AMENDED AND RESTATED
                         MULTICURRENCY REVOLVING CREDIT
                             AND TERM LOAN AGREEMENT




                          DATED AS OF OCTOBER 27, 1995



                                      AMONG
                              DYNATECH CORPORATION,
         EACH OF THE SUBSIDIARIES APPEARING ON THE SIGNATURE PAGE HERETO



                                       AND




                        THE FIRST NATIONAL BANK OF BOSTON

                        ABN AMRO BANK N.V., BOSTON BRANCH

                                MELLON BANK, N.A.

                                       AND

                       THE FIRST NATIONAL BANK OF BOSTON,
                             AS AGENT FOR THE BANKS




<PAGE>
                                      -1-

                                TABLE OF CONTENTS




SECTION 1. INTERPRETATION.                                                    1
1.1.    General Provisions Pertaining to Definitions.                         1

SECTION 2. THE LOAN.                                                         10
2.1.    Obligation to Make Advances.                                         10
2.2.    Termination of Total Commitment.                                     11
2.3.    Reduction or Termination by the Borrowers of Total Commitment.       11
2.4.    Reduction of Optional Currency Borrowings.                           11
2.5.    Fees.                                                                11
2.6.    Requests for Advances.                                               12
2.7.    Making the Advances.                                                 13
2.8.    Optional Currencies.                                                 14
2.9.    Interest Payable on the Loan, etc.                                   15
2.10.   Alternative Interest Rate.                                           17
2.11.   Loan Accounts; Notes.                                                17
2.12.   Repayments and Prepayments of the Loan.                              18
2.13.   Payments and Computations.                                           20
2.14.   Payments to be Free of Deductions.                                   21
2.15.   Additional Costs, Changes in Circumstances, Capital Adequacy, etc    21
2.16.   Indemnification for Losses.                                          23
2.17.   Sharing of Payments, Etc.                                            23
2.18.   Joint and Several Liability of the Borrowers.                        23

SECTION 2A    M/M RATE ADVANCES AND LOANS.                                   24
2A.1    Rate Quotations; M/M Rate Loan Requests.                             24
2A.2    Making of M/M Rate Advances.                                         24

SECTION 2B    LETTERS OF CREDIT AND BANKERS ACCEPTANCES.                     25
2B.1    Letter of Credit Commitments.                                        25
2B.1.1. Commitment to Issue Letters of Credit                                25
2B.1.2. Letter of Credit Applications                                        25
2B.1.3. Terms of Letters of Credit                                           25
2B.1.4. Reimbursement Obligations of Banks                                   25
2B.1.5. Participations of Banks                                              25
2B.2    Reimbursement Obligations of the Borrower.                           26
2B.3    Letter of Credit Payments.                                           26
2B.4    Obligations Absolute.                                                27
2B.5    Reliance by Issuer.                                                  27
2B.6    Letter of Credit Fee.                                                27
2B.7    Usage of Unused Commitment for Bankers Acceptances.                  28

SECTION 3    CONDITIONS OF LENDING.                                          28

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                                      -2-

3.1     Conditions to Closing.                                               29
3.2     Conditions to Making of each Advance and to the
          Conversion of Term Loans to or from Eurocurrency Loans             29

<PAGE>
                                      -3-

SECTION 4.    REPRESENTATIONS AND WARRANTIES.                                29
4.1.    Organization, Good Standing, Authority, etc.                         30
4.2.    Governmental Approvals.                                              30
4.3.    Subsidiaries.                                                        30
4.4.    Compliance with Other Instruments.                                   30
4.5.    Litigation.                                                          30
4.6.    No Adverse Contracts, Etc.                                           30
4.7.    Financial Statements.                                                30
4.8.    Changes.                                                             31
4.9.    Business.                                                            31
4.10.   Taxes.                                                               31
4.11.   Loan as Senior Indebtedness.                                         31
4.12.   No Defaults.                                                         31
4.13.   Regulation U.                                                        31
4.14.   Pension Plans.                                                       31
4.15.   Absence of Financing Statements.                                     32

SECTION 5.    CERTAIN AFFIRMATIVE COVENANTS.                                 32
5.1.    Current Ratio.                                                       32
5.2.    Tangible Net Worth.                                                  32
5.3.    Debt to Worth Ratio.                                                 32
5.4.    Fixed Charge Coverage.                                               32
5.5.    Punctual Payment.                                                    32
5.6.    Conduct of Business.                                                 32
5.7.    Taxes, etc.                                                          32
5.8.    Maintenance of Properties.                                           33
5.9.    Maintenance of Insurance.                                            33
5.10.   Records and Accounts.                                                33
5.11.   Financial Statements.                                                33
5.12.   Inspection.                                                          34
5.13.   Notice of Litigation.                                                34
5.14.   Further Assurances.                                                  34
5.15.   Domestic Material Subsidiaries as Borrowers.                         34
5.16.   Compliance with Laws, Licenses and Permits.                          35

SECTION 6.    CERTAIN NEGATIVE COVENANTS.                                    35
6.1.    Indebtedness.                                                        36
6.2.    Liens.                                                               37
6.3.    Investments.                                                         38
6.4.    Merger, Consolidation or Sale of Assets, Etc.                        38
6.5.    Sale and Lease-Back.                                                 38
6.6.    Change in Terms and Prepayment of Subordinated Indebtedness.         38
6.7.    Nature of Business.                                                  39
6.8.    Pension Plans.                                                       39

SECTION 7.    EVENTS OF DEFAULT; ACCELERATION.                               39

SECTION 8.    NOTICE AND WAIVERS OF DEFAULT.                                 41

<PAGE>
                                      -4-

8.1.    Notice of Default.                                                   41
8.2.    Waivers of Default.                                                  41


SECTION 9.    REMEDIES ON DEFAULT, ETC.                                      41
9.1.    Rights of Banks.                                                     41
9.2.    Set-off.                                                             41

SECTION 10.    THE AGENT.                                                    42

SECTION 11.    MISCELLANEOUS.                                                45
11.1.    Expenses.                                                           45
11.2.    Notices, etc.                                                       45
11.3.    Reliance, etc.                                                      46
11.4.    Captions.                                                           46
11.5.    Waiver, etc.                                                        46
11.6.    Benefit, Assignments, etc.                                          47
11.7.    Judgment Exchange Rate.                                             50
11.8.    Consent to Jurisdiction.                                            50
11.9.    No Marshalling.                                                     51
11.10.   Liabilities of Borrowers Not Affected.                              51
11.11.   Governing Law.                                                      52
11.12.   Counterparts.                                                       52
11.13.   Indemnification.                                                    52
11.14    Transitional Arrangements                                           52

SECTION 12.    GUARANTY.                                                     53
12.1     Guaranty of Payment and Performance                                 53
12.2     Guarantors' Agreement to Pay Enforcement Costs                      53
12.3     Waivers by Guarantors; Banks Freedom to Act                         53
12.4     Unenforceability of Obligations Against Borrowers                   54
12.5     Subrogation; Subordination                                          55
12.6     Security; Setoff                                                    55
12.7     Further Assurances                                                  55
12.8     Termination; Reinstatement                                          56

<PAGE>

                                      -5-

                                    SCHEDULES

Schedule 1    Existing Subsidiaries
      Schedule 2              Litigation
      Schedule 3              Liens
      Schedule 4              Sale & Lease-Back
      Schedule 5              Existing Material Subsidiaries
      Schedule 6.1(b)                Indebtedness


                                    EXHIBITS

      Exhibit A               Designated Sources
      Exhibit B               Form of Promissory Note
      Exhibit C               Form of Assignment and Acceptance

<PAGE>

                              AMENDED AND RESTATED
             MULTICURRENCY REVOLVING CREDIT AND TERM LOAN AGREEMENT


        This AMENDED AND RESTATED  MULTICURRENCY  REVOLVING CREDIT AND TERM LOAN
AGREEMENT is made as of October 27, 1995, by and among (a) DYNATECH  CORPORATION
("Dynatech"), each of the Subsidiaries of Dynatech appearing on the signature
pages hereto as a "Borrower")  (Dynatech and such  Subsidiaries  are referred to
collectively as the "Borrowers" and each individually as a "Borrower"), (b) each
of the  Subsidiaries  of Dynatech  appearing on the signature  pages hereto as a
"Guarantor" (such  Subsidiaries are referred to collectively as the "Guarantors"
and each  individually as a "Guarantor"),  (c) THE FIRST NATIONAL BANK OF BOSTON
("FNBB"),  ABN AMRO BANK N.V.,  BOSTON  BRANCH ("ABN AMRO"),  MELLON BANK,  N.A.
("Mellon")  and any  additional  lenders  who from time to time  become  parties
hereto in accordance with Section 11.6 hereof (collectively,  the "Banks"),  and
(d) THE FIRST NATIONAL BANK OF BOSTON as agent for the Banks (the "Agent").

        WHEREAS,  pursuant  to a  Multicurrency  Revolving  Credit and Term Loan
Agreement  dated as of  December  31, 1990 (as  amended  from time to time,  the
"Original  Credit  Agreement")  by and  among the  Borrowers,  the Banks and the
Agent,  the Banks made  available  to the Borrower  revolving  credit loans for,
among other things, general working capital purposes; and

        WHEREAS,  the  Borrowers,  the Banks and the Agent wish to further amend
the Original Credit Agreement in certain  respects,  including,  but not limited
to,  including the Guarantors as parties to the Loan  Documents (as  hereinafter
defined);

        NOW,  THEREFORE,  in consideration of the mutual promises and agreements
of the parties which are set forth herein,  the parties hereto agree that on the
Closing Date (as  hereinafter  defined) the Original  Credit  Agreement shall be
amended and restated in its entirety as set forth herein:

        SECTION 1.  INTERPRETATION.

     1.1. GENERAL PROVISIONS PERTAINING TO DEFINITIONS. For all purposes of this
Agreement,  except as otherwise  expressly provided herein or unless the context
otherwise requires:

                (a) terms  specifically  defined in Section  1.2 hereof have the
        meanings therein assigned to them, and other terms defined  elsewhere in
        this Agreement shall have the meanings therein assigned to them, and all
        such  definitions  shall be  applicable  to both the singular and plural
        forms of the terms defined;

                (b)  accounting  terms not  otherwise  defined  herein  have the
        meanings  assigned  to them in  accordance  with  accounting  principles
        generally  accepted  in  the  United  States  of  America  applied  on a
        consistent  basis by the accounting  entity to which they refer, and all
        terms  not  specifically   defined  herein  or  by  generally   accepted
        accounting  principles  and which are defined in the Uniform  Commercial
        Code as in effect in the Commonwealth of Massachusetts have the meanings
        assigned to them therein, with the term "instrument" being that  defined
        under Article 9 of the Uniform Commercial Code;


<PAGE>
     
                (c) a reference to  "Agreement" or "this  Agreement"  means this
        Agreement as originally executed, or if subsequently  modified,  amended
        or supplemented,  as so modified,  amended or supplemented and in effect
        at the time of reference  thereto and a reference to any other  document
        or  agreement  shall  include  such  document or  agreement  as amended,
        modified or supplemented  from time to time in accordance with its terms
        and the terms of this Agreement;

                (d) the words "herein," "hereof," "hereunder" and other words of
        similar  import  refer  to  this  Agreement  as a  whole  and not to any
        particular Section or other subdivision of this Agreement, and the words
        "include", "includes" and "including" are not limiting; and

          (e) a reference to any law includes any amendment or  modification  to
         such law.

          1.2. TERMS  DEFINED.  Subject to the provisions of Section 1.1 hereof,
     the following terms shall have the respective meanings set forth below:

        "Advance"  shall  mean any  advance  made or to be made to any  Borrower
pursuant to Sections 2.1 or 2A.2 hereof.

        "Affiliate"  shall mean any Person  that  would be  considered  to an an
affiliate of a Borrower  under Rule 144(a) of the Rules and  Regulations  of the
Securities  and Exchange  Commission,  as in effect on the date hereof,  if such
Borrower were issuing securities.

        "Agent" shall mean The First National Bank of Boston acting as agent for
all the Banks.

        "Assignment and Acceptance" shall have the meaning assigned to such term
in Section 11.6 hereof.

        "Bankers  Acceptances"  shall mean any drafts  drawn or to be drawn upon
any Bank which have been, or are to be accepted by, such Bank.

        "Base Rate" shall mean the rate of interest  announced from time to time
by the Agent at its head office in Boston as its Base Rate.

        "Base Rate Advance"  shall mean any Advance  denominated in Dollars upon
which interest will accrue based on the Base Rate.

        "Base Rate Loan" shall mean the  principal or a relevant  portion of the
principal amount  outstanding from time to time after the Commitment Expiry Date
denominated in Dollars upon which interest will accrue based on the Base Rate.

        "Borrower"  and  "Borrowers"  shall have the meanings  assigned to those
terms in the preamble of this Agreement.

        "Borrowing" shall mean a borrowing  hereunder by any Borrower consisting
of Advances to such Borrower by any or all of the Banks.

        "Borrowing  Date" shall mean,  in  relation to any  Advance,  the day on
which that Advance is made or is to be made to a Borrower.

<PAGE>

        "Business Day" shall mean a day on which banking  institutions  are open
for business in Boston,  Massachusetts,  U.S.A.  and  Pittsburgh,  Pennsylvania,
U.S.A, and if the applicable  Business Day relates to a Eurocurrency  Advance, a
day on which  dealings in Dollars and in foreign  currency  and  exchange can be
carried on between banking institutions in the applicable Eurocurrency interbank
market,  and if any currency  other than Dollars is involved,  in the  principal
financial center of the country of such currency.

        "Closing  Date"  shall mean the first date on which the  conditions  set
forth in Section 3 have been satisfied,  any Advance is to be made or any Letter
of Credit or Bankers'  Acceptance is to be issued hereunder,  and this Agreement
becomes effective.

        "Commitment"  shall  mean  for  each  Bank  the  amount  of such  Bank's
Commitment Percentage of the aggregate principal amount of the Total Commitment,
as such amount may be reduced from time to time  pursuant to Sections 2.3 or 2.4
hereof.

          "Commitment  Expiry Date" shall have the meaning assigned to that term
     in Section 2.2. hereof.

        "Commitment Fee" shall have the meaning specified in Section 2.5(a).

        "Commitment  Percentage" shall mean the percentage figure set opposite a
Bank's  name in Section  2.1, in each case  subject to change  upon  assignments
permitted by Section 11.6 hereof.

        "Consolidated" shall mean as applied to any term used in this Agreement,
the relevant figures for Dynatech and its  Subsidiaries on a consolidated  basis
determined in accordance with generally  accepted  accounting  principles  after
eliminating all intercompany items and minority interests.

        "Consolidated  Assets"  shall  mean  all  assets  of  Dynatech  and  its
Subsidiaries  which should,  in accordance  with generally  accepted  accounting
principles, be classified as assets.

        "Consolidated  Current Assets" shall mean all assets of Dynatech and its
Subsidiaries  which should,  in accordance  with generally  accepted  accounting
principles, be classified as current assets.

        "Consolidated   Current  Liabilities"  shall  mean  all  liabilities  of
Dynatech  and its  Subsidiaries  which  should,  in  accordance  with  generally
accepted accounting principles, be classified as current liabilities.

        "Consolidated  Gross  Revenues"  shall mean all revenues of Dynatech and
its Subsidiaries which should, in accordance with generally accepted  accounting
principles  consistently  applied, be classified as revenues on the consolidated
statement  of income of  Dynatech  and its  Subsidiaries,  less any  returns and
allowances.

          "Consolidated  Liabilities" shall mean all liabilities of Dynatech and
     its  Subsidiaries  properly  accounted  for  as  such  in  accordance  with
     generally accepted accounting principles.

        "Consolidated  Tangible  Net Worth" shall mean an amount  determined  in
accordance   with  generally   accepted   accounting   principles  by  deducting
Consolidated  Liabilities from the book value of Consolidated Assets,  excluding
from such  Consolidated  Assets the net book value of leasehold  improvements in
excess of $1,000,000, good will, patents,  franchises,  trademarks, trade names,
research and development  expenses,  any write-ups of assets subsequent to March
31, 1987  (except such  write-ups as the Majority  Banks may approve in writing)
and all other intangible items.

