This document is a copy of the legal opinion filed on paper on April 15, 1994. CHOATE, HALL & STEWART A Partnership Including Professional Corporations EXCHANGE PLACE 53 STATE STREET BOSTON, MASSACHUSETTS 02109-2891 TELEPHONE (617) 248-5000 FACSIMILE (617) 248-4000 TELEX 49615860 April 14, 1994 Stratus Computer, Inc. 55 Fairbanks Boulevard Marlborough, MA 01752 Gentlemen: This opinion is delivered to you in connection with a registration statement on Form S-3 (the "Registration Statement") to be filed on April 15, 1994, by Stratus Computer, Inc. (the "Company") under the Securities Act of 1933, as amended, for registration under said Act of 410,607 shares of Common Stock, $.01 par value per share (the "Common Stock") of the Company. Terms not otherwise defined herein shall be deemed to have the meaning ascribed such term in the Registration Statement. In connection with rendering this opinion, we have examined such corporate records, certificates and other documents as we have considered necessary for the purposes of this opinion. In such examination, we have assumed the genuineness of all signatures, the authenticity of all documents submitted to us as originals, the conformity to the original documents of all documents submitted to us as copies and the authenticity of the originals of such latter documents. As to any facts material to our opinion, we have, when relevant facts were not independently established, relied upon the aforesaid records, certificates and documents. Based upon the foregoing, we are of the opinion that the shares of Common Stock to be sold by the Selling Stockholders are and, when sold by the Selling Stockholders, will be, legally issued, fully paid and non-assessable. We hereby consent to be named in the Registration Statement and in any amendments thereto as counsel for the Company, to the statements with reference to our firm made in the Registration Statement, and to the filing and use of this opinion as an exhibit to the Registration Statement. Very truly yours, CHOATE, HALL & STEWART