SC TO-T/A

QuickLinks -- Click here to rapidly navigate through this document

AS FILED WITH THE SECURITIES AND EXCHANGE COMMISSION ON SEPTEMBER 14, 2001

SECURITIES AND EXCHANGE COMMISSION
WASHINGTON, D.C. 20549

SCHEDULE TO
(Rule 14d-100)
TENDER OFFER STATEMENT UNDER SECTION 14(d)(1) OR 13(e)(1)
OF THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 4)

FARGO ELECTRONICS, INC.
(Name of Subject Company (Issuer))

RUSHMORE ACQUISITION CORP.
ZEBRA TECHNOLOGIES CORPORATION
(Names of Filing Persons (Offeror))
COMMON STOCK, PAR VALUE $0.01 PER SHARE
(Title of Class of Securities)

30744P 10 2

(CUSIP Number of Class of Securities)

EDWARD L. KAPLAN
Chairman
Zebra Technologies Corporation
333 Corporate Woods Parkway
Vernon Hills, Illinois 60061
Tel.: (847) 634-6700

(Name, Address and Telephone Number of Person Authorized
to Receive Notices and Communications on Behalf of Filing Person)

COPIES TO:

HERBERT S. WANDER, ESQ. MARK D. WOOD, ESQ.	BRUCE A. MACHMEIER, ESQ. THOMAS A. LETSCHER, ESQ.
Katten Muchin Zavis 525 West Monroe Street Suite 1600 Chicago, Illinois 60661-3693 Tel.: (312) 902-5200	Oppenheimer Wolff & Donnelly LLP Plaza VII, Suite 3300 45 South Seventh Street Minneapolis, Minnesota 55402-1609 Tel.: (612) 607-7000

/ /	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: / /

    Zebra Technologies Corporation, a Delaware corporation ("Zebra"), and Rushmore Acquisition Corp., a Delaware corporation ("Merger Sub") and wholly-owned subsidiary of Zebra, hereby amend and supplement their Tender Offer Statement on Schedule TO, originally filed on August 3, 2001 and amended and supplemented by Amendment No. 1 thereto dated August 15, 2001, Amendment No. 2 thereto dated August 17, 2001 and Amendment No. 3 thereto dated August 30, 2001 (as so amended and supplemented, the "Schedule TO"), with respect to Merger Sub's offer to purchase all of the issued and outstanding shares of common stock, par value $0.01 per share (the "Common Stock"), including the associated rights to purchase preferred stock (collectively, the "Shares"), of Fargo Electronics, Inc., a Delaware corporation ("Fargo"), at a purchase price of $7.25 per Share, net to the seller in cash, without interest thereon, upon the terms and subject to the conditions set forth in the Offer to Purchase dated August 3, 2001 (the "Offer to Purchase") and the related Letter of Transmittal (which, together with the Offer to Purchase, as amended or supplemented from time to time, constitute the "Offer"), copies of which have been previously filed herewith as Exhibits 99.1(a)(1)(A) and 99.1(a)(1)(B), respectively. Capitalized terms used and not otherwise defined herein shall have the meanings assigned to such terms in the Offer to Purchase.

ITEM 11.  ADDITIONAL INFORMATION.

    Item 11 of the Schedule TO is hereby amended and supplemented to add the following information:

    Pursuant to the Acquisition Agreement, Zebra is extending the expiration of the Offer until 5:00 p.m., New York City time, on Friday, September 28, 2001, unless the Offer is further extended. The Offer was previously scheduled to expire at 12:00 Midnight, New York City time, on Friday, September 14, 2001. The extension of the Offer is made because the applicable waiting period under the HSR Act has not yet expired or been terminated. All references to "12:00 Midnight, New York City time, on Friday, September 14, 2001" as the "Expiration Date," or time of expiration of the Offer, are hereby amended to refer to "5:00 p.m., New York City time, on Friday, September 28, 2001."

    As of 12:00 p.m., New York City time, on September 14, 2001, 9,489,513 shares (including guaranteed deliveries) were validly tendered and not withdrawn, which represents approximately 80.7% of the outstanding shares.

    On September 14, 2001 Zebra and Fargo issued a joint press release announcing the extension of the expiration of the Offer until 5:00 p.m., New York City time, on Friday, September 28, 2001. The press release is contained in Exhibit 99.1(a)(5)(D) hereto, and the information set forth in the press release is incorporated herein by reference.

ITEM 12.  EXHIBITS.

    Item 12 of the Schedule TO is hereby amended and supplemented to include the following exhibit:

    99.1(a)(5)(D)     Joint Press Release issued by Zebra and Fargo on September 14, 2001.

1

SIGNATURE

    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.

