Exhibit 5.1


                                  July 1, 1997

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 2, 1997 (the
"Registration  Statement"),  in  connection  with  the  registration  under  the
Securities  Act of 1933,  as amended,  of  5,234,578  additional  shares of your
Common  Stock,  par value $.01 per share (the  "Shares"),  reserved for issuance
pursuant to the 1993 Long-Term  Incentive Plan (the "Plan").  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 Plan.

         It is our  opinion,  when issued and sold in the manner  referred to in
the Plan,  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,

                                        WILSON, SONSINI, GOODRICH & ROSATI
                                        Professional Corporation