<PAGE>   1
                                                                    EXHIBIT 10.3

ALL SECTIONS MARKED WITH TWO ASTERISKS (**) REFLECT PORTIONS WHICH HAVE BEEN
REDACTED AND FILED SEPARATELY WITH THE SECURITIES AND EXCHANGE COMMISSION BY
ROSS TECHNOLOGY, INC. AS PART OF A REQUEST FOR CONFIDENTIAL TREATMENT.

                                   AGREEMENT

         This agreement ("Agreement"), dated as of September 29, 1997, is
entered into by and between FUJITSU LIMITED, a Japanese Corporation
("Fujitsu"), and ROSS TECHNOLOGY, INC., a Delaware corporation (the "Company").

                                    RECITALS

         A.      Fujitsu and the Company are parties to a Development
Agreement, dated as of June 25, 1997 (the "Development Agreement"), pursuant to
which the Company has agreed to develop a microprocessor known as the Viper
(the "Viper").  Defined terms used herein without definition have the
respective meanings set forth in the Development Agreement.

         B.      Pursuant to the Development Agreement, the Company has agreed
to deliver to Fujitsu certain Deliverables on the schedule attached to the
Development Agreement as Exhibit A, including, without limitation, to deliver
to Fujitsu certain Architectural Specifications consistent with Milestone #2 of
Exhibit B of the Development Agreement (the "Architectural Specifications") on
June 30, 1997.

         C.      The Company timely delivered to Fujitsu the Architectural
Specifications but the Architectural Specifications were not in full conformity
with Milestone #2 of Exhibit B of the Development Agreement.  Nonetheless, and
in full satisfaction of the Company's obligations with respect to Milestone #2
and Deliverable #2 of Exhibit B of the Development Agreement, Fujitsu is
willing to accept the non-conforming architectural specifications attached
hereto as Appendix 1 (the "Alternate Deliverable"), provided that the Company
agrees that (1) such acceptance will not affect the Company's continuing
obligations to develop Viper in accordance with the Specifications, and
otherwise on the terms and conditions, set forth in the Development Agreement,
and (2) Milestone #3 of Exhibit B (Chip RTL Model) of the Development Agreement
be amended and restated as attached hereto as Appendix 2, all as set forth in
this Agreement.

         NOW, THEREFORE, for valuable consideration, the receipt and adequacy
of which are hereby acknowledged, the parties hereto hereby agree as follows:

                                   AGREEMENT

         1.      Delivery and Acceptance of Alternate Deliverable.  The Company
hereby delivers the Alternate Deliverable to Fujitsu for acceptance.  Subject
to and upon the terms and conditions of this Agreement, Fujitsu hereby accepts
the Alternate Deliverable in full satisfaction of the Company's obligations
with respect to Milestone #2 and Deliverable #2 of Exhibit B of the Development
Agreement.

         2.      Limited Nature of Acceptance.  The acceptance of the Alternate
Deliverable by Fujitsu shall not be deemed to modify in any respect the
performance specifications set forth in the Development Agreement (without
limitation, **) or the obligations of the Company under the Development 
Agreement.

         3.      Amendment of Milestone #3 (CHIP RTL MODEL).  Milestone #3 of
Exhibit B to the Development Agreement (pages 4/22, 5/22 and 6/22) is hereby
amended and restated in its entirety as attached hereto as Appendix 2.

<PAGE>   2
         4.      Payment Terms.  Fujitsu will make payment to the Company of
the amount specified in the Development Agreement for Deliverable #2 as soon as
is reasonably practicable.  The Company confirms that the total amount of such
payment is $4,600,000 and that no other amounts are due or payable by Fujitsu
to the Company at the present time under the Agreement.  Fujitsu agrees that
such payment shall be deemed fully earned upon the effectiveness of this
Agreement and shall be non-refundable.

         5.      Representations and Warranties.  Each party hereby represents
and warrants to the other that the execution and delivery by such party of this
Agreement have been duly authorized by all necessary corporate and other action
and do not and will not require any consent or approval of, notice to or action
by, any person (including any governmental agency) in order to be effective and
enforceable.  The Development Agreement, as amended by this Agreement,
constitutes the legal, valid and binding obligation of such party, enforceable
against it in accordance with its terms, without defense or counterclaim.

         6.      Reservation of Rights.  The Company acknowledges and agrees
that neither Fujitsu's forbearance in exercising its rights in connection with
the delivery of the Alternate Deliverable nor the execution by Fujitsu of this
Agreement shall be deemed (i) to create a course of dealing or otherwise
obligate Fujitsu to forbear or execute a similar agreement under the same or
similar circumstances in the future, or (ii) to waive, relinquish or impair any
right of Fujitsu to future performance by the Company of the Development
Agreement strictly in accordance with its terms.

         7.      Miscellaneous.

                 (a)      Except as herein expressly amended, all terms and
conditions of the Development Agreement are and shall remain in full force and
effect.  All references to the Development Agreement shall henceforth refer to
the Development Agreement as amended hereby.

                 (b)      This Agreement shall be binding upon and inure to the
benefit of the parties and their respective successors and assigns.  No third
party beneficiaries are intended in connection with this Agreement.

                 (c)      This Agreement shall be governed by and construed in
accordance with the law of the State of California (without regard to
principles of conflicts of laws).

                 (d)      This Agreement may be executed in counterparts, each
of which shall be deemed an original, but all such counterparts together shall
constitute but one and the same instrument.





                                      2
<PAGE>   3
IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the date first above written.

                                 ROSS TECHNOLOGY, INC.



                                 By: /s/ JACK W. SIMPSON
                                    -------------------------------------------
                                 Title: President and CEO
                                        ---------------------------------------
                                 
                                 FUJITSU LIMITED                       
                                                                             
                                                                             
                                 By: /s/ YASHIRO YOSHIOKA
                                    -------------------------------------------
                                 Title: Group President, Computer Systems Group
                                        ---------------------------------------





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                                  Appendix 1

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