<PAGE>

          "Consolidated  Working  Capital" shall mean the excess of Consolidated
     Current Assets over Consolidated Current Liabilities.

          "Current Ratio" shall mean the ratio of Consolidated Current Assets to
     Consolidated Current Liabilities.

        "Debt Service" shall mean for any period of four (4) consecutive  fiscal
quarters of Dynatech  and its  Subsidiaries,  the amount equal to the sum of (a)
the obligations of Dynatech and its  Subsidiaries  for such period in respect of
interest and fees payable on  Indebtedness,  plus (b) the rental  obligations of
Dynatech and its  Subsidiaries  for such period in respect of capitalized  lease
obligations,  plus (c) the  principal  amount of all current  maturities of long
term  Indebtedness  payable during such period,  but specifically  excluding the
principal  amount of any  Indebtedness  of the  Borrowers in respect of Advances
made by the Banks under this  Agreement from the date hereof up to and including
the  Commitment  Expiry Date minus (d) the  interest  income of Dynatech and its
Subsidiaries  for such period  determined in accordance with generally  accepted
accounting principles.

        "Debt to Worth Ratio" shall mean the ratio of  Consolidated  Liabilities
minus  Subordinated   Indebtedness  to  Consolidated  Tangible  Net  Worth  plus
Subordinated Indebtedness.

        "Default" shall have the meaning specified in Section 7.

        "Designated  Funding  Source"  shall  mean  any  branch,  subsidiary  or
affiliate of, or other entity designated by, a Bank, whose identity is set forth
by such Bank in Exhibit A attached hereto, and who may be caused by such Bank to
fund a M/M Rate Advance pursuant to Section 2A.4 hereof. Any Bank may, from time
to time,  change its  Designated  Funding  Source by notice given in  accordance
herewith.

        "Discount  Rate" shall mean with respect to a draft at any time, the bid
rate which is in effect at any Bank at such time for  acceptance by such Bank of
commercial  drafts or bills eligible for discount with the Federal  Reserve Bank
of the  district  in which  such Bank is located  in the same  denomination  and
having maturities on the same date as the maturity date of such draft.

          "Dollar(s)",  "$", and "U.S.$" shall mean dollars of the United States
     of America.

        "Domestic  Material   Subsidiary"  shall  mean  a  Material   Subsidiary
organized under the laws of the United States of America or any State thereof.

     "Eligible  Assignee"  shall mean (a) any commercial bank or finance company
organized  under the laws of the  United  States,  or any state  thereof  or the
District of Columbia, and having total assets in excess of $1,000,000,000, (b) a
savings and loan  association  or savings bank  organized  under the laws of the
United  States,  or any state thereof or the District of Columbia,  and having a
net worth of at least  $250,000,000  calculated  in  accordance  with  generally
accepted accounting  principles;  (c) a commercial bank organized under the laws
of any  other  country  which  is a  member  of the  Organization  for  Economic
Cooperation and Development (the "OECD"), or a political subdivision of any such
country, and having total assets in excess of $1,000,000,000, provided that such
bank is acting  through a branch or agency located in the country in which it is
organized or another country which is also a member of the OECD; (d) the central

<PAGE>

bank of any country  which is a member of the OECD;  (e) any  insurance  company
which has a Best's  rating of B+ or higher  and which can  provide  Loans in the
amounts and at the various  interest  rates offered to the Borrowers  under this
Agreement  and (f) if,  but only if, any Event of Default  has  occurred  and is
continuing,  any other bank,  insurance  company,  commercial finance company or
other  financial  institution  approved  by  the  Agent,  such  approval  not be
unreasonably withheld.

        "Environmental  Laws"  shall  mean any  judgment,  decree,  order,  law,
license,  rule or regulation  pertaining  to  environmental  matters,  including
without limitation,  those arising under the Resource  Conservation and Recovery
Act, the Comprehensive Environmental Response, Compensation and Liability Act of
1980 as amended,  the Superfund  Amendments and Reauthorization Act of 1986, the
Federal Clean Water Act, the Federal Clean Air Act, the Toxic Substances Control
Act,  or any  state or local  statute,  regulation,  ordinance,  order or decree
relating to health, safety or the environment.

        "ERISA" shall mean the Employee  Retirement Income Security Act of 1974,
as amended and in effect from time to time.

        "Eurocurrency Advance" shall mean any Advance denominated in an Optional
Currency or in Dollars upon which interest will accrue based on the Eurocurrency
Rate.

        "Eurocurrency  Liabilities" shall have the meaning assigned to that term
in Regulation D of the Board of Governors of the Federal Reserve  System,  as in
effect from time to time.

        "Eurocurrency  Loan" shall mean the  principal or a relevant  portion of
the principal amount  outstanding from time to time after the Commitment  Expiry
Date denominated in an Optional  Currency or in Dollars upon which interest will
accrue based on the Eurocurrency Rate.

        "Eurocurrency  Offered  Rate" shall mean,  with  respect to any Interest
Period, the rate per annum determined by the Agent at or about 11:00 a.m. London
time, on the Rate-Fixing Day with respect to the Interest Period in question, as
being that rate at which  deposits in Dollars,  or in such Optional  Currency in
which the portion of the principal of the Eurocurrency  Advances or, as the case
may be,  Eurocurrency Loans to be made, are offered to the Agent, by prime banks
in whatever  Eurocurrency  interbank  market may be selected by the Agent in its
sole  discretion,  acting in good  faith,  at the time of  determination  and in
accordance with the usual practice in such market, for delivery on the first day
of the  Interest  Period in  immediately  available  funds and having a maturity
equal to such  Interest  Period in an amount  equal (as nearly as may be) to the
Eurocurrency  Advances or Eurocurrency Loans to be outstanding for such Interest
Period.

     "Eurocurrency  Rate" shall mean, with respect to any Interest  Period,  the
Eurocurrency Offered Rate.

        "Event(s) of Default" shall have the meaning specified in Section 7.

        "Final  Repayment Date" shall mean the date specified as such in Section
2.12(a) hereof.

          "Foreign Material  Subsidiary" shall mean a Material  Subsidiary which
     is not a Domestic Material Subsidiary.

        "Guarantor" and "Guarantors"  shall have the meanings  assigned to those
terms in the preamble of this Agreement.

<PAGE>

        "Indebtedness"  shall  mean all  obligations  which in  accordance  with
generally accepted accounting principles should be classified upon the obligor's
balance sheet as  liabilities,  but in any event  including all  obligations  to
reimburse  the issuer in respect  of any letter of credit,  and all  guarantees,
endorsements  (other than endorsements for collection or deposit in the ordinary
course of business) and other obligations in respect of Indebtedness of others.

        "Interest  Payment  Date"  shall  mean,  with  respect  to  Eurocurrency
Advances, Eurocurrency Loans and M/M Rate Advances, the last day of any Interest
Period or such other date as may be determined under Section 2.9(c) hereof,  and
with respect to Base Rate  Advances and Base Rate Loans,  any date when interest
is due and payable as provided under Section 2.9(c) hereof.

        "Interest  Period"  shall mean,  (a) with  respect to each  Eurocurrency
Advance,  as  specified  by the  Borrower  of  such  Advance  in its  notice  of
borrowing,  the period  commencing on the Borrowing Date and expiring 1, 3, 6, 9
or 12 months from the  Borrowing  Date of such  Advance and (b) with  respect to
Eurocurrency  Advances  and  Eurocurrency  Loans as specified by the Borrower of
such Advances or Term Loans in a written notice  furnished to the Agent no later
than 11:00 a.m. London time three (3) Business Days prior to the Rate-fixing Day
with respect to such Eurocurrency  Advance or Eurocurrency  Loan, any successive
periods of 1, 3, 6, 9 or 12 months  commencing on the same day on which the next
preceding  Interest  Period  with  respect  to  such  Eurocurrency   Advance  or
Eurocurrency Loan shall have expired; provided, however, that no Interest Period
shall have an Interest Payment Date which occurs after the Final Repayment Date.
If the Agent  does not  receive  a notice of  election  for the  duration  of an
Interest  Period for a Eurocurrency  Advance or a Eurocurrency  Loan pursuant to
clause (b) above within the specified  time limit,  the Borrower of such Advance
or Term Loan shall be deemed to have elected to have such  Eurocurrency  Advance
or  Eurocurrency  Loan  converted  to a Base Rate Advance or  Eurocurrency  Loan
converted  to a Base Rate  Advance or, as  appropriate,  a Base Rate Loan on the
applicable  Interest  Payment Date.  If a Borrower has requested a  Eurocurrency
Advance or Eurocurrency Loan and does not elect otherwise,  each Interest Period
with  respect  to a  Eurocurrency  Advance or  Eurocurrency  Loan shall be three
months.  The number of days in each Interest  Period and the  particular  day on
which each Interest  Period ends and the next begins shall be fixed by the Agent
in accordance  with the Agent's  generally  accepted  practice in the applicable
Eurocurrency  interbank  market. If any Interest Period would otherwise end on a
day which is not a Business  Day,  such  Interest  Period shall end and the next
Interest  Period shall commence on the next preceding or the next succeeding day
which is a Business Day as  determined  conclusively  by the Agent in accordance
with the then current banking practice in the applicable  Eurocurrency interbank
market.  The  foregoing  definition  shall be  applicable  only to  Eurocurrency
Advances and Eurocurrency Loans.

        "Interest Period" shall mean (a) with respect to each Base Rate Advance,
the period  commencing on the Borrowing Date of such Advance and expiring on the
date when the Base Rate Advance is repaid or, as the case may be, converted to a
Eurocurrency Advance or M/M Rate Advance, and (b) with respect to each Base Rate
Loan, the period  commencing on the  Commitment  Expiry Date or, as the case may
be,  the date  when a  Eurocurrency  Loan is  converted  to a Base Rate Loan and
expiring  on the date when such Base Rate Loan is repaid or, as the case may be,
converted to a Eurocurrency  Loan. The foregoing  definition shall be applicable
only to Base Rate Advances or Base Rate Loans.

        "Interest  Period"  shall  mean with  respect  to M/M Rate  Advances  as
specified by the Borrower of such Advances in its initial request for a M/M Rate
Advance the period commencing on the Borrowing Date of such Advance and expiring
not more than 180 days from the Borrowing Date and  thereafter,  as specified by
the  Borrower of such  Advances in  subsequent  requests  for M/M Rate  Advances

<PAGE>

furnished to any Bank no later than the Interest Payment Date with respect to an
Outstanding M/M Rate Advance in accordance  with the time  limitations and other
provisions of Section 2A, any successive  period of up to 180 days commencing on
such  Interest  Payment  Date;  provided  that no Interest  Period shall have an
Interest  Payment  Date which occurs after the  Commitment  Expiry Date.  If any
Interest  Period would  otherwise end on a day which is not a Business Day, such
Interest Period shall be extended to the next succeeding day which is a Business
Day as determined  conclusively by the Agent. If such Bank does not receive such
notice  of  election  for  a  succeeding  Interest  Period  with  respect  to an
Outstanding  M/M Rate Advance within such specified time limit,  the Borrower of
such  Advance  shall be deemed to have elected to have any such M/M Rate Advance
converted  to a Base Rate Advance or Base Rate Loan on the  applicable  Interest
Payment  Date. If a Borrower does not specify  otherwise,  each Interest  Period
with respect to a M/M Rate Advance or shall be the shorter of (a) 90 days or (b)
the  number  of days from the start of such  Interest  Period to the  Commitment
Expiry Date.  The  foregoing  definition  shall be  applicable  only to M/M Rate
Advances.

        "Investments" shall mean expenditures made and all liabilities  incurred
(contingently  or otherwise) for the acquisition of stock or Indebtedness of, or
for loans,  advances,  capital contributions or transfer of property (other than
in the ordinary course of business) to any person,  and all expenditures made in
respect  of  any   guarantees   (or  other   commitments   as  described   under
Indebtedness), or obligations of any person other than as respects contributions
of capital to companies that are Subsidiaries as of June 30, 1995.

       "Letter of Credit" shall have the meaning specified in Section 2B hereof.

        "Letter of Credit  Application"  shall  have the  meaning  specified  in
Section 2B hereof.

        "Letter of Credit  Participation"  shall have the meaning  specified  in
Section 2B hereof.

        "Leverage Fee" shall have the meaning specified in Section 2.5(b).

        "Loans" shall mean, collectively,  the aggregate principal amount of all
Advances or Term  Loans,  as the case may be, made or to be made by the Banks to
the  Borrowers  upon the terms and subject to the  conditions  contained in this
Agreement, and "Loan" means any one of the Advances or Term Loans.

        "Loan Account" shall have the meaning specified in Section 2.11 hereof.

     "Loan Documents" shall mean this Agreement, the Notes, the Letter of Credit
Applications, the Letters of Credit and the Bankers' Acceptances.

        "Majority  Banks"  shall mean as of any date, a minimum of two (2) Banks
whose  Commitment  Percentages  aggregate  at  least  66%  (whether  or not  the
Commitments have been terminated).

        "Margin" shall mean the following percentage per annum: (a) with respect
to Eurocurrency  Advances and Eurocurrency Loans, one-half of one percent (1/2%)
per annum and (b) with respect to Base Rate  Advances and Base Rate Loans,  zero
percent (0%) per annum.

        "Material  Subsidiary" shall mean any Subsidiary to which more than five
percent (5%) of either (a)  Consolidated  Tangible Net Worth or (b) Consolidated
Gross Revenues (not  including  intercompany  transfers) is allocable.  Existing
Material  Subsidiaries and the contribution of each such Material  Subsidiary to
consolidated  Tangible Net Worth and Consolidated  Gross Revenues as of June 30,
1995, are set forth on Schedule 5 hereto.

<PAGE>

        "Maximum  Drawing Amount" shall mean the maximum  aggregate  amount that
the beneficiaries  may at any time draw under outstanding  Letters of Credit, as
such aggregate  amount may be reduced from time to time pursuant to the terms of
the Letter of Credit.

        "M/M Rate Advance"  shall mean any Advance  denominated  in Dollars upon
which interest will accrue based on the Money Market Rate.

        "Money Market Rate" shall mean the fixed rate of interest  quoted by any
Bank on the first day of any Interest  Period which rate such Bank is willing to
charge  with  respect to a M/M Rate  Advance to be made by such Bank during such
Interest Period as specified pursuant to Section 2A.

        "Net Revenues  Available for Debt Service"  shall mean for any period of
four (4)  consecutive  fiscal  quarters of Dynatech  and its  Subsidiaries,  the
consolidated  net income from  operations,  before  taxes,  of Dynatech  and its
Subsidiaries  (excluding any items of income which, in accordance with generally
accepted accounting  principles  consistently  applied,  should be classified as
extraordinary  items) after  deducting  therefrom all operating and  maintenance
expenses  (including  any items of expense which,  in accordance  with generally
accepted accounting  principles  consistently  applied,  should be classified as
extraordinary items), but before deducting interest and fees described in clause
(a) in the definition of Debt Service, depreciation and amortization.

        "Notes" shall have the meaning specified in Section 2.11(b) hereof.

     "Obligations"  shall mean all indebtedness,  obligations and liabilities of
any of the Borrowers and their  Subsidiaries  to any of the Banks and the Agent,
individually or collectively,  existing on the date of this Agreement or arising
thereafter, direct or indirect, joint or several, matured or unmatured, absolute
or  contingent,  liquidated or  unliquidated,  secured or unsecured,  arising by
contract,  operation  of  law or  otherwise,  arising  or  incurred  under  this
Agreement  or any of the other Loan  Documents or in respect of any of the Loans
made or the Reimbursement  Obligations  incurred or any of the Notes,  Letter of
Credit Applications,  Letters of Credit, Bankers Acceptances or other instrument
at any time evidencing any thereof.

        "Optional  Currency" shall mean any currency which is freely convertible
into Dollars and which is traded on any interbank  currency  deposits  market in
which  any  of  the  Banks  customarily  funds  loans  denominated  in  Optional
Currencies.

