<PAGE>   1


                                                                  EXHIBIT 10.39

                           [ LOGO UNITED BANK LOGO ]

                            BUSINESS LOAN AGREEMENT
<TABLE>
<CAPTION>
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  PRINCIPAL         LOAN DATE      MATURITY      LOAN NO      CALL       COLLATERAL      ACCOUNT      OFFICER      INITIAL
<S>                <C>              <C>          <C>           <C>          <C>          <C>            <C>        <C>      
$1,000,000.00      06-02-1997                    1009809       04           1465                        104         [SIG]
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            References in the shaded area are for Lender's use only and do not limit the applicability of this document
                                                  to any particular loan or item.
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BORROWER:  Smyth Systems, Inc. (TIN: 33-0761324)                LENDER:  UNITED NATIONAL BANK & TRUST CO.
           7100 Whipple Ave. N.W.                                        P.O. BOX 24190
           North Canton, OH  44720                                       220 MARKET AVENUE SOUTH
                                                                         CANTON, OH 44702
</TABLE>

THIS BUSINESS LOAN AGREEMENT between Smyth Systems, Inc. ("Borrower") and UNITED
NATIONAL BANK & TRUST CO. ("Lender") is made and executed on the following
terms and conditions. Borrower has received prior commercial loans from Lender
or has applied to Lender for a commercial loan or loans and other financial
accommodations, including those which may be described on any exhibit or 
schedule attached to this Agreement. All such loans and financial
accommodations, together with all future loans and financial accommodations
from Lender to Borrower, are referred to in this Agreement individually as the
"Loan" and collectively as the "Loans." Borrower understands and agrees that:
(a) in granting, renewing, or extending any Loan, Lender is relying upon
Borrower's representations, warranties, and agreements, as set forth in this
Agreement; (b) the granting, renewing, or extending of any Loan by Lender at
all times shall be subject to Lender's sole judgment and discretion; and (c)
all such Loans shall be and shall remain subject to the following terms and
conditions of this Agreement.

TERM. This Agreement shall be effective as of June 2, 1997, and shall continue
thereafter until all Indebtedness of Borrower to Lender has been performed in
full and the parties terminate this Agreement in writing.

DEFINITIONS. The following words shall have the following meanings when used
in this Agreement. Terms not otherwise defined in this Agreement shall have
the meanings attributed to such terms in the Uniform Commercial Code. All
references to dollar amounts shall mean amounts in lawful money in the United
States of America.

     AGREEMENT. The word "Agreement" means this Business Loan Agreement, as
     this Business Loan Agreement may be amended or modified from time to time,
     together with all exhibits and schedules attached to this Business Loan
     Agreement from time to time.

     BORROWER. The word "Borrower" means Smyth Systems, Inc. The word "Borrower"
     also includes, as applicable, all subsidiaries and affiliates of Borrower
     as provided below in the paragraph titled "Subsidiaries and Affiliates."

     CERCLA. The word "CERCLA" means the Comprehensive Environmental Response,
     Compensation, and Liability Act of 1980, as amended.

     CASH FLOW. The words "Cash Flow" mean net income after taxes, and exclusive
     of extraordinary gains and income, plus depreciation and amortization.

     COLLATERAL. The word "Collateral" means and includes without limitation all
     property and assets granted as collateral security for a Loan, whether real
     or personal property, whether granted directly or indirectly, whether
     granted now or in the future, and whether granted in the form of a security
     interest, mortgage, deed of trust, assignment, pledge, chattel mortgage,
     chattel trust, factor's lien, equipment trust, conditional sale, trust
     receipt, lien, charge, lien or title retention contract, lease or
     consignment intended as a security device, or any other security or lien
     interest whatsoever, whether created by law, contract, or otherwise.

     DEBT. The word "Debt" means all of Borrower's liabilities excluding
     Subordinated Debt.

     ERISA. The word "ERISA" means the Employee Retirement Income Security Act
     of 1974, as amended.

     EVENT OF DEFAULT. The words "Event of Default" mean and include without
     limitation any of the Events of Default set forth below in the section
     titled "EVENTS OF DEFAULT."

     GRANTOR. The word "Grantor" means and includes without limitation each and
     all of the persons or entitles granting a Security Interest in any
     Collateral for the Indebtedness, including without limitation all Borrowers
     granting such a Security Interest.

     GUARANTOR. The word "Guarantor" means and includes without limitation each
     and all of the guarantors, sureties, and accommodation parties in
     connection with any Indebtedness.

     INDEBTEDNESS. The word "Indebtedness" means and includes without limitation
     all Loans, together with all other obligations, debts and liabilities of
     Borrower to Lender, or any one or more of them, as well as all claims by
     Lender against Borrower, or any one or more of them whether now or
     hereafter existing, voluntary or involuntary, due or not due, absolute or
     contingent, liquidated or unliquidated; whether Borrower may be liable
     individually, or jointly with others; whether Borrower may be obligated as
     a guarantor, surety, or otherwise; whether recovery upon such Indebtedness
     may be or hereafter may become barred by any statute of limitations; and
     whether such Indebtedness may be or hereafter may become otherwise
     unenforceable.

     LENDER.  The word "Lender" means UNITED NATIONAL BANK & TRUST CO., its
     successors and assigns.

     LIQUID ASSETS. The words "Liquid Assets" mean Borrower's cash on hand plus
     Borrower's readily marketable securities.

     LOAN. The word "Loan" or "Loans" means and includes without limitation any
     and all commercial loans and financial accommodations from Lender to
     Borrower, whether now or hereafter existing, and however evidenced,
     including without limitation those loans and financial accommodations
     described herein or described on any exhibit or schedule attached to this
     agreement from time to time.

     NOTE. The word "Note" means and includes without limitation Borrower's
     promissory note or notes, if any, evidencing Borrower's Loan obligations in
     favor of Lender, as well as any substitute, replacement or refinancing note
     or notes therefor.

     PERMITTED LIENS. The words "Permitted Liens" mean: (a) liens and security
     interests securing Indebtedness owed by Borrower to Lender; (b) liens for
     taxes, assessments, or similar charges either not yet due or being
     contested in good faith; (c) liens of materialmen, mechanics, warehousemen,
     or carriers, or other like liens arising in the ordinary course of
     business and securing obligations which are not yet delinquent; (d)
     purchase money liens or purchase money security interests upon or in any
     property acquired or held by Borrower in the ordinary course of business to
     secure Indebtedness outstanding on the date of this Agreement or permitted
     to be incurred under the paragraph of this Agreement titled "Indebtedness
     and Liens"; (e) liens and security interests which, as of the date of this
     Agreement, have been disclosed to and approved by the Lender in writing;
     and (f) those liens and security interests which in the aggregate
     constitute an immaterial and insignificant monetary amount with respect to
     the net value of Borrower's assets.

     RELATED DOCUMENTS. The words "Related Documents" mean and include without
     limitation all promissory notes, credit agreements, loan agreements,
     environmental agreements, guaranties, security agreements, mortgages, deeds
     of trust, and all other instruments, agreements and documents, whether now
     or hereafter existing, executed in connection with the indebtedness.

     SECURITY AGREEMENT. The words "Security Agreement" mean and include without
     limitation any agreements, promises, covenants, arrangements,
     understandings or other agreements, whether created by law, contract, or
     otherwise, evidencing, governing, representing, or creating a Security
     Interest.

