<PAGE>
EXHIBIT 5.1
[LETTERHEAD OF FOLEY, HOAG & ELIOT LLP]
November 13, 2000
PRI Automation, Inc.
805 Middlesex Turnpike
Billerica, Massachusetts 01821
Ladies and Gentlemen:
We are familiar with the Registration Statement on Form S-8 (the "S-8
Registration Statement") filed today by PRI Automation, Inc., a Massachusetts
corporation (the "Company"), with the Securities and Exchange Commission under
the Securities Act of 1933, as amended. The S-8 Registration Statement relates
to the proposed offering by the Company of shares (the "Shares") of its Common
Stock, $0.01 par value per share ("Common Stock"), issuable pursuant to the
following plans: (a) Commotion Technology, Inc. 1998 Flexible Incentive Plan,
and (b) Commotion Technology, Inc. 2000 Flexible Stock Incentive Plan
(collectively, the "Plans").
In arriving at the opinions expressed below, we have examined and
relied on the following documents: (a) the Restated Articles of Organization of
the Company, as amended, and the Amended and Restated By-Laws of the Company;
(b) the records of meetings and consents of the Board of Directors and
stockholders of the Company provided to us by the Company; and (c) the Plans. In
addition, we have examined and relied on the originals or copies certified or
otherwise identified to our satisfaction of all such corporate records of the
Company and such other instruments and other certificates of public officials,
officers and representatives of the Company and such other persons, and we have
made such investigations of law, as we have deemed appropriate as a basis for
the opinions expressed below.
Based upon the foregoing, it is our opinion that:
1. the Company has corporate power adequate for the issuance of the
Shares in accordance with the S-8 Registration Statement;
2. the Company has taken all necessary corporate action required to
authorize the issuance and sale of the Shares; and
3. when certificates for the Shares have been duly executed and
countersigned, and delivered against due receipt of the exercise price for the
Shares as described in the Plans and any options relating to such Plans, the
Shares will be validly and legally issued, fully paid and non-assessable.
-20-
<PAGE>
We hereby consent to the filing of this opinion as an exhibit to the
S-8 Registration Statement.
Very truly yours,
FOLEY, HOAG & ELIOT LLP
By: /s/ William R. Kolb
-------------------
A Partner
-21-
