SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549

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


                                  SCHEDULE 13G


             INFORMATION STATEMENT PURSUANT TO RULES 13d-1 AND 13d-2
                    UNDER THE SECURITIES EXCHANGE ACT OF 1934
                                (Amendment No.1)




                                  RADISYS CORP.
                                (Name of Issuer)


                                  COMMON STOCK
                         (Title of Class of Securities)


                                    750459109
                                 (CUSIP Number)


     The  remainder  of this  cover  page  shall be filled  out for a  reporting
person's  initial  filing on this  form with  respect  to the  subject  class of
securities,  and for any subsequent amendment containing information which would
alter the disclosures provided in a prior cover page.
     The  information  required in the remainder of this cover page shall not be
deemed to be  "filed"  for the  purpose  of  Section  18 of the  Securities  and
Exchange  Act of 1934 ("Act") or otherwise  subject to the  liabilities  of that
section  of the Act but  shall be  subject  to all other  provisions  of the Act
(however, see the Notes.)




CUSIP No. 750459109           13G                          Page    of    Pages


________________________________________________________________________________
1.   NAME OF REPORTING PERSONS
     Lord, Abbett & Co.

     I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS (ENTITIES ONLY)
     13-5620131


________________________________________________________________________________
2.   CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP*
                                                                 (a)  [_]
                                                                 (b)  [_]

________________________________________________________________________________
3.   SEC USE ONLY



________________________________________________________________________________
4.   CITIZENSHIP OR PLACE OF ORGANIZATION

     NEW YORK

________________________________________________________________________________
  NUMBER OF    5.   SOLE VOTING POWER

   SHARES           1,694,142
               _________________________________________________________________
BENEFICIALLY   6.   SHARED VOTING POWER

  OWNED BY          0
               _________________________________________________________________
    EACH       7.   SOLE DISPOSITIVE POWER

  REPORTING         1,694,142
               _________________________________________________________________
   PERSON      8.   SHARED DISPOSITIVE POWER

    WITH            0
________________________________________________________________________________
9.   AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON

     1,694,142

________________________________________________________________________________
10.  CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*

                                                                          [_]
     N/A
________________________________________________________________________________
11.  PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9)

     10.34%

________________________________________________________________________________
12.  TYPE OF REPORTING PERSON*

     IA:PN

________________________________________________________________________________




Item 1.

     (a)      See Front Cover Page
     (b)      5445 NE Dawson Creek Dr.
              Hillsboro, OR  97124


Item 2.

     (a)      Lord, Abbett & Co.
     (b)      90 Hudson Street
              Jersey City, NJ 07302

     (c)      New York

     (d)      See Front Cover Page

     (e)      See Front Cover Page

Item 3.       If this statement is filed pursuant to Rule 13d-1(b), or
              13d-2(b), check whether the person filing is a:

     (e)      Investment Adviser registered under Section 203 of the Investment
              Advisers Act of 1940.

Item 4.       Ownership

     (a)      See No. 9
     (b)      See No. 11
     (c)
              (i)    See No. 5
              (ii)   See No. 6
              (iii)  See No. 7
              (iv)   See No. 8

Item 5.       Owner of Five Percent or Less of a Class

              N/A

Item 6.       Ownership of More than Five Percent on Behalf of Another Person

              N/A

Item 7.       Identification and Classification of the Subsidiary Which Acquired
              the Security Being Reported on By the Parent Holding Company

              N/A

Item 8.       Identification and Classification of Members of the Group

              N/A





Item 9.       Notice of Dissolution of Group

              N/A

Item 10.      Certification

     By signing  below I certify  that,  to the best of my knowledge and belief,
the  securities  referred  to above  were  acquired  in the  ordinary  course of
business  and were not acquired for the purpose of and do not have the effect of
changing or  influencing  the control of the issuer of such  securities and were
not acquired in connection  with or as a participant in any  transaction  having
such purpose or effect.

                                    SIGNATURE

     After  reasonable  inquiry and to the best of my  knowledge  and belief,  I
certify that the information  set forth in this statement is true,  complete and
correct.


                  January 20, 2000
Date


                  /s/ Paul A. Hilstad
                      General Counsel
Signature