<PAGE>
                                                                   EXHIBIT 10.56


                    LIMITED GUARANTY AND SURETYSHIP AGREEMENT


                                                               Contract No. 2911
--------------------------------------------------------------------------------

       THIS LIMITED GUARANTY AND SURETYSHIP AGREEMENT (this "AGREEMENT") is
entered into effective as of JULY 24, 2001 by PSC DEVELOPMENT COMPANY, L.L.C., A
DELAWARE LIMITED LIABILITY COMPANY ("SURETY") to and for the benefit of DVI
FINANCIAL SERVICES INC. ("DVI").

                                   BACKGROUND

       A. DVI has agreed, or may in the future agree, to extend, maintain or
continue certain loans, leases or other credit facilities (collectively, the
"CREDIT FACILITIES") to or for the benefit of SOUTH SHORE OPERATING COMPANY,
L.L.C., a Delaware limited liability company (individually and collectively, the
"OBLIGOR").

       B. Surety has a direct or indirect economic interest in Obligor and
Surety will be directly and materially benefited by the extension of the Credit
Facilities by DVI to Obligor.

       C. DVI, as a condition to its agreement to extend, maintain or continue
such Credit Facilities to Obligor, and as a material inducement thereto, has
required that Surety execute this Agreement for all of the purposes hereinafter
set forth.

             NOW, THEREFORE, for good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged and affirmed, and intending to
be legally bound hereby, Surety agrees as follows:

             1.   SPECIFIC DEFINITIONS. As used in this Agreement, the following
terns (whether used in the plural or singular form) will mean:

                  "AFFILIATE" means, with respect to any Person, any other
Person that directly or indirectly Controls, is controlled by or is under common
Control with that Person.

                  "CONTROL" means (a) the ownership of a majority of the voting
power of all classes of voting stock of a corporation, (b) the ownership of a
majority of the beneficial interest in income and/or capital of a Person (other
than a corporation or an individual) or (c) possession, directly or indirectly,
of power to direct or cause the direction of management or policies (whether
through ownership of securities or other interests in a Person (other than an
individual), partnership, by contract or otherwise).

                  "EVENT OF DEFAULT" has the meaning specified in SECTION 6
hereof.

                  "GOVERNMENTAL AUTHORITY" means any governmental or political
subdivision or any agency, authority, bureau, central bank, commission,
department or instrumentality thereof, or any court, tribunal, grand jury or
arbitrator, in any case, whether foreign or domestic.

                  "GUARANTEED OBLIGATIONS" means (a) the due and punctual
payment and performance by each Obligor of its respective obligations with
respect to all loans, leases and other credit facilities owed by it to DVI or
any Affiliate of DVI, whether now existing or hereafter arising (including,
without limitation, those owed by Obligor to others and acquired by DVI or any
Affiliate of DVI by purchase, assignment, or otherwise) and whether direct or
indirect, primary or as guarantor or surety, absolute or contingent, liquidated
or unliquidated, matured or unmatured and (b) any of the foregoing that arises
after the filing of a petition by or against an Obligor, or any of them, under
the United States Bankruptcy Code even if the obligations do not accrue because
of the automatic stay under the United States Bankruptcy Code Section 362 or
otherwise and (c) the payment on demand of all Lender Expenses (as defined in
the Loan Documents).

                  "LOAN DOCUMENTS" means all certificates, documents,
instruments, agreements and riders delivered by any Obligor or any other Person
to DVI pursuant to the terms of, or otherwise in connection with, this Agreement
or any of the Guaranteed Obligations, as the same may be amended, increased,
decreased, modified, replaced, supplemented, renewed or extended from time to
time.


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                                                               Contract No. 2911


                  "MATERIAL ADVERSE EFFECT" means, with respect to Surety or any
event or circumstance, a material adverse change in (a) the business, assets,
financial condition or operations of Surety or (b) the ability of Surety to
perform the Guaranteed Obligations.

                  "PERSON" means an individual, corporation, partnership,
limited liability company, trust, unincorporated association, joint venture,
joint-stock company, government (including, without limitation, political
subdivisions), Governmental Authority or any other entity.

