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                                  Exhibit 10.20

                       SIXTH AMENDMENT TO CREDIT AGREEMENT

      THE SIXTH AMENDMENT TO CREDIT AGREEMENT (this "Amendment") is entered into
as of November 7, 2001 by and between Invivo Corporation, a Delaware corporation
("Borrower"), and WELLS FARGO BANK, NATIONAL ASSOCIATION ("Bank").

                                    RECITALS

      WHEREAS, Borrower is currently indebted to Bank pursuant to the terms and
conditions of that certain Credit Agreement between Borrower and Bank dated as
of October 6, 1998, as amended from time to time ("Credit Agreement").

      WHEREAS, Bank and Borrower have agreed to certain changes in the terms and
conditions set forth in the Credit Agreement and have agreed to amend the Credit
Agreement to reflect said changes.

      NOW, THEREFORE, for valuable consideration, the receipt and sufficiency of
which are hereby acknowledged, the parties hereto agree that the Credit
Agreement shall be amended as follows:

      1.    Section 1.2(a) is hereby amended by deleting "December 2, 2001" as
            the last day on which Bank will make advances under the Line of
            Credit, and by substituting for said date "December 1, 2002," with
            such change to be effective upon the execution and delivery to Bank
            of a promissory note substantially in the form of Exhibit A attached
            hereto (which promissory note shall replace and be deemed the Line
            of Credit Note defined in and made pursuant to the Credit Agreement)
            and all other contracts, instruments and documents required by Bank
            to evidence such change.

      2.    Section 4.8 (e) is hereby deleted in its entirety, without
            substitution.

      3.    Except as specifically provided herein, all terms and conditions of
            the Credit Agreement remain in full force and effect, without waiver
            or modification. All terms defined in the Credit Agreement shall
            have the same meaning when used in this Amendment. This Amendment
            and the Credit Agreement shall be read together, as one document.

      4.    Borrower hereby remakes all representations and warranties contained
            in the Credit Agreement and reaffirms all covenants set forth
            therein. Borrower further certifies that as of the date of this
            Amendment there exists no Event of Default as defined in the Credit
            Agreement, nor any condition, act or event which with the giving of
            notice or the passage of time or both would constitute any such
            Event of Default.

      IN WITNESS WHEREOF, the parties hereto have caused this Amendment to be
executed as of the day and year first written above.

                                          WELLS FARGO BANK,
INVIVO CORPORATION                        NATIONAL ASSOCIATION

By:___________________________________    By:__________________________________
    James B. Hawkins                           Russ Rizzardi
    President                                  Vice President

By:___________________________________
    John F. Glenn
    Vice President, Finance

                                       17<PAGE>
EXHIBIT 10.1

                              TERMINATION AGREEMENT

         THIS TERMINATION AGREEMENT (this "AGREEMENT") is made and entered into
as of October 31, 2001 (the "EFFECTIVE DATE") by and between Broderbund
Properties LLC, ("Broderbund") with offices at 500 Redwood Boulevard, Novato,
California 94947 and International Microcomputer Software Inc. ("IMSI"), a
California corporation, with offices at 75 Rowland Way, Novato, California
94949.

                                    RECITALS

         WHEREAS, IMSI entered into a Software License Agreement (the "IMSI
LICENSE AGREEMENT") dated October 2, 1998, whereby IMSI was granted certain
rights to publish, use, distribute and sublicense the Org Plus software program;

         WHEREAS, IMSI failed to make $1.8 million in payments under the License
Agreement (the "ORG PLUS LICENSE FEE");

         WHEREAS, IMSI entered into a Fee Agreement dated as of January 21, 1999
(the "FEE AGREEMENT"), whereby IMSI agreed, inter alia, to issue to BRODERBUND's
predecessor in interest 200,000 common shares of IMSI (the "IMSI SHARES"), and
to register such shares, in satisfaction of its obligation to pay the Org Plus
License Fee;

         WHEREAS, BRODERBUND's predecessor in interest and IMSI entered into a
letter agreement dated April 9, 1999 (the "CONSENT LETTER") whereby BRODERBUND's
predecessor in interest became obligated to pay $200,000 to IMSI upon the
delivery by IMSI of certain computer software source code;

           WHEREAS, BRODERBUND and IMSI are entering into a Software License and
Distribution Agreement of even date herewith (the "PRODUCT LICENSE") whereby
IMSI is granting BRODERBUND certain rights in various software programs and
other items;

         WHEREAS, BRODERBUND and IMSI are entering into an Assignment of
Copyrights and Trademark Rights of even date herewith (the "ASSIGNMENT
AGREEMENT") whereby BRODERBUND is assigning certain rights in the Org Plus
software program to IMSI;

         WHEREAS, BRODERBUND and IMSI desire to terminate the IMSI License
Agreement and the Fee Agreement, and release each other from all further
obligations and liability thereunder, according to the terms set forth herein.

