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                                                                   Exhibit 10.52

                         SECOND ASSIGNMENT OF SUBLEASE

THIS SECOND ASSIGNMENT OF SUBLEASE (this "Second Assignment") is entered into as
of the 17th day of December, 1999, by and between Mack Technologies, Inc., of 27
Carlisle Road, Westford, MA 01886, a Delaware corporation (hereinafter referred
to as "Mack"), and ACT Manufacturing Corporation, of 2 Cabot Road, Hudson,
Massachusetts 01749, a Massachusetts corporation (hereinafter referred to as
"ACT").

WHEREAS under a Net Lease dated December 15, 1986 (the "Original Master Lease"),
James A. Progin and Peter M. Small, Trustees of 401 Elm Street Realty Trust
(together, the "Original Master Landlord"), leased to Honeywell, Inc., a
Delaware corporation (the "Original Tenant"), property in Marlborough,
Massachusetts, as more particularly described in the Original Master Lease (the
"Master Leased Premises"); and

WHEREAS a Notice of Lease dated December 18, 1986, between the Original Master
Landlord and the Original Tenant, concerning the Original Master Lease, was
recorded with the Middlesex South Registry of Deeds at Book 17683, Page 310 (the
"Original Lease Notice").

WHEREAS the Original Master Landlord and the Original Tenant agreed to amend the
Original Master Lease by a First Amendment dated November 17, 1988 (the "First
Master Lease Amendment"); and

WHEREAS the Original Tenant assigned its rights, interests and obligations in,
to and under the Original Master Lease, as so amended, to Loral Corporation, a
New York corporation ("Loral"), by an Assignment and Assumption of Lease dated
December 31, 1989 (the "First Master Lease Assignment"); and

WHEREAS Loral assigned its rights, interests and obligations in, to and under
the Original Master Lease, as so amended, to Loral Infrared & Imaging Systems,
Inc., a Delaware corporation (the "Original Sublandlord"), by an Assignment and
Assumption of Lease dated December 31, 1989 (the "Second Master Lease
Assignment"); and

WHEREAS Lockheed Martin Corporation, a Maryland corporation ("Lockheed"),
assumed and succeeded to the Original Sublandlord's rights, interests and
obligations under the Master Lease, as so amended, and the Original Sublease
under an Assignment and Assumption of Lease and Development Agreement dated
April 19, 1997, between the Original Sublandlord and Lockheed, and recorded with
the Middlesex South Registry of Deeds at Book 27500, Page 405; and

WHEREAS the Original Master Landlord and Lockheed agreed to amend the Original
Master Lease, as so amended, by a Second Amendment to Lease dated as of April
19, 1997, and a Third Amendment to Master Lease dated as of July 17, 1997,
notice of which recorded with the Middlesex South Registry of Deeds at Book
27500, Page 408 (said amendments, together with the First Master Lease
Amendment, being the "Master Lease Amendments"); and

WHEREAS the Original Master Landlord assigned, transferred and conveyed to
Lepercq Corporate Income Fund, L.P., a Delaware limited partnership (the "Master
Landlord"), (a) the Master Lease Premises by a Quitclaim Deed dated as of July,
1997 and recorded with the Middlesex South
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Registry of Deeds on July 22, 1997, as Instrument No. 678, and (b) the
landlord's rights, interests and obligations in, to and under the Master Lease,
as so amended, under an Assignment and Assumption Agreement dated as of July 22,
1997, and recorded with said Registry on July 23, 1997, as Instrument No. 645
(together, the "Master Landlord's Transfers"); and

WHEREAS the Original Master Lease, as amended and affected by the Master Lease
Amendments and as assigned and affected by the First Master Lease Assignment,
the Second Master Lease Assignment and the Master Landlord's Transfers, is
hereinafter referred to as the "Master Lease", a copy of which is attached to
this Second Assignment as a part of Exhibit A; and

WHEREAS under a Sublease Agreement dated October 16, 1992 (the "Original
Sublease"), the Original Sublandlord subleased to Stratus Computer, Inc., a
Massachusetts corporation ("Stratus"), a portion of the Master Leased Premises,
including the building commonly known as 401 Elm Street, Marlborough,
Massachusetts, as more particularly described in the Original Sublease (the
"Premises"); and

WHEREAS the Original Master Landlord consented to the execution of the Original
Sublease under a Consent of Master Landlord dated as of December 1992; and

WHEREAS Stratus assigned its rights, interests and obligations in, to and under
the Original Sublease to Mack by an Assignment of Sublease dated as of January
31, 1996 (the "First Sublease Assignment"); and

