<PAGE>   1
                                                                   EXHIBIT 10.3


            Amendment No. 4 to Letter Agreement Dated August 15, 1994

This Amendment No. 4 ("Amendment No. 3") to the Letter Agreement dated August
15, 1994 (the "Letter Agreement") amended as of October 17, 1994 ("Amendment No.
1"), as of August 16, 1996 ("Amendment No. 2") and August 31, 1997 ("Amendment
No. 3"), is made as of the 31st day of August, 1998 by and between Orchard
Capital Corporation, a California corporation, 10960 Wilshire Blvd., Suite 500,
Los Angeles, California 90024 ("Consultant") and MAI Systems Corporation, a
Delaware corporation, 9600 Jeronimo Road, Irvine, California 92718 ("MAI") with
reference to the following facts:

A.      On or about August 15, 1994, the parties entered into the Letter
        Agreement pursuant to which Consultant was to provide the services of
        its employee, Richard S. Ressler, to MAI, on various terms and
        conditions in exchange for certain consideration to be paid by MAI to
        Consultant.

B.      On or about October 17, 1994, pursuant to Amendment No. 1, certain terms
        of the Agreement were amended.

C.      On or about August 16, 1996, the term of the Agreement expired but the
        Consultant continued to perform services for MAI and, pursuant to
        Amendment No. 2, the parties extended the term of the consultancy up
        through and including August 31, 1997 and amended certain terms of the
        Agreement to be effective during the term extension.

D.      On or about August 31, 1997, the term of the Agreement (as extended by
        Amendment No. 2) expired but the Consultant continued to perform
        services for MAI and, pursuant to Amendment No. 3, the parties extended
        the term of the consultancy up through and including August 31, 1998 and
        amended certain terms of the Agreement to be effective during the term
        extension.

E.      The extended term of the Agreement in Amendment No. 3 has expired but
        Consultant has continued to perform services for MAI and the parties
        seek to extend the term of the consultancy and to amend certain terms of
        the Agreement to be effective during the term extension.

Now, therefore, in consideration of the mutual benefits to be derived hereunder,
the parties agree as follows:

1.      Extension of Term. The term of the consultancy shall be extended up
        through and including August 31, 1999.

2.      Fixed Compensation. During the period of extension, i.e. from September
        1, 1998 up through and including August 31, 1999, Consultant shall be
        compensated at the monthly rate of Twenty-four Thousand and no/100
        Dollars ($24,000).

3.      Equity Compensation. MAI shall consider the appropriate equity
        compensation for Consultant for services rendered during the term
        extension. The parties acknowledge that equity compensation may take the
        form of warrants to purchase shares of MAI's Common Stock, participation
        in one of its stock option plans, or otherwise. Nothing herein shall be
        construed to commit MAI to pay any equity compensation to Consultant for
        services during the period of extension.

4.      Confirmation of Other Terms and Conditions. In all other respects the
        parties reaffirm and acknowledge all of the terms and conditions set
        forth in the Agreement and Amendment Nos. 1, 2, and 3.

In witness whereof, the parties have executed this Amendment No. 4 as of the day
and year first written above.

Orchard Capital Corporation                 MAI Systems Corporation

By:                                         By:
    -----------------------------------         --------------------------------
    Richard S. Ressler                          George G. Bayz
    President                                   President