Document:

<PAGE>

                                   EXHIBIT 4.2

                 COMPENSATION AGREEMENTS WITH GEORGE G. CHACHAS

                                Wenthur & Chachas
                                Attorneys at Law
                     4180 La Jolla Village Drive, Suite 500
                           La Jolla ,California 92037
                                  May 15, 2001

Mr. Gregory J. Chachas
Covingham Capital Corp
174 Dorchester Drive
Salt Lake City, UT 84103

Re: Covingham Capital Corp.

Dear Dad:

         Per our discussion through and including the edgarizing and filing of
the Form 10-QSB for the quarter ended March 31, 2001, an my bill for legal and
edgarizing services would be $2,500 which I will accept 50,0000 shares of common
stock as full payment.

         If you have any questions ore need additional information please feel
free to call.

                                             Sincerely,

                                             /s/ George G. Chachas
                                             George G. Chachas

                                Wenthur & Chachas
                                Attorneys at Law
                     4180 La Jolla Village Drive, Suite 500
                           La Jolla ,California 92037
                                  May 15, 2001

Mr. Gregory J. chachas
Covingham Capital Corp
174 Dorchester Drive
Salt Lake City, Ut 84103

Re: Covingham Capital Corp.

         Through the filing of the filing of the 2002 Form 10-KSB my bill for
legal services is $2,500 which as previously, I will accept 50,000 shares of
common stock as full payment.

         If you have any questions or need additional information please feel
free to call.

                                             Sincerely,

                                             /s/ George G. Chachas
                                             George G. Chachas<PAGE>

                                   EXHIBIT 4.3

                     CONSULTING AGREEMENT WITH GORDON JONES.

                                      J & J

March 1, 2001

Covingham Capital Corp.
C/o Wenthur & Chachas, LLP
4180 L Jolla, California 92037

Dear Sirs,

We thank you for allowing us this opportunity to put into writing some of the
services that we can offer to your company. As you may know several years ago I
served as the auditor for many public and private companies at which time I
became very familiar with public reporting requirements and corporate financing.
I sold my CPA practice about 3 years ago and I have since worked as a consultant
to several small public and private companies.

The Consulting services we are offering are as follows;

!.       We Will prepare the MD&A sections of the form 10Q's and 10K's of the
         Company from the financial statements reviewed or audited by the
         Company's independent auditors.

Our annual fee for these services will be 25,000 shares of common stock of the
Company. The term of the agreement will be for 2 years, calendar years 2001 and
2002, and may be extended by mutual agreement.

If other projects come up we would charge per hour for those services. If this
is acceptable to you please sing below or make modification on the letter.
Please call me with any questions at 801-916-3884.

Sincerely,

/s/ R. Gordon Jones
J&J Consultants, LLC

Accepted:

/s/ Gregory J. Chachas
Covingham Capital Corp.<PAGE>

                                   EXHIBIT 4.4

                  PAYMENT AGREEMENT WITH FIDELITY TRANSFER CO.

                            Fidelity Transfer company
                        1800 South West Temple, suite 301
                           Salt Lake City, Utah 84115
                                  801-484-7222
                                Fax 801-466-4122

                               September 15, 2001

Covingham Capital Corp.
Covingham Capital Corp
174 Dorchester Drive
Salt Lake City, Ut 84103

This is confirm our telephone conversation regard payment for services. I agree
to accept 10,000 shares of common stock a payment for services rendered.

Yours truly,

/s/ Kevin Kopaunik, Preident
Fidelity Transfer company<PAGE>

                                                                  EXHIBIT 10.39

                                    ADDENDUM

THIS ADDENDUM TO LEASE AGREEMENT is made this first day of 29th day of May 2003,
and entered into by and between J & Lowtree Investors, LLC. ("Landlord") and
Simulations Plus, Inc. ("Tenant").

                                    RECITALS

A. Landlord and Tenant have entered into a written lease dated May 14, 1998 the
("lease") and Addendum dated July 7, 1998, and February 26, 2001 ("Addendum"),
whereby Landlord leased to Simulations Plus, Inc. ("Tenant') and Tenant leased
from Landlord premises located in the County of Los Angeles, State of
California, particularly described in the lease.