WHEREAS the Original Sublandlord consented to the First Sublease Assignment
under a Consent and Agreement dated January 31, 1996, among the Original
Sublandlord, Stratus and Mack, and the Original Master Landlord consented to the
First Sublease Assignment under a Consent and Agreement dated as of January 24,
1996, among the Original Master Landlord, Stratus and Mack (said instruments
entitled Consent and Agreement, together, being the "First Sublease Assignment
Consents"); and

WHEREAS Lockheed and Mack agreed to amend the Original Sublease, as so assigned,
under an agreement dated October 2, 1997 (the "Extension Amendment", a copy of
which is not included in Exhibit B); and

WHEREAS Lockheed and Mack agreed to amend the Original Sublease, as so assigned,
under a First Amendment to Sublease dated as of February 5, 1998 (the "Sublease
Amendment"; the Original Sublease, as assigned and affected by the First
Sublease Assignment, as affected by the First Sublease Assignment Consents and
as amended and affected by the Extension Amendment and the Sublease Amendment,
being hereinafter referred to as the "Sublease", a copy of which is attached to
this Second Assignment as Exhibit B); and

WHEREAS, Mack wishes to assign and transfer its rights, interests and
obligations under the Sublease to ACT as of January 1, 2000 (the "Effective
Date"), and ACT wishes to accept such assignment and transfer and assume all of
Mack's rights and obligations arising or accruing under the Sublease on and
after the Effective Date, on the terms and conditions of this Second Assignment;
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NOW, THEREFORE, in consideration of the mutual covenants set forth in this
Second Assignment, and for other good and valuable consideration, the receipt
and sufficiency of which Mack and ACT acknowledge, Mack and ACT agree as
follows:

1.  As of the Effective Date, Mack hereby assigns and transfers to ACT its
rights, interests and obligations arising or accruing under the Sublease on and
after the Effective Date, and ACT hereby accepts such assignment and transfer
and accepts all of Mack's rights, interests and obligations arising or accruing
under the Sublease on and after the Effective Date; provided, however, ACT shall
not have the right to extend the Sublease for the Second Extended Term (as
defined in the Sublease), unless Mack has received from Lockheed and Stratus,
respectively, an irrevocable release and discharge of Mack from all liabilities
and obligations to Lockheed or Stratus, as the case may be, arising or accruing
during such Second Extended Term (the "Release"), except with respect to any
Mack indemnity applicable to Mack's use of hazardous or toxic substances or oil
on the Premises.

2.  Beginning on the date of this Second Assignment, ACT shall have access to
the Premises for the sole purpose performing inspections, alterations,
improvements, installations and other work necessary or desired by ACT to
prepare the Premises for ACT's use and occupancy (collectively, "ACT's Work").
All of ACT's Work shall be undertaken by ACT in strict compliance with the terms
of the Sublease, and ACT shall not proceed to undertake any ACT's Work in the
Premises without first obtaining any approvals required under the Sublease, as
if performed after the Effective Date, nor undertake any other activity on or
about the Premises except in full compliance with the terms of the Sublease as
if ACT was then the sublessee thereunder.  If either Mack or ACT exercise their
respective rights to terminate this Second Assignment under Sections 11 of this
Second Assignment, or if ACT exercises its right to terminate this Second
Assignment under Section 12 of this Second Assignment, Mack may, at its option,
by written notice to ACT within 30 days after such termination, require ACT to
remove any or all of ACT's Work at ACT's expense.  ACT shall hold Mack harmless
from and against any and all costs or expenses associated with the removal of
ACT's Work and the restoration of the Premises to its original condition,
including, without limitation, any reasonable attorneys' fees and expenses
incurred to enforce this Section 2 or to collect such costs or expenses from
ACT.

3.  (a)  The amount of One Hundred Fifty-three Thousand Five Hundred Ten Dollars
($153,510.00) (the "Security Deposit") shall be paid to Mack by ACT upon
execution of this Second Assignment as security for ACT's performance under the
Sublease and under this Second Assignment.  Mack shall deposit the Security
Deposit in a separate, segregated, interest-bearing money-market account
identified as holding ACT's funds and shall pay all interest accruing on such
account to ACT no less frequently than annually.  If ACT fails to pay any
amounts due from the subtenant under the Sublease or otherwise fails to perform
any other obligation of ACT under the Sublease, Mack may use, apply or retain
all or any portion of the Security Deposit to the extent necessary to pay any
rent or other charge past due or any cost or expense which Mack may incur by
reason of ACT's default under the Sublease or this Agreement or to compensate
Mack for any loss or damage which Mack may suffer by reason of such failure of
ACT.  If Mack so uses or applies all or any portion of the Security Deposit, ACT
shall, within ten (10) days after written demand therefor, deposit cash with
Mack in an amount sufficient to restore the Security Deposit to the full amount
required under this Agreement.  Within thirty (30) days following expiration of
the Sublease, Mack shall return the Security Deposit, less any amounts properly
used, applied or retained under this Section 3.
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     (b) Upon receipt by Mack and ACT of all Consents (as hereinafter defined)
and the Release, Mack shall promptly pay the Security Deposit to Lockheed, to be
held as a security deposit and returned in accordance with the terms of the
Consent to be executed by Lockheed and ACT, at which time Mack shall be released
from all further obligations to ACT with respect to the Security Deposit.  If
either Mack or ACT exercise their respective rights to terminate this Second
Assignment under Sections 11 of this Second Assignment, or if ACT exercises its
right to terminate this Second Assignment under Section 12 of this Assignment,
Mack shall, within 30 days after such termination, return the Security Deposit
to ACT, after first deducting from the Security Deposit any costs and expenses
payable to Mack under Section 2 above.

