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September 30, 1999

Mr. Stephen F. Loughlin, Chief Financial Officer
RadiSys Corporation
5445 NE Dawson Creek Drive
Hillsboro, OR 97124

Dear Stephen:

I am pleased to advise you that U.S. Bank, National Association ("Bank") has
approved the renewal of, and an increase in, the revolving line of credit for
RadiSys Corporation, subject to the following terms and conditions:

Borrower:                    RadiSys Corporation ("RadiSys").

Operating Line of Credit
- ------------------------

Purpose:                     Working Capital and general corporate purposes.

Borrowing Limit:             $20,000,000 (Twenty Million Dollars)

Guarantors:                  None.

Expiry Date:                 September 30, 2000 or upon non-compliance with any
                             term or condition stated herein, or any material
                             misrepresentation of fact by the Borrower.

Pricing:

         Fees:               Upfront Fee of 5 basis points ($ 1 0,000) on the
                             committed amount, due upon acceptance.

                             Quarterly fee of 1/8 of I percent (annualized)
                             based upon the unused portion of the line, due
                             quarterly in arrears.


RadiSys Corporation                                                       Page 2
September 30, 1999
Commitment Letter


         Interest Rate:      Pricing based upon U.S. Bank, National
                             Association's Prime Rate/1, Bankers' Acceptances
                             ("BA"), or London Interbank Offering Rates
                             ("LIBOR"), at the Borrower's option. The Prime Rate
                             will be fully floating and computed on a 360 day
                             year.

                             The spread over the base rates will be determined
                             quarterly by the Borrower's Total Liabilities /
                             Tangible Net Worth* Ratio as expressed in the chart
                             below. The rate will be adjusted within 5 business
                             days of receipt of either the quarterly I O-Q
                             report or the audited annual financials.



                             Total Liabilities/
                             Tangible Net Worth               Prime     BA or LIBOR
                             ------------------               -----     -----------
                                                                       
                             Greater then 0.65: 1.00            + 0%         +2.00%
                             0.41:1.00 to 0.65: 1.00            + 0%         +1.75%
                             0.26:1.00 to 0.40: 1.00            + 0%         +1.50%
                             Less than or equal to 0.25: 1.00   + 0%         +1.25%


                             B/A financing available to Borrower in minimum
                             amount of $1,000,000 to maximum of 90 days.

                             LIBOR Terms:

                             A)  Minimum amount of $500,000 and $100,000
                                 increments thereafter.

                             B)  Maturity and availability: One, two or three
                                 month periods.

                             C)  Prepayment of LIBOR borrowings not permitted.

                             D)  Notification: Two day notification prior to
                                 12:00 noon on the day of notification.

                             E)  Irrevocability: Acceptance of a pricing
                                 commitment from the Bank will constitute an
                                 irrevocable agreement to borrow under the
                                 revolving line of credit.

- --------------

1/ If the interest rate charged to the Borrower is tied to the Prime Rate of
   U.S. Bank, Borrower is advised that U.S. Bank's Prime Rate is the rate of
   interest which the Bank from time to time identifies and publicly announces
   as its Prime Rate and is not necessarily, for example, the lowest rate of
   interest which the Bank collects from any borrower or group of borrowers.


RadiSys Corporation                                                       Page 3
September 30, 1999
Commitment Letter

                             F)  Interest computed on the basis of a 360 day
                                 year and the actual number of days elapsed.

                             *   Tangible Net Worth is defined as Total
                                 Shareholder's Equity less Intangibles (e.g.
                                 Goodwill, Patents, Software development costs,
                                 etc.). All other capitalized terms are defined
                                 in accordance with GAAP.

All reasonable out of pocket expenses for documentation and collateral
examination fees to be paid by Borrower.

Repayment Terms:             Optional advance note. Interest payable monthly, in
                             arrears. Principal due at maturity.

                             Repayment of each advance received by the Borrower
                             under the line of credit is subject to the ten-ns
                             and conditions of the promissory note evidencing
                             that advance as well as all conditions of this
                             letter. In the event of any conflict between the
                             two, the ten-ns and conditions of the promissory
                             note shall control.

Collateral:                  The revolving line of credit provides for a
                             flexible collateral position according to the
                             following matrix. The assets of the Borrower which
                             are referenced below include accounts and
                             inventory.

