<PAGE>

                                                                   EXHIBIT 10.19

                                    FIFTH AMENDMENT TO
                                REVOLVING CREDIT AGREEMENT


         Fifth Amendment dated as of December 26, 2000 to Revolving Credit
Agreement (this "Fifth Amendment"), by and among AZTEC TECHNOLOGY PARTNERS,
INC., a Delaware corporation (the "Borrower"), BLUEFLAME INC. (DE) (f/k/a
PROFESSIONAL COMPUTER SOLUTIONS, INC.) ("BlueFlame"), as Co-Borrower with
respect to $15,000,000 in outstanding principal amount of Acquisition Loans,
FLEET NATIONAL BANK (f/k/a BANKBOSTON, N.A.) and the other lending institutions
listed on SCHEDULE 1 to the Credit Agreement (as hereinafter defined) (the
"Banks"), amending certain provisions of the Revolving Credit Agreement dated as
of July 27, 1998 (as amended and in effect from time to time, the "Credit
Agreement") by and among the Borrower, the Banks and Fleet National Bank (f/k/a
BankBoston, N.A.) as agent for the Banks (the "Agent"). Terms not otherwise
defined herein which are defined in the Credit Agreement shall have the same
respective meanings herein as therein.

         WHEREAS, the Borrower has requested that the Banks amend certain
provisions contained in the Credit Agreement; and

         WHEREAS, the Banks have agreed with the Borrower, subject to the terms
and conditions contained herein, to modify certain terms and conditions of the
Credit Agreement as specifically set forth in this Fifth Amendment;

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

         SS. 1. AMENDMENT TOSS. 1 OF THE CREDIT AGREEMENT. Section 1.1 of the
Credit Agreement is hereby amended by inserting the following definitions in the
appropriate alphabetical order:

                FIFTH AMENDMENT. The Fifth Amendment to Revolving Credit
Agreement dated as of December 26, 2000, by and among the Borrower, PCSI, the
Agent and the Banks.

                MCDOWELL TUCKER. McDowell, Tucker & Co., Inc., a wholly owned
Subsidiary of Aztec.

                 PCM.  PCM, Inc., a wholly owned Subsidiary of Aztec.

                TAX REFUND. That certain federal tax refund, if any, received by
the Borrower or any of its Subsidiaries arising out of a tax refund claim
relating to the carry back of any net operating loss realized during calendar
year 2000 from the sale of PCM, McDowell Tucker or their assets, and carried
back to calendar year 1998.
<PAGE>

         SS. 2. AMENDMENT TOSS. 4 OF THE CREDIT AGREEMENT.

                (a) Section 4.8.2 of the Credit Agreement is hereby amended by
deleting the following language in clause (ii) (y):

                           (y) 80% of the Net Cash Sale Proceeds in excess of
the Minimum Net Cash Sale Proceeds for such Subsidiary

and replacing it with the following:

                           (y) (A) 100% of the Net Cash Sale Proceeds in excess
of the Minimum Net Cash Sale Proceeds for such Subsidiary in the case of
McDowell Tucker and PCM and (B) 80% of the Net Cash Sale Proceeds in excess of
the Minimum Net Cash Sale Proceeds for such Subsidiary in the case of any
Subsidiary other than McDowell Tucker and PCM.

                  (b) Section 4 of the Credit Agreement is hereby amended by
adding after subsection 4.8.2 a new subsection Section 4.8.3, as follows:

         4.8.3 TAX REFUND. The Borrower shall prepay Acquisition Loans in an
amount equal to 75% of the amount of the Tax Refund. The Borrower shall be
entitled to retain and use 25% of the Tax Refund, subject to the security
interest in favor of the Agent and the Lenders.

         SS. 3.   AMENDMENT TOSS. 9 OF THE CREDIT AGREEMENT.