     SECURITY INTEREST. The words "Security Interest mean and include without
     limitation, any type of collateral security, whether in the form of a lien,
     charge, mortgage, deed of trust, assignment, pledge, chattel mortgage,
     chattel trust, factor's lien, equipment trust, conditional sale, trust
     receipt, lien or title retention contract, lease or consignment intended as
     a security device, or any other security or lien interest whatsoever,
     whether created by law, contract, or otherwise.

     SARA. The word "SARA" means the Superfund Amendments and Reauthorization
     Act of 1988 as now or hereafter amended.

     SUBORDINATED DEBT. The words "Subordinated Debt" mean indebtedness and
     liabilities of Borrower which have been subordinated by written agreement
     to Indebtedness owed by Borrower to Lender in form and substance acceptable
     to Lender.

     TANGIBLE NET WORTH. The words "Tangible Net Worth" mean Borrower's total
     assets, excluding all intangible assets (i.e., goodwill, trademarks,
     patents, copyrights, organizational expenses, and similar intangible items,
     but including leaseholds and leasehold improvements) less total Debt.

     WORKING CAPITAL. The words "Working Capital" mean Borrower's current
     assets, excluding prepaid expenses, less Borrower's current liabilities.

CONDITIONS PRECEDENT TO EACH ADVANCE. Lender's obligation to make the initial
Loan Advance and each subsequent Loan Advance under this Agreement shall be
subject to the fulfillment to Lender's satisfaction of all of the conditions set
forth in this Agreement and in the Related Documents.

     LOAN DOCUMENTS. Borrower shall provide to Lender in form satisfactory to
     Lender the following documents for the Loan: (a) the Note, (b) Security
     Agreements granting to Lender security interests in the Collateral, 
     (c) Financing Statements perfecting Lenders Security Interests. (d) 
<PAGE>   2

6-02-1997                   BUSINESS LOAN AGREEMENT                      Page 2
1009809                           (Continued)

===============================================================================

        evidence of insurance as required below; and (e) any other documents
        required under this Agreement or by Lender or its counsel, including
        without limitation any guaranties described below.

        BORROWER'S AUTHORIZATION.  Borrower shall have provided in form and
        substance satisfactory to Lender properly certified resolutions, duly
        authorizing the execution and delivery of this Agreement, the Note and
        Related Documents, and such other authorizations and other documents and
        instruments as Lender or its counsel, in their sole discretion, may
        require.

        PAYMENT OF FEES AND EXPENSES.  Borrower shall have paid to Lender all
        fees, charges, and other expenses which are then due and payable as
        specified in this Agreement or any Related Document.

        REPRESENTATIONS AND WARRANTIES. The representations and warranties set
        forth in this Agreement, in the Related documents, and in any document
        or certificate delivered to Lender under this Agreement are true and
        correct.

        NO EVENT OF DEFAULT.  There shall not exist at the time of any advance a
        condition which would constitute an Event of Default under this
        Agreement.

REPRESENTATIONS AND WARRANTIES.  Borrower represents and warrants to Lender, as
of the date of this Agreement, as of the date of each Disbursement of Loan
proceeds, as of the date of any renewal, extension or modification of any Loan,
and at all times any indebtedness exists:

        ORGANIZATION:  Borrower is a corporation which is duly organized,
        validly existing, and in good standing under the laws of the State of
        Ohio and is validly existing and in good standing in all states in which
        Borrower is doing business. Borrower has the full power and authority to
        own its properties and to transact the businesses in which it is
        presently engaged or presently proposes to engage. Borrower also is duly
        qualified as a foreign corporation and is in good standing in all states
        in which the failure to so qualify would have a material adverse effect
        on its businesses of financial condition.

        AUTHORIZATION.  The execution, delivery, and performance of this
        Agreement and all Related Documents by Borrower, to the extent to be
        executed, delivered or performed by Borrower, have been duly authorized
        by all necessary action by Borrower; do not require the consent or
        approval of any other person, regulatory authority or governmental body;
        and do not conflict with, result in a violation of, or constitute a
        default under (a) any provision of its articles of incorporation or
        organization, or bylaws or code of regulations, or any agreement or
        other instrument binding upon Borrower or (b) any law, governmental
        regulation, court decree, or order applicable to Borrower.

        FINANCIAL INFORMATION. Each financial statement of Borrower supplied to
        Lender truly and completely disclosed Borrower's financial condition as
        of the date of the statement, and there has been no material adverse
        change in Borrower's financial condition subsequent to the date of the
        most recent financial statement supplied to Lender. Borrower has no
        material contingent obligations except as disclosed in such financial
        statements.

        LEGAL EFFECT.  This Agreement constitutes, and any instrument or
        agreement required hereunder to be given by Borrower when delivered will
        constitute, legal, valid and binding obligations of Borrower enforceable
        against Borrower in accordance with their respective terms.

        PROPERTIES.  Except as contemplated by this Agreement or as previously
        disclosed in Borrower's financial statements or in writing to Lender and
        as accepted by Lender, and except for property tax liens for taxes not
        presently due and payable, Borrower owns and has good title to all of
        Borrower's properties free and clear of all Security Interests, and has
        not executed any security documents or financing statements relating to
        such properties. All of Borrower's properties are titled in Borrower's
        legal name, Borrower has not used, or filed a financing statement under,
        any other name for at least the last five (5) years.

        HAZARDOUS SUBSTANCES.  The terms "hazardous waste," "hazardous
        substance," "disposal," "release," and "threatened release," as used in
        this Agreement, shall have the same meanings as set forth in the
        "CERCLA," "SARA," the Hazardous Materials Transportation Act, 49 U.S.C.
        Section 1801, et seq., the Resource Conservation and Recovery Act, 42
        U.S.C. Section 6901, et seq., or other applicable state or Federal laws,
        rules, or regulations adopted pursuant to any of the foregoing. Except
        as disclosed to and acknowledged by Lender in writing, Borrower
        represents and warrants that: (a) During the period of Borrower's
        ownership of the properties, there has been no use, generation,
        manufacture, storage, treatment, disposal, release or threatened release
        of any hazardous waste or substance by any person on, under, about or
        from any of the properties. (b) Borrower has no knowledge of, or reason
        to believe that there has been (i) any use, generation, manufacture,
        storage, treatment, disposal, release, or threatened release of any
        hazardous waste or substance on, under, about or from the properties by
        any prior owners or occupants of any of the properties, or (ii) any
        actual or threatened litigation or claims of any kind by any person
        relating to such matters. (c) Neither Borrower nor any tenant,
        contractor, agent or other authorized user of any of the properties
        shall use, generate, manufacture, store, treat, dispose of, or release
        any hazardous waste or substance on, under, about or from any of the
        properties; and any such activity shall be conducted in compliance with
        all applicable federal, state, and local laws, regulations, and
        ordinances, including without limitation those laws, regulations and
        ordinances described above. Borrower authorizes Lender and its agents to
        enter upon the properties to make such inspections and tests as Lender
        may deem appropriate to determine compliance of the properties with this
        section of the Agreement. Any inspections or liability or tests made by
        Lender shall be at Borrower's expense and for Lender's purposes only and
        shall not be construed to create any responsibility or liability on the
        part of Lender to Borrower or to any other person. The representations
        and warranties contained herein are based on Borrower's due diligence in
        investigating the properties for hazardous waste and hazardous
        substances. Borrower hereby (a) releases and waives any future claims
        against Lender to indemnity or contribution in the event the Borrower
        becomes liable for cleanup or other costs under any such laws, and (b)
        agrees to indemnify and hold harmless Lender against any and all claims,
        losses, liabilities, damages, penalties, and expenses which Lender may
        directly or indirectly sustain or suffer resulting from a breach of this
        section of the Agreement or as a consequence of any use, generation,
        manufacture, storage, disposal, release or threatened release occurring
        prior to Borrower's ownership or interest in the properties, whether or
        not the same was or should have been known to Borrower. The provisions
        of this section of the Agreement, including the obligation to indemnify,
        shall survive the payment of the indebtedness and the termination or
        expiration of this Agreement and shall not be affected by Lender's
        acquisition of any interest in any of the properties, whether by
        foreclosure or otherwise. 