B. Landlord and Tenant desire to amend the lease.

NOW, THEREFORE, incorporating the foregoing recitals of fact and for valuable
consideration, the receipt and sufficiency of which is acknowledged, Landlord
and Tenant agree as follows:

         1.       Tenant and Landlord agree to extend the ending date of the
                  lease until September 6, 2005. Both parties Acknowledge that
                  Tenant has no remaining options.
         2.       Starting September 7, 2003 the base rental rate shall increase
                  annually by four (4) percent.
         3.       Not withstanding any provisions in the lease to the contrary:
         4.       Except as set forth above, the lease shall remain unmodified
                  and in full force an effect.
         5.       This agreement shall be binding upon and inure to the benefit
                  of Landlord and Tenant and their respective successors,
                  assigns and personal representatives.

      "TENANT"
SIMULATIONS PLUS, INC.

   /S/ WALT WOLTOSZ
--------------------------
WALT WOLTOSZ
PRESIDENT & CEO

DATED 06/10/03

        "LANDLORD"
J & LOWTREE INVESTORS, LLC

     /S/ ROB MARTIN
--------------------------
ROB MARTIN
MANAGING MEMBER

DATED 06/14/03<PAGE>

                                                                  EXHIBIT 10.40

BUSINESS LENDING
CONFIRMATION LETTER

May 08, 2003

SIMULATIONS PLUS, INC.
1220 W Avenue J
Lancaster, CA 93534

RE: $500,000.00 PrimeLine

WELLS FARGO BANK, NATIONAL ASSOCIATION ("Bank") agrees to make available to
SIMULATIONS PLUS, INC. ("Borrower") a PrimeLine (the "Credit"). The Credit shall
bear interest and be repayable in accordance with the terms and conditions of
the Agreement. The Agreement consists of (1) this Confirmation Letter (this
"Letter"), (2) the Business Lending Disclosure dated July 01, 2002 (the
"Disclosure") and (3) any Related Documents. All terms and conditions of the
Disclosure and Related Documents are incorporated herein by reference for all
purposes. All capitalized terms not defined in this Letter are defined in the
Disclosure.

PROMISE TO PAY. Borrower promises to pay to Bank, or order, the principal amount
of $500,000.00, or so much as may be advanced and outstanding from time to time,
together with interest on the outstanding principal balance. Borrower will pay
Bank at Bank's address shown in this letter or at such other place as Bank may
designate in writing.

AVAILABILITY PERIOD. The Availability Period ends on May 10, 2004. During the
Availability Period Borrower may borrow, repay, and borrow again from time to
time under this revolving line of credit up to the Credit Limit.

FLOATING INTEREST RATE. Interest shall accrue on the unpaid outstanding
principal balance of the Credit at a floating rate per annurn equal to the sum
of Wells Fargo Prime Rate (the "Index") and a margin of 1.500%. The Wells Fargo
Prime Rate is the Prime Rate set by Wells Fargo Bank, National Association from
time to time which serves as the basis upon which effective rates of interest
are calculated for those loans making reference thereto. Each change in the
Index shall become effective on the date of each change in the Prime Rate. The
interest rate will change as and when the Index changes. The Index currently is
4.250% per annum.

INTEREST ACCRUAL BASIS. Interest shall be computed on a 365/360 simple interest
basis; that is, by multiplying the annual interest rate, times the outstanding
principal balance, times the actual number of days the principal is outstanding
and dividing by a year of 360 days.

REPAYMENT. Interest as it accrues shall be due and payable Monthly, commencing
on June 10, 2003 and continuing on the same date of each month thereafter until
maturity. The Credit shall mature on May 10, 2004, at which time all unpaid
principal, accrued interest, and any other unpaid amounts shall be due and
payable in full. Unless otherwise agreed, all sums received from Borrower may be
applied to interest, fees, principal, or any other amounts due to Bank in any
order at Bank's sole discretion.

PAYMENT AND RATE ADJUSTMENTS. If Bank fails for any reason to timely or properly
adjust the interest rate or payment amount, Bank may retroactively correct the
interest rate and reamortize and adjust the payment amount at any subsequent
time as may be appropriate to restore the intended amortization schedule.
Borrower will promptly notify Bank of any such oversight upon discovery of same.
In no event shall Bank's failure to properly reamortize or adjust payments
result in a forgiveness of any portion of the indebtedness.