        "Outstanding" when used with reference to the aggregate balance of Loans
(whether  Advances or Term  Loans),  shall mean and  include,  as at any date of
determination, the unpaid principal thereof.

        "Person" shall mean any  individual,  corporation,  partnership,  trust,
unincorporated  association,  business or other legal entity, and any government
or any governmental agency or political subdivision thereof.

        "Rate-fixing  Day" shall  mean the second  Business  Day  preceding  the
Business Day on which an Interest Period begins.

        "Register" shall have the meaning specified in Section 11.6 hereof.

<PAGE>

        "Reimbursement  Obligation"  shall  mean the  Borrowers'  obligation  to
reimburse  the Agent and the Banks on account of any drawing under any Letter of
Credit as provided in Section 2B.

        "Related Entity" shall mean any entity treated as a single employer with
the Company  pursuant to ss.414(b) or (c) of the Internal  Revenue Code of 1986,
as amended from time to time.

     "Repayment  Dates"  shall have the  meaning  specified  in Section  2.12(a)
hereof.

        "Reserve   Charge"  shall  mean,   for  any  Interest   Period  for  any
Eurocurrency  Advance or  Eurocurrency  Loan,  a rate  determined  on the second
Business Day prior to the last day of such Interest  Period in  accordance  with
the following formula:

                                    (a) x 100
                                    ---------
                                      (1-b)

where a is the applicable  Eurocurrency Offered Rate expressed as a decimal, and
b is the maximum  Reserve  Rate for  Eurocurrency  Liabilities,  expressed  as a
decimal,  determined by the Agent to be the rate or weighted  average rate which
would be applicable to such Interest Period under Regulation D (or any successor
or similar rule or regulation) of the Board of Governors of the Federal  Reserve
System (or any successor thereto);  provided, however, that, notwithstanding the
foregoing,  the Reserve Charge applicable to each of the Banks shall in no event
exceed  such  amounts  which  are  actually   incurred  by  such  Bank  and  any
participants in the Loans of such Bank to the extent that such amounts  incurred
by such participants do not exceed the amount that such Bank would have incurred
had it not participated  such Loans to such participants in connection with such
Eurocurrency  Advance or  Eurocurrency  Loan.  If an Advance or Term Loan is not
denominated  in U.S.  Dollars,  the  numerator  of such  fraction  shall  be the
Eurocurrency  Offered  Rate that would  have been in effect had such  Advance or
Term Loan been denominated in U.S. Dollars.

        "Reserve  Rate"  means the  reserve  rate for  Eurocurrency  Liabilities
(expressed  as a decimal) set forth in Regulation D of the Board of Governors of
the Federal Reserve System (or any successor or similar  regulation  relating to
such reserve requirements).

        "Subordinated  Indebtedness"  shall mean  Indebtedness  of any  Borrower
subordinated  to the extent and in a manner  satisfactory to the Majority Banks,
as evidenced by their written consent thereto.

        "Subsidiary"  shall mean any present or future corporation a majority of
whose shares of stock of any class (however  designated)  having ordinary voting
power for the election of a majority of the members of the board of directors or
other  governing  body of such  corporation  (other than stock having such power
only by reason of the happening of a contingency)  shall at the time be owned by
Dynatech or by one or more of Dynatech's  Subsidiaries.  Existing  Subsidiaries,
Dynatech's  interest  therein,  and the  place of  incorporation  are  listed on
Schedule 1 hereto. A wholly-owned  Subsidiary is a Subsidiary all of the capital
stock of which,  other than directors'  qualifying  shares, is owned directly or
indirectly by Dynatech.

        "Term Loan" shall mean either a Base Rate Loan or a Eurocurrency Loan.

        "Total  Commitment"  shall mean the sum of the  Commitments of each Bank
set forth in  Section  2.1,  as such  amount  may be  reduced  from time to time
pursuant to Section 2.3.

<PAGE>

        "Total Loan" shall mean the aggregate amount of the Loans outstanding at
the Commitment Expiry Date.

        "Uniform  Customs" shall mean with respect to any Letter of Credit,  the
Uniform   Customs  and  Practice  for  Documentary   Credits  (1993   Revision),
International  Chamber of Commerce  Publication No. 500 or any successor version
thereto  adopted by the Agent in the ordinary course of its business as a letter
of credit issuer and in effect at the time of issuance of such
Letter of Credit.

        "Unpaid   Reimbursement   Obligation"   shall  mean  any   Reimbursement
Obligation  for which the  Borrowers do not reimburse the Agent and the Banks on
the date specified in, and in accordance with, Section 2B.

        "Voting  Stock" shall mean stock or similar  interests,  of any class or
classes (however designated),  the holders of which are at the time entitled, as
such  holders,  to vote for the  election  of a majority  of the  directors  (or
persons performing  similar functions) of the corporation,  association or other
business entity  involved,  whether or not the right so to vote exists by reason
of the happening of a contingency.

        SECTION 2.  THE LOAN.

     2.1. OBLIGATION TO MAKE ADVANCES.  Each Bank severally agrees, on the terms
and conditions of this Agreement,  to make Advances, in Dollars and/or,  subject
to Section 2.8 hereof,  in an Optional  Currency,  to the Borrowers from time to
time from the date hereof to and  including the  Commitment  Expiry Date in such
sums as are  requested  by the  Borrowers up to an  aggregate  principal  amount
outstanding (after giving effect to all amounts requested) at any one time equal
to such Bank's Commitment minus such Bank's Commitment  Percentage of the sum of
the Maximum Drawing Amount and all Unpaid  Reimbursement  Obligations,  provided
that the sum of the  outstanding  amount of the Advances (after giving effect to
all  amounts   requested)  plus  the  Maximum  Drawing  Amount  and  all  Unpaid
Reimbursement Obligations shall not at any time exceed the Total Commitment.

        From and after the Closing Date,  the  respective  amount of each Bank's
initial Commitment and its Commitment Percentage shall be as follows:


<TABLE>
<CAPTION>

                                                 Amount of            Commitment
Bank                                             Commitment           Percentage
                                                 ----------           ----------
<S>                                             <C>                     <C>    
FNBB ..............................             $35,000,000              50.000%

ABN AMRO ..........................             $17,500,000              25.000%

Mellon ............................             $17,500,000              25.000%

Total .............................             $70,000,000             100.000%
</TABLE>
<PAGE>

        2.2.  TERMINATION  OF  TOTAL  COMMITMENT.   The  Total  Commitment  will
terminate  in full at 11:00 a.m.,  Boston  time,  on  September  30, 1998 unless
earlier terminated as provided in this Agreement ("Commitment Expiry Date").

        2.3.  REDUCTION OR  TERMINATION  BY THE  BORROWERS OF TOTAL  COMMITMENT.
Subject to the terms and  conditions of this Agreement the Borrowers may, at any
time on or prior to  September  30,  1998,  reduce by  $500,000  or an  integral
multiple  thereof or  terminate  entirely  the  unborrowed  portion of the Total
Commitment by Dynatech,  on behalf of the Borrowers  acting  jointly,  giving at
least ten (10)  Business  Days'  prior  written  notice  thereof  to the  Agent,
whereupon the  Commitments  of the Banks shall be reduced pro rata in accordance
with their  respective  Commitment  Percentages of the amount  specified in such
notice or, as the case may be,  terminated.  Promptly  after  receiving any such
notice  delivered  pursuant to this Section 2.3, the Agent will notify the Banks
of  the  substance  thereof.  Upon  the  effective  date  of  any  reduction  or
termination,  the Borrowers  jointly and severally agree to pay to the Agent for
the accounts of the Banks ratably in accordance with their respective Commitment
Percentages such amount as will reduce the unpaid principal balance of the Loans
to an amount not in excess of the desired reduced amount of the Total Commitment
and the full  amount of any  Commitment  Fee then  accrued  on the amount of the
reduction.  If,  pursuant  to this  Section  2.3,  any  reduction  of the  Total
Commitment  shall  occur at any time  while  M/M Rate  Advances  by any Bank are
outstanding, as a result of which the Outstanding Loans of any Bank exceeds such
Bank's  Commitment  Percentage of the then  Outstanding  Loans of all the Banks,
then the  Borrowers  of such  M/M  Rate  Advances  shall  convert  such M/M Rate
Advances to Base Rate Advances and each other Bank shall purchase participations
in the  Advances  made as a result of such  conversion  all in  accordance  with
Section  2.9(a)  hereof  such  that at the date of any  reduction  of the  Total
Commitment  hereunder each Bank shall share in the principal amount of the Loans
then  outstanding   according  to  their  respective   Commitment   Percentages.
Notwithstanding anything to the contrary in this Section 2.3, the effective date
of any such reduction or termination  shall be on and as of an Interest  Payment
Date, unless no payment is required to be made pursuant to the third sentence of
this  Section  2.3, or unless any such payment is made in respect of a Base Rate
Advance, in which case the effective date of such reduction or termination shall
be on and as of the date specified in the written  notice  provided to the Agent
by the Borrowers.

     2.4.  REDUCTION  OF OPTIONAL  CURRENCY  BORROWINGS.  The  principal  amount
available to the  Borrowers in Optional  Currencies  pursuant to Section  2.8(a)
hereof shall be reduced pro rata by any amount by which the Total  Commitment is
reduced under Section 2.3 hereof.

        2.5.  FEES.

                (a) The  Borrowers  jointly  and  severally  agree to pay to the
        Agent for the  accounts of the Banks a commitment  fee (the  "Commitment
        Fee") on the  average  daily  amount  during  each  calendar  quarter or
        portion  thereof from the date hereof to the Commitment  Expiry Date (or
        to the date of termination  in full of the Total  Commitment if earlier)
        by which  the Total  Commitment  minus  the sum of the  Maximum  Drawing
        Amount and all Unpaid  Reimbursement  Obligations  exceeds the aggregate
        outstanding  and unpaid  Advances  (such  amount is  referred  to as the
        "Excess Amount"). The portion of the aggregate Commitment Fee payable to
        each Bank shall be determined on the basis of a fraction,  the numerator
        of  which  is the  unused  portion  of such  Bank's  Commitment  and the
        denominator  of which is the Excess Amount (such Bank's  "Excess  Amount
        Fraction").  The  Commitment  Fee payable to each Bank shall be equal to
        such Bank's Excess Amount  Fraction of one-quarter of one percent (1/4%)
        per annum of the  Excess  Amount.  The  Commitment  Fee shall be payable
        quarterly in arrears on the first day of each  calendar  quarter for the
        immediately preceding calendar quarter commencing on the first such date
        following the date hereof, with a final payment on the Commitment Expiry
        Date (or on the date of termination in full of the Total Commitment,  if
        earlier).

<PAGE>

                (b) The  Borrowers  jointly  and  severally  agree to pay to the
        Agent  for the  accounts  of the  Banks on the  forty-fifth  day of each
        fiscal  quarter of Dynatech a leverage  fee (the  "Leverage  Fee") in an
        amount  equal to a percentage  per annum of (x) prior to the  Commitment
        Expiry Date, the Total  Commitment  and (y) after the Commitment  Expiry
        Date,  the Total  Loans (as  reduced  from time to time  pursuant to the
        terms hereof), determined as follows:

                         (i) If the Debt to Worth  Ratio  for the most  recently
                ended  fiscal  quarter  of  Dynatech  is less than 2.1 to 1, the
                percentage shall be 0;

                         (ii) if the Debt to Worth  Ratio for the most  recently
                ended  fiscal  quarter of Dynatech is at least 2.1 to 1 but less
                than 2.25 to 1, the percentage shall be twelve one hundredths of
                one percent (.0012);

                         (iii) if the Debt to Worth Ratio for the most  recently
                ended fiscal  quarter of Dynatech is at least 2.25 to 1 but less
                than  2.4 to 1,  the  percentage  shall  be one  quarter  of one
                percent (.0025); and

                         (iv) if the Debt to Worth  Ratio for the most  recently
                ended  fiscal  quarter is 2.4 to 1 or  greater,  the  percentage
                shall be one half of one percent (.0050).

        The portion of the aggregate  Leverage Fee payable to each Bank shall be
        equal to such Bank's  Commitment  Percentage of the  aggregate  Leverage
        Fee.

        2.6.  REQUESTS FOR ADVANCES.

                (a) Subject to the terms and  conditions  of this  Agreement,  a
        Borrower  may obtain  Base Rate  Advances  or M/M Rate  Advances  in the
        principal  amount of  $1,000,000  or some greater  integral  multiple of
        $100,000,  and Eurocurrency Advances in the approximate principal amount
        of  $1,000,000  or some greater  integral  multiple of $100,000,  or the
        equivalent  thereof in an Optional  Currency from the Banks from time to
        time from and after the date hereof, but not after the Commitment Expiry
        Date.  Each Borrowing  shall consist of Advances of the same type and in
        the same  currency made to the Borrower of such Advances on the same day
        by the  Banks  ratably  (except  as  otherwise  expressly  permitted  in
        Sections 2.8(a) and 2A hereof).

                (b)  Whenever a Borrower  desires and is entitled  hereunder  to
        receive any Advance,  such Borrower and Dynatech shall provide notice of
        the proposed Borrowing to the Agent in writing or by telephone confirmed
        immediately  in writing by such  Borrower  and  Dynatech,  and the Agent
        shall promptly  notify each of the Banks thereof,  in the case of a Base
        Rate Advance not later than 10:00 a.m., Boston time, on the Business Day
        immediately  preceding  the  Borrowing  Date;  and  in  the  case  of  a
        Eurocurrency  Advance not later than 11:00 a.m.,  London time, three (3)
        Business Days prior to the Rate-fixing Day with respect to such Advance.
        In the case of a M/M Rate  Advance,  the  Borrower  of such  Advance and
        Dynatech  shall notify the Banks in  accordance  with Section 2A hereof.
        All such notices shall  specify (i) the Borrowing  Date (which must be a
        Business Day) and the amount of such  Advance,  stated either in Dollars
        or, subject to ss.2.8 hereof, in an Optional Currency, (ii) with respect
        to a Eurocurrency  Advance or a M/M Rate Advance,  the initial  Interest
        Period of such Advance, and (iii) the applicable Borrower's bank account
        to which payment of the proceeds thereof is to be made.

<PAGE>

                (c) Each Advance shall mature and become due and payable in full
        on the last day of each Interest  Period for such Advance  (whether such
        Interest  Period  commenced  upon  an  initial  borrowing  or  upon  any
        conversion   or   continuation   pursuant  to  Sections  2.8  and  2.9).
        Notwithstanding  the  foregoing,  at such  maturity the Borrower of such
        Advance  shall be entitled to reborrow an amount equal to the  principal
        amount of such maturing  Advance as a new Advance of a different type by
        conversion,  or of the  same  type by  continuation,  for an  additional
        Interest Period pursuant to Sections 2.8 and 2.9,  subject to all of the
        conditions  precedent  set forth in Section 3.2. The  provisions of this
        paragraph (c) of Section 2.6 apply only to the repayment and reborrowing
        of  Advances  which do not  result  in a  decrease  or  increase  in the
        aggregate principal amount of Loans at the time outstanding.  Repayments
        reducing such aggregate principal amount and reborrowing increasing such
        aggregate  principal  amount are  governed by other  provisions  of this
        Agreement.

