OMB APPROVAL OMB Number: 3235-0145 Expires: December 31, 1997 Estimated average burden hours per response .... 14.90 UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 13G Under the Securities Exchange Act of 1934 (Amendment No. ___)* QUANTUM CORP HDDG COM (Name of Issuer) COMMON STOCK (Title of Class of Securities) 747906303 (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 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. 747906303 13G Page 2 of 2 Pages 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSON SANFORD C. BERNSTEIN & CO., INC. 767 FIFTH AVENUE NEW YORK NY 10153 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP (a) / / (b) / / 3 SEC USE ONLY 4 CITIZENSHIP OR PLACE OF ORGANIZATION 5 SOLE VOTING POWER 6,454,631 NUMBER OF SHARES 6 SHARED VOTING POWER* BENEFICIALLY 1,342,657 OWNED BY EACH 7 SOLE DISPOSITIVE POWER REPORTING PERSON 11,489,411 WITH 8 SHARED DISPOSITIVE POWER 0 9 AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 11,489,411 10 CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES / / 11 PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW 9 13.7% 12 TYPE OF REPORTING PERSON IA/BD * Sanford C. Bernstein & Co., Inc. clients who have appointed an independent voting agent with instructions to vote shares in the same manner as Sanford C. Bernstein & Co., Inc. Sanford C. Bernstein & Co., Inc. Investment Research and Management 1 North Lexington Avenue, White Plains NY 10601 914-993-2300 Fax 914-993-2616 Registered Investment Advisor Member, New York Stock Exchange, Inc. SCHEDULE G Under the Securities Exchange Act of 1934 Item 1(a): Quantum Corp HDDG Com Item 1(b): 500 McCarthy Blvd. Milpitas CA 93035 Item 2(a): Sanford C. Bernstein & Co., Inc. Item 2(b): 767 Fifth Avenue New York NY 10153 Item 2(c): New York Item 2(d): Common Item 2(e): 747906303 Item 3: Investment Advisor/Broker Dealer Item 4(a): 11,489,411 Item 4(b): 13.7% Item 4(c)(i): 6,454,631 Item 4(c)(ii):* 1,342,657 Item 4(c)(iii): 11,489,411 Item 4(c)(iv): 0 Item 5: Not Applicable Item 6: The security referred to in this schedule is held for the accounts of discretionary clients. These clients have the right to receive dividends from and the proceeds of the sale of such security. Item 7: Not Applicable Item 8: Not Applicable Item 9: Not Applicable Item 10: 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. * Sanford C. Bernstein & Co., Inc. clients who have appointed an independent voting agent with instructions to vote shares in the same manner as Sanford C. Bernstein & Co., Inc. Schedule G Under the Securities Exchange Act of 1934 Page Two 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. February 8, 2000 Date /s/ Michael Borgia Signature Michael Borgia, Senior Vice President Name/Title