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                                                                   EXHIBIT 10.21


                               FIRST AMENDMENT
                               ---------------
                        TO REVOLVING CREDIT AGREEMENT
                        -----------------------------

        This FIRST AMENDMENT TO AMENDED AND RESTATED REVOLVING CREDIT AGREEMENT
(this "First Amendment") dated as of November 13, 1995, by and among HPSC, INC.
(the "Borrower"), a Delaware corporation, THE FIRST NATIONAL BANK OF BOSTON
("FNBB"), BANK OF AMERICA ILLINOIS, CORESTATES BANK, N.A., THE DAIWA BANK,
LIMITED, SHAWMUT BANK, N.A. (collectively, the "Banks"), and THE FIRST NATIONAL
BANK OF BOSTON as Agent for the Banks and BANK OF AMERICA ILLINOIS as co-agent
for the Banks. Capitalized terms used herein without definition shall have the
meanings set forth in the Credit Agreement (as defined below).

        WHEREAS, the Borrower, the Agent and the Banks are parties to that
certain Amended and Restated Revolving Credit Agreement dated as of May 15,
1995 (as amended, modified or supplemented and in effect from time to time, the
"Credit Agreement");

        WHEREAS, the Borrower requested that the Credit Agreement be amended to
permit the Borrower to enter into that certain sales agreement dated as of
November ___, 1995 by and between the Borrower and Springfield Institution for
Savings substantially in the form of EXHIBIT A attached hereto and made a part
hereof.

        NOW, THEREFORE, in consideration of the premises contained herein, and
for other good and valuable consideration, the receipt and sufficiency of which
are hereby acknowledged, the parties hereto agree as follows:

        1.  AMENDMENT TO THE CREDIT AGREEMENT.

              1.1  CERTAIN DEFINITIONS.  Section 1 of the Credit Agreement 
is hereby amended by deleting the definition of SIS Credit Agreement and
inserting in lieu thereof the following definition:

              "SIS CREDIT AGREEMENT.  Together, (i) the dental practice
              receivables-backed credit agreement dated as of April 13, 1995 by
              and between the Borrower and SISB and (ii) the sale agreement
              dated as of November 3, 1995 by and between the Borrower and
              SISB."

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                                     -2-

        1.2.  AMENDMENT TO SECTION 8.2 OF THE CREDIT AGREEMENT. Section 8.2 of
the Credit Agreement is hereby amended by inserting the text "or SCHEDULE
8.2(m-1)" immediately after the text "SCHEDULE 8.2(m)."

        1.3.  AGENT'S AUTHORIZATION. Section 14.1 of the Credit Agreement is
hereby amended by adding the following new sentence at the end thereof:

        "Each of the Banks and the Agent further acknowledge and agree that (i) 
        the Agent is authorized to release the security interest created by the 
        Security Documents in the assets listed on SCHEDULE 8.2(m-1) and that 
        (ii) the Agent is authorized to execute and deliver, on behalf of the 
        Banks and the Agent, such partial releases under the Uniform Commercial 
        Code as may be necessary or desirable to accomplish a release of the 
        security interest created by the Security Documents in the assets 
        listed on SCHEDULE 8.2(m-1)."

        2.  CONDITIONS TO EFFECTIVENESS. This First Amendment shall not become
effective unless and until:                          

        (a)  the Agent receives counterparts of this First Amendment
             executed by each of the Borrower, the Majority Banks, the Agent
             and the Guarantor; and

        (b)  all proceedings in connection with the transactions
             contemplated by this First Amendment and all documents incident
             hereto, including, without limitation, the SIS Credit Agreement
             and related documents, shall be satisfactory in form and substance
             to the Agent, and the Agent shall have received all information
             and counterpart originals or certified or other copies of such
             documents, including, without limitation, the SIS Credit Agreement
             and related documents as the Agent may reasonably request.

        3.  REPRESENTATIONS AND WARRANTIES; NO DEFAULT.  The Borrower
represents and warrants to the Agent and the Banks that (a) each and every one
of the representations and warranties made by the Borrower to the Agent and the
Banks in sec. 6 or elsewhere in the Credit Agreement or in the other Loan
Documents, as amended by this First Amendment, are true and correct in all
material respects on and as of the date hereof except to the extent that any of
such representations and warranties relate, by the express terms thereof,
solely to a date prior hereto; (b) the Borrower has duly and properly
performed, complied with and observed each of its covenants, agreements and
obligations contained in secs. 7 and 8 or elsewhere in the Credit Agreement or
the other Loan Documents, as amended by this First Amendment; and (c) no event
has occurred or is continuing and no condition exists which constitutes a
Default or Event of Default.

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                                     -3-

        4.  RATIFICATION, ETC.  Except as expressly amended by this Amendment,
the Credit Agreement and the Loan Documents and all documents, instruments and
agreements related thereto, including, but not limited to the Security
Documents, are hereby ratified and confirmed in all respects and shall continue
in full force and effect. The Borrower confirms and agrees that the Obligations
of the Borrower to the Banks under the Loan Documents, as amended hereby, are
secured by, guarantied under, and entitled to the benefits, of the Security
Documents. The Borrower, the Guarantor, the Agent and the Banks hereby
acknowledge and agree that all references to the Credit Agreement and the
Obligations thereunder contained in any of the Loan Documents shall be
references to the Credit Agreement and the Obligations, as affected and
increased hereby and as the same may be amended, modified, supplemented, or
restated from time to time. The Security Documents and the perfected first
priority security interests of the Agent on behalf of the Banks thereunder
shall continue in full force and effect, and the collateral security and
guaranties provided for in the Security Documents shall not be impaired by this
Amendment. The Credit Agreement and this First Amendment shall be read and
construed as a single agreement.