        2.7.  MAKING THE ADVANCES.

               (a) Not later than 11 o'clock a.m.,  Boston time, on the proposed
          Borrowing Date, and subject to Section 2A with respect to any M/M Rate
          Advance, each of the Banks will make available to the Agent (i) in the
          case of an Advance  denominated  in Dollars,  at the  Agent's  address
          referred to in Section 11.2 hereof and in immediately available funds,
          such Bank's ratable portion of such Advance and (ii) in the case of an
          Advance  denominated in an Optional  Currency,  at such place as shall
          have been  designated by the Agent not less than two (2) Business Days
          prior  to the  Borrowing  Date in a telex  or  written  notice  to the
          applicable  Borrower  and the  Banks  and in such  funds  as  shall be
          customary  in the  country  of issue  of such  Optional  Currency  for
          settlement of international  payments in such Optional Currency,  such
          Bank's ratable portion of such Advance. Upon receipt from each Bank of
          the amount of its loan,  and upon the  satisfaction  of the applicable
          conditions of Section 3.2 hereof, the Agent will pay to the applicable
          Borrower  the  aggregate  amount  of  such  loans  by  credit  to such
          Borrower's  specified bank account in immediately  available funds not
          later than the close of business on such  Borrowing  Date. The failure
          or refusal of any Bank to make available to the Agent at the aforesaid
          time on any  Borrowing  Date the amount of the loan to be made by such
          Bank  thereon  shall not relieve  the other  Banks from their  several
          obligations  hereunder to make available their  respective  Commitment
          Percentages  of any requested  Loan,  but no Bank shall be responsible
          for the  failure of any other Bank to make the Loan to be made by such
          other Bank on any Borrowing Date.

                (b) The Agent may  (unless  notified  to the  contrary by a Bank
        prior to a Borrowing  Date) assume that each Bank has made  available to
        the Agent on such  Borrowing Date such Bank's  Commitment  Percentage of
        the Loans to be made on such  Borrowing  Date, and the Agent may (but it
        shall not be  required  to),  in  reliance  upon such  assumption,  make
        available to the applicable  Borrower a  corresponding  amount.  If such
        amount is made  available  to the Agent on a date after  such  Borrowing
        Date,  such Bank shall pay to the Agent on demand an amount equal to the
        product of (i) the average computed for the period referred to in clause
        (iii) below, of the weighted average interest rate paid by the Agent for
        Federal  funds  acquired by the Agent  during each day  included in such
        period, times (ii) the amount equal to such Bank's Commitment Percentage

<PAGE>

        of such Borrowing, times (iii) a fraction, the numerator of which is the
        number of days that elapse from and including such Borrowing Date to the
        date on which such Bank's Commitment  Percentage of such Borrowing shall
        become immediately  available to the Agent, and the denominator of which
        is 365. A statement  of the Agent  submitted to any Bank with respect to
        any amounts owing under this paragraph  shall be prima facie evidence of
        the amount due and owing. If such Bank's  Commitment  Percentage of such
        Loan is not in fact made  available  to the  Agent by such  Bank  within
        three (3)  Business  Days of such  Borrowing  Date,  the Agent  shall be
        entitled to recover such amount from the Borrowers jointly and severally
        on demand, with interest thereon at the rate per annum applicable to the
        Loans made on such Borrowing Date.

        2.8.  OPTIONAL CURRENCIES.

               (a) A Borrower may elect, prior to the Commitment Expiry Date, to
          draw down or convert,  or after the Commitment Expiry Date to convert,
          a portion of the funds available to such Borrower under this Agreement
          in, or to, an Optional Currency (if any),  provided that the aggregate
          principal amount  outstanding with respect to the Borrowers under this
          Agreement  immediately  following  any such  drawdown or conversion in
          Optional  Currencies  shall not exceed the lesser of the equivalent of
          US  $70,000,000  or the  Dollar  amount to which the Total  Commitment
          shall have been reduced  pursuant to Section 2.3 hereof,  and provided
          further that any funds  proposed to be converted at any one time under
          this  Section 2.8 shall be in amounts of not less than US $250,000 and
          shall  be an  integral  multiple  thereof,  or the  equivalent  in any
          Optional  Currency.  In order to  exercise  the  foregoing  option the
          applicable  Borrower  and  Dynatech  must  deliver a  written  notice,
          subject to any other notice requirements under this Agreement,  to the
          Agent,   which  shall  give  to  the  Banks  prompt  notice   thereof,
          designating  the  currency  into which the  designated  portion of the
          Loans is to be drawn down or, as the case may be, converted,  at least
          five (5) Business Days prior to the commencement of an Interest Period
          relating to such portion of the Loan and any such conversion  shall be
          effected  on such date.  If any such  notice is not  delivered  to the
          Agent by the  applicable  Borrower  and  Dynatech  within the required
          time,  such Borrower shall be deemed to have elected that the relevant
          portion of the principal amount of the Loan continue to be denominated
          in the currency in which it then currently stands denominated.

                If  any   Bank   determines   (which   determination   shall  be
        conclusive),  on or prior to the second Business Day preceding the first
        day of any Interest  Period  during which a portion of the  principal of
        the  Loan  is to be  denominated  in any  Optional  Currency,  that  the
        Optional  Currency  is not  freely  transferable  and  convertible  into
        Dollars  or that it will be  impracticable  for  such  Bank to fund  the
        Advance or Term Loan in such Optional Currency,  then such Bank shall so
        notify the Agent,  which  notification shall be given immediately by the
        Agent to the applicable  Borrower and Dynatech,  and that portion of the
        principal  amount  of  the  Loan  shall,  notwithstanding  any  contrary
        election by such Borrower or any other provisions hereof, be denominated
        in Dollars and be in the form of a Base Rate  Advance or as the case may
        be, a Base Rate Loan.

                (b) For  all  purposes  of this  Agreement,  the  amount  in one
        currency which shall be equivalent on any particular date to a specified
        amount  in  another  currency  shall  be that  amount  (as  conclusively
        ascertained  by the  Agent) in the first  currency  which is or could be
        purchased by the Agent (in accordance with its normal banking practices)
        with such specified  amount in the second currency in the London foreign
        currency  deposits  market for delivery on such date at the spot rate of
        exchange prevailing at or about 11:00 a.m., London time, on such date.

<PAGE>

               (c) In the event that any  portion of the funds  available  under
          the terms of this  Agreement is  denominated  in one or more  Optional
          Currencies the Dollar equivalent of such portion of the funds shall be
          calculated  pursuant to paragraph (b) above.  The amount so determined
          shall then be added to the amount  already  outstanding in Dollars for
          the purpose of determining  the remaining  availability of funds under
          Section  2.8(a)  hereof  and any  required  repayments  under  Section
          2.12(e) hereof. Notwithstanding the foregoing, if at any time prior to
          the Commitment Expiry Date the U.S. Dollar equivalent of the aggregate
          principal  amount   outstanding   hereunder  shall  exceed  the  Total
          Commitment  by five (5)  percent or more,  the  Borrowers  jointly and
          severally  agree to pay to the  Agent  for the  accounts  of the Banks
          ratably  according  to the then  outstanding  principal  amount of the
          Loans being  repaid,  immediately  upon demand made by the Agent,  all
          amounts and in the relevant currencies required in order to reduce the
          principal  amount  outstanding  to the U.S.  Dollar  equivalent of the
          Total  Commitment.  To  the  extent  that  as  a  result  of  currency
          fluctuations  any Bank has funded  and/or  maintained  Advances to the
          Borrowers  hereunder  in an amount  equalling  such Bank's  Commitment
          Percentage of the Total Commitment,  all Advances  thereafter shall be
          made by the other Banks until such time as the  Advances  made by such
          Bank have been repaid so as to permit  additional  borrowings  (not in
          excess of such Bank's  Commitment  Percentage of the Total Commitment)
          from such Bank. On the Commitment  Expiry Date the amount of the Total
          Loan shall be  calculated  in Dollars and any amount by which the U.S.
          Dollar  equivalent of all amounts  outstanding  hereunder  exceeds the
          Total  Commitment  shall be  repaid.  At that time the Agent will also
          calculate  a  schedule  of  repayments,  on  a  pro  forma  basis,  in
          accordance with Section 2.12(a)  hereof.  If the Dollar  equivalent of
          all amounts  outstanding  hereunder on any of the  repayment  dates so
          established  shall  exceed  the  amount  indicated  in the  pro  forma
          calculation  for that  repayment  date or if at any  time  the  Dollar
          equivalent  of  all  amounts   outstanding  shall  exceed  the  amount
          indicated  by the pro forma  calculation  for that period by more than
          five (5) per cent,  then the Borrowers  jointly and severally agree to
          pay to the Agent for the  accounts of the Banks  ratably  according to
          the then outstanding  principal amount of the Loans,  immediately upon
          demand made by the Agent,  all amounts and in the relevant  currencies
          required in order to reduce the principal  amount then  outstanding to
          that  amount  which  would  have  been  outstanding  had the Loan been
          denominated entirely in Dollars.

        2.9.  INTEREST PAYABLE ON THE LOAN, ETC.

                (a) With  respect  to any  Advance or Term Loan  denominated  in
        Dollars,  the rate of interest  which shall be payable by the  Borrowers
        with  respect  to such  Advance  or Term  Loan on the  unpaid  principal
        outstanding shall be the annual  percentage rate of interest  determined
        by the Agent,  or, in the case of a M/M Rate  Advance by the  applicable
        Bank or Banks, to be the sum of (i) the applicable Margin in effect plus
        (ii)  the  Base  Rate,  or if the  applicable  Borrower  has so  elected
        pursuant  to  this   paragraph   (a)  the  Money  Market  Rate,  or  the
        Eurocurrency  Rate relating to the Interest  Period with respect to such
        Advance or Term Loan. A Borrower may elect,  (A) prior to the Commitment
        Expiry  Date to draw down a portion  of the funds  available  under this
        Agreement in Dollars upon which  interest  will accrue based on the Base
        Rate,  Money Market  Rate,  or  Eurocurrency  Rate or (B) to convert any
        portion  of the Loan to or from a Base Rate  Advance or a Base Rate Loan
        to or from a M/M Rate Advance  Eurocurrency Advance or Eurocurrency Loan
        denominated  in  Dollars  on the last  day of an  Interest  Period  with
        respect  to the  Advance  or Term  Loan to be  converted.  In  order  to
        exercise the foregoing option, the applicable Borrower and Dynatech must

<PAGE>

          deliver  a   written    notice,    subject    to   any  other   notice
          requirements  under this Agreement,  to the Agent, which shall give to
          the Banks prompt notice thereof, designating the election of the basis
          on which  the  interest  rate  will be  determined  at least  five (5)
          Business  Days  (with   respect  to   Eurocurrency   Advances   and/or
          Eurocurrency  Loans) prior to the  commencement of the Interest Period
          relating to such  portion of the Loan on which such  conversion  is to
          occur.  With respect to the conversion of any portion of the Loan to a
          M/M Rate Advance the applicable Borrower and Dynatech shall notify the
          Banks  on the  first  day  of  such  subsequent  Interest  Period,  in
          accordance with Section 2A hereof, and shall otherwise comply with the
          provisions of Section 2A as to the  obtaining of  quotations  from the
          Banks of the Money Market Rate to be applicable to the total amount of
          the M/M Rate Advances so requested.  Each Borrower  further agrees and
          directs that insofar as any portion of the M/M Rate  Advances  made by
          any Bank  pursuant  to Section 2A hereof is in excess of the amount of
          such Bank's  Outstanding  Advances which are part of such  conversion,
          such excess amount shall immediately be paid by such Bank to the Agent
          for the  accounts of the other  Banks,  as a  reduction  of such other
          Banks' Outstanding  Advances which would otherwise have been converted
          to M/M Rate  Advances  by such other  Banks had such  conversion  been
          effected  ratably  as to all  Banks.  If,  as a result  of an  initial
          Borrowing or any portion  thereof  consisting of a M/M Rate Advance or
          the conversion of any portion of the Loans to a M/M Rate Advance,  the
          Outstanding  Advances of any Bank shall exceed such Bank's  Commitment
          Percentage of the principal amount of the Loans then outstanding, then
          upon the subsequent conversion of such Bank's M/M Rate Advances or any
          portion thereof to a Base Rate Advance or a Eurocurrency Advance, each
          other Bank shall  purchase from such Bank such  participations  in the
          Advances made as a result of such  conversion as shall cause each Bank
          to  share  in  the  outstanding  principal  amount  of  such  Advances
          according to their respective  Commitment  Percentages.  Each Borrower
          agrees that any Bank so purchasing a participation  in such Borrower's
          Loans from such other Bank  pursuant  to this  Section 2.9 may, to the
          fullest  extent  permitted by law,  exercise all its rights of payment
          with respect to such  participation  as fully as if such Bank were the
          direct creditor of such Borrower in the amount of such participation.

                (b) The rate of interest which shall be payable by the Borrowers
        on any portion of the  principal  of the Loan  extended to any  Borrower
        denominated  in an  Optional  Currency  for the time  being  outstanding
        during  each  Interest  Period  relating  thereto  shall  be the  annual
        percentage rate of interest determined by the Agent to be the sum of (i)
        the applicable Margin in effect plus (ii) the Eurocurrency Rate relating
        to such Interest Period.

                (c) The  Borrowers  jointly and  severally  agree that  interest
        shall be payable by the Borrowers in arrears in Dollars, or, as the case
        may be, in the Optional  Currency in which that portion of the principal
        amount of the Loan extended to a Borrower in respect of which payment is
        made is denominated (i) with respect to M/M Rate Advances,  Eurocurrency
        Advances and  Eurocurrency  Loans, on each Interest  Payment Date and on
        the Final Repayment Date, provided, however, that if the duration of any
        such Interest Period is longer than three months or, as the case may be,
        90 days,  the Borrowers  jointly and severally  agree to pay the accrued
        interest on the last Business Day of each  successive 90 day period with
        respect to M/M Rate  Advances  and three month  period  with  respect to
        Eurocurrency  Advances and  Eurocurrency  Loans and (ii) with respect to
        Base Rate  Advances  and Base Rate Loans,  quarterly  on the last day of
        each March, June,  September and December hereafter,  and on any earlier
        date when a Base Rate  Advance or Base Rate Loan is  converted  to a M/M
        Rate Advance, Eurocurrency Advance or Eurocurrency Loan or is repaid.

<PAGE>

                (d) Each  determination  of any interest  rate by the Agent with
        respect to any Base Rate Advance, Base Rate Loan,  Eurocurrency Advance,
        or  Eurocurrency  Loan,  or by any  Bank  with  respect  to any M/M Rate
        Advance  shall  be  conclusive  in the  absence  of  manifest  error  in
        recordation, computation or transmission. Base Rate interest rates shall
        change as the Base Rate shall  change,  and any  change in the  interest
        rates shall become effective as of the beginning of the day during which
        such change in the Base Rate occurs.  The Agent will promptly notify the
        Borrowers and the Banks of each change in the Base Rate.

               (e) Overdue  principal and, to the extent permitted by applicable
          law, overdue interest and other amounts overdue under any provision of
          this Agreement  shall bear interest at a rate per annum equal to three
          percent  (3%)  above  the  rate  of  interest  which  at the  time  of
          determination would otherwise be payable pursuant to this Agreement in
          respect of principal, not at the time overdue and after the expiration
          of any Interest  Period  related to such overdue  amount,  the overdue
          amount will  thereafter  bear interest at three percent (3%) above the
          sum of the Base  Rate and the  applicable  Margin.  Such  interest  on
          overdue principal and overdue interest and other amounts overdue shall
          be payable on demand and shall continue to accrue from the due date of
          such  principal,  interest or amounts and shall be compounded  monthly
          until the  obligation  of the  Borrowers  in  respect  of the  payment
          thereof is discharged  (whether before or, to the extent  permitted by
          law, after judgment).

        2.10.  ALTERNATIVE  INTEREST RATE. Except as otherwise  provided in this
Agreement,  if on any Rate-fixing Day on which the interest rate with respect to
any Advance or Term Loan is to be based on the Eurocurrency Rate, any Bank shall
determine (which  determination shall be conclusive) that, it is unable to quote
the Eurocurrency  Rate, or that it is unable to or it is impracticable for it to
fund the Advance or Term Loan for the  requested  Interest  Period,  or that the
Eurocurrency  Rate, as applicable,  does not or will not accurately  reflect the
cost to such Bank of obtaining or  maintaining  the  applicable  Advance or Term
Loan during any Interest Period, then such Bank shall so notify the Agent, which
notification shall be given immediately by the Agent to the Borrowers,  and that
portion of the principal amount of the Loan shall,  notwithstanding any contrary
election by any  Borrower or any other  provisions  hereof,  be  denominated  in
Dollars as a Base Rate Advance or Base Rate Loan.