                  (a) Section 9 of the Credit Agreement is hereby amended
by deleting Section 9.4(i) in its entirety and replacing it with the following:

                           "(i)  at 2:00 p.m. Boston time on Thursday,
September 14, 2000 and at 2:00 p.m. Boston time on each two-week anniversary
thereof, or at such other time and day on which the Borrower, the Agent and the
Required Lenders mutually agree, the Borrower will make financial and other
appropriate officers of the Borrower and its Subsidiaries available to the Agent
and the Banks for a dial-in conference call (the "Conference Call"), which will
be arranged by the Borrower and of which arrangements the Borrower shall notify
the Agent and the Banks at least one Business Day prior to each such call, to
discuss the information in any of the foregoing reports or other reports
delivered to the Banks by the Borrower or its Subsidiaries and answer any
questions the Agent or the Banks may have regarding the Borrower and its
Subsidiaries. From January 4, 2001, until the Agent has received the proceeds of
the sale of PCSI, a written statement on the status of the sale of PCSI shall be
provided by the investment banking firm engaged to assist Aztec in the sale of
PCSI to the Agent and Lenders together with the usual materials provided by
Aztec in connection with the Conference Call. In addition, the Borrower will use
commercially reasonable efforts to continue to provide reports to the Banks of
its cash flow on a bi-weekly basis."

                 (b) Section 9 of the Credit Agreement is hereby amended by
adding the following language at the end of Section 9.8:
<PAGE>

         The Borrower shall file a request for the Tax Refund to which it may be
entitled, and shall file all tax returns or amendments to tax returns required
to be filed to process such request, as promptly as is reasonably practical.

                  (c) Section 9 of the Credit Agreement is hereby amended by
adding the following to the end of Section 9.23:

         The Borrower hereby agrees to pay all reasonable expenses, including
legal fees and disbursements incurred by the Agent and the Banks in connection
with the Fifth Amendment and the transactions contemplated thereby and any other
expenses, legal fees and disbursements required to be paid pursuant to ss. 17.1
of the Revolving Credit Agreement for which an invoice is submitted after the
date of the Fifth Amendment within 30 days after the date of the respective
invoice. The Borrower also agrees on or before December 31, 2000 to deliver to
the Agent a business plan for calendar year 2001 for PCSI. The Borrower
furthermore agrees to use its best efforts to obtain a letter of intent with
respect to the sale of PCSI on or before January 31, 2001.

         SS. 4. CONDITIONS TO EFFECTIVENESS. This Fifth Amendment shall become
effective only upon the satisfaction of the following conditions:

                  (a) this Fifth Amendment shall have been executed by the
Borrower, PCSI, all of the Banks and the Agent and the Ratification of Guaranty
in the form attached hereto shall have been executed by each Guarantor;

                  (b) the Borrower shall have delivered to the Agent and the
Banks an opinion of counsel satisfactory in form and substance to the Agent as
to the corporate power and authority of the Borrower, due authorization,
execution and delivery, validity and enforceability of the Fifth Amendment and
other customary provisions;

                  (c) the Borrower shall have delivered to the Agent a guaranty,
security agreement and UCC-1 financing statements, as required by the Credit
Agreement, with respect to Blueflame, Inc., a Delaware corporation;

                  (d) the Borrower shall have paid all reasonable expenses,
including legal fees and disbursements incurred by the Agent and the Banks in
connection with this Fifth Amendment and the transactions contemplated hereby
and any other expenses, legal fees and disbursements required to be paid
pursuant to ss. 17.1 of the Credit Agreement and not heretofore paid by the
Borrower for which an invoice has been submitted.

