<PAGE>

                                                                    EXHIBIT 10.9

                      SECOND MODIFICATION TO LOAN DOCUMENTS

      THIS SECOND MODIFICATION TO LOAN DOCUMENTS (herein the "MODIFICATION") is
made and entered into as of this 1st day of September, 2005, by and between
INTELLIGENT SYSTEMS CORPORATION, a Georgia corporation (herein the "BORROWER"),
QS TECHNOLOGIES, INC., a Georgia corporation, VISAER, INC., a Delaware
corporation, CORECARD SOFTWARE, INC., a Delaware corporation, and CHEMFREE
CORPORATION, a Georgia corporation (the aforesaid four corporations being
individually and collectively referred to herein as the "GUARANTORS"), and
FIDELITY BANK, a Georgia state chartered bank (f/k/a Fidelity National Bank )
(herein the "LENDER").

                                    RECITALS:

      WHEREAS, on October 1, 2003, Lender made a loan to Borrower in the
original principal amount of One Million Five Hundred Thousand and No/100
Dollars ($1,500,000.00) (the "LOAN") evidenced by that certain Commercial
Promissory Note dated October 1, 2003 executed by Borrower in favor of Lender
(herein the "NOTE").

      WHEREAS, the Loan and the Note are secured and evidenced by, among other
instruments, the following:

      (a)   Security Agreement from Borrower in favor of Lender dated of even
            date with the Note (herein the "SECURITY AGREEMENT");

      (b)   Loan Agreement by and between Borrower and Lender dated of even date
            with the Note (herein the "LOAN AGREEMENT");

      (c)   Financing Statement filed in Gwinnett County, Georgia records, File
            no. 067-2003-010805 (herein the "FINANCING STATEMENT").

      (d)   Negative Pledge Agreement by and between Borrower and Lender dated
            of even date with the Note (herein the "NEGATIVE PLEDGE AGREEMENT");

      (e)   Assignment of Policy as Collateral Security from Borrower in favor
            of Lender dated of even date with the Note (herein the "LIFE
            INSURANCE ASSIGNMENT"); and

      (f)   Subordination Agreements from Borrower and certain of the Guarantors
            in favor of Lender dated of even date with the Note (herein
            "SUBORDINATION AGREEMENTS").

The Security Agreement, the Loan Agreement, the Financing Statement, the
Negative Pledge Agreement, the Life Insurance Assignment and the Subordination
Agreements are collectively referred to herein as the "LOAN DOCUMENTS".

      WHEREAS, on October 1, 2003, each of the Guarantors executed a Guaranty in
favor of Lender whereby each of the Guarantors guaranteed all of the obligations
of Borrower to Lender contained under the Loan, Note and Loan Documents (herein
collectively the "Guaranties");

      WHEREAS, in order to secure their obligations under the terms of the
Guaranties, each of the Guarantors executed in favor of Lender certain Security
Agreements dated October 1, 2003 (herein the "Guarantor Security Agreements"),
which Guarantor Security Agreements are further evidenced by a Financing
Statement filed in Gwinnett County, Georgia Records File No. 067-2003-010805 and
that certain Financing Statement filed with the Delaware Department of State
under Filing No. 3274987 (herein collectively the "Guarantor Financing
Statements") (the Guaranties, the Guarantor Security Agreements and the
Guarantor Financing Statements are herein collectively referred to herein as the
"Guaranty Documents");

<PAGE>

      WHEREAS, Lender, Borrower and the Guarantors entered into that certain
First Modification of Loan Documents dated as of September 1, 2004 for the
purpose of extending the Maturity Date of the Loan on the Note from September 1,
2004 to September 1, 2005 (all references to the Loan, Note, Loan Documents and
Guaranty shall be as amended by the aforesaid First Modification of Loan
Documents);

      WHEREAS, Borrower has requested and Lender has agreed to extend the
Maturity Date of the Loan and Note from September 1, 2005 to September 1, 2006
and to increase the maximum availability under the Loan and the Note from
$1,500,000 to $2,000,000 and Borrower, Guarantors and Lender desire to enter
into this Agreement in order to modify and ratify certain other terms and
conditions of the Note, the Loan Documents and the Guaranty Documents as more
particularly set forth herein.

      NOW, THEREFORE, for and in consideration of Ten and No/100 Dollars
($10.00) and other good and valuable consideration, the receipt, adequacy and
sufficiency of which are hereby acknowledged, Lender, Borrower and Guarantors
hereby agree as follows:

      1. Recitals. The foregoing recitals are true and correct and are
incorporated herein by this reference.

      2. Capitalized Terms. All capitalized terms contained in this Modification
shall have the same meaning afforded to them in the Note, Loan Documents and
Guaranty Documents.