        2.11.  LOAN ACCOUNTS; NOTES.

                (a) Each Bank  will open and  maintain  a loan  account  (each a
        "Loan  Account") on its books in the name of each of the Borrowers  with
        respect to such Bank's  Advances  and Term Loans.  Each Advance and Term
        Loan made by a Bank will be debited,  and each payment or  prepayment on
        account thereof will be credited,  and any  adjustments  required by the
        conversion  of  Advances  and Term Loans  shall be  recorded in the Loan
        Account maintained by such Bank. Each Bank shall render to Dynatech (for
        distribution  to each of the Borrowers) and the Agent,  on or before the
        fifth  Business Day of each  calendar  quarter,  a statement of its Loan
        Account as of the last day of the prior calendar quarter;  provided that
        the failure of any Bank to render any such statement in a timely fashion
        shall not affect or impair the  validity  or binding  nature of any Loan
        Account.

                (b) Any Bank may at any time request that any Loans  outstanding
        to such Bank be evidenced by a promissory note or notes (the "Notes") of
        the applicable  Borrower.  Upon such request,  the  applicable  Borrower
        shall promptly  execute and deliver to such Bank, with a copy thereof to
        the Agent, a promissory note  substantially in the forms attached hereto
        as Exhibits B-1 or B-2, as applicable.  Upon execution and delivery by a
        Borrower of a promissory  note, such Borrower's  obligation to repay the
        Loans made to it by such Bank and all interest  thereon shall thereafter
        be evidenced by such promissory note.

<PAGE>

        2.12.  REPAYMENTS AND PREPAYMENTS OF THE LOAN.

               (a) Unless the M/M Rate Advances  shall become due and payable at
          an  earlier  date as  expressly  provided  for  herein,  all M/M  Rate
          Advances  shall  become due and  payable  on and as of the  Commitment
          Expiry Date, and the Borrowers jointly and severally hereby absolutely
          and  unconditionally  promise  to pay to the  Agent on the  Commitment
          Expiry Date for the  accounts of the  respective  Banks,  all M/M Rate
          Advances which are  outstanding on the Commitment  Expiry Date. On and
          as of the Commitment  Expiry Date,  the principal  amount of the Loans
          then outstanding shall be the "Total Loan".  Provided that no Event of
          Default  has  occurred  and is  continuing,  the Total  Loan  shall be
          payable in  installments  over a term of two (2) years as set forth in
          this  paragraph  (a).  The  Borrowers  jointly  and  severally  hereby
          absolutely  and  unconditionally  promise  to pay to the Agent for the
          accounts  of the  Banks  ratably  according  to the  then  outstanding
          principal amount of the Total Loan, on the last day of each September,
          December,  March and June, commencing on September 30, 1998 and ending
          on June 30, 2000 (each of such eight (8) dates hereinafter referred to
          as a  "Repayment  Date"),  and there shall become  absolutely  due and
          payable on each Repayment Date, a fixed installment of principal in an
          amount equal to one-eighth  (1/8) of the principal amount of the Total
          Loan. All such  repayments  shall be made in the currency in which the
          Loan to be repaid or any portion thereof is denominated. The Borrowers
          jointly and severally hereby absolutely and  unconditionally  agree to
          pay to the Agent for the  accounts of the Banks  ratably  according to
          the then  outstanding  principal amount of the Total Loan, on June 30,
          2000 (the "Final Repayment  Date"),  and there shall become absolutely
          due and  payable  on the  Final  Repayment  Date,  the  entire  unpaid
          principal amount of the Total Loan outstanding on such date,  together
          with all accrued and unpaid interest thereon.

                (b) The Borrower will repay all of the outstanding Loans and the
        Commitments  will  automatically  terminate on the  ninetieth day (or if
        such ninetieth day is not a Business Day, the next  succeeding  Business
        Day) after any Person or group of  Persons  acquires  51% or more of the
        outstanding  Voting  Stock of  Dynatech  unless  both (i) the  acquiring
        Person  provides  evidence  satisfactory to the Banks within ninety (90)
        days after such  acquisition  that the debt securities of such acquiring
        Person,  after such  acquisition,  are rated in one of the three highest
        categories by a nationally recognized securities rating organization and
        (ii) within ten (10) Business Days after such acquisition, the acquiring
        Person   provides  a  guaranty,   in  form  and   substance   reasonably
        satisfactory  to the Banks,  of all of the  obligations of the Borrowers
        hereunder  to the Banks.  Notwithstanding  any other  provision  of this
        Agreement,  the  Borrowers  and the Banks  agree  that the terms of this
        Section 2.12(b) shall not be amended or waived without the prior written
        consent of all of the Banks;  provided,  that any Bank which  determines
        not to waive the  provisions of this Section  2.12(b) may be required to
        sell its  Commitment  and its Loans on terms and  conditions  reasonably
        satisfactory  to all of the Banks as  evidenced  by an amendment to this
        Agreement in form and substance reasonably satisfactory to the Banks.

                (c) A Borrower may,  pursuant to this  paragraph  (c),  elect to
        prepay the  principal of the Loans  extended to such Borrower in full or
        in part on the Interest  Payment Date of any Interest Period relating to
        the unpaid principal to be prepaid,  in which case such prepayment shall
        be without  premium or  penalty,  or in the case of Loans other than M/M
        Rate  Advances on any date other than such  Interest  Payment  Date,  in

<PAGE>

        which case such prepayment shall be subject to the provisions of Section
        2.16 hereof; provided, that, (i) the amount of any partial prepayment of
        the unpaid  principal of the Loans  pursuant to this paragraph (c) shall
        be either a principal amount of $500,000 or an integral multiple thereof
        with  respect  to M/M Rate  Advances,  Base Rate  Advances  or Base Rate
        Loans,  and  $500,000 or an integral  multiple  thereof  with respect to
        Eurocurrency  Advances and Eurocurrency  Loans or the equivalent thereof
        in the Optional  Currency in which that portion of the principal  amount
        of  the  Loan  in  respect  of  which  the  payment  is  to be  made  is
        denominated,  (ii) the applicable Borrower shall give the Agent at least
        five (5) Business  Days prior  written  notice of its election to prepay
        all or any  part  of  the  principal  of  any  Eurocurrency  Advance  or
        Eurocurrency  Loan  pursuant to this clause,  such notice to specify the
        date of such prepayment and the amount of principal to be prepaid, (iii)
        all such prepayments  shall be made to the Agent for the accounts of the
        Banks  ratably according to the then outstanding principal amount of the
        Loans,  and (iv) all such  prepayments  shall be made in the currency in
        which the Loan to be prepaid  or any  portion  thereof  is  denominated.
        Amounts prepaid pursuant to this paragraph (c) may, subject to the terms
        and  conditions  of this  Agreement,  be  reborrowed  on or  before  the
        Commitment  Expiry Date. Any such prepayment after the Commitment Expiry
        Date may not be  reborrowed  and shall be  applied to  installments  due
        under Section 2.12(a) hereof in the inverse order of maturity.

                (d) If, pursuant to Section 2.12(c), any prepayment of the Loans
        shall occur at any time while M/M Rate Advances or Eurocurrency Advances
        or Eurocurrency  Loans  denominated in any Optional Currency by any Bank
        are outstanding,  as a result of which the Outstanding Loans of any Bank
        exceeds such Bank's Commitment  Percentage of the then Outstanding Loans
        of all  the  Banks,  then  notwithstanding  the  provisions  of  Section
        2.12(c),  any such prepayment shall be applied by the Agent first (i) to
        the  prepayment of the  Outstanding  Loans of such Bank, to be allocated
        among such  Advances or Term Loans and in such manner as the  applicable
        Borrower  shall  elect,  or if such  Borrower  fails to so  elect,  on a
        ratable basis as determined by the Agent, until the Outstanding Loans of
        each Bank shall  equal such  Bank's  Commitment  Percentage  of the then
        Outstanding  Loans of all the  Banks;  and  then  (ii)  ratably  for the
        accounts of the Banks in accordance with Section 2.12(c).

                (e) If at any Interest Payment Date for any Advance or Term Loan
        denominated  in an  Optional  Currency,  the  Dollar  equivalent  of the
        aggregate  principal amount outstanding of all such Advances and/or Term
        Loans hereunder shall exceed,  prior to the Commitment  Expiry Date, the
        Total  Commitment,  or after the Commitment  Expiry Date, the Total Loan
        (and as such is reduced from time to time  pursuant to Sections  2.12(a)
        and 2.12(c) hereof), the Borrowers jointly and severally agree to pay to
        the  Agent  for  the  accounts  of the  Banks  in  accordance  with  the
        provisions  of Section  2.12(d),  immediately  upon  demand  made by the
        Agent,  all  amounts  required in order to reduce the  principal  amount
        outstanding to the Total Commitment, or as the case may be, to the Total
        Loan (as it may be reduced),  or the  equivalent  thereof in one or more
        Optional Currencies.

                (f) Upon each  repayment or  prepayment  of any principal of any
        Advance made or Term Loan  extended to any  Borrower  pursuant to any of
        the provisions of this  Agreement,  the Borrowers  jointly and severally
        hereby  absolutely and  unconditionally  promise to pay to the Agent for
        the  accounts of the Banks  ratably  according  to the then  outstanding
        principal amount of the Loans, and there shall become absolutely due and
        payable on the date of each such  repayment  or  prepayment,  all of the
        unpaid  interest  accrued to such date on the amount of the principal of
        the Advance or Term Loan being repaid or prepaid on such date,  together
        with all, if any,  other sums then due and payable  hereunder in respect
        of the  principal of the Advance or Term Loan being repaid or prepaid on
        such date, including, but not limited to, any sums payable in accordance
        with Section 2.16 hereof which have been  ascertained on or prior to the
        date of such repayment or  prepayment.  Whenever any interest on and any
        principal of the Advance or Term Loan are paid simultaneously hereunder,
        the whole  amount paid shall be applied  first to interest  then due and
        payable.

<PAGE>

               (g)  The  applicable  Borrower  shall  specify  the  duration  of
          Interest Periods relating to M/M Rate Advances,  Eurocurrency Advances
          or  Eurocurrency  Loans made to it so that, on each Repayment Date and
          on the Final  Repayment Date, the amount of principal that becomes due
          with respect to such Interest  Periods  shall  together with all other
          amounts of  principal  outstanding  which are being repaid shall be no
          less than the amount of principal to be repaid on a Repayment  Date or
          Final  Payment  Date.  If a  Borrower  fails  to  specify  appropriate
          Interest Periods to meet such repayment schedules, the Agent shall fix
          the duration of relevant Interest Periods.

                (h) Each Term Loan shall  mature  and become due and  payable in
        full on the  last  day of each  Interest  Period  for  such  Term  Loan.
        Notwithstanding  the  foregoing,  at such  maturity the Borrower of such
        Term Loan shall be entitled to reborrow an amount equal to the principal
        amount of such maturing Term Loan as a new Term Loan of a different type
        by conversion,  or of the same type by  continuation,  for an additional
        Interest Period pursuant to Sections 2.8 and 2.9,  subject to all of the
        conditions  precedent  set forth in Section 3.2, and further  subject to
        the provisions of paragraphs (a) and (g) of this Section 2.12.

        2.13.  PAYMENTS AND COMPUTATIONS

                (a)  Each  payment  payable  by  the  Borrowers   hereunder  (i)
        denominated  in Dollars shall be made to the Agent at its head office at
        100 Federal  Street,  Boston,  Massachusetts,  in immediately  available
        funds,  or, (ii)  denominated in any Optional  Currency shall be made in
        immediately  available  funds,  for  the  account  of  the  Agent  at  a
        depository designated by the Agent to the Borrowers and the Banks in the
        country in which such Optional Currency is legal tender. The Agent will,
        promptly after receipt, distribute like funds relating to the payment of
        principal or interest or Commitment  Fees ratably to the Banks  (subject
        to  Sections  2.5 and  2.12(d)  hereof)  and like funds  relating to the
        payment of any other  amount  payable to any Bank for the account of the
        applicable  office of such Bank specified from time to time by such Bank
        to the Borrowers and the Agent.

                (b) If any sum would,  but for the  provisions  of this  Section
        2.13(b),  become  due and  payable  hereunder  on a day  which  is not a
        Business  Day,  then such sum shall become due and payable on either the
        Business Day next preceding or the Business Day next  succeeding the day
        on which such sum would otherwise have become due and payable hereunder,
        such Business Day to be selected  (which  selection  shall be conclusive
        and binding on the  Borrowers) by the Agent in accordance  with the then
        current  banking  practice in Boston or in the  applicable  Eurocurrency
        interbank  market,  and interest and Commitment  Fees hereunder shall be
        adjusted accordingly.

                (c) All  computations  of interest and  Commitment  Fees payable
        hereunder  shall be made by the Agent on the  basis of actual  number of
        days elapsed and on a 360-day year. The outstanding  amount of the Loans
        as  reflected  on the  Agent's  records  from  time  to  time  shall  be
        considered  correct and binding on the  Borrowers  and the Banks  unless
        within ninety (90) days (excluding Saturdays, Sundays and legal holidays
        in the Commonwealth of Massachusetts) after receipt of any notice by the
        Agent of such outstanding  amount, the applicable Borrower or any of the
        Banks, as the case may be, notify the Agent to the contrary.

<PAGE>

                (d) Each  determination by the Agent of an amount of interest or
        Commitment  Fee  payable  by the  Borrowers  hereunder  shall,  save for
        manifest  error  in  recordation,   computation  or   transmission,   be
        conclusive and binding upon the Borrowers and the Banks.

        2.14. PAYMENTS TO BE FREE OF DEDUCTIONS.    All payments by any Borrower
under this Agreement shall be made without set-off or counterclaim  and free and
clear of and without deduction for any taxes, levies, imposts,  duties, charges,
fees, deductions, withholdings,  compulsory loans, restrictions or conditions of
any nature now or  hereafter  imposed or levied by any country or any  political
subdivision thereof or taxing or other authority therein unless such Borrower is
compelled by law to make such deduction or  withholding.  If any such obligation
is imposed upon any Borrower with respect to any amount  payable by it hereunder
to the Agent or any Bank,  such Borrower shall promptly notify the Agent or such
Bank of such obligation and the Borrowers  jointly and severally agree to pay to
the Agent,  for the account of the Agent or such Bank,  on the date on which the
said amount becomes due and payable  hereunder,  such additional amount as shall
be  necessary  to enable the Agent or such Bank to  receive  the same net amount
which it would  have  received  on such  due date had no such  obligations  been
imposed upon such Borrower. Each Borrower will deliver promptly to the Agent and
the Banks  certificates  or other valid  vouchers for all taxes or other charges
deducted from or paid with respect to payments made by such Borrower  hereunder.
The Borrowers  jointly and severally agree to pay any present or future stamp or
documentary  taxes or any other  excise or  property  taxes,  charges or similar
levies  which  arise  from  any  payment  made by  them  hereunder  or from  the
execution,  delivery or  registration  of, or  otherwise  with  respect to, this
Agreement. The foregoing provisions of this Section 2.14 shall not apply, in the
case of each Bank and the Agent,  to taxes  charged  upon or by reference to its
overall net income, profits or gains.