         NOW, THEREFORE, in consideration of the mutual promises and covenants
contained herein, BRODERBUND and IMSI agree as follows:

         1. Subject to the conditions set forth below, BRODERBUND and IMSI
hereby terminate the IMSI License Agreement and the Fee Agreement as of the date
hereof, and hereafter such agreements are null and of no further force and
effect and all rights and obligations of BRODERBUND and IMSI thereunder shall
terminate including without limitation IMSI's obligation to pay the Org Plus
License Fee; provided, however, that the provisions of Section 4.1

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(Support) of the IMSI License Agreement shall survive such termination in
addition to those Sections specified in Section 5.6. Execution of the Software
License and Distribution Agreement, dated October 31, 2001, and the Assignment
Agreement dated October 31, 2001 are both a condition precedent to the
effectiveness of this Agreement and the rights conveyed herein.

         2. BRODERBUND shall transfer ownership of the IMSI Shares to IMSI as
soon as reasonably possible after the effective date of this Agreement.

         3. IMSI hereby releases BRODERBUND, and any of its parent, subsidiary
and affiliate companies (each a "BRODERBUND AFFILIATE"), and all directors,
officers, employees and agents of BRODERBUND and all BRODERBUND Affiliates, from
any claim it has or may have, now known or later discovered, against such
persons for any amount under the Consent Letter or in any way related to the
Source Code License and Distribution Agreement between BRODERBUND's predecessor
in interest and Microsoft Corporation dated as of April 2, 1999. IMSI knowingly
and voluntarily expressly waives all rights it has or may have under California
Civil Code Section 1542, which provides as follows:

         "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES
         NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME OF EXECUTING THE
         RELEASE, WHICH IF KNOWN BY HIM MUST HAVE MATERIALLY AFFECTED HIS
         SETTLEMENT WITH THE DEBTOR,"

or under any similar law or rule of any other jurisdiction with respect to the
foregoing release. IMSI understands and acknowledges the significance and
consequences of waiving the provisions and benefits of Section 1542, and IMSI
specifically intends to waive both known and unknown claims under this provision
as well as under any similar federal or common law principle.

         4. IMSI shall pay BRODERBUND $160,000 in four equal quarterly
installments, commencing on the same date (currently August 15, 2002) and
continuing on the dates that payments are made by IMSI to its unsecured
creditors pursuant to IMSI's agreement with CMA Business Credit Services,
Northern California Division of San Leandro, CA. BRODERBUND shall be paid
interest on the unpaid balance of this amount at 8% from February 1, 2000 to
August 15, 2002, and at 12% interest thereafter until paid, the same as other
creditors to receive payment under the agreement with CMA. This $160,000 shall
constitute payment in full of any and all payment obligations IMSI has had, has,
or may have with respect to any and all business relationships existing between
the parties prior to the effective date of this Agreement, and both parties
hereby agree to mutually release and forever discharge the other from any
claims, liabilities, damages, expenses, fees, indemnification obligations, or
any other amounts which either of them may owe the other relating to any such
business relationships. In entering into this agreement and making this release,
both parties expressly waive the provisions of Section 1542 of the California
Civil Code which provides as follows:

         "A GENERAL RELEASE DOES NOT EXTEND TO CLAIMS WHICH THE CREDITOR DOES
         NOT KNOW OR SUSPECT TO EXIST IN HIS FAVOR AT THE TIME OF EXECUTING THE
         RELEASE, WHICH IF KNOWN BY HIM, MUST HAVE MATERIALLY AFFECTED HIS
         SETTLEMENT WITH THE DEBTOR,"

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or under any similar law or rule of any other jurisdiction with respect to the
foregoing release. Each party understands and acknowledges the significance and
consequences of waiving the provisions and benefits of Section 1542, and each
specifically intends to waive both known and unknown claims under this provision
as well as under any similar federal or common law principle.

         5. Neither party shall have the right under any agreement with the
other or any affiliate of the other entered into prior to the Effective Date to
audit the books or records of the other or its affiliates, whether for purposes
of royalty calculations or otherwise. Any provision to the contrary contained in
any such agreement is hereby null and of no further force or effect.

         6. This Agreement constitutes the entire agreement between the parties
with respect to the subject matter hereof and the transactions contemplated
hereby, and, except as specifically provided for herein, supersedes all previous
oral and written agreements and all contemporaneous oral negotiations,
commitments, writings and understandings. This Agreement shall be governed under
the laws of the State of California.

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

BRODERBUND PROPERTIES LLC.            INTERNATIONAL MICROCOMPUTER
                                      SOFTWARE, INC.

By: /s/ Andrew Freedman               By: /s/  Gordon Landies

Name: /s/ Andrew Freedman             Name: /s/  Gordon Landies

Its: CFO                              Its: President

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