        LITIGATION AND CLAIMS.  No litigation, claim, investigation,
        administrative proceeding or similar action (including those for unpaid
        taxes) against Borrower is pending or threatened, and no other event has
        occurred which may materially adversely affect Borrower's financial
        condition or properties, other than litigation, claims, or other events,
        if any, that have been disclosed to and acknowledged by Lender in
        writing. 

        TAXES.  To the best of Borrower's knowledge, all tax returns and reports
        of Borrower that are or were required to be filed, have been filed, and
        all taxes, assessments and other governmental charges have been paid in
        full, except those presently being or to be contested by Borrower in
        good faith in the ordinary course of business and for which adequate
        reserves have been provided.

        LIEN PRIORITY.  Unless otherwise previously disclosed to Lender in
        writing, Borrower has not entered into or granted any Security
        Agreements, or permitted the filing or attachment of any Security
        interests on or affecting any of the Collateral directly or indirectly
        securing repayment of Borrower's Loan and Note, that would be prior or
        that may in any way be superior to Lender's Security interests and
        rights in and to such Collateral.

        BINDING EFFECT.  This Agreement, the Note, all Security Agreements
        directly or indirectly securing repayment of Borrower's Loan and Note
        and all of the Related Documents are binding upon Borrower as well as
        upon Borrower's successors, representatives and assigns, and are legally
        enforceable in accordance with their respective terms.

        COMMERCIAL PURPOSES.  Borrower intends to use the Loan proceeds solely
        for business or commercial related purposes.

        EMPLOYEE BENEFIT PLANS.  Each employee benefit plan as to which Borrower
        may have any liability complies in all material respects with all
        applicable requirements of law and regulations, and (i) no Reportable
        Event nor Prohibited Transaction (as defined in ERISA) has occurred with
        respect to any such plan, (ii) Borrower has not withdrawn from any such
        plan or installed steps to do so, (iii) no steps have been taken to
        terminate any such plan, and (iv) there are no unfunded liabilities
        other than those previously disclosed to Lender in writing.

        LOCATION OF BORROWER'S OFFICES AND RECORDS.   Borrower's place of
        business, or Borrower's Chief executive office, if Borrower has more
        than one place of business, is located at 7100 Whipple Ave. N.W., North
        Canton, OH 44720. Unless Borrower has designated otherwise in writing
        this location is also the office or offices where Borrower keeps its
        records concerning the Collateral.

        INFORMATION.  All information heretofore or contemporaneously herewith
        furnished by Borrower to Lender for the purposes of or in connection
        with this Agreement or any transaction contemplated hereby is, and all
        information hereafter furnished by or on behalf of Borrower to Lender
        will be, true and accurate in every material respect on the date as of
        which such information is dated or certified; and none of such
        information is or will be incomplete by omitting to state any material
        fact necessary to make such information not misleading.

        SURVIVAL OF REPRESENTATIONS AND WARRANTIES.  Borrower understands and
        agrees that Lender, without independent investigation, is relying upon
        the above representations and warranties in extending Loan Advances to
        Borrower. Borrower further agrees that the foregoing representations and
        warranties shall be continuing in nature and shall remain in full force
        and effect until such time as Borrower's indebtedness shall be paid in
        full, or until this Agreement shall be terminated in the manner provided
        above, whichever is the last to occur.

AFFIRMATIVE COVENANTS.  Borrower covenants and agrees with Lender that, while
this Agreement is in effect, Borrower will:

        LITIGATION.  Promptly inform Lender in writing of (a) all material
        adverse changes in Borrower's financial condition, and (b) all existing
        and all threatened litigation, claims, investigations, administrative
        proceedings or similar actions affecting Borrower or any Guarantor which
        could materially affect the financial condition of Borrower or the
        financial condition of any Guarantor.
        
        FINANCIAL RECORDS.  Maintain books and records in accordance with
        generally accepted accounting principles, applied on a consistent basis,

<PAGE>   3
06-02-1997                  BUSINESS LOAN AGREEMENT                      Page 3
Loan No 1009809                   (Continued)
===============================================================================

   and permit Lender to examine and audit Borrower's books and records at all
   reasonable times.

   FINANCIAL STATEMENTS.  Furnish Lender with, as soon as available, but in no
   event later than ninety (90) days after the end of each fiscal year,
   Borrower's balance sheet and income statement for the year ended, audited by
   a certified public accountant satisfactory to Lender, and, as soon as
   available, but in no event later than thirty (30) days after the end of each
   fiscal quarter, Borrower's balance sheet and profit and loss statement for
   the period ended, prepared and certified as correct to the best knowledge and
   belief by Borrower's chief financial officer or other officer or person
   acceptable to Lender. All financial reports required to be provided under
   this Agreement shall be prepared in accordance with generally accepted
   accounting principles, applied on a consistent basis, and certified by
   Borrower as being true and correct.

   ADDITIONAL INFORMATION.  Furnish such additional information and statements,
   lists of assets and liabilities, agings of receivables of payables, inventory
   schedules, budgets, forecasts, tax returns, and other reports with respect to
   Borrower's financial condition and business operations as Lender may request
   from time to time. 

   FINANCIAL COVENANTS AND RATIOS.  Comply with the following covenants and
   ratios:

        TANGIBLE NET WORTH.  Maintain a minimum Tangible Net Worth of not less
   than $1,100,000.00.

        CURRENT RATIO.  Maintain a ratio of Current Assets to Current
   Liabilities in excess of 1.25 to 1.00.

   The following provisions shall apply for purposes of determining compliance
   with the foregoing financial covenants and ratios: December 31, 1997.  Except
   as provided above, all computations made to determine compliance with the
   requirements contained in this paragraph shall be made in accordance with
   generally accepted accounting principles, applied on a consistent basis, and
   certified by Borrower as being true and correct.

   INSURANCE.  Maintain fire and other risk insurance, public liability
   insurance, and such other insurance as Lender may require with respect to
   Borrower's properties and operations, in form, amounts, coverages and with
   insurance companies reasonably acceptable to Lender. Borrower, upon request
   of Lender, will deliver to Lender from time to time the policies or
   certificates of insurance in form satisfactory to Lender, including
   stipulations that coverages will not be cancelled or diminished without at
   least ten (10) days' prior written notice to Lender. Each insurance policy
   also shall include an endorsement providing that coverage in favor of Lender
   will not be impaired in any way by any act, omission or default of Borrower
   or any other person.  In connection with all policies covering assets in
   which Lender holds or is offered a security interest for the Loans, Borrower
   will provide Lender with such loss payable or other endorsements as Lender
   may require.