                  Quick Ratio                          Collateral
                  -----------                          ----------
           Greater than 1.50:1.00             Unsecured with negative pledge
                                              agreement.
           Less than or equal to 1.50:1.00    Unsecured with negative pledge,
                                              if not borrowing, but converts to
                                              secured if ratio falls below 1.50
                                              benchmark for two consecutive
                                              quarters. If Borrowing and equal
                                              to, or less than 1.50, then the
                                              line of credit is secured.
           Less than or equal to 1.15:1.00    Line is secured and margined at
                                              80% of eligible A/R**.

           * Quick Ratio is defined as ((Cash plus Trade Accounts Receivable,
             Net)/(Current Liabilities))

         Advances:

                             Advances limited to the Borrowing Limit when Quick
                             Ratio is greater than 1. 15: I.O. When Quick Ratio
                             is less than or equal to 1. 15: 1. 00 the advances
                             will be limited to


RadiSys Corporation                                                       Page 4
September 30, 1999
Commitment Letter

                             80% of eligible A/R to 90 days after date of
                             invoice. Ineligible accounts will be datings, COD
                             or cash sales, inter-company, employee, progress
                             billings, consignments, retainage, potential offset
                             and accounts where more than 25% of the balance is
                             beyond 90 days after date of invoice. Foreign
                             accounts receivable will be considered eligible at
                             the discretion of the Bank. Disbursements under the
                             line of credit shall terminate on the earlier
                             occurrence of the date indicated above as the
                             Expiry Date or the date on which this Bank, in its
                             sole discretion, determines that there has been a
                             material adverse change in the financial condition
                             or management of the Borrower, or determines that
                             there has been any noncompliance with any term or
                             condition stated herein. Noncompliance with the
                             conditions and terms of this letter of will be
                             considered as an event of default, entitling the
                             Bank to all the default provisions as provided for
                             in documents evidencing this line of credit.

General Conditions:
- -------------------

         Covenants:          The following covenants will be measured quarterly:

                             1.   Minimum Current Ratio: The ratio of Current
                                  Assets to Current Liabilities not to be less
                                  than 2.00 to 1.00.

                             2.   Maximum Leverage Ratio: The ratio of Total
                                  Liabilities to Tangible Net Worth not to be
                                  more than 0.75 to 1.00.

                             3.   Minimum Tangible Net Worth: Tangible Net
                                  Worth shall not be less than $75,000,000.

         Failure to comply with any the above listed covenants constitutes an
         event of default under the terms of the Bank's documents.

Financial Reporting:

                             1.   Audited annual financial statements.

                             2.   Quarterly interim financial statements and all
                                  material documents filed with the SEC. RadiSys
                                  Corporation Page 5 September 30, 1999
                                  Commitment Letter


RadiSys Corporation                                                       Page 5
September 30, 1999
Commitment Letter

                             3.   If the Quick Ratio (as defined above) falls
                                  below 1. 1 5 to 1.00: A borrowers certificate
                                  with each advance, and a borrowers certificate
                                  to accompany the monthly A/R and A/P agings.
                                  Additionally, if a Bank Collateral Survey is
                                  performed then further refinement of the
                                  advance structure may be necessary.

Documentation:               Execution of notes, loan agreements, borrowing
                             resolutions, incumbency certificates and other
                             documents as required by the Bank on forms prepared
                             by the Bank.


If the above terms and conditions to extend credit to RadiSys Corporation are
acceptable to you, please sign and return the acknowledgment copy of this letter
on or before October 15, 1999.

We are pleased to provide you this borrowing accommodation and look forward to
serving your banking needs in the future.


Respectfully,


ROSS A. BEATON


Ross A. Beaton
Vice President


BY OREGON STATUE (ORS 41.580), THE FOLLOWING DISCLOSURE IS REQUIRED: UNDER
OREGON LAW MOST AGREEMENTS PROMISES AND COMMITMENTS MADE BY LENDERS AFTER
OCTOBER 1989 CONCERNING LOANS AND OTHER CREDIT EXTENSIONS WHICH ARE NOT FOR
PERSONAL, FAMILY OR HOUSEHOLD PURPOSES OR SECURED SOLELY BY THE BORROWER'S
RESIDENCE MUST BE IN WRITING, EXPRESS CONSIDERATION AND BE SIGNED BY THE LENDER
TO BE ENFORCEABLE


RadiSys Corporation                                                       Page 6
September 30, 1999
Commitment Letter


THE UNDERSIGNED HEREBY ACKNOWLEDGES AND ACCEPTS THIS OFFER TO EXTEND CREDIT
SUBJECT TO THE TERMS AND CONDITIONS STATED ABOVE.

RadiSys Corporation

BY: STEPHEN F. LOUGHLIN    CFO            September 30, 1999
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