        2.15. ADDITIONAL COSTS, CHANGES IN CIRCUMSTANCES, CAPITAL ADEQUACY, ETC.

                (a) Anything  hereinbefore to the contrary  notwithstanding,  if
        any present or future applicable law (which expression,  as used in this
        Agreement,  includes  statutes and rules and regulations  thereunder and
        interpretations thereof by any competent court or by any governmental or
        other regulatory body or official charged with the administration or the
        interpretation  thereof  and  requests,  directives,   instructions  and
        notices at any time or from time to time  heretofore  or hereafter  made
        upon or  otherwise  issued  to any  Bank by any  central  bank or  other
        fiscal, monetary or other authority,  whether or not having the force of
        law) shall (i) subject such Bank to any tax, levy, impost, duty, charge,
        fee,  deduction  or  withholding  of any  nature  with  respect  to this
        Agreement, the amount of such Bank's Commitment,  or the payment to such
        Bank of any amounts due to it hereunder,  or (ii) materially  change the
        basis of  taxation  of  payments  to such Bank of the  principal  or the
        interest  on or any other  amounts  payable to such Bank  hereunder,  or
        (iii)   impose  or  increase  or  render   applicable   any  special  or
        supplemental special deposit or reserve or similar requirements (whether
        or not having the force of law)  against  assets held by, or deposits in
        or for the account of, or any  eligible  liabilities  of, or loans by an
        office of such Bank, or (iv) impose on such Bank any other  condition or
        requirement  with respect to this  Agreement or such Bank's  Commitment,
        and the result of any of the  foregoing  is (A) to increase  the cost of
        such Bank of making, funding or maintaining all or nay part of its Loan,
        or (B) to reduce  the  amount of  principal,  interest  or other  amount
        payable to such Bank hereunder,  or (C) to require such Bank to make any
        payment or to forego any  interest or other sum payable  hereunder,  the
        amount of which payment or foregone  interest or other sum is calculated
        by  reference  to the  gross  amount  of any sum  receivable  or  deemed
        received by such Bank from the Borrowers  hereunder,  then,  and in each
        such case, the Borrowers  jointly and severally agree,  upon demand made
       
<PAGE>

       by such Bank, to pay to the Agent for the account of such Bank additional
        amounts  sufficient to compensate  such Bank for such  additional  cost,
        reduction,  payment or foregone interest or other sum; provided that the
        foregoing provisions of this sentence shall not apply in the case of any
        additional cost,  reduction,  payment or foregone  interest or other sum
        resulting from any taxes charged upon or by reference to the overall net
        income, profits or gains of such Bank.

                (b) If any Bank shall  determine  that any change in  applicable
        law shall make it  unlawful  for such Bank to comply with or to maintain
        its  obligations to fund  Eurocurrency  Advances or  Eurocurrency  Loans
        hereunder  or that it is not  possible for such Bank to continue to fund
        the  unpaid  principal  of such  Advances  or Term  Loans,  or any  part
        thereof, in the Eurocurrency  interbank market,  then, on notice thereof
        and demand therefor by such Bank to the Borrowers and the Agent, (i) the
        Bank's  obligations  to fund  the  Loans  as  Eurocurrency  Advances  or
        Eurocurrency Loans shall terminate in full on and as of the date of such
        notice,  and (ii) such Loans shall on the  Interest  Payment Date of any
        Interest  Period which is current when the  Borrowers are so notified be
        converted to Base Rate Loans.

                (c) CAPITAL ADEQUACY. If any Bank shall have determined that any
        present or future applicable law, rule, regulation, guideline, directive
        or  request  (whether  or not  having  force of law)  regarding  capital
        requirements  for  banks or bank  holding  companies  generally,  or any
        change therein or in the interpretation or administration thereof by any
        governmental  authority,  central bank or comparable agency charged with
        the interpretation or administration thereof, or compliance by such Bank
        with any of the  foregoing,  imposes or increases a requirement  by such
        Bank to allocate capital  resources to such Bank's Commitment to make or
        issue, or to such Bank's  maintenance  of, Loans or Bankers  Acceptances
        hereunder,  which has or would have the effect of reducing the return on
        such  Bank's  capital  to a level  below that which such Bank could have
        achieved (taking into  consideration  such Bank's then existing policies
        with respect to capital  adequacy and assuming full  utilization of such
        Bank's  capital)  but for such  applicability,  change,  interpretation,
        administration  or  compliance,  by any amount deemed by such Bank to be
        material,  such Bank  shall  promptly  after its  determination  of such
        occurrence  give notice  thereof to the Agent and each of the Borrowers.
        The  Borrowers  and such Bank shall  thereafter  attempt to negotiate in
        good faith an adjustment to the  compensation  payable  hereunder  which
        will  adequately  compensate  such  Bank  for  such  reduction.  If  the
        Borrowers  and such Bank are unable to agree to such  adjustment  within
        thirty days of the day on which the Borrowers receive such notice,  then
        commencing  on the  date  of such  notice  (but  not  earlier  than  the
        effective  date  of  any  such  applicability,  change,  interpretation,
        administration or compliance), the fees payable hereunder shall increase
        by an  amount  which  will,  in such  Bank's  reasonable  determination,
        compensate such Bank for such reduction,  such Bank's  determination  of
        such  amount to be  conclusive  and  binding  on the  Borrowers,  absent
        manifest  error.  In  determining  such  amount,  such  Bank may use any
        reasonable   methods  of  averaging,   allocating  or  attributing  such
        reduction among its customers.  In the event that any Bank increases the
        fees payable  hereunder  pursuant to this ss.2.15(c) after such Bank and
        the Borrowers  have failed to agree on an  adjustment  to the fees,  the
        Borrowers  shall  have the option of  selecting  a  replacement  bank to
        purchase  the  Commitment  and  the  Loans  of the  Bank  imposing  such
        increased fees on terms and conditions reasonably satisfactory to all of
        the Banks as evidenced  by an  amendment  to this  Agreement in form and
        substance reasonably satisfactory to the Banks.

<PAGE>

                (d) Each Bank,  as of the last day of any Interest  Period,  may
        require  a  Borrower  to pay,  contemporaneously  with each  payment  of
        interest  on  Eurocurrency  Advances  or  Eurocurrency  Loans  for  such
        Interest Period, as the case may be, additional  interest on the related
        Advance  or Term  Loan,  as the case  may be of such  Bank at a rate per
        annum equal to the Reserve  Charge.  Any Bank requiring  payment of such
        additional  amounts shall notify the applicable  Borrower and the Agent,
        in which  case  such  additional  amounts  payable  in  respect  of such
        Eurocurrency  Advances or Eurocurrency  Loans, as the case may be, shall
        be payable to such Bank.

        2.16.  INDEMNIFICATION  FOR LOSSES.  The Borrowers jointly and severally
agree,  on demand by any Bank at any time,  to  indemnify  such Bank against any
losses, costs or expenses which such Bank may at any time incur as a consequence
of (i) the  breach  by any  Borrower  of its  obligations  to  borrow a M/M Rate
Advance or Eurocurrency Advance on the Borrowing Date thereof,  (ii) the failure
by any Borrower to pay,  punctually on the due date thereof,  any amount payable
hereunder,  (iii) the  accelerated  payment of any  obligations  of any Borrower
hereunder  as the  result  of an Event of  Default,  or (iv)  the  repayment  or
prepayment of any principal  under a M/M Rate Advance,  Eurocurrency  Advance or
Eurocurrency  Loan on a date other than an Interest  Payment Date of an Interest
Period  relating to such principal,  such losses,  costs or expenses to include,
but not to be limited to, (A) any costs  incurred by such Bank in carrying funds
which were to have been borrowed by a Borrower or in carrying funds to cover the
amount of any overdue  principal  of or overdue  interest  on the Loan,  (B) any
interest  payable by such Bank to lenders of the funds  borrowed by such Bank in
order to carry the funds  referred to in the  immediately  preceding  sub-clause
(A), and (C) any losses  (excluding  losses of anticipated  profit)  incurred by
such Bank in  liquidating or  re-employing  funds acquired from third parties to
effect or maintain all or any part of the Loan or such portion thereof.

        2.17.  SHARING OF  PAYMENTS,  ETC. If any Bank shall  obtain any payment
(whether voluntary,  involuntary,  through the exercise of any right of set-off,
or otherwise) on account of its Loans (other than pursuant to Sections  2.12(d),
2.14,  2.15 or 2.16) in  excess  of its  ratable  share  (according  to the then
outstanding  principal  amount of the Loans) of payments on account of the Loans
obtained by all the Banks,  such Bank shall  purchase  from the other Banks such
participations  in the Loans held by them as shall cause such purchasing Bank to
share such payment ratably according to the then outstanding principal amount of
the Loans with each of them;  provided,  however,  that if all or any portion of
such payment is thereafter  recovered  from such  purchasing  Bank, the purchase
shall be  rescinded  and the  purchase  price  restored  to the  extent  of such
recovery, but without interest. Each Borrower agrees that any Bank so purchasing
a  participation  in such  Borrower's  Loans from another Bank  pursuant to this
Section  2.17 may, to the fullest  extent  permitted  by law,  exercise  all its
rights of payment  with respect to such  participation  as fully as if such Bank
were the direct creditor of such Borrower in the amount of such participation.

        2.18.  JOINT  AND  SEVERAL  LIABILITY  OF  THE  BORROWERS.  Each  of the
Borrowers  shall be jointly and severally  liable for all of the  obligations of
all of the Borrowers under this Agreement,  including  without  limitation,  the
obligation  to pay interest and  principal as they become due and payable on all
Advances  and Term Loans and to pay all other  fees,  charges  or other  amounts
owing to any Bank,  the Agent or any other  party  pursuant to the terms of this
Agreement.

        SECTION 2A.  M/M RATE ADVANCES.

<PAGE>

        2A.1. RATE QUOTATIONS; M/M RATE LOAN REQUESTS. Subject to the conditions
set forth  herein,  from the  Closing  Date until the  Commitment  Expiry Date a
Borrower  may request any or all of the Banks (with a copy of all such  requests
to the Agent) on any Business Day to give such Borrower a firm  quotation of the
Money Market Rate which would be  applicable to a M/M Rate Advance to be made on
such day  except  that any such quote made by a  Designated  Funding  Source may
vary, within such hour, and the applicable rate will be the rate offered by such
Designated  Funding Source at the time of the Borrowers'  acceptance  thereof by
each such Bank  pursuant  to Section  2A.2.  Each such  Advance for which such a
quotation is requested shall be in an integral  multiple of $100,000.  Each such
request (a "Rate  Request"),  which  shall be in writing or may be by  telephone
immediately  confirmed  to such  Bank by telex or  telecopy  (with a copy to the
Agent), shall (a) specify the applicable Interest Period (commencing on the date
of such Rate Request) to which such rate quotation would apply,  (b) specify the
aggregate  principal amount of the M/M Rate Advance to which such rate quotation
would  apply,  and (c) shall be received by such Bank not later than 11:00 A.M.,
Boston time,  on such day. A Borrower  shall not be permitted to request any M/M
Rate Advance which would have a maturity  beyond the Commitment  Expiry Date. At
or before 12:00 noon,  Boston time, each Bank of which such a rate quotation has
been  requested  shall notify the  applicable  Borrower by  telephone,  telex or
telecopy of the Money  Market  Rate which would apply to such M/M Rate  Advance;
provided,  however,  that no Bank shall be  obligated  to give a quotation of an
applicable  Money  Market Rate in response to any such Rate  Request.  Such rate
quotation  will  remain in effect  for one hour on such  day.  If such  Borrower
wishes to accept a rate quotation from any Bank, and thereby  request such a M/M
Rate  Advance,  such  Borrower and Dynatech  shall so give the  applicable  Bank
written  notice of  acceptance,  no later than the  expiration  of such one hour
period.  Such notice of acceptance  (a "M/M Rate Loan  Request") may be given by
telex or telecopy  (confirmed by letter),  and shall confirm such Borrower's and
Dynatech's  acceptance of such rate  quotation,  the duration of the  applicable
Interest Period (commencing on such day), and the aggregate  principal amount of
the M/M Rate Advance requested. Such Bank shall promptly notify the Agent of the
same,  and shall  promptly  deliver to the Agent a copy of such  Borrower's  and
Dynatech's confirmation of its acceptance of such Bank's rate quotation.

        2A.2.  MAKING OF M/M RATE  ADVANCES.  In the case of  proposed  M/M Rate
Advances,  the  requested  M/M Rate Advance shall be made in its entirety by the
Bank  (or its  Designated  Funding  Source)  whose  rate  quotation  has been so
accepted on such day,  which shall be the first day of the  applicable  Interest
Period  for  such M/M  Rate  Advance;  provided,  however,  that  the  aggregate
outstanding principal amount of all Loans made under this Agreement by each such
Bank (or its  Designated  Funding  Source) shall at no time exceed the amount of
such  Bank's  Commitment,  and  further  provided  that  any M/M  Rate  Advances
outstanding on and as of the  Commitment  Expiry Date shall be repaid in full in
cash on the  Commitment  Expiry  Date.  To the extent  that the  Borrowers  have
utilized the  provisions of this Section 2A to require the making by any Bank of
M/M Rate Advances and as a result thereof such Bank has funded and/or maintained
Advances  to  the  Borrowers  hereunder  in  an  amount  equalling  such  Bank's
Commitment Percentage of the Total Commitment,  all Advances thereafter shall be
made by the other  Banks  until  such time as such M/M Rate  Advances  have been
repaid  so as to permit  additional  borrowings  (not in  excess of such  Bank's
Commitment Percentage of the Total Commitment) from such Bank.

<PAGE>

        SECTION 2B.  LETTERS OF CREDIT AND BANKERS ACCEPTANCES.

         2B.1.  LETTER OF CREDIT COMMITMENTS.

         2B.1.1 COMMITMENT TO ISSUE LETTERS OF CREDIT.  Subject to the terms and
conditions hereof and the execution and delivery by the Borrowers of a letter of
credit   application  on  the  Agent's  customary  form  (a  "Letter  of  Credit
Application"),  the  Agent on  behalf  of the  Banks  and in  reliance  upon the
agreement of the Banks set forth in Section 2B.1.4 and upon the  representations
and  warranties of the Borrowers  contained  herein,  agrees,  in its individual
capacity,  to issue,  extend and renew for the account of the  Borrowers  one or
more  standby  or  documentary  letters  of credit  (individually,  a "Letter of
Credit"),  in such form as may be requested  from time to time by the  Borrowers
and agreed to by the Agent; provided, however, that, after giving effect to such
request,  (a) the sum of the  aggregate  Maximum  Drawing  Amount and all Unpaid
Reimbursement  Obligations  shall not exceed  $7,500,000 at any one time and (b)
the sum of (i) the Maximum  Drawing  Amount on all  Letters of Credit,  (ii) all
Unpaid Reimbursement Obligations,  and (iii) the amount of all Loans outstanding
shall not exceed the Total Commitment.  Notwithstanding the foregoing, the Agent
shall have no  obligation to issue any Letter of Credit to support or secure any
Indebtedness of the Borrower or any of its  Subsidiaries to the extent that such
Indebtedness was incurred prior to the proposed  issuance date of such Letter of
Credit, unless in any such case the Borrowers demonstrate to the satisfaction of
the Agent that (x) such prior incurred Indebtedness were then fully secured by a
prior perfected and unavoidable  security interest in collateral provided by the
Borrowers  or such  Subsidiary  to the  proposed  beneficiary  of such Letter of
Credit or (y) such prior incurred Indebtedness were then secured or supported by
a letter of credit  issued for the account of the  Borrowers or such  Subsidiary
and the reimbursement obligation with respect to such letter of credit was fully
secured by a prior  perfected and  unavoidable  security  interest in collateral
provided  to the  issuer  of such  letter of  credit  by the  Borrowers  or such
Subsidiary.

         2B.1.2 LETTER OF CREDIT APPLICATIONS. Each Letter of Credit Application
shall be  completed  to the  satisfaction  of the  Agent.  In the event that any
provision of any Letter of Credit  Application  shall be  inconsistent  with any
provision of this Credit Agreement, then the provisions of this Credit Agreement
shall, to the extent of any such inconsistency, govern.

         2B.1.3  TERMS OF  LETTERS  OF  CREDIT.  Each  Letter of Credit  issued,
extended or renewed  hereunder  shall,  among other things,  (a) provide for the
payment of sight drafts for honor  thereunder  when presented in accordance with
the terms thereof and when accompanied by the documents  described therein,  and
(b) have an expiry date no later than the date which is fourteen  (14) days (or,
if the Letter of Credit is confirmed  by a confirmer  or otherwise  provides for
one or more  nominated  persons,  forty-five  (45) days) prior to the Commitment
Expiry  Date.  Each  Letter of Credit so issued,  extended  or renewed  shall be
subject to the Uniform Customs.

