[LETTERHEAD GRAY CARY WARE & FREIDENRICH, LLP]
 
                                                                       EXHIBIT 5
 
                                 August 6, 1998
 
Securities and Exchange Commission
450 Fifth Street, N.W.
Washington, D.C. 20549
 
Ladies and Gentlemen:
 
    As legal counsel for Network Computing Devices, Inc., a California
corporation (the "Company"), we are rendering this opinion in connection with
the registration under the Securities Act of 1933, as amended, of up to 700,000
shares of the Common Stock, no par value, of the Company which may be issued
pursuant to the exercise of options and purchase rights granted under the
Network Computing Devices, Inc. 1989 Stock Option Plan and the 1992 Employee
Stock Purchase Plan (the "Plans").
 
    We have examined all instruments, documents and records which we deemed
relevant and necessary for the basis of our opinion hereinafter expressed. In
such examination, we have assumed the genuineness of all signatures and the
authenticity of all documents submitted to us as originals and the conformity to
the originals of all documents submitted to us as copies. We are admitted to
practice only in the State of California and we express no opinion concerning
any law other than the law of the State of California and the federal law of the
United States.
 
    Based on such examination, we are of the opinion that the 700,000 shares of
Common Stock which may be issued upon exercise of options and purchase rights
granted under the Plans are duly authorized shares of the Company's Common
Stock, and, when issued against receipt of the consideration therefor in
accordance with the provisions of the Plans will be validly issued, fully paid
and nonassessable. We hereby consent to the filing of this opinion as an exhibit
to the Registration Statement referred to above and the use of our name wherever
it appears in said Registration Statement.
 
                                          Respectfully submitted,
 
                                          /s/ Gray Cary Ware & Freidenrich
                                          GRAY CARY WARE & FREIDENRICH LLP