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                                                                    Exhibit 4.16

                              REVOLVING DEMAND NOTE

THIS NOTE HAS NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED,
OR ANY OTHER APPLICABLE SECURITIES LAWS. IT MAY NOT BE SOLD OR OTHERWISE
TRANSFERRED UNDER CIRCUMSTANCES THAT WOULD RESULT IN A VIOLATION OF THE
REGISTRATION REQUIREMENTS OF THE SECURITIES ACT OF 1933 OR SUCH OTHER LAWS.

$64,170,000.00                Wilmington, Delaware                 July 21, 1999

         FOR VALUE RECEIVED, the undersigned Divico, Inc. a Delaware corporation
("Maker"), promises to pay to the order of Liuco, Inc., a Delaware corporation
("Payee"), in lawful money of the United States of America, the principal sum of
Sixty-Four Million One Hundred Seventy Thousand Dollars ($64,170,000.00) or if
less, the aggregate outstanding principal amount of the Revolving Loans made by
the Lender to the Company pursuant to this Promissory Note ("Note"). The Maker
further promises to pay interest on the outstanding principal amount of the
Revolving Loans from time to time in accordance with the terms of this Note.

         1. REVOLVING LOANS. The Payee agrees to make loans to the Maker (each a
"Revolving Loan" and collectively the "Revolving Loans") fro time to time upon
the request of the Maker, PROVIDED, that the aggregate principal amount of all
Revolving Loans outstanding from time to time may not exceed One Hundred Twenty
Million Dollars ($120,000,000.00). Request for revolving Loans shall be made at
least three days before the requested date for advancement of the Revolving Loan
and shall specify the amount of the requested Revolving Loan and the date of the
requested Revolving Loan.

         2. PLACE OF PAYMENT. All payments will be made at Payee's address at
103 Foulk Road, Suite 202., Wilmington, DE 19803 or such other place as the
holder hereof may from time to time appoint in writing.

         3. PAYMENT. The Principal balance of any Revolving Loan shall be due
and payable in whole or in part on demand.

         4. PREPAYMENT. This Note may be prepaid in part or in full at any time
without premium or penalty upon two days prior to notice.

         5. COSTS OF COLLECTION. The Maker will pay on demand all costs of
collection, legal expenses and reasonable attorneys' fees incurred or paid by
the Payee in collecting or enforcing this Note.

         6. INTEREST. From the date of this Note until the outstanding principle
balance is repaid, interest shall accrue on the outstanding principle balance of
this Note at the Prime Rate (as defined below) PLUS two percent (2%) per annum.
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         Accrued interest under this Note shall be due and payable in arrears on
the last day of each March, June, September and December.

         "Prime Rate" means the rate of interest per annum as published from
time to time by The Wall Street Journal on the last business day of each March,
June, September and December as its prime rate in effect at its principle office
in New York City; provided that from the date of issuance through December 31,
1999, the Prime Rate effect hereunder shall be 8.25%.

         If any payment hereunder is not received by Payee within (30) days
after the date that the payment was due, Payee shall have the right to collect
late charge of five percent (5%) of each such late installment of part thereof.
Any late charge shall be due and payable immediately upon demand.

         Interest on the principle of this Note shall be calculated on the basis
of the actual number of days elapsed over a year of three hundred sixty-five
(365) days.

         7. SECURITY. This Note is secured by that certain security agreement
between Maker and Payee (the "Security Document") dated as of even date
herewith.

         8. WAIVER. Maker and each surety, endorse  guarantor, and other party
now or hereafter liable for payment of this Note, severally waive demand,
presentment for payment, notice of dishonor, protest, notice of protest,
diligence in collecting or bringing suit against any party liable hereon, and
further agree to any and all extensions, renewals, modifications, partial
payments, substitutions of evidence of indebtedness, and the taking or  release
of any collateral with or without notice before or after demand by Payee for
payment hereunder.

         9. COSTS AND ATTORNEYS' FEES. In the event this Note is placed in the
hands of any attorney for collection or suit is filed hereon or if proceedings
are had in bankruptcy, receivership, reorganization, or other legal or judicial
proceedings for the collection hereof, Maker and any guarantor hereby jointly
and severally agree to pay to Payee all expenses and costs of collection,
including, but not limited to, reasonable attorneys' fees incurred in connection
with any such collection, suit, or proceeding, in addition to the principal and
interest then due.

         10. TIME OF ESSENCE. Time is of the essence with respect to all of
Maker's obligations and agreements under this Note.

         11. JURISDICTION AND VENUE. THIS NOTE SHALL BE GOVERNED BY THE LAWS OF
THE STATE OF DELAWARE, WITHOUT REGARD TO CHOICE OF LAW PRINCIPLES THEREOF, AND
MAKER CONSENTS TO JURISDICTION IN THE COURTS LOCATED IN DELAWARE.

         12. NOTICE. Notice to the Maker or Payee shall be given in accordance
with the notice provisions of the Security Agreement.

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         13. SUCCESSORS AND ASSIGNS. All the covenants, obligation, promises and
agreements contained in this Note made by Maker shall be binding upon its
successors and assigns; notwithstanding the foregoing, Maker shall not assign
this Note or its performance hereunder without the prior written consent of
Payee.

                                            DIVICO, INC.


                                            /s/ JASON C. LIU
                                            ------------------------------------
                                                Jason C. Liu
                                                Chief Financial Officer