Exhibit 5.1

[STOEL RIVES LLP LETTERHEAD]

                                November 20, 2000

Board of Directors
RadiSys Corporation
5445 NE Dawson Creek Drive
Hillsboro, OR 97124

         We have acted as counsel for RadiSys Corporation (the "Company") in
connection with the preparation and filing of a Registration Statement on Form
S-3 (the "Registration Statement") under the Securities Act of 1933, as amended,
covering $100,000,000 aggregate principal amount of the Company's 5 1/2%
Convertible Subordinated Notes due 2007 (the "Notes") and shares of the
Company's common stock issuable upon conversion of the Notes (the "Shares"). We
have reviewed the corporate action of the Company in connection with this matter
and have examined the documents, corporate records and other instruments we
deemed necessary for the purpose of this opinion, including, but not limited to,
the Indenture dated August 9, 2000 between the Company and U.S. Trust Company,
National Association (the "Indenture").

         Based on the foregoing, it is our opinion that:

         1.       The Company is a corporation existing under the laws of the
                  State of Oregon;

         2.       The Notes have been duly authorized and legally issued and are
                  fully paid and non-assessable; and

         3.       The Shares have been duly authorized and, when issued pursuant
                  to the terms of the Indenture, will be legally issued, fully
                  paid and non-assessable.

         We consent to the use of our name in the Registration Statement and in
the Prospectus filed as a part thereof and to the filing of this opinion as an
exhibit to the Registration Statement.

                                                     Very truly yours,

                                                     /s/ STOEL RIVES LLP

                                                     STOEL RIVES LLP