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                                                                     EXHIBIT 5.1

                 [Letterhead of Goodwin, Procter & Hoar LLP] 






                               October 10, 1997



Alpha-Beta Technology, Inc.
Three Biotech Park
One Innovation Drive
Worcester, Massachusetts  01605

         Re:   THE ALPHA-BETA TECHNOLOGY, INC. 1997 STOCK OPTION AND GRANT PLAN

Ladies and Gentlemen:

         This opinion is furnished in connection with the registration pursuant
to the Securities Act of 1933, as amended (the "Act"), of 837,165 shares (the
"Shares") of Common Stock, par value $.01 per share (the "Common Stock"), of
Alpha-Beta Technology, Inc. (the "Company") which may be issued pursuant to the
Company's 1997 Stock Option and Grant Plan (the "Plan").

         We have acted as counsel to the Company in connection with the
registration of the Shares under the Act. We have examined the Amended and
Restated Articles of Organization and the By-laws of the Company, each as
amended to date; such records of the corporate proceedings of the Company as we
deemed material; the Registration Statement on Form S-8 under the Act relating
to the Shares to be filed with the Securities and Exchange Commission on the
date hereof (the "Registration Statement"); and such other certificates,
receipts, records and documents as we considered necessary for the purposes of
this opinion.

         We are attorneys admitted to practice in The Commonwealth of
Massachusetts. We express no opinion concerning the laws of any jurisdictions
other than the laws of the United States of America and The Commonwealth of
Massachusetts.

         Based upon the foregoing, we are of the opinion that upon the issuance
and delivery of the Shares in accordance with the terms of the Registration
Statement and the Plan, the Shares will be legally issued, fully paid and
non-assessable.




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         The foregoing assumes that all requisite steps will be taken to comply
with the requirements of the Act and applicable requirements of state laws
regulating the offer and sale of securities.

         We hereby consent to the filing of this opinion as part of the
above-referenced Registration Statement and to the use of our name therein.

                                              Very truly yours,

                                              /s/ Goodwin, Procter & Hoar LLP

                                              GOODWIN, PROCTER & HOAR LLP




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