<PAGE>
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
---------------
Amendment No. 3
to
SCHEDULE TO
(Rule 14d-100)
TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934
Protocol Systems, Inc.
(Name of Subject Company (Issuer))
Welch Allyn Acquisition Corporation
Welch Allyn, Inc.
(Names of Filing Persons (Offerors))
Common Stock, par value $0.01 per share
(Title of Class of Securities)
74371R106
(CUSIP Number of Class of Securities)
M. Jack Rudnick, Esq.,
Vice President and General Counsel
Welch Allyn, Inc.
4341 State Street Road
Skaneateles Falls, New York 13153
(315) 685-2500
With copy to:
Ronald C. Berger, Esq.
Bond, Schoeneck & King, LLP
One Lincoln Center
Syracuse, New York 13202-1355
(315) 422-0121
(Name, Address and Telephone Numbers of Person
Authorized to Receive Notices and Communications on Behalf of Filing Persons)
July 13, 2000
[_]Check the box if the filing relates solely to preliminary communications
made before the commencement of a tender offer.
Check the appropriate boxes below to designate any transactions to which the
statement relates:
[X]third-party tender offer subject to Rule 14d-1.
[_]issuer tender-offer subject to Rule 13e-4.
[_]going private transaction subject to Rule 13e-3.
[_]amendment to Schedule 13D under Rule 13d-2.
Check the following box if the filing is a final amendment reporting the
results of the tender offer: [_]
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
2
<PAGE>
Welch Allyn Acquisition Corporation (the "Purchaser") and Welch Allyn, Inc.
hereby amend and supplement their Tender Offer Statement on Schedule TO (the
"Statement"), originally filed on June 7, 2000 and subsequently amended on June
22, 2000 and July 6, 2000, with respect to the cash tender offer by the
Purchaser to purchase all the outstanding shares of common stock, par value
$0.01 per share, of Protocol Systems, Inc. Capitalized terms used, but not
defined, herein have the respective meanings assigned to such terms in the
Statement.
Item 11. Additional Information
On July 13, 2000, Parent issued a press release, a copy of which is attached
hereto as Exhibit (a)(11) and is incorporated herein by reference.
Item 12. Exhibits.
<TABLE>
<C> <S>
*(a)(1) Offer to Purchase.
*(a)(2) Letter of Transmittal.
*(a)(3) Notice of Guaranteed Delivery.
*(a)(4) Letter to Brokers, Dealers, Banks, Trust Companies and Other
Nominees.
*(a)(5) Letter to Clients for Use by Brokers, Dealers, Banks, Trust Companies
and Other Nominees.
*(a)(6) Guidelines for Certification of Taxpayer Identification Number on
Substitute Form W-9.
*(a)(7) Summary Advertisement dated June 7, 2000.
*(a)(8) Joint Press Release dated May 25, 2000, issued by the Company and
Parent (incorporated herein by reference to the Tender Offer
Statement on Schedule TO filed with the Securities and Exchange
Commission on May 25, 2000 by the Purchaser and Parent).
*(a)(9) Joint Press Release dated June 22, 2000 issued by the Company and
Parent.
*(a)(10) Press Release dated July 6, 2000 issued by Parent.
(a)(11) Press Release dated July 13, 2000 issued by Parent.
*(b)(1) Agreement, dated as of May 18, 2000, by and between Parent and Bank
One, NA concerning a $40 million bridge loan.
*(b)(2) $40 million Master Note (Fixed and Floating Rates), dated May 18,
2000, made by Parent.
*(d)(1) Agreement and Plan of Merger, dated as of May 24, 2000, by and among
the Purchaser, Parent and the Company (incorporated herein by
reference to Exhibit 2.1 to the Current Report on Form 8-K filed with
the Securities and Exchange Commission on May 25, 2000 by the Company
(Commission File No. 0-19943)).
*(d)(2) Confidentiality Agreement, dated as of March 9, 2000, between Parent
and the Company (incorporated herein by reference to Exhibit (e)(2)
to the Solicitation/Recommendation Statement on Schedule 14D-9 filed
with the Securities and Exchange Commission on June 7, 2000 by the
Company ("Schedule 14D-9")).
