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                                                                     EXHIBIT 5.1



                         [COOLEY GODWARD LLP LETTERHEAD]



March 12, 1998

JTS Corporation
166 Baypointe Parkway
San Jose, California  95134


Ladies and Gentlemen:

You have requested our opinion with respect to certain matters in connection
with the filing by JTS Corporation (the "Company") of a Registration Statement
on Form S-8 (the "Registration Statement") with the Securities and Exchange
Commission covering the offering of up to an additional 5,000,000 shares of the
Company's Common Stock, $.001 par value, (the "Plan Shares") pursuant to its
1995 Amended and Restated Stock Option Plan (the "Plan") and up to 7,000,000
shares of the Company's Common Stock $.001 par value, (the "ESPP Shares")
pursuant to its 1997 Employee Stock Purchase Plan (the "ESPP").

In connection with this opinion, we have examined the Registration Statement and
related Prospectus, your Certificate of Incorporation and By-laws, as amended,
and such other documents, records, certificates, memoranda and other instruments
as we deem necessary as a basis for this opinion. We have assumed the
genuineness and authenticity of all documents submitted to us as originals, the
conformity to originals of all documents submitted to us as copies thereof, and
the due execution and delivery of all documents where due execution and delivery
are a prerequisite to the effectiveness thereof.

On the basis of the foregoing, and in reliance thereon, we are of the opinion
that the Plan Shares and the ESPP Shares, when sold and issued in accordance
with the Plan and the ESPP, respectively, the Registration Statement and related
Prospectus, will be validly issued, fully paid, and nonassessable (except as to
shares issued pursuant to certain deferred payment arrangements, which will be
fully paid and nonassessable when such deferred payments are made in full).

We consent to the filing of this opinion as an exhibit to the Registration
Statement.

Very truly yours,

COOLEY GODWARD LLP



By:     /s/ ANDREI M. MANOLIU
   ----------------------------
        ANDREI M. MANOLIU