         SS. 5. REPRESENTATIONS AND WARRANTIES. The Borrower hereby repeats, on
and as of the date hereof, each of the representations and warranties made by it
in ss. 8 of the Credit Agreement, and such representations and warranties remain
true as of the date hereof (except in such respects (none of which shall be
materially adverse) as may be set forth on the DISCLOSURE SCHEDULE required to
be delivered pursuant to ss. 9.23 of the Credit Agreement, as amended hereby,
and to the extent of changes resulting from transactions contemplated or
permitted by the Credit Agreement and the other Loan Documents and changes
occurring in the ordinary course of business that singly or in the aggregate are
not materially adverse, and to the extent that such representations and
warranties relate expressly to an earlier date), PROVIDED, that all references
therein to the Credit Agreement shall refer to such Credit Agreement as amended
hereby. In
<PAGE>

addition, the Borrower hereby represents and warrants that (a) the execution and
delivery by the Borrower and each Guarantor of this Fifth Amendment and the
performance by the Borrower and each Guarantor of all of its agreements and
obligations under the Credit Agreement as amended hereby and the other Loan
Documents are within the corporate authority of the Borrower and each Guarantor
and have been duly authorized by all necessary corporate action on the part of
the Borrower and each Guarantor party thereto and (b) the Borrower has filed in
a timely manner each report required to be filed by it with the Securities and
Exchange Commission pursuant to Sections 13, 14 or 15(d) of the Securities
Exchange Act of 1934 since December 31, 1998.

         SS. 6. SCHEDULES. The Credit Agreement is hereby amended to delete
SCHEDULE A attached to the Third Amendment and to substitute SCHEDULE A attached
hereto in its place, as if the same were SCHEDULE A to such Third Amendment. The
Credit Agreement is hereby amended, effective on and after January 31, 2001, to
delete SCHEDULE 1 attached to the Credit Agreement and to substitute SCHEDULE 1
attached hereto in its place, as if the same were SCHEDULE 1 to the Credit
Agreement. Schedule 8.19(a) to the Credit Agreement is hereby amended to add
"Blueflame Inc., a Delaware corporation."

         SS. 7. AMENDMENT TO REGISTRATION RIGHTS AGREEMENT. The Registration
Rights Agreement dated as of April 21, 2000, among the Borrower, the Agent and
the Banks (as amended to date, the "Registration Rights Agreement") is hereby
amended to provide that the date in Section 1.2 by which the Borrower shall have
filed a Form S-3 (or Form S-1 if Form S-3 is not available to the Borrower)
Registration Statement with respect to the shares of the Borrower's common stock
underlying the Warrants (as defined therein) shall be extended from October 10,
2000 (as provided in the First Amendment to Registration Rights Agreement) to
April 30, 2001, provided that the Borrower continues to exercise best efforts to
effect such filing and have it declared effective.

         SS. 8. RATIFICATION, ETC. Except as expressly amended hereby, the
Credit Agreement and all documents, instruments and agreements related thereto,
including, but not limited to the Registration Rights Agreement and the Security
Documents, are hereby ratified and confirmed in all respects and shall continue
in full force and effect, except as specifically amended hereby. The Credit
Agreement and this Fifth Amendment shall be read and construed as a single
agreement. All references in the Credit Agreement or any related agreement or
instrument to the Credit Agreement shall hereafter refer to the Credit Agreement
as amended hereby.

         SS. 9. NO WAIVER. 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 the Banks consequent thereon, except such
waivers as are specifically set forth herein.

         SS. 10. RELEASE OF CLAIMS. The Borrower and, by executing the attached
Ratification of Guaranty, each of the Borrower's Subsidiaries hereby releases
the Agent and the Banks and all agents, officers, directors, shareholders, or
anyone acting at the direction or control of the Agent or each or all Banks from
any and all liabilities and claims under the Credit Agreement, this Fifth
Amendment, the Registration Rights Agreement or any Security Documents or
otherwise in connection with the transactions contemplated thereby, except those
arising after the time of execution and delivery of this Fifth Amendment.
<PAGE>

         SS. 11. COUNTERPARTS. This Fifth 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.

         SS. 12. GOVERNING LAW. THIS FIFTH AMENDMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE COMMONWEALTH OF MASSACHUSETTS
(WITHOUT REFERENCE TO CONFLICT OF LAWS).
<PAGE>

         IN WITNESS WHEREOF, the parties hereto have executed this Fifth
Amendment as a document under seal as of the date first above written.