*(d)(3) Amended and Restated Executive Employment Agreement between the
Company and Edward M. Kolasinski dated May 23, 2000 (incorporated
herein by reference to Exhibit (e)(3) to Schedule 14D-9).
*(d)(4) Amended and Restated Executive Employment Agreement between the
Company and Robert F. Adrion dated May 23, 2000 (incorporated herein
by reference to Exhibit (e)(4) to Schedule 14D-9).
*(d)(5) Executive Employment Agreement between the Company and Ann P. Demaree
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(5) to Schedule 14D-9).
</TABLE>
3
<PAGE>
<TABLE>
<C> <S>
*(d)(6) Amended and Restated Executive Employment Agreement between the
Company and James P. Fee dated May 23, 2000 (incorporated herein by
reference to Exhibit (e)(6) to Schedule 14D-9).
*(d)(7) Amended and Restated Executive Employment Agreement between the
Company and Donald M. Abbey dated May 23, 2000 (incorporated herein
by reference to Exhibit (e)(7) to Schedule 14D-9).
*(d)(8) Amended and Restated Executive Employment Agreement between the
Company and James P. Welch dated May 23, 2000 (incorporated herein by
reference to Exhibit (e)(8) to Schedule 14D-9).
*(d)(9) Amended and Restated Executive Employment Agreement between the
Company and Richard L. Roa dated May 23, 2000 (incorporated herein by
reference to Exhibit (e)(9) to Schedule 14D-9).
*(d)(10) Amended and Restated Executive Employment Agreement between the
Company and Chris E. Tew dated May 23, 2000 (incorporated herein by
reference to Exhibit (e)(10) to Schedule 14D-9).
*(d)(11) Amended and Restated Executive Employment Agreement between the
Company and Allen L. Oyler dated May 23, 2000 (incorporated herein by
reference to Exhibit (e)(11) to Schedule 14D-9).
*(d)(12) Retention Bonus Agreement between the Company and James P. Welch
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(12) to Schedule 14D-9).
*(d)(13) Retention Bonus Agreement between the Company and Robert F. Adrion
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(13) to Schedule 14D-9).
*(d)(14) Retention Bonus Agreement between the Company and Ann P. Demaree
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(14) to Schedule 14D-9).
*(d)(15) Retention Bonus Agreement between the Company and James P. Fee dated
May 23, 2000 (incorporated herein by reference to Exhibit (e)(15) to
Schedule 14D-9).
*(d)(16) Retention Bonus Agreement between the Company and Edward M.
Kolasinski dated May 23, 2000 (incorporated herein by reference to
Exhibit (e)(16) to Schedule 14D-9).
*(d)(17) Retention Bonus Agreement between the Company and Allen L. Oyler
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(17) to Schedule 14D-9).
*(d)(18) Retention Bonus Agreement between the Company and Richard L. Roa
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(18) to Schedule 14D-9).
*(d)(19) Retention Bonus Agreement between the Company and Chris E. Tew dated
May 23, 2000 (incorporated herein by reference to Exhibit (e)(19) to
Schedule 14D-9).
*(d)(20) Retention Bonus Agreement between the Company and Donald M. Abbey
dated May 23, 2000 (incorporated herein by reference to Exhibit
(e)(20) to Schedule 14D-9).
*(d)(21) Supplement to Amended and Restated Executive Employment Agreement
between the Company and Robert F. Adrion dated May 24, 2000
(incorporated herein by reference to Exhibit (e)(21) to Schedule 14D-
9).
*(d)(22) First Amendment to Rights Agreement, dated as of May 24, 2000,
between the Company and ChaseMellon Shareholder Services, L.L.C., as
the Rights Agent (incorporated herein by reference to Exhibit (e)(22)
to Schedule 14D-9).
</TABLE>
-------
* Previously filed.
4
<PAGE>
SIGNATURE
After due inquiry and to the best of our knowledge and belief, we certify
that the information set forth in this statement is true, complete and correct.
Dated: July 13, 2000
Welch Allyn Acquisition Corporation
/s/ M. Jack Rudnick
By: _____________________________________
Name: M. Jack Rudnick
Title: Vice President
Welch Allyn, Inc.
/s/ Peter H. Soderberg
By: _____________________________________
Name: Peter H. Soderberg
Title: President and Chief Executive
Officer
4
