SCHEDULE 13D Amendment No. 23 Quantum Corporation Common Stock Cusip # 747906105 Filing Fee: No Cusip # 747906105 Item 1: Reporting Person - FMR Corp. - (Tax ID: 04-2507163) Item 4: PF Item 6: Commonwealth of Massachusetts Item 7: None Item 8: None Item 9: 3,096,100 Item 10: None Item 11: 3,096,100 Item 13: 5.99% Item 14: HC PREAMBLE The filing of this Schedule 13D is not, and should not be deemed to be, an admission that such Schedule 13D is required to be filed. See the discussion under Item 2. Item 1. Security and Issuer. This statement relates to shares of the Common Stock, $0.01 par value (the "Shares") of Quantum Corporation, a Delaware corporation (the "Company"). The principal executive offices of the Company are located at 500 McCarthy Boulevard, Milpitas, CA 95035. Item 2. Identity and Background. Item 2 is amended as follows: This statement is being filed by FMR Corp., a Massachusetts Corporation ("FMR"). FMR is a holding company one of whose principal assets is the capital stock of a wholly-owned subsidiary, Fidelity Management & Research Company ("Fidelity"), which is also a Massachusetts corporation. Fidelity is an investment advisor which is registered under Section 203 of the Investment Advisors Act of 1940 and which provides investment advisory services to more than 30 investment companies which are registered under Section 8 of the Investment Company Act of 1940 and serves as investment advisor to certain other funds which are generally offered to limited groups of investors (the "Fidelity Funds"). Fidelity Management Trust Company ("FMTC"), a wholly- owned subsidiary of FMR Corp. and a bank as defined in Section 3(a)(6) of the Securities Exchange Act of 1934, serves as trustee or managing agent for various private investment accounts, primarily employee benefit plans and serves as investment adviser to certain other funds which are generally offered to limited groups of investors (the "Accounts"). Various directly or indirectly held subsidiaries of FMR are also engaged in investment management, venture capital asset management, securities brokerage, transfer and shareholder servicing and real estate development. The principal offices of FMR, Fidelity, and FMTC are located at 82 Devonshire Street, Boston, Massachusetts 02109. Members of the Edward C. Johnson 3d family are the predominant owners of Class B shares of common stock representing approximately 49% of the voting power of FMR Corp. Mr. Johnson 3d owns 12.0% and Abigail Johnson owns 24.5% of the aggregate outstanding voting stock of FMR Corp. The Johnson family group and all other Class B shareholders have entered into a shareholders' voting agreement under which all Class B shares will be voted in accordance with the majority vote of Class B shares. Accordingly, through their ownership of voting common stock and the execution of the shareholders' voting agreement, members of the Johnson family may be deemed, under the Investment Company Act of 1940, to form a controlling group with respect to FMR Corp. Mr. Johnson 3d is Chairman of FMR Corp. The business address and principal occupation of Mr. Johnson 3d is set forth in Schedule A hereto. The Shares to which this statement relates are owned directly by three of the Fidelity Funds, and one of the Accounts. The name, residence or business address, principal occupation or employment and citizenship of each of the executive officers and directors of FMR are set forth in Schedule A hereto. Within the past five years, none of the persons named in this Item 2 or listed on Schedule A has been convicted in any criminal proceeding (excluding traffic violations or similar misdemeanors) or has been a party to any civil proceeding and as a result thereof was or is subject to any judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to federal or state securities laws or finding any violations with respect to such laws. Item 3. Source and Amount of Funds or Other Consideration. Item 3 is amended as follows: The Fidelity Funds which own or owned Shares purchased in the aggregate 24,784,525 Shares for cash in the amount of approximately $367,995,758, including brokerage commissions. The Fidelity Funds used their own assets in making such purchase and no part of the purchase price is represented by borrowed funds. Proceeds from 21,717,625 Shares sold aggregated approximately $347,259,780. The attached Schedule B sets forth Shares purchased and/or sold since September 16, 1995. The Accounts of FMTC which own or owned Shares purchased in the aggregate 1,009,895 Shares for cash in the amount of approximately $17,563,998, including brokerage commissions. The Accounts used their own assets in making such purchase and no part of the purchase price is represented by borrowed funds. Proceeds from 989,511 Shares sold aggregated approximately $15,049,228. Item 4. Purpose of Transaction. Item 4 is amended as follows: The purpose of Fidelity and FMTC in having the Fidelity Funds and the Accounts purchase Shares is to acquire an equity interest in the Company in pursuit of specified investment objectives established by the Board of Trustees of the Fidelity Funds and by the investors in the Accounts. Fidelity and FMTC, respectively, may continue to have the Fidelity Funds and the Accounts purchase Shares subject to a number of factors, including, among others, the availability of Shares of sale at what they consider to be reasonable prices and other investment opportunities that may be available to the Fidelity Funds and Accounts. Fidelity and FMTC, respectively, intend to review continuously the equity position of the Fidelity Funds and Accounts in the Company. Depending upon future evaluations of the business prospects of the Company and upon other developments, including, but not limited to, general economic and business conditions and money market and stock market conditions, Fidelity may determine to cease making additional purchases of Shares or to increase or decrease the equity interest in the Company by acquiring additional Shares, or by disposing of all or a portion of the Shares. Neither Fidelity nor FMTC has any present plan or proposal which relates to or would result in (i) an extraordinary corporate transaction, such as a merger, reorganization, liquidation, or sale of transfer of a material amount of assets involving the Company or any of its subsidiaries, (ii) any change in the Company's present Board of Directors or management, (iii) any material changes in the Company's present capitalization or dividend policy or any other material change in the Company's business or corporate structure, (iv) any change in the Company's charter or by-laws, or (v) the Company's common stock becoming eligible for termination of its registration pursuant to Section 12(g)(4) of the 1934 Act. Item 5. Interest in Securities of Issuer. Item 5 is amended as follows: FMR, Fidelity, and FMTC, beneficially own all 3,096,100 Shares. (a) FMR beneficially owns, through Fidelity, as investment advisor to the Fidelity Funds, 3,066,900 Shares, or approximately 5.94% of the outstanding Shares of the Company, and through FMTC, the managing agent for the Accounts, 29,200 Shares, or approximately 0.06% of the outstanding Shares of the Company. Neither FMR, Fidelity, FMTC, nor any of its affiliates nor, to the best knowledge of FMR, any of the persons name in Schedule A hereto, beneficially owns any other Shares. The combined holdings of FMR, Fidelity, and FMTC, are 3,096,100 Shares, or approximately 5.99% of the outstanding Shares of the Company. (b) FMR, through its control of Fidelity, investment advisor to the Fidelity Funds, and the Funds each has sole power to dispose of the Shares. Neither FMR nor Mr. Johnson has the