                          AZTEC TECHNOLOGY PARTNERS, INC.


                          By: /s/ Ira Cohen
                              -------------------------------------------
                              Title: President and Chief Operating Officer


                          BLUEFLAME INC. (DE)
                          (f/k/a PROFESSIONAL COMPUTER
                          SOLUTIONS, INC.)
                          (HAVING JOINT AND SEVERAL LIABILITY FOR A
                          PORTION OF THE ACQUISITION LOANS HAVING AN
                          OUTSTANDING PRINCIPAL AMOUNT OF $15,000,000)


                          By: /s/ T. Kenwood Mullare
                              --------------------------------------------------
                              Title:  Secretary


                          CITIZENS BANK OF MASSACHUSETTS


                          By: /s/ James M. Ray
                              --------------------------------------------------
                              Name:  James M. Ray
                              Title:  Vice President


                          FLEET NATIONAL BANK (AS AGENT AND AS A BANK)


                          By: /s/ RICHARD E. LYNCH
                              --------------------------------------------------
                              Name:  Richard E. Lynch
                              Title:  Vice President


                          THE FUJI BANK, LIMITED


                          By: /s/ Masahito Fukuda
                              --------------------------------------------------
                              Name:  Masahito Fukuda
                              Title:  Senior Vice President and Group Head
<PAGE>

                          NATIONAL CITY BANK OF KENTUCKY


                          By: /s/ Glenn E. Nord
                              --------------------------------------------------
                              Name:  Glenn E. Nord
                              Title:  Vice President


                          LASALLE BANK NATIONAL ASSOCIATION


                          By: /s/ John J. McGuire
                              --------------------------------------------------
                              Name:  John J. McGuire
                              Title:  First Vice President


                          PEOPLE'S BANK


                          By: /s/ Dante Fazzina
                              -------------------------------------------------
                              Name:  Dante Fazzina
                              Title:  Vice President
<PAGE>

                            RATIFICATION OF GUARANTY

         Each of the undersigned guarantors hereby acknowledges and consents to
the foregoing Fifth Amendment as of December 26, 2000, and agrees that the
Guaranty dated as of (a) July 27, 1998; (b) September 17, 1998; (c) October 2,
1998, (d) June 26, 2000 or (e) November 1, 2000 from each of the undersigned
Guarantors remain in full force and effect, and each of the Guarantors confirms
and ratifies all of its obligations thereunder.


                                      AZTEC INTERNATIONAL LLC


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      AZTEC TECHNOLOGY PARTNERS OF NEW
                                      ENGLAND LLC (f/k/a BAY STATE
                                      COMPUTER GROUP LLC)


                                      By: /s/ Ira Cohen
                                          --------------------------------------
                                          Title:  President


                                      ENTRA COMPUTER CORP.


                                      By: /s/ Ira Cohen
                                          --------------------------------------
                                          Title:  President


                                      PCM, INC.


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      MCDOWELL, TUCKER & CO., INC.


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary
<PAGE>

                                      BLUEFLAME INC. (DE) (f/k/a
                                      PROFESSIONAL COMPUTER SOLUTIONS, INC.)


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      SOFTECH COMMUNICATIONS, INC.


                                      By: /s/ Ira Cohen
                                          --------------------------------------
                                          Title:  President


                                      SOLUTIONS E.T.C. INC.


                                      By: /s/ Ira Cohen
                                          --------------------------------------
                                          Title:  President


                                      DIGITAL NETWORK ASSOCIATES LLC


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      PROFESSIONAL NETWORK SERVICES, INC.


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      OFFICE EQUIPMENT SERVICE, INC.


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary


                                      BLUEFLAME, INC.


                                      By: /s/ T. Kenwood Mullare
                                          --------------------------------------
                                          Title:  Secretary