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                                                                  EXHIBIT 99(D)

September 4, 1997


Mr. Jerry P. Johnson
1601 Francisco Drive
El Dorado Hills, CA 95762


Dear Jerry:

OSI is pleased to confirm our offer of employment to you for the position of
Chief Technology Officer in our Folsom location reporting to Tom Johnson and
Dick Vento.  Your start date will be September 2, 1997.  In this position, your
base salary will be $7,292 paid semi-monthly, which equates to $175,000 per
year.

You will receive a signing bonus of $40,000 (less normal withholdings and
deductions).  The bonus is to be paid when the company is profitable and after
payment of all other employee bonuses.

In addition, you will be eligible to receive incentive compensation earnings up
to 25% of your base salary at target performance.  33% of target incentive
earnings may be paid semi-annually based upon completion of individual
performance objectives mutually agreed upon in writing between yourself and your
management.  The balance of your incentive earnings, or 67% of target incentive
compensation, will be based upon corporate financial performance defined by the
Board of Directors and OSI executive management and will be paid on an annual
basis.  All incentive compensation will be based upon base earnings for the
period between your hire date and the end of OSI's fiscal year.

Upon hire, OSI will grant 250,000 stock options of OSII common stock priced at
Fair Market Value on the day the Board of Directors approves the option grant.
Options vest over 4 years from the date of grant in accordance with the
following schedule:  25% of the Shares subject to the Option shall vest twelve
(12) months after the Vesting Commencement Date, and 1/48 of the Shares subject
to the Option shall vest each month thereafter provided the employee is in
active service with OSI.

A performance review will be given after a three month New Employee Introductory
Period with performance evaluations conducted annually thereafter in accordance
with our standard policy.

Your  insurance benefits will become effective on the first day of the month
following the completion of 30 calendar days of employment based upon your hire
date.  During  your first year of employment you will earn three weeks of
vacation/sick time in accordance with our
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Jerry P. Johnson
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policy. Based upon OSI's success and profitability, a discretionary contribution
may be placed in the OSI Profit Sharing Program at the end of each fiscal year
in accordance with the plan guidelines and eligibility requirements (completion
of 90 days of employment and over 1000 hours of service in the plan year July 1
through June 30.) Additionally, you may choose to contribute any amount up to a
specified tax limit of before tax compensation to the OSI 401(k) program. You
may also participate in the Employee Stock Purchase Plan beginning with the
earliest eligible enrollment date of either May 1st or November 1st.

You will need to agree to the terms of and sign the attached Employee Invention
agreement.  Other such agreements may be required on a per client basis and you
will be expected to approve it in order to work on that client's project.  In
accordance with the Immigration and Naturalization Act of 1986, this offer is
made contingent upon your ability to provide proof of your right to work in this
country and completion of INS Form I-9. Your employment shall be governed by the
traditional legal principals of employment at will, and either you or OSI have
the right at anytime to terminate the employment relationship with or without
notice and with or without cause.  OSI will provide salary continuation for a
period of one year if at any time you are involuntarily terminated, other than
for cause.  In addition, stock vesting will continue one year.  Except for the
employment at will relationship, OSI reserves the right to modify job
assignments, wages, hours and working conditions for any employee at any time.

We are eager for you to join us and encourage you to accept this rewarding and
challenging opportunity.  We would appreciate your signing this letter below and
returning it to me along with the signed Employee Invention agreement and the
completed Form I-9 as soon as possible.  Please return copies of supporting
identification(s) specified on the Form I-9 or be prepared to provide them on
your first day of employment.

This letter contains all details relating to the agreed offer of employment.  No
OSI person has the authority to modify or add new terms or conditions without
the signed approval of an officer of the Corporation.  Please feel free to
contact me at (916) 353-2590 x4701 if you have any questions.  This offer will
be rescinded within seven working days if no reply is received.



Sincerely,                                      Accepted by:



____________________________                    _____________________________
BECKY WAGNER                                    JERRY P. JOHNSON       Date
Director of Human Resources

BW/Klh