      3. Specific Modifications to Documents.

            a.    The Note, each of the Loan Documents and each of the Guaranty
                  Documents are hereby modified to reflect that the Maturity
                  Date of the Loan and the Note is hereby extended from
                  September 1, 2005 to September 1, 2006.

            b.    The Note is hereby modified to provide that payments of
                  interest only, in arrears, shall continue to be due and
                  payable on the first (1st) day of each month hereafter as set
                  forth under the terms of the Note, with the entire outstanding
                  principal balance and all accrued interest and other charges
                  being due and payable in full on September 1, 2006.

            c.    Section 11.1 of the Loan Agreement is hereby modified to
                  replace the date "September 1, 2005" contained in the third
                  line of such section with the date "September 1, 2006".

            d.    The Note, each of the Loan Documents and each of the Guaranty
                  Documents are hereby modified to reflect that the maximum
                  availability under the terms of the Loan is hereby increased
                  from $1,500,000 to $2,000,000.

            e.    A new Section 8.11 is hereby added to the Loan Agreement as
                  follows:

                        Borrower will not use any of the proceeds of the Loan to
                        make a capital investment or provide a loan to any third
                        parties without first obtaining the prior written
                        consent of Lender with respect to such investment or
                        loan, which consent may be granted by Lender in its sole
                        and absolute discretion.

      4. No Impairment. Borrower and Guarantors agree that the terms and
provisions hereof shall in no manner impair, limit, restrict or otherwise affect
the obligations of Borrower and Guarantors to Lender

                                       2

<PAGE>

or the priority of any lien evidenced by the Note, the Loan Documents or the
Guaranty Documents, except as modified hereby.

      5. No Defenses. Borrower and Guarantors acknowledge that they have no
offsets, claims, counterclaims or defenses against Lender or under any of their
obligations contained in the Note, the Loan Documents or the Guaranty Documents
and to the extent any such offsets, claims, counterclaims, or defenses exist,
the same are hereby waived by the Borrower and Guarantors.

      6. Ratification. Except as amended hereby, each and every term and
provision of the Note, the Loan Documents and the Guaranty Documents are hereby
ratified and affirmed by Borrower and Guarantors and shall remain in full force
and effect. The Guarantors hereby specifically acknowledge and consent to the
increase of the availability under the Loan form $1,500,000 to $2,000,000.

      7. No Novation. It is the intention of the parties hereto that the
execution and delivery of this Modification shall in no way constitute a
novation or extinguishment of the debt evidenced by the Note, Loan Documents or
the Guaranty Documents.

      8. Effect of Modification. In signing this Modification, the parties
hereto expressly certify and covenant that they have carefully read all
provisions contained herein, have had an opportunity to consult with legal
counsel of their choosing and to consider the ramifications and terms of this
Modification, and they have voluntarily signed this Modification with the
understanding that it will be final and binding as to their interests and they
have had a sufficient opportunity to review the Modification and consult with
counsel of their choice prior to making such decision to execute this
Modification. The parties hereby represent and warrant that this Modification is
executed without reliance on any statement or representation of the other,
except as expressly set forth in the within and foregoing Modification, and this
Modification constitutes the entire Modification between the parties hereto and
that no promise or inducement or consideration, other than that expressed in the
within and foregoing Modification, has been offered or accepted and all such
prior inducements or considerations are deemed merged herein.

                  [REMAINDER OF PAGE INTENTIONALLY LEFT BLANK]

                     [SIGNATURES COMMENCE ON FOLLOWING PAGE]

                                       3

<PAGE>

      IN WITNESS WHEREOF, Borrower, Guarantors and Lender have set their hands
and seals to this Modification as of the day and year first above-written.

                                    BORROWER:
                                    INTELLIGENT SYSTEMS CORPORATION,
                                    a Georgia corporation

                                    By: /s/ J. Leland Strange
                                        -------------------------------
                                    Title: President & CEO
                                    Attest: ___________________________
                                    Title: ____________________________

                                              [CORPORATE SEAL]

                                    GUARANTORS:
                                    QS TECHNOLOGIES, INC., a Georgia corporation

                                    By: /s/ Kevin Davidson
                                        -------------------------------
                                    Title: President
                                    Attest: ___________________________
                                    Title: ____________________________

                                              [CORPORATE SEAL]

                                    VISAER, INC., a Delaware corporation

                                    By: /s/ David Spellman
                                        -------------------------------
                                    Title: President
                                    Attest: ___________________________
                                    Title: ____________________________

                                              [CORPORATE SEAL]

                                    CORECARD SOFTWARE, INC.,
                                    a Delaware corporation

                                    By: /s/ J. Leland Strange
                                        ------------------------------
                                    Title: President
                                    Attest: ___________________________
                                    Title: ____________________________

                                              [CORPORATE SEAL]

                                    CHEMFREE CORPORATION,
                                    a Georgia corporation

                                    By: /s/ Francis A. Marks
                                        -----------------------------
                                    Title: President
                                    Attest: __________________________
                                    Title: ____________________________

                                              [CORPORATE SEAL]

                    (SIGNATURES CONTINUED ON FOLLOWING PAGE)

                                       4

<PAGE>

            (SIGNATURE PAGE TO SECOND MODIFICATION TO LOAN DOCUMENTS)

                                    LENDER:

                                    FIDELITY BANK,
                                    a Georgia state chartered bank
                                    (f/k/a Fidelity National Bank)

                                    By: /s/ Rusty Bramlett
                                        ----------------------------
                                    Title: Vice President

                                              (BANK SEAL)

                                       5