        5.  MISCELLANEOUS.  The Borrower hereby agrees to pay to the Agent, on
demand by the Agent, all reasonable out-of-pocket costs and expenses incurred
or sustained by the Agent or any of the Banks in connection with the
preparation of this First Amendment and the documents referred to herein
(including reasonable legal fees). Nothing contained herein shall constitute a
waiver of, impair or otherwise affect any Obligations, any other obligation of
the Borrower or any rights of the Agent or either of the Banks consequent
thereon. This First Amendment may be executed in one or more counterparts, each
of which shall be deemed an original but which together shall constitute one
and the same instrument. Section headings in this First Amendment are included
herein for convenience of reference only and shall not constitute part of this
First Amendment for any other purpose. This First Amendment shall be governed
by, and construed in accordance with, the laws of the Commonwealth of
Massachusetts (without reference to conflict of laws).

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                                     -4-

        IN WITNESS WHEREOF, the undersigned have duly executed this First
Amendment as a sealed instrument as of the date first set forth above.

                                           HPSC, INC.

                                           By:   /s/ John W. Everets
                                               ----------------------------
                                                 Name: John W. Everets 
                                                 Title: Chairman & CEO

                                           THE FIRST NATIONAL BANK
                                            OF BOSTON, individually and
                                            as Agent

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

                                           BANK OF AMERICA ILLINOIS,
                                           individually and as co-agent

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

                                           SHAWMUT BANK, N.A.

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

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                                     -4-

        IN WITNESS WHEREOF, the undersigned have duly executed this First
Amendment as a sealed instrument as of the date first set forth above.

                                           HPSC, INC.

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

                                           THE FIRST NATIONAL BANK
                                            OF BOSTON, individually and
                                            as Agent

                                           By:  /s/ Mitchell B. Feldman
                                               ----------------------------
                                                 Name: Mitchell B. Feldman
                                                 Title: Managing Director

                                           BANK OF AMERICA ILLINOIS,
                                           individually and as co-agent

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

                                           SHAWMUT BANK, N.A.

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

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                                     -4-

        IN WITNESS WHEREOF, the undersigned have duly executed this First
Amendment as a sealed instrument as of the date first set forth above.

                                           HPSC, INC.

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

                                           THE FIRST NATIONAL BANK
                                            OF BOSTON, individually and
                                            as Agent

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

                                           BANK OF AMERICA ILLINOIS,
                                           individually and as co-agent

                                           By:  /s/ Mark N. Hurley
                                               ----------------------------
                                                 Name: Mark N. Hurley
                                                 Title: Managing Director

                                           SHAWMUT BANK, N.A.

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

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                                     -4-

        IN WITNESS WHEREOF, the undersigned have duly executed this First
Amendment as a sealed instrument as of the date first set forth above.

                                           HPSC, INC.

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

                                           THE FIRST NATIONAL BANK
                                            OF BOSTON, individually and
                                            as Agent

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

                                           BANK OF AMERICA ILLINOIS,
                                           individually and as co-agent

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

                                           SHAWMUT BANK, N.A.

                                           By:  /s/ Salvatore Salzillo
                                               ----------------------------
                                                 Name: Salvatore Salzillo
                                                 Title: Assistant Vice President

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                                     -5-

                                           CORESTATES BANK, N.A.
                                           
                                           By:  /s/ Verna R. Prentice
                                               ----------------------------
                                                 Name: Verna R. Prentice
                                                 Title: Vice President

                                           THE DAIWA BANK, LIMITED

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

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

Consented to by the undersigned Guarantor:

AMERICAN COMMERCIAL
 FINANCE CORPORATION

By:
   ------------------------------

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                                     -5-

                                           CORESTATES BANK, N.A.
                                           
                                           By:
                                               ----------------------------
                                                 Name:
                                                 Title:

                                           THE DAIWA BANK, LIMITED

                                           By:  /s/ Alfred DeGemmis
                                               ----------------------------
                                                 Name: Alfred DeGemmis
                                                 Title: Vice President

                                           By:  /s/ Daniel G. Eastman
                                               ----------------------------
                                                 Name: Daniel G. Eastman
                                                 Title: Vice President & Manager

Consented to by the undersigned Guarantor:

AMERICAN COMMERCIAL
 FINANCE CORPORATION

By:
   ------------------------------

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                                     -5-

                                           CORESTATES BANK, N.A.
                                           
                                           By:  
                                               ----------------------------
                                                 Name: 
                                                 Title: 

                                           THE DAIWA BANK, LIMITED

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

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

Consented to by the undersigned Guarantor:

AMERICAN COMMERCIAL
 FINANCE CORPORATION

By: /s/ John R. Everets
   ------------------------------
   John R. Everets