<PAGE>

                  FIRST AMENDMENT TO REVOLVING CREDIT AGREEMENT


     This Amendment (the "Amendment") is made on this 14th day of August, 
1997 by and between Eltrax Systems, Inc., a Minnesota corporation, Nordata, 
Inc., a California corporation d/b/a Datatech, Atlantic Network Systems, 
Inc., a North Carolina corporation, EJG Techline, Incorporated, a California 
corporation, and Four Corners Technology, Inc., an Arizona corporation 
(individually a "Borrower" and collectively, the "Borrowers"), and State 
Street Bank and Trust Company, a Massachussetts trust company with its 
principal office at 225 Franklin Street, Boston, Massachusetts 02110 (the 
"Bank"); and

     WHEREAS, the Borrowers and the Bank are parties to a Revolving Credit 
Agreement dated as of October 31, 1996, as amended, which provides for the 
Bank to make available to the Borrowers a $5,000,000 Revolving Line of Credit 
(the "Credit Agreement");

     WHEREAS, the Borrowers desire that the Bank increase the Revolving Line 
of Credit by an additional $500,000, to a total of $5,500,000, such increase 
to be effective only until September 30, 1997 after which the amount of the 
Revolving Line of Credit will revert to $5,000,000, and the Bank is willing 
to make available to the Borrowers this increase in the Revolving Line of 
Credit, on the terms and conditions set forth therein.

     NOW, THEREFORE, the Borrowers, jointly and severally, and the Bank, 
hereby agree as follows:

1.  Section 1(a) of the Credit Agreement is hereby amended by changing the 
    definition of Commitment Amount, as set forth therein, to the following:

     "COMMITMENT AMOUNT:  From and after the date of the Amendment until 
September 30, 1997, $5,500,000"; thereafter $5,000,000.

2.  Section 2(a)(iii) of the Credit Agreement is hereby amended by deleting 
    the first sentence thereof and inserting the following in lieu thereof:

     "The Revolving Credit Loan shall be evidenced by an Amended and Restated 
     Commercial Promissory Note in the original principal amount of 
     $5,500,000 in substantially the form of EXHIBIT I hereto (the "Revolving
     Credit Note"), dated as of the date of the First Amendment to the Credit
     Agreement, and completed with appropriate insertions, which Revolving
     Credit Note shall be due and payable in full on the Maturity date."

3.  REPRESENTATIONS AND WARRANTIES.  Each of the Borrowers jointly and severally
    represents and warrants to the Bank as follows:
<PAGE>

     (a)  REPRESENTATIONS AND WARRANTIES.  The representations and warranties 
contained in Section 4 of the Credit Agreement and in each Instrument of 
Adherence (Credit Agreement) executed and delivered by one or more of the 
Borrowers to the Bank (the "Instrument of Adherence"), were true and correct 
in all material respects when made.  Except to the extent that such 
representations and warranties expressly relate to a specific date or were 
based on facts which have changed in the ordinary course of business, 
which changes either singly or in the aggregate, have not been materially 
adverse, the representations and warranties contained in Section 4 of the 
Credit Agreement and the Instruments of Adherence, after giving effect to 
this Amendment, are true and correct on the date hereof.

     (b)  ENFORCEABILITY.  The execution and delivery by each of the 
Borrowers of this Amendment, and the performance by each of the Borrowers of 
the Amendment and the Credit Agreement, as amended hereby, are within the 
corporate authority of such Person and have been duly authorized by all 
necessary corporate proceedings.  This Amendment and the Credit Agreement, as 
amended hereby, are valid and legally binding obligations of each of the a 
Borrowers, enforceable in accordance with their terms, except as limited by 
bankruptcy, insolvency, reorganization, moratorium or similar laws relating 
to the enforcement of creditors' rights in general.

     (c)  NO DEFAULT.  Except as set forth in the Compliance Certificate 
attached hereto, no Default or Event of Default has occurred and is 
continuing, and no Default or Event of Default will exist after the execution 
and delivery of this Amendment.

     (d)  OTHER AGREEMENTS.  The execution and delivery by each of the 
Borrowers of this Amendment, and the performance by each of the Borrowers of 
this Amendment and the Credit Agreement, as amended hereby, will not conflict 
with, or result in a breach of any term, condition or provision of, or 
constitute a default under, such Borrowers' charter or by-laws as presently 
in effect or any other agreement, trust, deed, indenture, mortgage or other 
instrument to which such Person is a party or by which such Person or any of 
the property of such Person is bound or affected.

4.  AFFIRMATION OF THE BORROWERS.  Each of the Borrowers hereby affirms its 
    absolute and unconditional, joint and several promise to pay to the Bank 
    the Loans and all other amounts due under the Credit Agreement on the 
    Maturity Date provided in the Credit Agreement, as amended hereby.

5.  EFFECTIVENESS.  The effectiveness of this Amendment shall be conditioned 
    upon receipt by the Bank of this Amendment, executed by each of the 
    Borrowers and the Bank. Execution of this Amendment by the Bank does not 
    constitute a waiver by the Bank of any defaults, notices of default or 
    rights of the Bank under the Credit


                                        2
<PAGE>

Agreement, as amended hereby, all of which are unaffected hereby and remain 
in full force and effect.

6.  MISCELLANEOUS PROVISIONS.

     (a)  Except as otherwise expressly provided by this Amendment, all of 
the terms, conditions and provisions of the Credit Agreement shall remain the 
same. It is declared and agreed by each of the parties hereto that the 
Credit Agreement, as amended hereby, is and shall continue in full force and 
effect, and that this Amendment and such Credit Agreement shall be read and 
construed as one instrument.

     (b)  This Amendment is intended to take effect as an agreement under 
seal and shall be construed according to and governed by the laws of the 
Commonwealth of Massachusetts.
  
     (c)  This Amendment may be executed in any number of counterparts, but 
all such counterparts shall together constitute but one instrument. In making 
proof of this Amendment it shall not be necessary to produce or account for 
more than one counterpart signed by each party hereto by and against which 
enforcement hereof is sought.

     (d)  Each of the Borrowers hereby jointly and severally agrees to pay to 
the Bank, on demand by the Bank, all reasonable out-of-pocket costs and 
expenses incurred or sustained by the Bank in connection with the preparation 
of this Amendment and the documents referred to herein (including reasonable 
legal fees).

     IN WITNESS WHEREOF, the parties have executed this Amendment as of the 
date first above written.

                                       ELTRAX SYSTEMS, INC.


                                       By: /s/ Nicholas J. Pyett
                                           -------------------------------
                                       Title: Treasurer
                                              ----------------------------


                                       NORDATA, INC. d/b/a Datatech


                                       By: /s/ Nicholas J. Pyett
                                           -------------------------------
                                       Title: Treasurer
                                              ----------------------------




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<PAGE>
                                       ATLANTIC NETWORK SYSTEMS, INC.


                                       By: /s/ Nicholas J. Pyett
                                           -------------------------------
                                       Title: Treasurer
                                              ----------------------------


                                       EJG TECHLINE INCORPORATED


                                       By: /s/ Nicholas J. Pyett
                                           -------------------------------
                                       Title: Treasurer
                                              ----------------------------


                                       FOUR CORNERS TECHNOLOGY, INC.


                                       By: /s/ Nicholas J. Pyett
                                           -------------------------------
                                       Title: Treasurer
                                              ----------------------------


                                       STATE STREET BANK AND TRUST COMPANY


                                       By: /s/ Frederic Epstein
                                           -------------------------------
                                       Title: Vice President
                                              ----------------------------




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