   INSURANCE REPORTS.  Furnish to Lender, upon request of Lender, reports on
   each existing insurance policy showing such information as Lender may
   reasonably request, including without limitation the following: (a) the name
   of the insurer; (b) the risks insured; (c) the amount of the policy; (d) the
   properties insured; (e) the then current property values on the basis of
   which insurance has been obtained, and the manner of determining those
   values; and (f) the expiration date of the policy.  In addition, upon request
   of Lender (however not more often than annually), Borrower will have an
   independent appraiser satisfactory to Lender determine, as applicable, the
   actual cash value or replacement cost of any Collateral.  The cost of such
   appraisal shall be paid by Borrower.

   GUARANTIES.  Prior to disbursement of any Loan proceeds, furnish executed
   guaranties of the Loans in favor of Lender, executed by the guarantor named
   below, on Lender's forms, and in the amount and under the conditions spelled
   out in those guaranties.

        GUARANTOR                                  AMOUNT
        ---------                                  ------
        BRISTOL TECHNOLOGY SYSTEMS, INC.        $1,000,000.00

   OTHER AGREEMENTS.  Comply with all terms and conditions of all other
   agreements, whether now or hereafter existing, between Borrower and any other
   party and notify Lender immediately in writing of any default in connection
   with any other such agreements.

   LOAN PROCEEDS.  Use all Loan proceeds solely for Borrower's business
   operations, unless specifically consented to the contrary by Lender in
   writing. 

   TAXES, CHARGES AND LIENS.  Pay and discharge when due all of its indebtedness
   and obligations, including without limitation all assessments, taxes,
   governmental charges, levies and liens, of every kind and nature, imposed
   upon Borrower or its properties, income, or profits, prior to the date on
   which penalties would attach, and all lawful claims that, if unpaid, might
   become a lien or charge upon any of Borrower's properties, income or profits.
   Provided, however, Borrower will not be required to pay and discharge any
   such assessment, tax, charge, levy, lien or claim so long as (a) the legality
   of the same shall be contested in good faith by appropriate proceedings, and
   (b) Borrower shall have established on its books adequate reserves with
   respect to such contested assessment, tax, charge, levy, lien, or claim in
   accordance with generally accepted accounting practices. Borrower, upon
   demand of Lender, will furnish to Lender evidence of payment of the
   assessments, taxes, charges, levies, liens and claims and will authorize the
   appropriate governmental official to deliver to Lender at any time a written
   statement of any assessments, taxes, charges, levies, liens and claims
   against Borrower's properties, income or profits.

   PERFORMANCE.  Perform and comply with all terms, conditions, and provisions
   set forth in this Agreement and in the Related Documents in a timely manner,
   and promptly notify Lender if Borrower learns of the occurrence of any event
   which constitutes an Event of Default under this Agreement or under any of
   the Related Documents.

   OPERATIONS.  Maintain executive and management personnel with substantially
   the same qualifications and experience as the present executive and
   management personnel; provide written notice to Lender of any change in
   executive and management personnel; conduct its business affairs in a
   reasonable and prudent manner and in compliance with all applicable federal,
   state and municipal laws, ordinances, rules and regulations respecting its
   properties, charters, businesses and operations, including without
   limitation, compliance with the Americans With Disabilities Act and with all
   minimum funding standards and other requirements of ERISA and other laws
   applicable to Borrower's employee benefit plans.   

   INSPECTION.  Permit employees or agents of Lender at any reasonable time to
   inspect any and all Collateral for the Loan or Loans and Borrower's other
   properties and to examine or audit Borrower's books, accounts, and records
   and to make copies and memoranda of Borrower's books, accounts, and records.
   If Borrower now or at any time hereafter maintains any records (including
   without limitation computer generated records and computer software programs
   for the generation of such records) in the possession of a third party,
   Borrower, upon request of Lender, shall notify such party to permit Lender
   free access to such records at all reasonable times and to provide Lender
   with copies of any records it may request, all at Borrower's expense.

   COMPLIANCE CERTIFICATE.  Unless waived in writing by Lender, provide Lender
   at least annually and at the time of each disbursement of Loan proceeds with
   a certificate executed by Borrower's chief financial officer, or other
   officer or person acceptable to Lender, certifying that the representations
   and warranties set forth in this Agreement are true and correct as of the
   date of the certificate and further certifying that, as of the date of the
   certificate, no Event of Default exists under this Agreement.

   ENVIRONMENTAL COMPLIANCE AND REPORTS.  Borrower shall comply in all respects
   with all environmental protection federal, state and local laws, statutes,
   regulations and ordinances; not cause or permit to exist, as a result of an
   intentional or unintentional action or omission on its part or on the part
   of any third party, on property owned and/or occupied by Borrowers, any
   environmental activity where damage may result to the environment, unless
   such environmental activity is pursuant to and in compliance with the
   conditions of a permit issued by the appropriate federal, state or local
   governmental authorities; shall furnish to Lender promptly and in any event
   within thirty (30) days after receipt thereof a copy of any notice, summons,
   lien, citation, directive, letter or other communication from any
   governmental agency or instrumentality concerning any intentional or
   unintentional action or omission on Borrower's part in connection with any
   environmental activity whether or not there is damage to the environment and
   /or other natural resources.

   ADDITIONAL ASSURANCES.  Make, execute and deliver to Lender such promissory
   notes, deeds of trust, security agreements, financing statements,
   instruments, documents and other agreements as Lender or its attorneys may
   reasonably request to evidence and secure the Loans and to perfect all
   Security interests. 

NEGATIVE COVENANTS.  Borrower covenants and agrees with Lender that while this
Agreement is in effect, Borrower shall not, without the prior written consent
of Lender:

   INDEBTEDNESS AND LIENS.  (a) Except for trade debt incurred in the normal
   course of business and indebtedness to Lender contemplated by this Agreement,
   create, incur or assume indebtedness for borrowed money, including capital
   leases, (b) except as allowed as a Permitted Lien, sell, transfer, mortgage,
   assign, pledge, lease, grant a security interest in, or encumber any of
   Borrower's assets, or (c) sell with recourse any of Borrower's accounts,
   except to Lender.

   CONTINUITY OF OPERATIONS.  (a) Engage in any business activities
   substantially different than those in which Borrower is presently engaged,
   (b) cease operations, liquidate, merge, transfer, acquire or consolidate with
   any other entity, change ownership, change its name, dissolve or transfer or
   sell Collateral out of the ordinary course of business, (c) pay any dividends
   on Borrower's stock (other than dividends payable in its stock), provided,
   however, that notwithstanding the foregoing, but only so long as no Event of
   Default has occurred and is continuing or would result from the payment of
   dividends, if Borrower is a "Subchapter S Corporation" (as defined in the
   Internal Revenue Code of 1986, as amended), Borrower may pay cash dividends
   on its stock to its shareholders from time to time in amounts necessary to
   enable the shareholders to pay income taxes and make estimated income tax
   payments to satisfy their liabilities under federal and state law which arise
   solely from their status as Shareholders of a Subchapter S Corporation
   because of their ownership of shares of stock of Borrower, or (d) purchase or
   retire any of Borrower's outstanding shares or alter or amend Borrower's
   capital structure.
<PAGE>   4

6-02-1997                   BUSINESS LOAN AGREEMENT                       Page 4
1009809                           (Continued)
===============================================================================

        LOANS, ACQUISITIONS AND GUARANTIES. (a) Loan, invest in or advance
        money or assets, (b) purchase, create or acquire any interest in any
        other enterprise or entity, or (c) incur any obligation as surety or
        guarantor other than in the ordinary course of business.