             2.   THE GUARANTY. Subject to the limitations on the amount of
Surety's liability hereunder as described in Rider A attached hereto, Surety
hereby irrevocably, unconditionally and absolutely guarantees to DVI, its
successors, endorsees and assigns (a) the prompt payment when due, whether at
maturity or upon earlier acceleration, of all Guaranteed Obligations and (b) the
prompt and complete compliance with and performance by each Obligor of all
covenants, agreements, indemnities and other obligations to be performed by each
Obligor pursuant to the terms of the Loan Documents.

             3.   GUARANTEED OBLIGATIONS ABSOLUTE AND UNCONDITIONAL. Subject to
the limitations on the amount of Surety's liability hereunder as described in
Rider A attached hereto, this Agreement will constitute an (a) agreement of
suretyship as well as of guaranty and (b) absolute and unconditional undertaking
by Surety with respect to the payment and performance of the Guaranteed
Obligations by each Obligor. The liability of Surety hereunder will be direct
and may be enforced without DVI being required to resort to any other right,
remedy or security. This Agreement will be enforceable against Surety, its
successors and assigns, without the necessity of any notice of (i) acceptance of
this Agreement, (ii) DVI's intention to act in reliance hereon, (iii) any loan,
lease or other credit facility to or other transaction between DVI and any
Obligor, or (iv) any default by any Obligor, all of which Surety hereby
expressly waives.

             4.   FURTHER UNDERTAKINGS.

                  (a) Surety expressly: (i) agrees that the validity of this
Agreement will in no way be terminated, affected or impaired by reason of the
assertion or the failure to assert by DVI against any Obligor, or its successors
or assigns, or any collateral securing the Guaranteed Obligations of any of the
rights or remedies reserved pursuant to the Loan Documents or otherwise
available to DVI at law or in equity, (ii) waives any right that Surety might
otherwise have under any statute, rule of law or practice or custom to require
DVI to take any action against any Obligor or to proceed against or exhaust any
security held by DVI before proceeding against Surety, (iii) except for notices
expressly required hereunder, waives any notice of (A) any presentment, demand,
protest, notice of protest and of dishonor, notices of default and all other
notices with respect to any of the Guaranteed Obligations and (B) the
commencement or prosecution of any enforcement proceeding, including any
proceeding in any court, against any Obligor or any other person or entity with
respect to any of the Guaranteed Obligations and (iv) agrees that any failure by
DVI to exercise any right hereunder will not be construed as a waiver of the
right to exercise the same or any other right at any other time and from time to
time thereafter.

                  (b) Until the earlier of (i) all of the Guaranteed Obligations
are completely fulfilled to the satisfaction of DVI and each and every one of
the terms, covenants, and conditions of this Agreement are fully performed, or
(ii) Surety has paid to DVI the full amount of its liability hereunder as
limited by the terms of Rider A attached hereto, the liability of Surety under
this Agreement will not be released, discharged or in any way impaired by: (i)
any amendment or modification of, supplement to or extension or renewal of any
Loan Document or any agreements made or to be made between DVI and any Obligor
with respect to any of the Guaranteed Obligations, (ii) any exercise or
non-exercise by DVI of any right, power, remedy or privilege under or with
respect to any Loan Document or this Agreement or any waiver, consent or
approval by DVI with respect to any of the covenants, terms, conditions or
agreements contained in any Loan Document, or any indulgence, forbearance or
extension of time for performance or observance allowed to any Obligor by DVI
from time to time and for any length of time, (iii) any bankruptcy, insolvency,
reorganization, arrangement, readjustment, composition, liquidation or similar
proceeding relating to any Obligor, its successors or assigns or any of their
respective properties, (iv) any transfer by an Obligor of all or any part of
that Obligor's interest in any collateral or (v) any act or circumstances which
might, but for the terms and provisions of this SECTION 4, be deemed a legal or
equitable discharge of Surety.

                  (c) Surety hereby expressly waives and surrenders any defenses
(other than satisfaction of the Guaranteed Obligations) to Surety's liability
hereunder based upon any of the foregoing acts, omissions, agreements or waivers
by DVI, it being the purpose and intent of this Agreement that the obligations
of Surety hereunder are absolute and unconditional.