         2B.1.4  REIMBURSEMENT  OBLIGATIONS OF BANKS. Each Bank severally agrees
that it shall be  absolutely  liable,  without  regard to the  occurrence of any
Default or Event of Default or any other condition precedent whatsoever,  to the
extent of such Bank's  Commitment  Percentage,  to reimburse the Agent on demand
for the amount of each draft  paid by the Agent  under each  Letter of Credit to
the extent  that such  amount is not  reimbursed  by the  Borrowers  pursuant to
Section  2B.2 (such  agreement  for a Bank being  called  herein the  "Letter of
Credit Participation" of such Bank).

         2B.1.5. PARTICIPATIONS OF BANKS. Each such payment made by a Bank shall
be treated  as the  purchase  by such Bank of a  participating  interest  in the
Borrowers'  Reimbursement  Obligation  under  Section 2B.2 in an amount equal to
such  payment.  Each  Bank  shall  share in  accordance  with its  participating
interest in any interest which accrues pursuant to Section 2B.2.

<PAGE>

         2B.2.  REIMBURSEMENT OBLIGATION OF THE BORROWER. In order to induce the
Agent to  issue,  extend  and  renew  each  Letter  of  Credit  and the Banks to
participate  therein,  the  Borrowers  hereby  jointly  and  severally  agree to
reimburse or pay to the Agent,  for the account of the Agent or (as the case may
be) the Banks, with respect to each Letter of Credit issued, extended or renewed
by the Agent hereunder,

                  (a) except as otherwise expressly provided in Sections 2B.2(b)
         and (c),  on each date that any draft  presented  under such  Letter of
         Credit is honored by the Agent,  or the Agent otherwise makes a payment
         with  respect  thereto,  (i) the amount paid by the Agent under or with
         respect  to  such  Letter  of  Credit,  and  (ii)  the  amount  of  any
         out-of-pocket   taxes,  fees,  charges  or  other  costs  and  expenses
         whatsoever  incurred  by the Agent or any Bank in  connection  with any
         payment  made by the Agent or any Bank under,  or with respect to, such
         Letter of Credit,

                  (b) upon the  reduction  (but not  termination)  of the  Total
         Commitment to an amount less than the Maximum Drawing Amount, an amount
         equal to such  difference,  which amount shall be held by the Agent for
         the  benefit  of the  Banks and the  Agent as cash  collateral  for all
         Reimbursement Obligations, and

                  (c) upon  the  termination  of the  Total  Commitment,  or the
         acceleration  of the  Reimbursement  Obligations  with  respect  to all
         Letters of Credit in accordance  with Sections 7 and 9, an amount equal
         to the then  Maximum  Drawing  Amount on all  Letters of Credit,  which
         amount  shall be held by the Agent for the benefit of the Banks and the
         Agent as cash collateral for all Reimbursement Obligations.

Each such  payment  shall be made to the  Agent at the  Agent's  head  office in
immediately available funds. Interest on any and all amounts remaining unpaid by
the  Borrower  under this  Section  2B.2 at any time from the date such  amounts
become due and payable  (whether as stated in this Section 2B.2, by acceleration
or otherwise)  until payment in full (whether before or after judgment) shall be
payable  to the Agent on demand at the rate  specified  in  Section  2.9(e)  for
overdue principal on the Loans.

     2B.3.  LETTER OF CREDIT PAYMENTS.  If any draft shall be presented or other
demand for  payment  shall be made under any Letter of Credit,  the Agent  shall
notify the Borrowers of the date and amount of the draft presented or demand for
payment and of the date and time when it expects to pay such draft or honor such
demand for payment.  If the Borrowers fail to reimburse the Agent as provided in
Section  2B.2 on or before the date that such draft is paid or other  payment is
made by the Agent, the Agent may at any time thereafter  notify the Banks of the
amount of any such  Unpaid  Reimbursement  Obligation.  No later  than 3:00 p.m.
(Boston  time) on the  Business Day next  following  the receipt of such notice,
each Bank shall make available to the Agent, at its head office,  in immediately
available funds, such Bank's Commitment  Percentage of such Unpaid Reimbursement
Obligation,  together  with an amount  equal to the product of (a) the  average,
computed for the period referred to in clause (c) below, of the weighted average
interest rate paid by the Agent for federal  funds  acquired by the Agent during
each day  included  in such  period,  times (b) the amount  equal to such Bank's
Commitment  Percentage  of such  Unpaid  Reimbursement  Obligation,  times (c) a
fraction,  the  numerator  of which is the number of days that  elapse  from and
including  the date the Agent paid the draft  presented  for honor or  otherwise
made  payment to the date on which such  Bank's  Commitment  Percentage  of such
Unpaid Reimbursement Obligation shall become immediately available to the Agent,
and the  denominator  of which is 360.  The  responsibility  of the Agent to the
Borrowers and the Banks shall be only to determine that the documents (including
each  draft)  delivered  under  each  Letter of Credit in  connection  with such
presentment  shall be in conformity in all material respects with such Letter of
Credit.

<PAGE>

         2B.4.  OBLIGATIONS  ABSOLUTE.  The  Borrowers'  obligations  under this
Section 2B shall be absolute and  unconditional  under any and all circumstances
and  irrespective  of the  occurrence  of any Default or Event of Default or any
condition precedent whatsoever or any setoff, counterclaim or defense to payment
which the  Borrowers  may have or have had  against  the Agent,  any Bank or any
beneficiary  of a Letter of Credit.  The Borrowers  further agree with the Agent
and the Banks that the Agent and the Banks shall not be responsible for, and the
Borrowers'  Reimbursement  Obligations  under Section 2B.2 shall not be affected
by,  among other  things,  the  validity or  genuineness  of documents or of any
endorsements  thereon,  even if such documents should in fact prove to be in any
or all respects  invalid,  fraudulent or forged, or any dispute between or among
the  Borrowers,  the  beneficiary  of any  Letter  of  Credit  or any  financing
institution  or other party to which any Letter of Credit may be  transferred or
any claims or defenses  whatsoever of the Borrowers  against the  beneficiary of
any Letter of Credit or any such  transferee.  The Agent and the Banks shall not
be  liable  for any  error,  omission,  interruption  or delay in  transmission,
dispatch  or  delivery  of  any  message  or  advice,  however  transmitted,  in
connection with any Letter of Credit.  The Borrowers agree that any action taken
or omitted by the Agent or any Bank under or in  connection  with each Letter of
Credit and the related  drafts and  documents,  if done in good faith and absent
gross negligence or willful misconduct,  shall be binding upon the Borrowers and
shall not  result in any  liability  on the part of the Agent or any Bank to the
Borrowers.

         2B.5.  RELIANCE BY ISSUER.  To the extent not inconsistent with Section
2B.4,  the Agent  shall be  entitled to rely,  and shall be fully  protected  in
relying upon, any Letter of Credit, draft, writing, resolution, notice, consent,
certificate, affidavit, letter, cablegram, telegram, telecopy, telex or teletype
message,  statement,  order or other  document  believed by it to be genuine and
correct and to have been  signed,  sent or made by the proper  Person or Persons
and upon advice and statements of legal  counsel,  independent  accountants  and
other  experts  selected  by the Agent.  The Agent shall be fully  justified  in
failing or  refusing  to take any action  under this  Agreement  unless it shall
first have  received  such advice or  concurrence  of the  Majority  Banks as it
reasonably deems  appropriate or it shall first be indemnified to its reasonable
satisfaction by the Banks against any and all liability and expense which may be
incurred by it by reason of taking or  continuing  to take any such action.  The
Agent shall in all cases be fully  protected in acting,  or in  refraining  from
acting, under this Agreement in accordance with a request of the Majority Banks,
and such request and any action taken or failure to act pursuant  thereto  shall
be binding upon the Banks and all future  holders of the Notes or of a Letter of
Credit Participation.

     2B.6. LETTER OF CREDIT FEE. The Borrowers shall, on the date of issuance or
any extension or renewal of any Letter of Credit and at such other time or times
as such charges are  customarily  made by the Agent,  pay a fee (in each case, a
"Letter of Credit  Fee") to the Agent (a) in respect of each  standby  Letter of
Credit equal to one and  one-half  percent (1 1/2%) per annum of the face amount
of such standby  Letter of Credit plus the Agent's  customary  issuance fee, and
(b) in respect of each  documentary  Letter of Credit  equal to (i) the  Agent's
customary  issuance fee or amendment fee, as the case may be, which issuance fee
or amendment fee, as the case may be, shall not be more than $110 per occurrence
plus (ii) the Agent's  customary time negotiation fee per document  examination,
which  fee  shall not be more than  $110 per  document  examination  plus  (iii)
one-quarter  of one  percent  (1/4%)  per  annum  on the  face  amount  of  such
documentary Letter of Credit,  such Letter of Credit Fee (but not such issuance,
amendment,  negotiation or document  examination  fee) to be for the accounts of
the Banks in accordance with their respective Commitment Percentages.

<PAGE>

        2B.7. USAGE OF UNUSED COMMITMENT FOR BANKERS ACCEPTANCES. Each Bank may,
in its sole discretion at the request of a Borrower or Dynatech, and pursuant to
such documentation as such Bank may require,  issue Bankers  Acceptances in lieu
of Advances or Loans which would  otherwise be permitted to be made  pursuant to
the terms of this Agreement, in such amount and upon such terms as such Bank and
such  Borrower  and  Dynatech may agree upon;  provided,  however,  that (a) the
amount  of each  such  draft  shall  reduce  the  unused  portion  of the  Total
Commitment and such Bank's  Commitment  available to the Borrowers for borrowing
hereunder by such amount;  (b) any such unpaid  Bankers  Acceptance  shall,  for
purposes of  determining  the  Commitment  Fee payable from time to time and for
purposes of Section 9.2 hereof,  be deemed to constitute  outstanding and unpaid
Loans;  (c) the  drafts to be so  accepted  by such Bank shall be  eligible  for
discount  with the Federal  Reserve Bank of the district in which the  accepting
Bank  is  located   under  any   requirements   imposed  by  law,   regulations,
administrative  ruling,  interpretation,  practice  or  custom,  imposed on such
discount  at the time such  Bankers  Acceptance  are  created;  and (d) no draft
accepted  shall have a maturity  date later  than the  Commitment  Expiry  Date.
Drafts to be  accepted  under the terms  thereof  shall be drawn on such Bank at
such Bank's  discount  rate,  plus a commission not to exceed three percent (3%)
per annum.  The aggregate  amount of such drafts to be presented at any one time
shall be at least  $100,000.  All  shipping  documents  and  warehouse  receipts
securing  such  Bankers  Acceptances  shall  be held by  such  Bank  for its own
benefit.  The Borrowers jointly and severally agree, on the maturity date of any
such  draft  accepted  by such  Bank,  to pay such Bank the face  amount of such
draft.

        SECTION 3.  CONDITIONS OF LENDING.

        3.1.  CONDITIONS TO CLOSING.  The  obligations  of the Banks to make the
initial  Advances  and of the Agent to issue any  Letters of Credit and  Bankers
Acceptances,  and the  effectiveness  of this Agreement  shall be subject to the
satisfaction of the following conditions precedent:

                (a) Each of the Loan Documents shall have been duly executed and
        delivered by the respective parties thereto,  shall be in full force and
        effect and shall be in form and  substance  satisfactory  to each of the
        Banks.  Each Bank shall have received a fully executed copy of each such
        document.

                (b) The  representations  and warranties  contained in Section 4
        shall  be  true  and   accurate   (except  to  the   extent   that  such
        representations and warranties relate to an earlier date).

                (c) There  shall  have been no  material  adverse  change in the
        business or financial affairs of Dynatech and its Subsidiaries since the
        year-end  financial  statements  delivered  to each of the Banks for the
        most recent year.

               (d)  The  Agent  shall  have  received  certified  copies  of the
          following  in form and  substance  satisfactory  to the  Agent  and in
          sufficient copies for each Bank:

                    (i) The resolutions of the Board of Directors of each of the
               Borrowers  and the  Guarantors  approving  the Loan  Documents to
               which each is a party;

                    (ii) all  documents  evidencing  other  necessary  corporate
               action and the  governmental  approvals,  if any, with respect to
               the  Loan  Documents  to  which  each  of the  Borrowers  and the
               Guarantors is a party; and

<PAGE>
                         (iii)  a  secretary's  certificate  certifying  that no
                change to the charter or other  incorporation  documents of each
                of the Borrowers has occurred  since  December 22, 1992,  and an
                incumbency certificate for each Borrower and Guarantor.

                (e) The Banks shall have  received an opinion  addressed  to the
        Agent and the Banks from Messrs.  Goodwin,  Procter & Hoar,  counsel for
        the Borrowers and the Guarantors,  in form and substance satisfactory to
        the Banks.

        3.2. CONDITIONS TO MAKING OF EACH ADVANCE.  The obligations of the Banks
to make any Advances  and of the Agent to issue,  renew or extend any Letters of
Credit and Bankers  Acceptances,  and to convert  the  Advances to the Term Loan
shall be subject to the following:

                (a) The Agent and,  in the case of M/M Rate  Advances,  the Bank
        making such  Advance  shall have  timely  received  from the  applicable
        Borrower (and  Dynatech,  if applicable)  any notice  required under any
        provisions  of this  Agreement,  signed  by the  President  or the chief
        financial  officer of such  Borrower  (and  Dynatech,  respectively,  if
        applicable)  which request  without more will constitute a certification
        by such  officer(s) as to the matters set forth in paragraphs  (b), (c),
        and (d)(i) below.

          (b) The representations and warranties contained in Section 4 shall be
        true and accurate in all material respects.

          (c) No  Default  or  Event  of  Default  shall  have  occurred  and be
        continuing.

                (d) The making of the Loan shall not  contravene any law or rule
        or  regulation  thereunder  binding  upon (i) any Borrower or any of its
        Subsidiaries or (ii) the Banks.

                (e) If an acquisition  of the type described in Section  2.12(b)
        occurs,  the Banks shall not be required to make any Advances unless and
        until the  conditions  set forth in clauses (i) and (ii) of said Section
        2.12(b) have been satisfied; provided, that unless or until repayment is
        required  to be made  pursuant  to  ss.2.12(b),  the  Borrowers  will be
        permitted to retain outstanding those Advances outstanding prior to such
        acquisition  and to  convert  outstanding  Advances  to  other  types of
        Advances in accordance with ss.2.9(a) hereof.

        SECTION 4.  REPRESENTATIONS AND WARRANTIES.

     Each of the Borrowers  and the  Guarantors  represents  and warrants to the
Banks and the Agent that:

        4.1.  ORGANIZATION,  GOOD  STANDING,  AUTHORITY,  ETC.  Such Borrower or
Guarantor, as the case may be, and each of its Subsidiaries (a) is a corporation
duly organized, existing and in good standing under the laws of the jurisdiction
of its incorporation,  (b) has all requisite corporate power to own its property
and conduct its business as now conducted and as presently  contemplated and (c)
is  duly  qualified  to  do  business  and  is in  good  standing  as a  foreign
corporation  in each  jurisdiction  where the  nature of its  properties  or its
business requires such qualification except where the failure to so qualify will
not have a materially adverse effect on such Borrower or Guarantor,  as the case
may be, and its  Subsidiaries.  The execution,  delivery and performance of this
Agreement and the  transactions  contemplated  hereby and thereby are within the
corporate authority of such Borrower or Guarantor, as the case may be, have been

<PAGE>

authorized by proper  corporate  proceedings  and do not and will not contravene
any provisions of its charter,  other incorporation papers, by-laws or any stock
provision  or  any  amendment  thereof  or,  any  provisions  of  law  or of any
indenture,  material  agreement,  instrument  or  undertaking  binding upon such
Borrower or Guarantor,  as the case may be, or any of its  Subsidiaries,  or any
property  of such  Borrower  or  Guarantor,  as the case  may be,  or any of its
Subsidiaries.  The execution, delivery and performance of this Agreement by such
Borrower  or  Guarantor,  as the case may be,  will  result in valid and legally
binding  obligations  of  such  Borrower  or  Guarantor,  as the  case  may  be,
enforceable  in accordance  with their  respective  terms,  except as limited by
bankruptcy, insolvency, reorganization,  moratorium or other laws relating to or
affecting generally the enforcement of creditor's rights.