CESSATION OF ADVANCES. If Lender has made any commitment to make any Loan to
Borrower, whether under this Agreement or under any other agreement, Lender
shall have no obligation to make Loan Advances or to disburse Loan proceeds if:
(a) Borrower or any Guarantor is in default under the terms of this Agreement
or any of the Related Documents or any other agreement that Borrower or any
Guarantor has with Lender; (b) Borrower or any Guarantor becomes insolvent,
files a petition in bankruptcy or similar proceedings, or is adjudged a
bankrupt; (c) there occurs a material adverse change in Borrower's financial
condition, in the financial condition of any Guarantor, or in the value of any
Collateral securing any Loan; (d) any Guarantor seeks, claims or otherwise
attempts to limit, modify or revoke such Guarantor's guaranty of the Loan or
any other loan with Lender; or (e) Lender in good faith deems itself insecure,
even though no Event of Default shall have occurred.

RIGHT OF SETOFF. Borrower grants to Lender a contractual possessory security
interest in, and hereby assigns, conveys, delivers, pledges, and transfers to
Lender all Borrower's right, title and interest in and to, Borrower's accounts
with Lender (whether checking, savings, or some other account), including
without limitation all accounts held jointly with someone else and all accounts
Borrower may open in the future, excluding however all IRA and Keogh accounts,
and all trust accounts for which the grant of a security interest would be
prohibited by law. Borrower authorizes Lender, to the extent permitted by
applicable law, to charge or setoff all sums owing on the indebtedness against
any and all such accounts.

EVENTS OF DEFAULT. Each of the following shall constitute an Event of Default
under this Agreement:

        DEFAULT ON INDEBTEDNESS. Failure of Borrower to make any payment when
        due on the Loans.

        OTHER DEFAULTS. Failure of Borrower or any Grantor to comply with or to
        perform when due any other term, obligation, covenant or condition
        contained in this Agreement or in any of the Release Documents, or
        failure of Borrower to comply with or to perform any other term,
        obligation, covenant or condition contained in any other agreement
        between Lender and Borrower.

        DEFAULT IN FAVOR OF THIRD PARTIES. Should Borrower or any Grantor
        default under any loan, extension of credit, security agreement,
        purchase or sales agreement, or any other agreement, in favor of any
        other creditor or person that may materially affect any of Borrower's
        property or Borrower's or any Grantor's ability to repay the Loans or
        perform their respective obligations under this Agreement or any of the
        Related Documents.
        
        FALSE STATEMENTS. Any warranty, representation or statement made or
        furnished to Lender by or on behalf of Borrower or any Grantor under
        this Agreement or the Related Documents is false or misleading in any
        material respect at the time made or furnished, or becomes false or
        misleading at any time thereafter.

        DEFECTIVE COLLATERALIZATION. This Agreement or any of the Related
        Documents ceases to be in full force and effect (including failure of
        any Security Agreement to create a valid and perfected Security
        interest) at any time and for any reason.

        INSOLVENCY. The dissolution or termination of Borrower's existence as a
        going business, the insolvency of Borrower, the appointment of a
        receiver for any part of Borrower's property, any assignment for the
        benefit of creditors, any type of creditor workout, or the commencement
        of any proceeding under any bankruptcy or insolvency laws by or against
        Borrower.

        CREDITOR OR FORFEITURE PROCEEDINGS. Commencement of foreclosure or
        forfeiture proceedings, whether by judicial proceeding, self-help,
        repossession or any other method, by any creditor of Borrower, any
        creditor of any Grantor against any collateral securing the
        indebtedness, or by any governmental agency. This includes a
        garnishment, attachment, or levy on or of any of Borrower's deposit
        accounts with Lender. However, this Event of Default shall not apply if
        there is a good faith dispute by Borrower or Grantor, as the case may
        be, as to the validity or reasonableness of the claim which is the basis
        of the creditor or forfeiture proceeding, and if Borrower or Grantor
        gives Lender written notice of the creditor or forfeiture proceeding and
        furnishes reserves or a surety bond for the creditor or forfeiture
        proceeding satisfactory to Lender. 

        EVENTS AFFECTING GUARANTOR. Any of the preceding events occurs with
        respect to any Guarantor of any of the indebtedness or any Guarantor
        dies or becomes incompetent, or revokes or disputes the validity of, or
        liability under, any Guaranty of the indebtedness. Lender, at its
        option, may, but shall not be required to, permit the Guarantor's estate
        to assume unconditionally the obligations arising under the guaranty in
        a manner satisfactory to Lender, and, in doing so, cure the Event of
        Default.

        CHANGE IN OWNERSHIP. Any change in ownership of twenty-five percent
        (25%) or more of the common stock of Borrower.

        ADVERSE CHANGE. A material adverse change occurs in Borrower's financial
        condition, or Lender believes the prospect of payment or performance of
        the indebtedness is impaired.

        INSECURITY. Lender, in good faith, deems itself insecure.

        RIGHT TO CURE. If any default, other than a Default on indebtedness, is
        curable and if Borrower or Grantor, as the case may be, has not been
        given a notice of a similar default within the preceding twelve (12)
        months, it may be cured (and no Event of Default will have occurred) if
        Borrower or Grantor, as the case may be, after receiving written notice
        from Lender demanding cure of such default: (a) cures the default within
        fifteen (15) days; or (b) if the cure requires more than fifteen (15)
        days, immediately initiates steps which Lender deems in Lender's sole
        discretion to be sufficient to cure the default and thereafter continues
        and completes all reasonable and necessary steps sufficient to produce
        compliance as soon as reasonably practical.

EFFECT OF AN EVENT OF DEFAULT. If any Event of Default shall occur, except
where otherwise provided in this Agreement or the Related Documents, all
commitments and obligations of Lender under this Agreement or the Related
Documents or any other agreement immediately will terminate (including any
obligation to make the Loan Advances or disbursement), and, at Lender's option,
all indebtedness immediately will become due and payable, all without notice of
any kind to Borrower, except that in the case of an Event of Default of the
type described in the "Insolvency" subsection above, such acceleration shall be
automatic and not optional. In addition, Lender shall have all the rights and
remedies provided in the Related Documents or available at law, in equity, or
otherwise. Except as may be prohibited by applicable law, all of Lender's
rights and remedies shall be cumulative and may be exercised singularly or
concurrently. Election by Lender to pursue any remedy shall not exclude pursuit
of any other remedy, and an election to make expenditures or to take action to
perform an obligation of Borrower or of any Grantor shall not affect Lender's
right to declare a default and to exercise its rights and remedies.

MISCELLANEOUS PROVISIONS. The following miscellaneous provisions are a part of
this Agreement.

        AMENDMENTS. This Agreement, together with any Related Documents,
        constitutes the entire understanding and agreement of the parties as to
        the matters set forth in this Agreement. No alteration of or amendment
        to this Agreement shall be effective unless given in writing and signed
        by the party or parties sought to be charged or bound by the
        acceleration or amendment.