                  (d) Surety hereby further agrees and consents that DVI may,
without affecting the liability of Surety hereunder: (i) exchange, surrender or
release any property pledged by any Obligor or any other Person or accept
additional security for the Guaranteed Obligations or any of them, (ii) renew,
extend and change the terms of any Guaranteed Obligation,



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                                                               Contract No. 2911


(iii) waive any of DVI's rights or remedies against any Obligor or any other
surety or guarantor for any Guaranteed Obligation, (iv) release, substitute or
add any one or more surety or other sureties or (v) proceed against Surety
without first resorting to, utilizing or invoking the remedies available against
any Obligor or any other surety or guarantor under the Loan Documents whether at
law or in equity. No enforcement of rights and remedies under this Agreement or
any of the Loan Documents will constitute an irrevocable election of remedies by
DVI. DVI will not be obligated to marshal remedies or assets as a condition to
enforcing the liabilities incurred hereunder against Surety. The liability of
Surety hereunder will be in addition to that stated in any other guaranty or
suretyship agreement, if any, heretofore or hereafter delivered to DVI.

                  (e) This Agreement and Surety's payment obligations hereunder
will continue to be effective or be reinstated, as the case may be, if at any
time payment of any of the Guaranteed Obligations is rescinded or must otherwise
be restored or returned by DVI all as though such payments had not been made.
DVI's good faith determination as to whether a payment must be restored or
returned shall be binding on Surety.

             5.   NO SUBROGATION. Nothing herein contained is intended or will
be construed to give Surety any right of subrogation in, to or under any Loan
Document or any right to participate in any way therein, notwithstanding any
payments by Surety to DVI hereunder. SURETY HEREBY IRREVOCABLY WAIVES ANY AND
ALL RIGHTS IT MAY HAVE AT ANY TIME (WHETHER ARISING DIRECTLY OR INDIRECTLY, BY
OPERATION OF LAW OR CONTRACT) TO ASSERT ANY CLAIM AGAINST ANY OBLIGOR ON ACCOUNT
OF PAYMENTS MADE UNDER THIS AGREEMENT, INCLUDING, WITHOUT LIMITATION, ANY AND
ALL RIGHTS OF SUBROGATION, REIMBURSEMENT, EXONERATION, CONTRIBUTION OR
INDEMNITY, UNLESS AND UNTIL THE GUARANTEED OBLIGATIONS ARE SATISFIED IN FULL.

             6.   EVENTS OF DEFAULT. Each of the following shall constitute an
"EVENT OF DEFAULT" hereunder:

                  (a) If there occurs an "Event of Default" under any other Loan
Document (whether or not an Obligor is a party thereto) and such event of
default is not remedied within the applicable notice, grace or cure period, if
any, provided in such other Loan Document,

                  (b) If Surety fails to observe or perform any covenant,
condition or agreement to be observed or performed hereunder and such failure is
not cured within thirty (30) days of written notice of such failure from DVI to
Surety. If such failure is capable of cure but cannot be cured within such
thirty (30) day period, Surety will have an additional thirty (30) days to cure
such failure, provided that Surety promptly commences such cure upon receipt of
the foregoing written notice and, at all times thereafter, diligently pursues
such cure. The notice and cure periods set forth in this SECTION 6(B) apply only
to the extent that the Event of Default in question is not specifically covered
by another subparagraph of this SECTION 6,

                  (c) If Surety revokes or attempts to revoke this Agreement or

                  (d) If a Material Adverse Effect occurs. All notice, grace and
cure periods provided herein shall run concurrently with all notice, grace and
cure periods provided in any other Loan Documents.

             7.   SET-OFF. DVI shall have a lien upon, a security interest in
and a right of set-off against all property of Surety now or at any time
hereafter in the possession of or under the control of DVI or any DVI Affiliate
in any capacity whatsoever, as security for this undertaking, provided that
Surety may deal with and/or dispose of such property prior to an Event of
Default hereunder. Each such lien, security interest and right of set-off may be
enforced or exercised without demand or notice to Surety, shall continue in full
force and effect unless specifically waived or released by DVI in writing and
shall not be deemed waived by any conduct of DVI, by any failure of DVI to
exercise any such right of set-off or to enforce any such lien or security
interest or by any neglect or delay in so doing.

             8.   REPRESENTATIONS AND WARRANTIES. Surety acknowledges that it
has received copies of, and read, all of the Loan Documents. Surety, by its
signature hereto, agrees to be bound by all of the terms, conditions,
representations, warranties and covenants set forth in the Loan Documents
applicable to Surety, all of which are incorporated herein and made a part
hereof.