4.  Subject to receipt of all Consents, Mack shall pay to ACT on the Effective
Date the amount of Three Hundred Seventy-eight Thousand Dollars ($378,000.00) as
an allowance for alterations and improvements to the Premises contemplated by
the ACT.

5.  To the best of its knowledge, Mack represents and warrants to ACT that:

(a)  The copy of the Master Lease attached hereto as Exhibit A is complete and
     accurate copy of the Master Lease, which has not been amended except as set
     forth in said Exhibit A, and represents the entire agreement between
     Lockheed and the Master Landlord with respect to the Premises;

(b)  The Master Lease is in full force and effect and is enforceable against the
     Master Landlord and Lockheed in accordance with the terms set forth in said
     Exhibit A;

(c)  The Master Landlord is the holder of the landlord's rights, interests and
     obligations under the Master Lease, and Lockheed is the holder of the
     tenant's rights, interests and obligations under the Master Lease, and such
     rights, interests and obligations have not been assigned except as set
     forth in said Exhibit A; and

(d)  Mack has no knowledge of a default by the Master Landlord or Lockheed under
     the Master Lease or any event which, after the giving of any applicable
     notice and the expiration of any applicable cure period, would ripen into a
     default under the Master Lease.

6.  Mack warrants and represents to ACT that


(a)  The copy of the Sublease attached hereto as Exhibit B is complete and
     accurate copy of the Sublease, which has not been amended except as set
     forth in said Exhibit B, and represents the entire agreement between
     Lockheed and Mack with respect to the Premises;

(b)  The Extension Amendment did not amend or otherwise affect the Sublease in
     any way other than an extension of the Initial Term (as defined in the
     Sublease) by one month to April 30, 1998;
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(c)  The Sublease is in full force and effect and is enforceable against the
     sublandlord in accordance with the terms set forth in said Exhibit B;

(d)  To the best of its knowledge, Lockheed is the holder of the sublandlord's
     rights, interests and obligations under the Sublease, and Mack is the
     holder of the subtenant's rights, interests and obligations under the
     Sublease, and such rights, interests and obligations have not been
     assigned, mortgaged or otherwise encumbered except as set forth in said
     Exhibit B;

(e)  Mack has no knowledge of a default by Lockheed under the Sublease or any
     event which, after the giving of any applicable notice and the expiration
     of any applicable cure period, would ripen into a default by Lockheed under
     the Sublease;

(f)  Mack is not in default under the Sublease, nor has any event occurred
     which, after the giving of any applicable notice and the expiration of any
     applicable cure period, would ripen into a default by Mack under the
     Sublease;

(g)  All rent, additional rent and other charges due under the Sublease have
     been or will be paid as billed or required in the normal course through
     December 31, 1999;

(h)  All improvements installed on the Premises by Mack prior to the date of
     this Second Assignment comply with all building codes now in effect or are
     otherwise acceptable to governmental authorities by irrevocable waiver or
     exemption from the current building code; and Mack shall indemnify and hold
     harmless ACT from and against (1) any costs or expenses incurred by ACT in
     connection with (a) the removal of any such improvements, if required by
     any governmental authority due to non-compliance with the current building
     code, and (b) the installation of compliant replacement improvements, and
     (2) any claim by any governmental authority or Lockheed or the Master
     Landlord (or their respective successors in interest under the Sublease and
     the Master Lease) by reason of any improvements which are determined not to
     be in compliance with any applicable building code, provided that ACT
     present Mack with an estimate of the cost to rectify the situation; and
     should Mack not agree with such estimate, Mack may so notify ACT within 30
     days after receipt of such estimate and, at its expense, correct the
     situation as required by the applicable governmental authority or Lockheed
     or the Master Landlord; and

(i)  Neither Mack nor its officers, shareholders, employees, agents, contractors
     or invitees have released, discharged or otherwise allowed the emission of
     Hazardous Materials (as hereinafter defined) at the Premises.