        APPLICABLE LAW. This Agreement has been delivered to Lender and accepted
        by Lender in the State of Ohio. If there is a lawsuit, Borrower agrees
        upon Lender's request to submit to the jurisdiction of the courts of
        STARK County, the State of Ohio. Lender and Borrower hereby waive the
        right to any jury trial in any action, proceeding, or counterclaim
        brought by either Lender or Borrower against the other. This Agreement
        shall be governed by and construed in accordance with the laws of the
        State of Ohio.

        CAPTION HEADINGS. Caption headings in this Agreement are for convenience
        purposes only and are not to be used to interpret or define the
        provisions of this Agreement.

        MULTIPLE PARTIES; CORPORATE AUTHORITY. All obligations of Borrower under
        this Agreement shall be joint and several, and all references to
        Borrower shall mean each and every Borrower. This means that each of the
        persons signing below is responsible for all obligations in this
        Agreement.

        CONSENT TO LOAN PARTICIPATION. Borrower agrees and consents to Lender's
        sale or transfer, whether now or later, of one or more participation
        interests in the Loans to one or more purchasers, whether related or
        unrelated to Lender. Lender may provide, without any limitation
        whatsoever, to any one or more purchasers, or potential purchasers, any
        information or knowledge Lender may have about Borrower or about any
        other matter relating to the Loan, and Borrower hereby waives any rights
        to privacy it may have with respect to such matters. Borrower also
        agrees that the purchasers of any such participation interests will be
        considered as the absolute owners of such interests in the Loans and
        will have all the rights granted under the participation agreement or
        agreements governing the sale of such participation interests. Borrower
        further waives all rights of offset or counterclaim that it may have
        now or later against Lender or against any purchaser of such a
        participation interest and unconditionally agrees that either Lender or
        such purchaser may enforce Borrower's obligation under the Loans
        irrespective of the failure or insolvency of any holder of any interest
        in the Loans. Borrower further agrees that the purchaser of any such
        participation interests may enforce its interests irrespective of any
        personal claims or defenses that Borrower may have against Lender. 

        COSTS AND EXPENSES. Borrower agrees to pay upon demand all of Lender's
        expenses, including without limitation attorney's fees, incurred in
        connection with the preparation, execution, enforcement, modification
        and collection of this Agreement or in connection with the Loans made
        pursuant to this Agreement. Lender may pay someone else to help collect
        the Loans and to enforce this Agreement, and Borrower will pay that
        amount. This includes, subject to any limits under applicable law,
        Lender's attorney's fees and Lender's legal expenses, whether or not
        there is a lawsuit, including attorney's fees for bankruptcy proceedings
        (including efforts to modify or vacate any automatic stay or
        injunction), appeals, and any anticipated post-judgment collection
        services. Borrower also will pay any court costs, in addition to all
        other sums provided by law.

        NOTICES. All notices required to be given under this Agreement shall be
        given in writing, may be sent by telefacsimile, and shall be effective
        when actually delivered or when deposited with a nationally recognized
        overnight courier or deposited in the United States mail, first class,
        postage 
<PAGE>   5

6-02-1997                 BUSINESS LOAN AGREEMENT
LOAN NO 1009809                 (CONTINUED)
================================================================================

        prepaid, addressed to the party to whom the notice is to be given at the
        address shown above. Any party may change its address for notices under
        this Agreement by giving formal written notice to the other parties,
        specifying that the purpose of the notice is to change the party's
        address. To the extent permitted by applicable law, if there is more
        than one Borrower, notice to any Borrower will constitute notice to all
        Borrowers. For notice purposes, Borrower will keep Lender informed at
        all times of Borrower's current address(es).

        SEVERABILITY.  If a court of competent jurisdiction finds any provision
        of this Agreement to be invalid or unenforceable as to any person or
        circumstance, such finding shall not render that provision invalid or
        unenforceable as to any other persons or circumstances. If feasible, any
        such offending provision shall be deemed to be modified to be within the
        limits of enforceability or validity; however, if the offending
        provision cannot be so modified, it shall be stricken and all other
        provisions of this Agreement in all other respects shall remain valid
        and enforceable.

        SUBSIDIARIES AND AFFILIATES OF BORROWER.  To the extent the context of
        any provisions of this Agreement makes it appropriate, including without
        limitation any representation, warranty or covenant, the word "Borrower"
        as used herein shall include all subsidiaries and affiliates of
        Borrower. Notwithstanding the foregoing however, under no circumstances
        shall this Agreement be construed to require Lender to make any Loan or
        other financial accommodation to any subsidiary or affiliate of
        Borrower.*

        SUCCESSORS AND ASSIGNS.  All covenants and agreements contained by or on
        behalf of Borrower shall bind its successors and assigns and shall inure
        to the benefit of Lender, its successors and assigns. Borrower shall
        not, however, have the right to assign its rights under this Agreement
        or any interest therein, without the prior written consent of Lender.

        SURVIVAL.  All warranties, representations, and covenants made by
        Borrower in this Agreement or in any certificate or other instrument
        delivered by Borrower to Lender under this Agreement shall be considered
        to have been relied upon by Lender and will survive the making of the
        Loan and delivery to Lender of the Related Documents, regardless of any
        investigation made by Lender or on Lender's behalf.

        TIME IS OF THE ESSENCE.  Time is of the essence in the performance of
        this Agreement.

        WAIVER.  Lender shall not be deemed to have waived any rights under this
        Agreement unless such waiver is given in writing and signed by Lender.
        No delay or omission on the part of Lender in exercising any right shall
        operate as a waiver of such right or any other right. A waiver by Lender
        of a provision of this Agreement shall not prejudice or constitute a
        waiver of Lender's right otherwise to demand strict compliance with that
        provision or any other provision of this Agreement. No prior waiver by
        Lender, nor any course of dealing between Lender and Borrower, or
        between Lender and any Grantor, shall constitute a waiver of any of
        Lender's rights or of any obligations of Borrower or of any Grantor as
        to any future transactions. Whenever the consent of Lender is required
        under this Agreement, the granting of such consent by Lender in any
        instance shall not constitute continuing consent in subsequent instances
        where such consent is required, and in all cases such consent may be
        granted or withheld in the sole discretion of Lender.

BORROWER ACKNOWLEDGES HAVING READ ALL THE PROVISIONS OF THIS BUSINESS LOAN
AGREEMENT, AND BORROWER AGREES TO ITS TERMS. THIS AGREEMENT IS DATED AS OF JUNE
2, 1997.

BORROWER:

Smyth Systems, Inc.

By: /s/ ROBERT T. SMYTH                By:  /s/ RICHARD H. WALKER
    ---------------------------             ---------------------------
    Robert T. Smyth, President              Richard H. Walker, Vice President

LENDER:

UNITED NATIONAL BANK & TRUST CO.

By:     [SIG]
    ---------------------------
     Authorized Officer

================================================================================

*For purposes of this Business Loan Agreement, Bristol Technology Systems,
Inc., who is the parent corporation of Smyth Systems, Inc., shall not be
considered as "Borrower".

UNS ________   Smyth Systems, Inc. ________
<PAGE>   6
                               [UNITED BANK LOGO]
                        UNITED NATIONAL BANK & TRUST CO.

