<PAGE>   1



                                EXHIBIT 10.57

                       AGREEMENT DATED AUGUST 13, 1996
                          BY AND BETWEEN THE COMPANY
                         AND AT&T CAPITAL CORPORATION




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                                    Exhibit
                                     10.57
                                     =====

                                                    [LOGO]  AT&T
                                                            CAPITAL CORPORATION
        -----------------------------------------------------------------------
        STEPHAN M. TAFT                                    44 Whippany Road
        Director Credit Operations                         Morristown, NJ 07962
                                                           201 397-4098
                                August 13, 1996            FAX 201 397-4375

Mr. Greg Azcuy
ECCS, Inc.
One Sheila Drive, Building GA
Tinton Falls, NJ 07724

        Re:  Approval of Line of Credit with AT&T Commercial Finance
             Corporation 

Dear Mr. Azcuy,

AT&T Commercial Finance Corporation ("AT&T-CFC") is pleased to advise you of
our commitment to offer ECCS, Inc. (the "Borrower") a line of credit in an
amount not to exceed $2,000,000.00 (the "Line of Credit"). This commitment is
made subject to the following terms and conditions:

1.      Amount of Line of Credit
        ------------------------

        The Line of Credit shall be in a MAXIMUM amount of $2,000,000.00.
AT&T-CFC may from time to time finance sums above the committed line at its
sole discretion. Further, any such additional advances are not intended to be
and should not be construed as a permanent commitment above the approved line
and are subject to immediate repayment, at our sole option, upon notice by
AT&T-CFC. There shall be no minimum extension of credit required of AT&T-CFC
under this commitment. All extensions of credit shall be made in the sole and
complete discretion of AT&T-CFC. The outstanding balance under the Line of
Credit shall be computed by adding the principal outstanding amount and the
amount of unpurchased approvals.

2.      Duration of Line of Credit
        --------------------------

        The term of the Line of Credit shall commence on July 1, 1996, and
shall continue until May 1, 1997 at which time the Line of Credit shall
terminate and expire. AT&T-CFC will annually review the line for renewal based
on our receipt and satisfactory review of your next fiscal year end, at our
sole option, AT&T-CFC may. In its sole and absolute discretion, extend the Line
of Credit for such additional periods of time and under such terms and
conditions as AT&T-CFC determines to be appropriate. No advances will be made
by AT&T-CFC until AT&T-CFC actually receives executed copies of any and all
documentation required by AT&T-CFC.

3.      Early Termination
        -----------------

        The Line of Credit may be terminated by AT&T-CFC at any time prior to
        May 1, 1997, If:

        a)  The Borrower fails to execute and/or deliver any and all financing
            documents required by AT&T-CFC, which financing documents shall
            include, but shall not be limited to, an Agreement for Wholesale
            Financing.

        b)  The Borrower in breach of any of the provisions of any of the
            financing documents required by AT&T-CFC or is in default under any
            such document.   
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        c)  The Borrower fails to provide in form and substance satisfactory to
AT&T-CFC, at its sole discretion, quarterly interim financial statements within
60 days of closing, annual financial statements within 90 days of closing along
with Inventory an Accounts Receivable aging reports for each Interim and annual
reporting period.

        d)  There has occurred any adverse change in the financial condition of
business prospects of the Borrower or any guarantor of the Borrower's
indebtedness to AT&T-CFC or if AT&T-CFC shall learn of any misrepresentation or
omission of a fact or circumstance by the Borrower (or any guarantor of the
Borrower's indebtedness to AT&T-CFC) or if AT&T-CFC shall learn of any
misrepresentation or omission of a fact or circumstance by the Borrower (or
any guarantor) that AT&T-CFC deems to be material. The Borrower and all
guarantors shall be obligated to notify AT&T-CFC in writing of any change in
either of their financial condition, structure, ownership, or business
prospects. 

4.      Prior Agreements

        This letter shall replace and supersede all prior commitment letters
from AT&T-CFC to Borrower, including without limitation, that certain
commitment letter dated May 6, 1996.
        
5.      No Assignment
        -------------

        This commitment may not be assigned by the Borrower without the prior
written consent of AT&T-CFC, which consent shall be granted or withheld in the
sole and absolute discretion of AT&T-CFC.

        We look forward to working with you.

                                            Very truly yours,

                                            AT&T Commercial Finance Corporation
                                  
                                            BY:         /s/
                                               --------------------------------
                                                        (Name)

                                                        /s/
                                               --------------------------------
                                                        (Title)
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Schedule of Additional covenant(s)

        Terms defined in the Agreement for wholesale financing between AT&T and
Dealer (the "Agreement") and not otherwise defined herein have those meanings
assigned to them in the Agreement.  Notwithstanding anything contained in the
Agreement or otherwise to the contrary, Dealer hereby covenants and agrees that
at all times Dealer will maintain on its premises or otherwise in its
possession, or under its custody or control, Inventory And Accounts Receivable
subject to the first lien of AT&T having an actual value from time to time
equal to at least one hundred fifty percent (150%) of the Indebtedness
outstanding from time to time.  For the purpose of this Schedule, the term
Accounts Receivable shall mean 85% of Dealer's accounts receivable, not
including those accounts receivable which have aged more than 90 days,  Within
fifteen (15) days after the end of each month, Dealer shall provide AT&T with
evidence satisfactory to AT&T in all respects that dealer is in compliance with
this covenant, and from time to time Dealer shall pay AT&T such amounts as are
necessary to reduce the Indebtedness outstanding from time to time to an amount
whereby Dealer shall be in compliance with this covenant at all times.

        Dealer shall, at all times, maintain Tangible Net worth, calculated
according to GAAP, of at least $5,500,000.00.  Dealer shall from time to time,
or upon reasonable notice from AT&T, provide AT&T with satisfactory evidence of
its compliance with this covenant.

        Without AT&T's prior written consent, Dealer shall not: 1) declare or
pay any dividend, purchase, redeem, retire or otherwise acquire for value any
of its capital stock now or hereafter outstanding; ii) make any distribution of
assets to its shareholders as such, whether in cash, assets or in obligations
of Dealer, or otherwise set apart any sum for the payment of any dividend or
distribution on, or for the purchase, redemption, or retirement of, any shares
of its capital stock: or iii) make any other distribution by reduction of
capital or otherwise in respect of any shares of its capital stock.


Date:  8/2/96

ECCS, Inc.

By:     /s/
   --------------

Title:   V.P. Finance & Administration
      ---------------------------------
One Sheila Drive, Building 6A
Tinton Falls, NJ  07724


AT&T COMMERCIAL FINANCE CORPORATION

By:    /s/
   ---------------------------

Title: VP Credit & Ops.
      ------------------------
44 Whippany road
Morristown, NJ  07962