ZEBRA TECHNOLOGIES CORPORATION
By:	/s/ Edward L. Kaplan

Name:	Edward L. Kaplan
Title:	Chairman and Chief Executive Officer

RUSHMORE ACQUISITION CORP.
By:	/s/ John H. Kindsvater

Name:	John H. Kindsvater
Title:	President

September 14, 2001

2

EXHIBIT INDEX

Exhibit Number	Description
99.1(a)(1)(A)	Offer to Purchase, dated August 3, 2001
99.1(a)(1)(B)	Letter of Transmittal
99.1(a)(1)(C)	Notice of Guaranteed Delivery
99.1(a)(1)(D)	Letter from the Information Agent to Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees
99.1(a)(1)(E)	Letter to Clients for use by Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees
99.1(a)(1)(F)	Guidelines for Certification of Taxpayer Identification Number on Substitute Form W-9
99.1(a)(1)(G)	Summary Advertisement as published in the Wall Street Journal on August 3, 2001
99.1(a)(5)(A)	Complaint filed by James Stewart in District Court, Fourth Judicial District, County of Hennepin, State of Minnesota on August 13, 2001
99.1(a)(5)(B)	Joint Press Release issued by Zebra and Fargo on August 17, 2001
99.1(a)(5)(C)	Joint Press Release issued by Zebra and Fargo on August 30, 2001
99.1(a)(5)(D)*	Joint Press Release issued by Zebra and Fargo on September 14, 2001
99.1(d)(1)	Acquisition Agreement, dated July 31, 2001, by and among Fargo, Zebra and Merger Sub
99.1(d)(2)	Confidentiality Agreement, dated July 10, 2001, by and between Zebra and Fargo
99.1(d)(3)	Exclusivity Agreement, dated July 10, 2001, by and between Zebra and Fargo
99.1(d)(4)	Form of Stockholder Agreement, dated as of July 31, 2001, by and between Zebra and each of certain entities affiliated with TA Associates, Inc. and St. Paul Venture Capital, Inc.
99.1(d)(5)	Form of Stockholder Agreement, dated as of July 31, 2001, by and between Zebra and each of Fargo's directors and executive officers
99.1(d)(6)	Amendment No. 1 to Acquisition Agreement, dated as of August 30, 2001, by and among Fargo, Zebra and Merger Sub

*

Filed herewith; all others previously filed.

3

QuickLinks

SIGNATURE
EXHIBIT INDEX

EX-99.1(A)(5)(D)

QuickLinks -- Click here to rapidly navigate through this document

Zebra Technologies Corporation
333 Corporate Woods Parkway
Vernon Hills, Illinois 60061.3109 U.S.A.
Telephone +1.847.634.6700
Facsimile +1.847.913.8766
www.zebracorporation.com

FOR IMMEDIATE RELEASE

Zebra Technologies Extends Tender Offer
for All Outstanding Shares of Fargo Common Stock

Vernon Hills, IL, and Eden Prairie, MN, September 14, 2001—Zebra Technologies Corporation (Nasdaq: ZBRA) and Fargo Electronics, Inc., (Nasdaq: FRGO) today announced that Zebra is extending its tender offer for all outstanding shares of common stock (including associated rights to purchase preferred stock) of Fargo for $7.25 per share in cash to 5:00 PM, New York City time, on September 28, 2001. The extension is necessary, because the applicable Hart-Scott-Rodino antitrust review waiting period has yet to expire or be terminated. The tender offer commenced on August 3, 2001, and was previously scheduled to expire at Midnight, New York City time, on September 14, 2001.

Zebra and Fargo are in the process of responding to and discussing with regulators the request for additional information received from the Federal Trade Commission under the Hart-Scott-Rodino Antitrust Improvements Act of 1976. Zebra intends to extend the offer at least until expiration or termination of the Hart-Scott-Rodino antitrust review waiting period, subject to the provisions of the acquisition agreement. Pursuant to the definitive acquisition agreement signed by Zebra and Fargo, the tender offer will generally be extended in increments of 10 business days.

As of Noon New York City time on September 14, 2001, 9,489,513 shares of Fargo common stock (including guaranteed deliveries), which represent 80.7% of total shares outstanding, had been tendered.

This press release is neither an offer to purchase nor a solicitation of an offer to sell shares of Fargo common stock. All stockholders should read the tender offer statement, as amended (including the offer to purchase, a related letter of transmittal and other offer documents), that was filed with the SEC by Zebra, and the solicitation/recommendation statement that was filed with the SEC by Fargo. These statements contain important information that stockholders should consider before making any decision regarding tendering their shares. Stockholders are able to obtain these statements, as well as other filings containing information about Zebra and Fargo, without charge, at the SEC's Web site www.sec.gov. Stockholders are also able to obtain copies of these documents, at no charge, by contacting Zebra's information agent, Mellon Investor Services LLC, at (800) 261-8056. Copies of these documents may also be obtained, at no charge, by directing such requests to Zebra's Chief Financial Officer at (847) 793-6730.

Fargo Electronics, Inc., is the world's leader in innovative technologies for desktop plastic card personalization systems. Fargo printing systems create personalized plastic identification cards complete with digital images and text, lamination, and electronically encoded information. More than 50,000 Fargo systems are currently installed throughout the U.S. and in over 100 other countries. For more information, visit Fargo's Web site at http://www.fargo.com.

Zebra Technologies Corporation manufactures and distributes Zebra-brand on-demand thermal bar code label printers and Eltron®-brand instant-issuance plastic card printers used in automatic identification, personalization and security applications worldwide. The company, with an installed base of two million printers, also offers software and related supplies, including more than 1,000 label and

ribbon combinations. Zebra's customers include more than 70 percent of the FORTUNE 500. Information about Zebra Technologies Corporation can be found at www.zebracorporation.com.

For Information, Contact:
Charles R. Whitchurch Chief Financial Officer Zebra Technologies Corporation Phone: 847.634.6700 Fax: 847.821.2545	Paul Stephenson Chief Financial Officer Fargo Electronics, Inc. Phone: 952.946.6330 Fax: 952.941.7836

QuickLinks

Zebra Technologies Extends Tender Offer for All Outstanding Shares of Fargo Common Stock