Exhibit 5.1


                                 July 27, 2000

Quantum Corporation
500 McCarthy Boulevard
Milpitas, CA 95035

     RE:  REGISTRATION STATEMENT ON FORM S-8

Ladies and Gentlemen:

     We have examined the Registration Statement on Form S-8 to be filed by you
with the Securities and Exchange Commission on or about July 26, 2000 (the
"Registration Statement"), in connection with the registration under the
Securities Act of 1933, as amended, of 5,027,013 shares of Quantum Corporation--
HDDG Common Stock, par value $.01 per share, and 9,445,182 shares of Quantum
Corporation--DSSG Common Stock, par value $0.01 per share (the "Shares"),
reserved for issuance pursuant to the 1993 Long-Term Incentive Plan and the
Employee Stock Purchase Plan (the "Plans"). As your counsel in connection with
the transaction, we have examined the proceedings taken and are familiar with
the proceedings proposed to be taken by you in connection with the sale and
issuance of the Shares pursuant to the Plans.

     It is our opinion, when issued and sold in the manner referred to in the
Plans, the Shares will be legally and validly issued, fully paid and
nonassessable.

     We consent to the use of this opinion as an exhibit to the Registration
Statement and further consent to the use of our name wherever appearing in the
Registration Statement and any amendment thereto.

                                        Very truly yours,

                                        /s/ WILSON SONSINI GOODRICH & ROSATI
                                        Professional Corporation