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                                                                     EXHIBIT 5.1

                                PERKINS COIE LLP
          1201 THIRD AVENUE, 40TH FLOOR SEATTLE, WASHINGTON 98101-3099
                 TELEPHONE: 206 583-8888 FACSIMILE: 206 583-8500


                                December 17, 1998

Wall Data Incorporated
11332 N.E. 122nd Way
Kirkland, WA  98034-6931

        RE:    150,000 SHARES OF COMMON STOCK (NO PAR VALUE) OF
               WALL DATA INCORPORATED (THE "COMPANY")

Ladies and Gentlemen:

        We have acted as counsel to you in connection with the preparation of a
Registration Statement on Form S-8 (the "Registration Statement") pursuant to
the Securities Act of 1933, as amended (the "Act"), which you are filing with
the Securities and Exchange Commission with respect to 150,000 shares of Common
Stock, no par value (the "Shares"), of Wall Data Incorporated (the "Company"),
which are to be issued pursuant to the Company's 1994 Nonofficer Stock Option
Plan As Amended and Restated on October 15, 1996.

        We have examined the Registration Statement and such other documents and
records of the Company as we have deemed relevant and necessary for the purposes
of this opinion. In giving this opinion, we are assuming the authenticity of all
instruments presented to us as originals, the conformity with originals of all
instruments presented to us as copies and the genuineness of all signatures.

        Based upon and subject to the foregoing, we are of the opinion that the
Shares that will be issued pursuant to the Plan, upon the due execution by the
Company and the registration by its registrar of the Shares and the issuance
thereof by the Company 


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Wall Data Incorporated
December 17, 1998
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in accordance with the terms of the Plan, and the receipt of consideration
therefor in accordance with the terms of the Plan, will be validly issued,
fully paid and nonassessable.

        We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement. In giving such consent, we do not admit that we are in
the category of persons whose consent is required under Section 7 of the Act.

                                            Very truly yours,


                                            PERKINS COIE LLP