PAYMENT DUE DATE DEFERRAL. Payment statements will be sent on a date (the
"billing date") which is prior to each payment due date. If this Credit is
booked after the billing date for the first scheduled payment, Bank may defer
each

                                        1

<PAGE>

scheduled payment date and the maturity date by one month.

AUTOMATIC DEBIT OF PAYMENTS. Borrower agrees to maintain Wells Fargo Bank,
National Association deposit account number 0784259301 from which Bank is
authorized to debit loan payments, fees and such other sums as may be payable
under the Agreement as they become due with respect to this Credit, and shall
keep such deposit account in good standing at all times. If for any reason,
Borrower fails to maintain its primary deposit account with Bank or any
affiliate of Bank (defined as the deposit account into which substantially all
of Borrower's receipts from its operations are deposited and from which
substantially all of Borrower's disbursements for its operations are made), or
if Bank is not able to collect all payments on this Credit by charging
Borrower's primary deposit account, whether because Borrower cancels the
authorization of Bank to do so, or Borrower fails to maintain sufficient sums in
said deposit account, or the account is closed, or for any other reason, then
Bank may increase the pre-maturity interest rate applicable to this Credit
immediately and without notice up to one percent (1%). This authorization shall
remain in full force and effect until written revocation from the Borrower
and/or the account holder has been received and processed by Bank at the
following office address: Business Lending, 177 Park Center Plaza MAC#
A0514-011, San Jose, CA 95113. Borrower agrees that such a revocation without
Bank's consent shall constitute an event of default.

DISBURSEMENT INFORMATION. The proceeds of the Credit shall be disbursed as
follows (estimated):

       $1.00       Wells Fargo Bank         Loan Payoff         XXXXXXXXXXXXXXXX

COLLATERAL. Subject to the terms and conditions of the Disclosure, as security
for the obligations set forth in Section 2.1 of the Disclosure, SIMULATIONS
PLUS, INC., as Grantor, pledges and grants to Bank a first priority security
interest in the following personal property, whether existing or hereafter
arising, now owned or hereafter acquired, and wherever located, and all Proceeds
of the foregoing (including insurance):

          All the Grantor's Personal Property

          The property described in Exhibits (if any) attached hereto and made a
part hereof.

FEES. Borrower will pay at closing fees as follows:

UCC Filing Fee            $50.00          From Account            XXXXXXXXXX

Commitment Fee           $2,500.00        From Account            XXXXXXXXXX

LATE CHARGES. For each payment of principal, interest, and/or fees which has not
been paid in full within fifteen days after its date due, Borrower will pay to
Bank a late charge of $15.00 or five percent (5%) of the amount due, whichever
is greater. Borrower acknowledges and agrees that the amount of this late fee is
reasonable with respect to this Credit, taking into account Bank's expectation
of timely receipt of payments with regard to the favorable pricing of this
Credit, and the operational, administrative and regulatory burdens flowing from
late payments and delinquencies. To the extent this late fee or any other fee or
charge set forth in this Agreement may be prohibited or exceed any limit
provided by any present or future applicable law, such fee or charge shall be
reduced to the maximum amount allowed.

TRADE FINANCE SUBFEATURE. At Bank's sole discretion, Bank may make available to
Borrower a Letter of Credit Subfeature and/or a Foreign Exchange Subfeature in
an amount not to exceed in the aggregate the lesser of $500,000.00 or the
available principal amount of the Credit. Such subfeature(s) shall be subject to
the terms of the Disclosure and all additional agreements pertaining to such
services. A Letter of Credit Subfeature simplifies the issuance of commercial
and/or standby letters of credit; however, this is not a commitment to issue
letters of credit. The issuance of any letter of credit is subject to the Bank's
discretion, the execution of additional letter of credit agreements, and other
conditions.

PREPAYMENT TERMS. Borrower may prepay principal of the Credit at any time, in
any amount, without penalty.

OTHER INDEBTEDNESS. Borrower will not obtain a working capital line of credit
from another Bank without the prior written consent of Bank.

