<PAGE>
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
------------------------
AMENDMENT NO. 19
TO SCHEDULE 14D-1
TENDER OFFER STATEMENT
(PURSUANT TO SECTION 14(D)(1) OF THE SECURITIES EXCHANGE ACT OF 1934)
QUICKTURN DESIGN SYSTEMS, INC.
(Name of Subject Company)
MENTOR GRAPHICS CORPORATION
MGZ CORP.
(Bidders)
COMMON STOCK, PAR VALUE $.001 PER SHARE
(including the Associated Rights)
(Title of Class of Securities)
74838E102
(CUSIP Number of Class of Securities)
------------------------
WALDEN C. RHINES
PRESIDENT AND CHIEF EXECUTIVE OFFICER
MENTOR GRAPHICS CORPORATION
8005 S.W. BOECKMAN ROAD
WILSONVILLE, OREGON 97070-7777
(503) 685-1200
(Name, Address and Telephone Number of Persons Authorized
to Receive Notices and Communications on Behalf of Bidders)
COPY TO:
JOHN J. HUBER, ESQ. CHRISTOPHER L. KAUFMAN, ESQ.
LATHAM & WATKINS LATHAM & WATKINS
1001 PENNSYLVANIA AVENUE, N.W. 75 WILLOW ROAD
WASHINGTON, DC 20004 MENLO PARK, CALIFORNIA 94025
(202) 637-2200 (650) 328-4600
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
<PAGE>
MGZ Corp., a Delaware corporation ("Purchaser"), and Mentor Graphics
Corporation, an Oregon corporation ("Parent"), hereby amend and supplement their
Tender Offer Statement on Schedule 14D-1 filed on August 12, 1998 (the
"Statement"), as amended, with respect to the offer by Purchaser to purchase all
outstanding shares of Common Stock, par value $.001 per share, of Quickturn
Design Systems, Inc., a Delaware corporation, for a purchase price of $12.125
per share, net to the seller in cash, without interest thereon, as set forth in
this Amendment No. 19. Capitalized terms used herein and not defined have the
meanings ascribed to them in the Statement.
ITEM 10. ADDITIONAL INFORMATION.
Item 10(f) of the Statement is hereby amended and supplemented by the
following:
1. On November 2, 1998, Parent issued a press release, a copy of which is
attached hereto as Exhibit (a)(37) and is incorporated herein by reference,
relating to the extension of the Offer until 12:00 midnight, New York City time,
on Monday, November 30, 1998, unless further extended.
ITEM 11. MATERIAL TO BE FILED AS EXHIBITS.
(a)(37) Press Release dated November 2, 1998.
2
<PAGE>
SIGNATURES
After due 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.
<TABLE>
<S> <C> <C>
Dated: November 2, 1998 MENTOR GRAPHICS CORPORATION
By: /s/ GREGORY K. HINCKLEY
--------------------------------------
Name Gregory K. Hinckley
Title: Executive Vice President, Chief Operating
Officer and Chief Financial Officer
MGZ CORP.
By: /s/ GREGORY K. HINCKLEY
--------------------------------------
Name: Gregory K. Hinckley
Title: Secretary and Chief Financial Officer
</TABLE>
3
<PAGE>
MENTOR GRAPHICS TENDER OFFER FOR QUICKTURN DESIGN SYSTEMS
EXTENDED TO NOVEMBER 30
-- SHARES TENDERED, TOGETHER WITH THOSE ALREADY OWNED BY MENTOR, REPRESENT A
MAJORITY OF QUICKTURN'S SHARES --
WILSONVILLE, OR, NOVEMBER 2, 1998 -- Mentor Graphics Corporation (Nasdaq: MENT)
today announced that it has extended its $12.125 per share cash tender offer for
all outstanding shares of the common stock of Quickturn Design Systems, Inc.
(Nasdaq: QKTN) to 12:00 Midnight, New York City time, on Monday, November 30,
1998, unless extended.
As of 12:00 Midnight, New York City time, on October 30, 1998, the date on which
the Offer was scheduled to expire, 8,849,856 shares of Quickturn common stock
had been validly tendered into the Offer, which, together with the 591,500
shares already owned by Mentor, represents approximately 53.0 percent of
Quickturn's outstanding common stock (based upon 17,809,000 shares outstanding
as of September 30, 1998). The shares tendered represent 49.7 percent of the
outstanding common stock.
Dr. Walden C. Rhines, President and Chief Executive Officer of Mentor Graphics,
said: "We are pleased that the shares tendered, together with the 3.3 percent we
already own, represent a majority of Quickturn's outstanding shares. It is time
for Quickturn's Board of Directors to listen to its stockholders, stop its
entrenchment actions and sit down with Mentor."
Mentor Graphics' Offer to Purchase and ancillary documents are available on a
Mentor Graphics World Wide Web site at http://www.mentorg.com/file.
The Dealer Manager for the Offer is Salomon Smith Barney. The Information Agent
for the Offer is MacKenzie Partners, Inc., which can be reached toll-free at
800-322-2885 or by collect call at 212-929-5500.
Contacts: Anne M. Wagner Roy Winnick/Todd Fogarty
Vice President, Marketing Kekst and Company
503/685-1462 212/521-4800
# # #