffrey L. Neuman, President

LENDER:


    /s/ Jeffrey L. Neuman
---------------------------------------
Jeffrey L. Neuman, as trustee of the
Tudor Trust u/d/t December 12,
1997 and not individually


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                                    Exhibit A

                  AMENDED AND RESTATED SECURED PROMISSORY NOTE

$17,500,000
Boulder, Colorado                                                  June 19, 2000


         FOR VALUE RECEIVED, the undersigned AZUL HOLDINGS INC., a Delaware
corporation with a principal place of business located at 2362 Spotswood Place,
Boulder, Colorado 80304 (hereinafter, the "Borrower"), promises to pay in U.S.
Dollars to the order of Jeffrey L. Neuman as trustee of the Tudor Trust u/d/t
dated December 12, 1997 (hereinafter, with any subsequent holder, the "Lender"),
at the Lender's principal office located at 450 North Roxbury Drive, Beverly
Hills, California, the Liabilities then outstanding under the loan made by the
Lender to the Borrower pursuant to that certain Second Amended and Restated
Secured Advance Facility Loan Agreement executed between the Borrower and the
Lender dated July 1, 1998, as amended by that First Amendment to Second Amended
and Restated Secured Advance Facility Loan Agreement dated as of December 31,
1998, that Second Amendment to Second Amended and Restated Secured Advance
Facility Loan Agreement dated as of December 7, 1999, that Third Amendment to
Second Amended and Restated Secured Advance Facility Loan Agreement dated as of
March 31, 2000, and that Fourth Amendment to Second Amended and Restated Secured
Advance Facility Loan Agreement dated as of the date hereof (as amended, the
"Loan Agreement"). Advances made pursuant to the Loan Agreement shall, from time
to time after the date hereof, bear interest at the rate from time to time as
provided in the Loan Agreement, and after any Default under the Loan Agreement
at the rate of twelve (12) percent per annum, calculated based upon a 360-day
year end and actual day months.

         Interest at the rate provided in the Loan Agreement shall be paid as
provided in Section 3.2 of the Loan Agreement. Unless a Default under the Loan
Agreement shall have occurred earlier, the principal balance of this Promissory
Note shall be due and payable in full on March 31, 2001.

         All payments by the Borrower to the Lender under Article III of the
Loan Agreement shall be applied first to principal and then to interest.

         To secure the obligations of the Borrower under this Promissory Note,
(i) the Lender has been granted a security interest in all of the Borrower's
presently existing and hereafter acquired property pursuant to that certain
Sixth Amended and Restated Security Agreement executed between the Borrower and
Lender dated November 10, 1997 (the "Security Agreement"), and (ii) the Lender
has been granted a security interest in 2,800,000 shares of Common Stock of
Xyvision Enterprise Solutions, Inc. held of record

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by the Borrower pursuant to that certain Pledge Agreement executed between the
Borrower and the Lender dated as of December 31, 1998. All capitalized terms
used herein, unless otherwise defined herein, shall have the meanings ascribed
to them in the Security Agreement.

         No delay or omission by the Lender in exercising or enforcing any of
the Lender's powers, rights, privileges, remedies or discretions hereunder or
under the Loan Agreement shall operate as a waiver thereof on that occasion or
on any other occasion.

         After demand by the Lender, the Borrower shall pay all reasonable
attorney fees and out-of-pocket expenses incurred by the Lender in recovering
the amounts due to the Lender from the Borrower hereunder.

         This Promissory Note shall be binding upon the Borrower and upon its
successors, assigns and representatives, and shall inure to the benefit of the
Lender and its successors, endorsees and assigns.

         This Promissory Note amends and restates that Amended and Restated
Secured Promissory Note dated May, 2000 in the principal amount of $12,357,150
previously made by the Borrower in favor of the Lender, and is taken in
substitution but not in satisfaction thereof.

         This Promissory Note shall be governed by the laws of the Commonwealth
of Massachusetts and shall take effect as a sealed instrument.

Witnessed:                               AZUL HOLDINGS INC.,
                                         a Delaware corporation

 /s/ Eugene Valk                         By:  /s/ Jeffrey L. Neuman
 -----------------------                     ----------------------------------
                                             Jeffrey L. Neuman, President


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