                                        2

<PAGE>

ADDITIONAL PROVISIONS. This document may be signed in any number of separate
copies, each of which shall be effective as an original, but all of which taken
together shall constitute a single document. An electronic transmission or other
facsimile of this Letter or any signed document shall be deemed an original and
shall be admissible as evidence of the document and the signer's execution. The
Agreement shall be governed by the laws of the state of California and
applicable Federal Law except to the extent any related document is governed by
the law of another state due to the location of the collateral.

PURPOSE. The proceeds of the Credit shall be used primarily for business or
commercial purposes.

RELATED DOCUMENTS. The Credit also is conditioned upon execution and delivery of
this Confirmation Letter and the following Related Documents:

                  *Authorization to Payoff and Close

At the time the Agreement is signed and delivered to Bank, the persons signing
below, including without limitation the Borrower(s), any Grantor(s) and any
Guarantor(s), acknowledge receipt of the Agreement, including the Disclosure and
Related Documents, and accept all terms and conditions contained in them. Unless
a fully signed copy of this Letter and all Related Documents is received by Bank
within 30 days, this offer to extend credit will expire. This offer is not
transferable or assignable, and may be withdrawn or modified at any time prior
to Bank's receipt of the above fully signed documents.

FINAL AGREEMENT. The persons and entities signing below ("Party", or
collectively, the "Parties") acknowledge and agree that each Party's execution
of this Agreement constitutes acknowledgment that such Party (i) agrees that
there are no oral agreements relating to this Credit (this "Loan"), (ii) agrees
that agreements will be binding upon Lender only if in writing and signed by
Lender, and (iii) acknowledges receipt of the following Notice, and to the
fullest extent allowed by law, agrees to be bound by the terms of this Agreement
and this Notice:

NOTICE: THIS DOCUMENT AND ALL OTHER DOCUMENTS RELATING THIS LOAN CONSTITUTE A
WRITTEN LOAN AGREEMENT WHICH REPRESENTS THE FINAL AGREEMENT BETWEEN THE PARTIES
AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR SUBSEQUENT
ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN
THE PARTIES RELATING TO THIS LOAN.

Please sign and return this original letter to:

WELLS FARGO BANK, NATIONAL ASSOCIATION, Business Lending, 177 Park Center Plaza
MAC# A0514-011, San Jose, CA 95113

                                        3

<PAGE>

If you have any questions, please contact me at (661) 861-4760. For future
reference, please send all correspondence to the Bank to the following address:
Business Lending, 177 Park Center Plaza MAC# A0514-011, San Jose, CA 95113.

WELLS FARGO BANK, NATIONAL ASSOCIATION

BY:     /S/ PHYLLIS E. MAPLES
   --------------------------------
Name: PHYLVIS E MAPLES
Title: Vice-President

Dated: May 08, 2003

BORROWER ACKNOWLEDGMENT AND ACCEPTANCE:

By signing below, Borrower acknowledges receipt of the Agreement, including the
Disclosure and Related Documents, and agrees to the terms and provisions
contained in them, including without limitation the prepayment penalty described
in the Prepayment section of this Letter, if any.

SIMULATIONS PLUS, INC.

BY:     /S/ MOMOKO BERAN                          BY:    /S/ WALTER S. WOLTOSZ
   -----------------------                           ---------------------------
NAME: Momoko Beran                                NAME: Walter S. Woltosz
TITLE: CFO                                        TITLE: President / CEO
ADDRESS: 1220 W Avenue J, Lancaster, CA 93534

GRANTOR ACKNOWLEDGMENT AND ACCEPTANCE:

By signing below, Grantor acknowledges receipt of a copy of the Disclosure and
agrees to the terms and provisions of this Letter and Chapter 2 of the
Disclosure.

Grantor represents and warrants: (a) All Collateral consisting of tangible
personal property (except goods in transit) is located or domiciled at the
following address(es): 1220 W Avenue J, Lancaster, CA 93534 (b) SIMULATIONS
PLUS, INC. is Incorporated/ Formed/ Registered in the state of CA and located at
1220 W Avenue J, Lancaster, CA 93534.

                                        4

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00058-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00058-of-00352.parquet"}], [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00058-of-00352.parquet"}], [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00058-of-00352.parquet"}], [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00058-of-00352.parquet"}]]