             9.   DELAY AND WAIVER. No delay or omission to exercise any right
shall impair any such right or be a waiver thereof, but any such right may be
exercised from time to time and as often as may be deemed expedient. A waiver on
one occasion is limited to that particular occasion.


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                                                               Contract No. 2911


             10.  COMPLETE AGREEMENT. This Agreement, together with any riders,
schedules and exhibits attached hereto are the complete agreement of the parties
hereto and supersede all previous understandings relating to the subject matter
hereof This Agreement may be amended only by an instrument in writing that
explicitly states that it amends this Agreement and is signed by the party
against whom enforcement of the amendment is sought.

             11.  COUNTERPARTS. This Agreement may be executed in counterparts,
each of which will be an original and all of which will constitute a single
agreement.

             12.  SEVERABILITY. If any part of this Agreement or the application
thereof to any Person or circumstance is held invalid, the remainder of this
Agreement will be unaffected thereby. The section headings herein are included
for convenience only and may not be deemed to be a part of this Agreement.

             13.  BINDING EFFECT; ASSIGNMENT. This Agreement will be binding
upon and inure to the benefit of Surety and DVI and their respective successors
and assigns, except that Surety will not have the right to assign or delegate
its rights or obligations under any of such documents. DVI may at any time
assign or grant participation in all or any portion of this Agreement and the
amounts due thereunder.

             14.  INTERPRETATION. All references herein to Surety or DVI will
include their respective successors or assigns.

             15.  NOTICES. All notices, requests and other communications made
or given in connection with this Agreement will be in writing and will be deemed
to be received (a) upon personal delivery to the individual or division or
department to whose attention notices to a party are to be addressed by private
carrier, (b) three (3) business days after being sent by registered or certified
mail, return receipt requested or (c) upon confirmed receipt by telecopy or
e-mail with the original forwarded by first-class mail, in all cases, with
charges prepaid, addressed to Surety, at the address set forth on the signature
page hereof, and to DVI, at the addresses set forth below:

<TABLE>
<S>                                                         <C>
                  To DVI:                                   With copies to:

                     DVI Financial Services Inc.               DVI, Inc.
                     2500 York Road                            2500 York Road
                     Jamison, PA 18929                         Jamison, PA 18929
                     Attention: Chief Credit Officer           Attention: Legal Department
                     Telephone: (215) 488-5000                 Telephone: (215) 488-5000
                     Facsimile: (215) 488-5010                 Facsimile: (215) 488-5415
                     E-Mail: DVI@dvi-inc.com                   E-Mail: DVI@dvi-inc.com
</TABLE>

Any party may change such address by sending notice of the change to the other
parties; such change of address is effective only upon actual receipt of such
notice by the other parties.

             16.  GOVERNING LAW. ALL ACTS AND TRANSACTIONS HEREUNDER AND THE
RIGHTS AND OBLIGATIONS OF THE PARTIES HERETO ARE GOVERNED, CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE COMMONWEALTH OF PENNSYLVANIA
WITHOUT RESORT TO PRINCIPLES OF CONFLICTS OF LAWS.

             17.  JURISDICTION. The state and federal courts in the Commonwealth
of Pennsylvania will have jurisdiction over all matters arising out of this
Agreement and the Loan Documents; provided, however, that nothing contained
herein will prohibit DVI from initiating action against Surety in any
jurisdiction in which Surety resides or is located, as the case may be. Service
of process in any such proceeding will be effective if mailed to Surety at the
address described in SECTION 15 of this Agreement. Surety waives any right it
may have to assert the defense of forum non convenes or to object to such venue
in any such proceeding.

             18.  WAIVER OF TRIAL BY JURY. DVI AND SURETY HEREBY WAIVE THE RIGHT
TO TRIAL BY JURY OF ANY MATTERS ARISING OUT OF THIS AGREEMENT OR ANY OF THE LOAN
DOCUMENTS OR THE CONDUCT OF THE RELATIONSHIP BETWEEN DVI AND SURETY. EACH PARTY
HERETO ACKNOWLEDGES THAT SUCH WAIVER HAS BEEN GRANTED AFTER CONSULTATION WITH
COUNSEL.