                                PROMISSORY NOTE
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------------
Principal       Loan Date       Maturity        Loan No.        Call    Collateral      Account         Officer         Initials
$1,000,000      06-02-1997                      1009809          04     1465                            104             
-----------------------------------------------------------------------------------------------------------------------------------
References in the shaded area are for Lender's use only and do not limit the applicability of this document to any particular loan
or item.
-----------------------------------------------------------------------------------------------------------------------------------
<S>        <C>                                             <C>      <C>
Borrower:  Smyth Systems, Inc. (TIN: 33-0751324            Lender:  UNITED NATIONAL BANK & TRUST CO.
           7100 Whipple Ave. N.W.                                   P.O. BOX 24190
           North Canton, OH 44720                                   220 MARKET AVENUE SOUTH
                                                                    CANTON, OH 44702
===================================================================================================================================
</TABLE>

Principal Amount: $1,000,000  Initial Rate: 9.000%  Date of Note: June 2, 1997

PROMISE TO PAY. Smyth Systems, Inc. ("Borrower") promises to pay to UNITED
NATIONAL BANK & TRUST CO. ("Lender"), or order, in lawful money of the United
States of America, on demand, the principal amount of One Million & 00/100
Dollars ($1,000,000) or so much as may be outstanding, together with interest
on the unpaid outstanding principal balance of each advance. Interest shall be
calculated from the date of each advance until repayment of each advance. The
interest rate will not increase above 25.000%.

PAYMENT. Borrower will pay this loan immediately upon Lender's demand. In
addition, Borrower will pay regular monthly payments of all accrued unpaid
interest due as of each payment date, beginning July 2, 1997, with all
subsequent interest payments to be due on the same day of each month after
that. Interest on this Note is computed on a 365/360 simple interest basis;
that is, by applying the ratio of the annual interest rate over a year of 360
days, multiplied by the outstanding principal balance, multiplied by the actual
number of days the principal balance is outstanding. Borrower will pay Lender
at Lender's address shown above or at such other place as Lender may designate
in writing. Unless otherwise agreed or required by applicable law, payments
will be applied first to any unpaid collection costs and any late charges, then
to any unpaid interest, and any remaining amount to principal.

VARIABLE INTEREST RATE. The interest rate on this Note is subject to change
from time to time based on changes in an index which is the UNITED NATIONAL
BANK BASE LENDING RATE. The Base Rate will be determined by the Loan Committee
and then reported to the Executive Committee. The Base Rate will be established
upon consideration of the following factors: (1) The prime or base rate of
money bank centers in Cleveland, Pittsburgh and New York. (2) Competitive
conditions for the commercial loan market in the Bank's lending area. (3) The
Bank's money position and cost of funds. The Loan Committee shall periodically
review the Base Rate and make adjustments as needed reflecting the fluctuation
in the prime rate and pressures in the market. Debtor will then be notified
each time Bank changes the Base Rate, (the "Index"). The Index is not
necessarily the lowest rate charged by Lender on its loans and is set by Lender
in its sole discretion. If the Index becomes unavailable during the term of
this loan, Lender may designate a substitute index after notifying Borrower.
Lender will tell Borrower the current index rate upon Borrower's request.
Borrower understands that Lender may make loans based on other rates as well.
The interest rate change will not occur more often than each day. The index
currently is 8.500% per annum. The interest rate to be applied to the unpaid
principal balance of this Note will be at a rate of 0.500 percentage points
over the index, adjusted if necessary for the maximum rate limitation described
below, resulting in an initial rate of 9.000% per annum. Notwithstanding any
other provision of this Note, the variable interest rate or rates provided for
in this Note will be subject to the following maximum rate. NOTICE: Under no
circumstances will the interest rate on this Note be more than (except for any
higher default rate shown below) the lesser of 25.000% per annum or the maximum
rate allowed by applicable law.

PREPAYMENT; MINIMUM INTEREST CHARGE. Borrower agrees that all loan fees and
other prepaid finance charges are earned fully as of the date of the loan and
will not be subject to refund upon early payment (whether voluntary or as a
result of default), except as otherwise required by law. In any event, even
upon full prepayment of this Note, Borrower understands that Lender is entitled
to a minimum interest charge of $75.00. Other than Borrower's obligation to pay
any minimum interest charge, Borrower may pay without penalty all or a portion
of the amount owed earlier than it is due. Early payments will not, unless
agreed to by Lender in writing, relieve Borrower of Borrower's obligation to
continue to make payments of accrued unpaid interest. Rather, they will reduce
the principal balance due.

DEFAULT. Borrower will be in default if any of the following happens: (a)
Borrower fails to make any payment when due. (b) Borrower breaks any promise
Borrower has made to Lender, or Borrower fails to comply with or to perform
when due any other term, obligation, covenant, or condition contained in this
Note or any agreement related to this Note, or in any other agreement or loan
Borrower has with Lender. (c) Borrower defaults under any loan, extension of
credit, security agreement, purchase or sales agreement, or any other
agreement, in favor of any other creditor or person that may materially affect
any of Borrower's property or Borrower's ability to repay this Note or perform
Borrower's obligations under this Note or any of the Related Documents. (d) Any
representation or statement made or furnished to Lender by Borrower or on
Borrower's behalf is false or misleading in any material respect either now or
at the time made or furnished. (e) Borrower becomes insolvent, a receiver is
appointed for any part of Borrower's property, Borrower makes an assignment for
the benefit of creditors, or any proceeding is commenced either by Borrower or
against Borrower under any bankruptcy or insolvency laws. (f) Any creditor
tries to take any of Borrower's property on or in which Lender has a lien or
security interest. This includes a garnishment of any of Borrower's accounts
with Lender. (g)Any guarantor dies or any of the other events described in this
default section occurs with respect to any guarantor of this Note. (h) A
material adverse change occurs in Borrower's financial condition, or Lender
believes the prospect of payment or performance of the indebtedness is
impaired. (i) Lender in good faith deems itself insecure.

If any default, other than a default in payment, is curable and if Borrower has
not been given a notice of a breach of the same provision of this Note within
the proceeding twelve (12) months, it may be cured (and no event of default
will have occurred) if Borrower, after receiving written notice from Lender
demanding cure of such default: (a) cures the default within fifteen (15) days;
or (b) if the cure requires more than fifteen (15) days, immediately initiates
steps which Lender deems in Lender's sole discretion to be sufficient to cure
the default and thereafter continues and completes all reasonable and necessary
steps sufficient to produce compliance as soon as reasonably practical.

LENDER'S RIGHTS. Upon default, Lender may declare the entire unpaid principal
balance on this Note and all accrued unpaid interest immediately due, without
notice, and then Borrower will pay that amount. Upon default, including failure
to pay upon final maturity, Lender, at its option, may also, if permitted under
applicable law, increase the variable interest rate on this Note to 5.500
percentage points over the Index. The interest rate will not exceed the maximum
rate permitted by applicable law. Lender may hire or pay someone else to help
collect this Note if Borrower does not pay. Borrower also will pay Lender that
amount. This includes, subject to any limits under applicable law, Lender's
attorneys' fees and Lender's legal expenses whether or not there is a lawsuit,
including attorneys' fees and legal expenses for bankruptcy proceedings
(including efforts to modify or vacate any automatic stay or injunction),
appeals, and any anticipated post-judgment collection services. If not
prohibited by applicable law, Borrower also will pay any court costs, in
addition to all other sums provided by law. This Note has been delivered to
Lender and accepted by Lender in the State of Ohio. If there is a lawsuit,
Borrower agrees upon Lender's request to submit to the jurisdiction of the
courts of STARK County, the State of Ohio. Lender and Borrower hereby waive the
right to any jury trial in any action, proceeding, or counterclaim brought by
either Lender or Borrower against the other. This Note shall be governed by and
construed in accordance with the laws of the State of Ohio.