7.  Subject to Section 12 of this Second Assignment, and except with respect to
existing environmental conditions, ACT accepts the Premises "AS IS", and the
taking of possession or use of the Premises by ACT for any purpose shall
conclusively establish that ACT has inspected the Premises and accepts them as
being in good and sanitary order, condition and repair.  ACT acknowledges that
neither Mack nor any of Mack's brokers or agents has made any representations or
warranties as to the suitability or fitness of the Premises for the conduct of
ACT's business, or for
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any other purpose, except as set forth in this Second Assignment, and that
neither Mack nor any of Mack's agents has agreed to undertake any alterations or
additions or construct any improvements to the Premises, except for the payment
of the allowance under Section 4 of this Second Assignment.

8.  Mack shall pay and perform, and shall indemnify and hold harmless ACT from
and against, all obligations of the sublessee under the Sublease arising or
accruing before the Effective Date.  ACT shall pay and perform, and shall
indemnify and hold harmless Mack from and against, all obligations and
liabilities of the sublessee under the Sublease arising or accruing after the
Effective Date.

9.  All of the rights, interests and obligations of the sublessee under the
Sublease may be reassigned by ACT and any subsequent assignee, but only with (a)
the prior written consent of Lockheed and the Master Landlord, or their
respective successors in interest under the Master Lease, and (b) if Mack has
not then received the Release, the prior written consent of Mack, but only if
the net worth of the assignee is less than the net worth of ACT as of the date
of this Second Assignment, which consent Mack shall not unreasonably withhold,
delay or condition.

10.  Mack and ACT each represent and warrant to the other that Spaulding & Slye
("Broker") is the only real estate broker with whom it has dealt in connection
with this Second Assignment.  Mack and ACT shall each indemnify and hold
harmless the other from any and all damages, cost, and expenses (including but
not limited to reasonable attorneys' fees and disbursements) incurred as a
result of any claim by any real estate broker, finder, or other person (other
than Broker) alleging to have dealt with the indemnifying party in connection
with this Second Assignment.  Mack shall be responsible for the payment of any
real estate brokerage commissions due to Broker as a result of entering into
this Second Assignment.

11.  The assignment of the rights, interests and obligations of the sublessee
under the Sublease and the respective rights and obligations of Mack and ACT
under Sections 1 and 8 of this Second Assignment are subject to, and shall be
effective only upon receipt of, a Consent and Agreement, in form and substance
acceptable to Mack and ACT, executed by Mack, ACT and each of Stratus, Lockheed,
and the Master Landlord (collectively, the "Consents").  If Mack and ACT do not
receive all of the consents on or before the Effective Date, then either Mack or
ACT shall have the right to terminate this Second Assignment by written notice
to the other party.

12.  Before the Effective Date, ACT shall have the right to enter upon the
Premises to complete such tests, inspections and assessments of the soil, water,
groundwater, air and improvements on or under the Premises, including without
limitation a determination of the presence of any Hazardous Materials (as
hereinafter defined), and to prepare such reports evaluating the results of such
tests, inspections and assessments and the compliance of the Premises with
Environmental Laws (as hereinafter defined).  "Environmental Laws" shall mean
any federal, state and local statutes, laws, codes, rules, regulations,
ordinances, by-laws, judgments, orders, standards, permits, licenses and
requirements pertaining to the protection, preservation, conservation or
regulation of the environment and human health.  "Hazardous Materials" shall
mean any petroleum, petroleum products, asbestos, asbestos-containing materials,
polychlorinated biphenyls, radioactive materials and any other hazardous,
dangerous or toxic chemicals, materials, wastes, pollutants, contaminants or
other substances, the use, exposure, release, emission, discharge, generation,
manufacture, sale, transport, handling, storage, treatment, presence, disposal
or recycling of which is regulated under
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any Environmental Law. If the results of such tests, inspections, assessments,
determinations, evaluations or reports is unsatisfactory to ACT, in its sole
discretion, ACT shall have the right to terminate this Second Assignment by
written notice to Mack at any time before the Effective Date.

Mack and ACT execute this Second Assignment under seal as of the day and year
first written above.

FOR MACK TECHNOLOGIES, INC.:            FOR ACT MANUFACTURING CORPORATION:

Signature: /s/ Ron Jellison             Signature: /s/ Jeffrey B. Lavin
           -----------------                       ----------------------
Print Name:  Ron Jellison               Name: Jeffrey B. Lavin
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Title:  President/Vice President        Title: Vice President and Treasurer


Signature:  /s/ Florence M. Belnap
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Print Name:  Florence M. Belnap
            --------------------
Title:  Treasurer/Assistant Treasurer