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                                                               Contract No. 2911


             19.  PRESS RELEASE. Surety will not issue any press release or make
any public announcement relating to this Agreement or any Credit Facilities
extended to Obligor without DVI's express written consent except for disclosures
required by applicable law.

             20.  AUTOMATIC ADJUSTMENT IN LIABILITY. In the event that the
guaranty and suretyship established hereunder would constitute a "fraudulent
conveyance" under any applicable Federal, state or local statute, regulation or
court decision and thereby result in the invalidity or unenforceability of this
Agreement, in whole or in part, with respect to Surety, then the maximum
liability of Surety hereunder will automatically be limited to the greatest
dollar amount to which Surety could be liable hereunder without this Agreement
so constituting a fraudulent conveyance with respect to Surety with the intent
and effect that this Agreement will be so interpreted and construed to be valid
and enforceable to the maximum extent permitted by law.

             21.  CONTRACT NUMBER. The inclusion of a Contract Number herein is
not intended, and should not be interpreted, to limit in any way the
enforceability or applicability of this Agreement solely to the Guaranteed
Obligations relating to such Contract Number.



             [THE REMAINDER OF THIS PAGE HAS BEEN INTENTIONALLY LEFT BLANK]









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                                                               Contract No. 2911


               SIGNATURE PAGE - GUARANTY AND SURETYSHIP AGREEMENT

       IN WITNESS WHEREOF, Surety has executed this Agreement by its duly
authorized representative effective as of the date first above.

                                 PSC DEVELOPMENT COMPANY, L.L.C., A DELAWARE
                                 LIMITED LIABILITY COMPANY


                                 By:
                                    --------------------------------------------
                                 Name:
                                      ------------------------------------------
                                 Title:
                                       -----------------------------------------
                                 Address:
                                         ---------------------------------------

                                 -----------------------------------------------
                                 Contact Person:
                                                --------------------------------
                                 Telephone:
                                           -------------------------------------
                                 Facsimile:
                                           -------------------------------------
                                 E-Mail:
                                        ----------------------------------------







                                                                     Page 6 of 6
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                           RIDER A TO LIMITED GUARANTY
                            AND SURETYSHIP AGREEMENT
                               (LIMITED RECOURSE)

(R)2000, DVI Financial Services Inc., All Rights Reserved      Contract No. 2911

        THIS RIDER A TO LIMITED GUARANTY AND SURETYSHIP AGREEMENT (this "RIDER")
is entered into effective as of JULY 24, 2001, by and between PSC DEVELOPMENT
COMPANY, L.L.C., A DELAWARE LIMITED LIABILITY COMPANY ("SURETY") and DVI
FINANCIAL SERVICES INC. ("DVI")

                                   BACKGROUND

        A. By a certain Limited Guaranty and Suretyship Agreement of even date
herewith (the "Guaranty"), Surety has agreed to guarantee and become surety for
all Guaranteed Obligations, subject to the limitations set forth herein.

        B. All capitalized terms not otherwise defined herein have the meanings
set forth in the Guaranty.

             NOW, THEREFORE, for good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged and affirmed, and intending to
be legally bound hereby, the parties hereto agree as follows:

             1. LIMITATION ON LIABILITY. The liability of Surety under the
Guaranty will be limited to (a) the Collateral pledged by Surety to DVI-under
that certain Master Security Agreement dated JULY 24, 2001, plus (b) the amount
of all Lender Expenses actually incurred by DVI to enforce the Guaranty, plus
(c) interest on the sum of (a) and (b) accrued at the rate of eighteen (18%) per
annum from the date of demand until payment in full of all amounts due under the
Guaranty.

             2. EFFECT OF RIDER. All terms and conditions of the Guaranty not
expressly modified hereby are in full force and effect as ratified and confirmed
by the parties hereto.

             IN WITNESS WHEREOF, the parties have executed this Rider by their
duly authorized representatives effective as of the date first above written.

                                   PSC DEVELOPMENT COMPANY, L.L.C., A DELAWARE
                                   LIMITED LIABILITY COMPANY


                                   By:
                                      ------------------------------------------
                                   Name:
                                        ----------------------------------------
                                   Title:
                                         ---------------------------------------


                                   DVI FINANCIAL SERVICES INC.

                                   By:
                                      ------------------------------------------
                                   Name:
                                        ----------------------------------------
                                   Title:
                                         ---------------------------------------






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