CONFESSION OF JUDGMENT. Borrower hereby irrevocably authorizes and empowers any
attorney-at-law, including an attorney hired by Lender, to appear in any court
of record and to confess judgment against Borrower for the unpaid amount of
this Note as evidenced by an affidavit signed by an officer of Lender setting
forth the amount then due, plus attorneys' fees as provided in this Note plus
costs of suit, and to release all errors, and all rights of appeal. If a copy
of this Note, verified by an affidavit, shall have been filed in the
proceeding, it will not be necessary to file the original as a warrant of
attorney. Borrower waives the right to any stay of execution and the benefit of
all exemption laws now or hereafter in effect. No single exercise of the
foregoing warrant and power to confess judgment will be deemed to exhaust the
power, whether or not any such exercise shall be held by any court to be
invalid, voidable, or void; but the power will continue undiminished and may be
exercised from time to time as Lender may elect until all amounts owing on this
Note have been paid in full. Borrower waives any conflict of interest that an
attorney hired by Lender may have in acting on behalf of Borrower in confessing
judgment against Borrower while such attorney is retained by Lender. Borrower
expressly consents to such attorney acting for Borrower in confessing judgment.

DISHONORED ITEM FEE. Borrower will pay a fee to Lender of $23.00 if Borrower
makes a payment on Borrower's loan and the check or preauthorized charge with
which Borrower pays is later dishonored.

RIGHT OF SETOFF. Borrower grants to Lender a contractual possessory security
interest in, and hereby assigns, conveys, delivers, pledges, and transfers to
Lender all Borrower's right, title and interest in and to, Borrower's accounts
with Lender (whether checking, savings, or some account), including without
limitation all accounts hold jointly with someone else and all accounts
Borrower may open in the future, excluding however all IRA and Keogh accounts,
and all trust accounts for which the grant of a security interest would be
prohibited by law. Borrower authorizes Lender, to the extent permitted by
applicable law, to charge or setoff all sums owing on this Note against any and
all such accounts.

COLLATERAL. This Note is secured by a Blanket lien on all business assets.

LINE OF CREDIT. This Note evidences a revolving line of credit. Advances under
this Note may be requested either orally or in writing by Borrower or by an
authorized person. Lender may, but need not require that all oral requests be
confirmed in writing. All communications, instructions, or directions by
telephone or otherwise to Lender are to be directed to Lender's office shown
above. The following party or parties are authorized to request advances under
the line of credit until Lender receives from Borrower at Lender's address
shown above written notice of revocation of their authority: Robert T. Smyth,
President; and Richard H. Walker, Vice President. Borrower agrees to be liable
for all sums either (a) advanced in
<PAGE>   7

6-02-1997                       PROMISSORY NOTE                          Page 2
LOAN NO. 1009809                  (Continued)

===============================================================================

accordance with the instructions of an authorized person or (b) credited to any
of Borrower's accounts with Lender. The unpaid principal balance owing on this
Note at any time may be evidenced by endorsements on this Note or by Lender's
internal records, including daily computer print-outs. Lender will have no
obligation to advance funds under this Note if: (a) Borrower or any guarantor is
in default under the terms of this Note or any agreement that Borrower or any
guarantor has with Lender, including any agreement made in connection with the
signing of this Note; (b) Borrower or any guarantor ceases doing business or is
insolvent; (c) any guarantor seeks, claims or otherwise attempts to limit,
modify or revoke such guarantor's guarantee  of this Note or any other loan with
Lender; (d) Borrower has applied funds provided pursuant to this Note for
purposes other than those authorized by Lender; or (e) Lender in good faith
deems itself insecure under this Note or any other agreement between Lender and
Borrower.

GENERAL PROVISIONS. This note is payable on demand. The inclusion of specific
default provisions or rights of Lender shall not preclude Lender's right to
declare payment of this Note on its demand. If any part of this Note cannot be
enforced, this fact will not affect the rest of the Note. In particular, this
section means (among other things) that Borrower does not agree or intend to
pay, and Lender does not agree or intend to contract for, charge, collect, take,
reserve or receive (collectively referred to herein as "charge or collect"), any
amount in the nature of interest or in the nature of a fee for this loan, which
would in any way or event (including demand, prepayment, or acceleration) cause
Lender to charge or collect more for this loan than the maximum lender would be
permitted to charge or collect by federal law or the law of the State of Ohio
(as applicable). Any such excess interest or unauthorized fee shall, instead of
anything stated to the contrary, be applied first to reduce the principal
balance of this loan, and when the principal has been paid in full, be refunded
to Borrower. Lender may delay or forgo enforcing any of his rights or remedies
under this Note without losing them. Borrower and any other person who signs,
guarantees or endorses this Note, to the extent allowed by law, waive
presentment, demand for payment, protest and notice of dishonor. Upon any change
in the terms of this Note, and unless otherwise expressly stated in writing, no
party who signs this Note, whether as maker, guarantor, accommodation maker or
endorser, shall be released from liability. All such parties agree that Lender
may renew or extend (repeatedly and for any length of time) this loan, or
release any party or guarantor or collateral; or impair, fail to realize upon or
perfect Lender's security interest in the collateral; and take any other action
deemed necessary by Lender without the consent of or notice to anyone. All such
parties also agree that Lender may modify this loan without the consent of or
notice to anyone other than the party with whom the modification is made.

PRIOR TO SIGNING THIS NOTE, BORROWER READ AND UNDERSTOOD ALL THE PROVISIONS OF
THIS NOTE, INCLUDING THE VARIABLE INTEREST RATE PROVISIONS. BORROWER AGREES TO
THE TERMS OF THIS NOTE AND ACKNOWLEDGES RECEIPT OF A COMPLETED COPY OF THE NOTE.

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NOTICE: FOR THIS NOTICE "YOU" MEANS THE BORROWER AND "HIS" MEANS LENDER.

WARNING -- BY SIGNING THIS PAPER YOU GIVE UP YOUR RIGHT TO NOTICE AND COURT
TRIAL. IF YOU DO NOT PAY ON TIME, A COURT JUDGMENT MAY BE TAKEN AGAINST YOU
WITHOUT YOUR PRIOR KNOWLEDGE AND THE POWERS OF A COURT CAN BE USED TO COLLECT
FROM YOU REGARDLESS OF ANY CLAIMS YOU MAY HAVE AGAINST THE CREDITOR WHETHER FOR
RETURNED GOODS, FAULTY GOODS, FAILURE ON HIS PART TO COMPLY WITH THE AGREEMENT,
OR ANY OTHER CAUSE.
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BORROWER:

Smyth Systems, Inc.



By:   /s/ Robert T. Smyth             By:      /s/ Richard H. Walker  
   --------------------------            ---------------------------------
   Robert T. Smyth, President            Richard H. Walker, Vice President

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