<PAGE>
- --------------------------------------------------------------------------------
- --------------------------------------------------------------------------------
SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549
------------------------
AMENDMENT NO. 28
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. 28. 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 December 3, 1998, Parent issued a press release, a copy of which is
attached hereto as Exhibit (a)(52) and is incorporated herein by reference.
ITEM 11. MATERIAL TO BE FILED AS EXHIBITS.
(a)(52) Press Release dated December 3, 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: December 3, 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>
DELAWARE CHANCERY COURT STRIKES DOWN QUICKTURN
POISON-PILL PROVISION; DECISION CLEARS THE WAY FOR MENTOR
GRAPHICS' TENDER OFFER TO MOVE FORWARD
-- MENTOR CALLS ON QUICKTURN BOARD TO SIT DOWN AND NEGOTIATE AN
AGREEMENT WITH MENTOR; CHALLENGES QUICKTURN BOARD TO STOP IGNORING THE
WILL OF THE MAJORITY OF ITS STOCKHOLDERS --
WILSONVILLE, OR, DECEMBER 3, 1998 -- Mentor Graphics Corporation (Nasdaq: MENT)
announced today that the Delaware Court of Chancery has invalidated the deferred
redemption provision of Quickturn Design Systems, Inc.'s poison pill. The
decision clears the way for the vote by Quickturn stockholders at a special
meeting on January 8, 1999.
The Court determined that the Quickturn directors breached their fiduciary
duties to Quickturn stockholders by amending Quickturn's poison pill in an
attempt to defeat the $12.125 per share, all-cash offer commenced by Mentor on
August 12, 1998. In finding that the Quickturn directors breached their
fiduciary duties, the Court stated that the Quickturn directors were "unable to
articulate a cogent reason" why they adopted the deferred redemption provision.
Gregory K. Hinckley, Executive Vice President, Chief Operating Officer and Chief
Financial Officer of Mentor Graphics, said: "The decision clears the way for
our all-cash, premium offer to move forward. Quickturn stockholders now have the
opportunity to elect a new Board that can remove the remaining impediments to
the completion of Mentor's offer."
Mentor added that it remains ready to negotiate with the Quickturn Board. Mr.
Hinckley said: "Now is the time for the Quickturn Board to sit down and
negotiate an agreement with Mentor. Quickturn's stockholders should be outraged
that the Quickturn Board has decided to appeal the decision and thereby continue
to blatantly ignore the will of the majority of the company's stockholders who
have tendered their shares to Mentor's offer. If the Quickturn Board continues
to waste more of their stockholders' money, instead of negotiating with Mentor,
we urge the stockholders to elect Mentor's slate of directors at the January 8,
1999 special meeting."
<PAGE>
Mentor expects that if the nominees are elected, the new directors, subject to
their fiduciary duties to all Quickturn stockholders, will take the steps
necessary to facilitate the stockholders' ability to accept Mentor's $12.125 per
share all-cash offer.
The special meeting of Quickturn stockholders that Mentor had called for
December 11, 1998 will now be held on January 8, 1999, as a result of the Court
upholding Quickturn's bylaw amendments setting the date for a special meeting.
The record date for the special meeting is November 10, 1998. Mentor expects to
send supplemental proxy materials to all record holders shortly. Mentor added
that it presently does not intend to appeal the decision.
Mentor's Offer to Purchase, proxy solicitation materials and related documents
are available on a Mentor 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: Ry Schwark Todd Fogarty/Roy Winnick
Director of Public Relations Kekst and Company
503/685-1660 212/521-4800
# # #