        4.2. GOVERNMENTAL  APPROVALS. No approval or consent of, or filing with,
any  governmental  agency or  authority  is  required  to make valid and legally
binding the execution,  delivery and  performance of this Agreement and the Loan
Documents  and  consummation  of  the  transactions  among  the  parties  hereto
contemplated hereby or thereby.

        4.3. SUBSIDIARIES.  Dynatech is the owner, directly or indirectly,  free
and clear of all liens and  encumbrances,  of all of the issued and  outstanding
voting  stock of each  Subsidiary  as  indicated  in Schedule 1 attached  hereto
(except Dynatech owns only 65% of the voting stock of Datatel France and except,
in the case of foreign Subsidiaries, for directors' qualifying shares and shares
held by nominees as required by law). All shares of such stock have been validly
issued and are fully paid  (except  the stock of  Dynatech  Holdings,  Ltd.  and
Dynatech  Euromedical,  Ltd., both of Guernsey,  C.I.) and non-assessable and no
rights to subscribe to additional shares have been granted.

        4.4.  COMPLIANCE  WITH OTHER  INSTRUMENTS.  Neither  any  Borrower,  any
Guarantor  nor any of  their  Subsidiaries  is in  material  default  under  any
provisions  of  its  charter,  other  incorporation  papers,  by-laws  or  stock
provisions or any amendment thereof or of any indenture or material agreement or
of any order,  regulation,  ruling or  requirement  of a court or public body or
authority by which it is bound.

        4.5.  LITIGATION.  Except as disclosed in Schedule 2 attached hereto, no
action,  suit,  investigation or proceeding is pending or known to be threatened
against any  Borrower,  any  Guarantor or any of their  Subsidiaries  before any
court or administrative agency which, if adversely determined,  would, either in
any  case or in the  aggregate,  result  in a  liability  of any  Borrower,  any
Guarantor or any of their  Subsidiaries  in excess of $3,000,000  not covered by
insurance, nor is any substantial basis for any such litigation known to exist.

        4.6. NO ADVERSE CONTRACTS,  ETC. Neither any Borrower, any Guarantor nor
any of their  Subsidiaries  is subject to any  provision of its  charter,  other
incorporation papers,  by-laws or stock provisions or any amendment thereof or a
party to or otherwise bound by any indenture or agreement or bound by any order,
regulation,  ruling or requirement of a court or public body or authority  which
will, under current or foreseeable  conditions,  materially adversely affect its
normal operations or impair its financial condition or prospects.

        4.7. FINANCIAL STATEMENTS.  Dynatech has furnished to each of the Banks:
a  consolidated  balance  sheet as at March 31,  1995 and  related  consolidated
statements of income and retained  earnings,  changes in financial  position and
additional  paid-in capital of Dynatech and its Subsidiaries for the fiscal year
then ended,  certified by Coopers & Lybrand.  The balance  sheet and  statements
described  above  have been  prepared  in  conformity  with  generally  accepted
accounting  principles  applied on a  consistent  basis  throughout  the periods
specified  and  present  fairly  the  financial  position  of  Dynatech  and its
Subsidiaries as at the date thereof.

<PAGE>

        4.8. CHANGES.  Since the date of the financial  statements  described in
Section  4.7  hereof  there  has  been no  change  in the  assets,  liabilities,
financial  condition  or business of Dynatech or any of its  Subsidiaries  other
than changes the effect of which has not been in any case, or in the  aggregate,
materially adverse.

        4.9. BUSINESS.  Each Borrower,  Guarantor and each of their Subsidiaries
has good and  marketable  title to its  properties  and assets,  including  such
properties  and  assets  as are  reflected  in the  consolidated  balance  sheet
referred to in Section 4.7 hereof  (except such assets as have been  disposed of
in the ordinary course of business subsequent to the date thereof) subject to no
security  interests  except as is  specifically  set forth in  Schedule  3. Each
Borrower,   Guarantor  and  each  of  their  Subsidiaries  enjoys  peaceful  and
undisturbed possession under all leases of real or personal property of which it
is lessee, none of which contains any burdensome provision which will materially
adversely  affect or impair the operation of such Borrower,  Guarantor or any of
their  Subsidiaries,  and all such leases are valid and  subsisting  and in full
force and effect. To the best of each Borrower's and Guarantor's knowledge, such
Borrower,  Guarantor and each of their  Subsidiaries owns or possesses the right
to use all the franchises, rights and licenses, necessary for the conduct of its
business as now  conducted  and as proposed to be  conducted,  without any known
conflict with the rights of others.

        4.10. TAXES. All federal,  state and other tax returns of each Borrower,
Guarantor  and their  Subsidiaries  required by law to be filed have been filed,
and all  federal,  state and other  taxes,  assessments  and other  governmental
charges upon each Borrower, Guarantor and their Subsidiaries or their properties
which are due and  payable  have been  paid,  except  those as are being in good
faith  appropriately  contested and as to which  appropriate  reserves have been
established in accordance with generally accepted  accounting  principles.  Each
Borrower and each  Guarantor  has set aside on its books  provisions  reasonably
adequate for the payment of all taxes for periods  subsequent to the periods for
which such returns have been filed.

        4.11. LOAN AS SENIOR INDEBTEDNESS.  The Indebtedness hereunder evidenced
by this Agreement will constitute "Senior  Indebtedness" or "Senior Debt" in any
instrument   evidencing   Indebtedness   which   purports  to  be   Subordinated
Indebtedness.

     4.12. NO DEFAULTS. No event has occurred and is continuing and no condition
exists which  constitutes or which after notice or lapse of time, or both, would
constitute an Event of Default.

        4.13.  REGULATION U. No Borrower or Guarantor is engaged in the business
of owning or carrying  margin stock  (within the meaning of  Regulation U of the
Board of Governors of the Federal Reserve  System),  and no part of the proceeds
of the Loans will be used to  purchase  or carry any  margin  stock or to extend
credit to others for the purpose of  purchasing  and carrying any margin  stock,
except for the purchase by Dynatech of its capital  stock to be held as treasury
stock,  restored to unissued  status or eliminated  from its authorized  shares,
provided that such purchase does not violate said Regulation U.

        4.14.  PENSION  PLANS.  Neither any  Borrower,  any Guarantor nor any of
their Subsidiaries maintains or contributes to any pension plan, the benefits of
which are  guaranteed,  in whole or in part,  by the  Pension  Benefit  Guaranty
Corporation.

<PAGE>

       4.15.  ABSENCE OF  FINANCING  STATEMENTS.  Except  with  respect to liens
permitted  by Section  6.2 hereof,  there is no  financing  statement,  security
agreement,  chattel  mortgage,  real estate  mortgage or other document filed or
recorded with any filing records, registry or other public office, that purports
to cover,  affect or give notice of any  present or possible  future lien on, or
security interest in, any assets or property of the Borrowers, the Guarantors or
any of their Subsidiaries or any rights relating thereto.

        SECTION 5.  CERTAIN AFFIRMATIVE COVENANTS.

        The Borrowers  and the  Guarantors  jointly and  severally  covenant and
agree that,  so long as any amounts are owing with respect to this  Agreement or
any Bank has any obligation to make any Loans or the Agent has any obligation to
issue,  extend or renew any  Letters of Credit,  each of the  Borrowers  and the
Guarantors will (and to the extent applicable to any Subsidiary, will cause each
such Subsidiary to):

     5.1. CURRENT RATIO. Cause Dynatech to maintain at all times a Current Ratio
of at least 1.75:1.00.

        5.2.  TANGIBLE  NET  WORTH.  Cause  Dynatech  to  maintain  Consolidated
Tangible  Net  Worth  of not  less  than  the sum of (a)  $90,000,000  plus  (b)
seventy-five  percent  (75%) of the  cumulative  net  profits  (after  taxes) of
Dynatech and its  Subsidiaries  for each fiscal  quarter  commencing on or after
April 1, 1995, excluding from the computation of such cumulative net profits any
net loss in any such fiscal period, plus (c) 100% of the aggregate amount of the
proceeds  from any sale  made by  Dynatech  after  April 1,  1995 of its  equity
securities or warrants or subscription rights for such securities,  exclusive of
sales of such securities pursuant to employee stock option, purchase, benefit or
401(k) plans or other employee benefit arrangements.

     5.3. DEBT TO WORTH RATIO.  Cause Dynatech to maintain a Debt to Worth Ratio
of not more than 2.50:1.00.

        5.4.  FIXED CHARGE  COVERAGE.  Cause Dynatech to maintain a ratio of (a)
Net Revenues  Available for Debt Service for each period of four (4) consecutive
fiscal quarters, to (b) Debt Service for such period, of at least 3.00:1.00.

     5.5.  PUNCTUAL  PAYMENT.  Duly and  punctually  pay or cause to be paid the
principal  of and  interest  and all other  sums due  under  this  Agreement  in
accordance with the terms of this Agreement.

        5.6. CONDUCT OF BUSINESS.  Carry on its business in an efficient manner;
cause to be done all things  necessary  to  preserve  and keep in full force and
effect its corporate existence,  rights and franchises;  effect and maintain its
foreign  qualifications,  licensing,  domestication or  authorization  except as
terminated  by the Board of  Directors of such  Borrower,  Guarantor or of their
Subsidiaries in the exercise of its reasonable judgment;  comply in all material
respects with all applicable  laws; and not become  obligated under any contract
or  binding  arrangement  which  materially   adversely  impairs  the  financial
condition or business of Dynatech and its Subsidiaries as a whole.

        5.7.  TAXES,  ETC.  Duly  pay and  discharge,  or  cause  to be paid and
discharged,  before the same shall become in arrears, all taxes, assessments and
other  governmental  charges  imposed  upon it and  its  properties,  sales  and
activities,  or any part thereof,  or upon the income or profits  therefrom,  as
well as all claims for labor,  materials,  or supplies  which if unpaid might by
law become a lien or charge upon any of its property;  provided,  however,  that
neither any  Borrower,  any  Guarantor  nor any of their  Subsidiaries  shall be
required  to pay any  such  item if the  validity  thereof  shall  currently  be
appropriately  contested in good faith and if such Borrower, such Guarantor or a
Subsidiary,  as the case may be,  shall  have set  aside on its  books  reserves
deemed by it adequate with respect to such item.

<PAGE>

        5.8. MAINTENANCE OF PROPERTIES. Maintain and keep the properties used or
deemed by it to be useful in its  business  in good  repair,  working  order and
condition,  and make or cause to be made all needful and proper repairs  thereto
and replacements thereof.

        5.9.  MAINTENANCE  OF  INSURANCE.  Maintain with  financially  sound and
reputable  insurers,   insurance,   including   specifically  product  liability
insurance,  with respect to properties and business of such Borrower,  Guarantor
and their  Subsidiaries  against such casualties and  contingencies  and in such
types and amounts as shall be in accordance  with sound  business  practices for
companies in similar businesses similarly situated.

        5.10.  RECORDS AND  ACCOUNTS.  Keep true records and books of account in
which full,  true and correct  entries will be made in accordance with generally
accepted  accounting  principles and maintain adequate accounts and reserves for
all taxes (including income taxes),  all depreciation,  depletion,  obsolescence
and  amortization  of its  properties,  all other  contingencies,  and all other
proper reserves.

        5.11.  FINANCIAL STATEMENTS. Cause to be furnished to each of the Banks:

     (a) as soon as practicable and, in any event,  within 45 days after the end
of each of the first three  quarterly  periods of each fiscal year of  Dynatech,
consolidated  balance sheets of Dynatech and its  Subsidiaries  as at the end of
such  period,  and  consolidated  statements  of income and  retained  earnings,
changes in financial position and additional paid-in capital of Dynatech and its
Subsidiaries  for such  period  and for the  period  from the  beginning  of the
current fiscal year to the end of such period, setting forth in comparative form
the figures for the  corresponding  periods of the previous  fiscal year, all in
reasonable  detail  satisfactory  to the  Agent,  prepared  in  accordance  with
generally accepted accounting principles applied on a consistent basis except as
otherwise  disclosed and  certified as complete and correct,  subject to changes
resulting  from  audit and  year-end  adjustments,  by the  principal  financial
officer of Dynatech who, at the time of delivery thereof,  shall also certify as
to the compliance with Sections 5.1 through 5.4 of this Agreement,  and provide,
and  certify as to the  accuracy  of,  the  computations  evidencing  compliance
therewith;

                (b) as soon as  practicable  and,  in any event,  within 90 days
after the end of each fiscal year (or within such shorter  period as  applicable
stock  exchange  regulations  may require  for  mailing of the annual  report to
stockholders),  consolidated  balance sheets,  statements of income and retained
earnings,  changes  in  financial  position  and  additional  paid in capital of
Dynatech and its  Subsidiaries as at the end of such year, each setting forth in
comparative  form the figures for the previous  fiscal year,  all in  reasonable
detail satisfactory to the Agent, prepared in accordance with generally accepted
accounting  principles  applied  on  a  consistent  basis  except  as  otherwise
disclosed, and accompanied by a report and opinion of Coopers & Lybrand or other
independent  certified  public  accountants of recognized  standing  selected by
Dynatech and satisfactory to the Agent, which opinion and report shall have been
prepared in accordance with generally accepted auditing standards;

                (c) upon each  delivery  of  financial  statements  pursuant  to
paragraph  (b) of this  Section  5.11,  a copy of  Schedule 5 to this  Agreement
revised to reflect  the  Material  Subsidiaries  existing  on and as of the date
thereof and the  contribution  of each such Material  Subsidiary to Consolidated
Tangible Net Worth and Consolidated  Gross Revenues as of the end of such fiscal
year.

<PAGE>

                (d)  promptly  upon  their  becoming  available,  copies  of all
financial statements,  reports, notices and proxy statements sent by Dynatech or
any of its Subsidiaries to stockholders, and of all regular and periodic reports
filed by Dynatech or any of its  Subsidiaries  with any  securities  exchange or
with the  Securities  and  Exchange  Commission  or any  governmental  authority
succeeding to any or all of the functions of said Commission;

                (e)  from  time to  time  any  such  information  regarding  the
financial and other affairs of Dynatech and its  Subsidiaries and such operating
statements,  cost  analysis  and  proposed  budgets as the Agent or any Bank may
reasonably request.

        At the  time  of each  delivery  of  financial  statements  pursuant  to
paragraph  (b) of this  Section  5.11,  Dynatech  shall  furnish a statement  of
independent certified public accountants that they have caused the provisions of
this Agreement to be reviewed, insofar as they relate to accounting matters, and
that they have no knowledge of the existence of any Default or Event of Default,
or if they have such  knowledge,  specifying  the nature and period of existence
thereof.  Such  statement  shall  also  contain  the  accountant's  computations
evidencing  compliance  with the  provisions of Sections 5.1 through 5.4 of this
Agreement.  If any  Borrower  shall at any other time  obtain  knowledge  of the
existence  of any Default or Event of Default,  such  Borrower  shall  forthwith
deliver  to the Agent  (with  sufficient  copies  for the  Banks) a  certificate
specifying  the nature  and  period of  existence  thereof  and what  action the
Borrowers propose to take with respect thereto.

        5.12.  INSPECTION.  Permit the Banks,  through the Agent or any of their
designated  representatives,  at the Banks' expense, to visit and inspect any of
its  properties  and to examine its books and discuss the affairs,  finances and
accounts of the Borrowers,  the Guarantors or any of their Subsidiaries with its
officers, all at such reasonable times and as often as the Agent or any Bank may
reasonably  request.  Each Bank agrees to keep  confidential  any and all of the
information obtained hereby, provided that (i) such information may be available
for  inspection  or examination by any  governmental regulatory authority having
jurisdiction  over the Agent or any Bank and (ii) such  information  may be made
available to any bank or institutional  lender in connection with the assignment
by any Bank of, or the  granting  by any Bank of  participations  in,  the Loans
hereunder provided that such bank or institutional  lender agrees to comply with
the provisions of this sentence as if such bank or  institutional  lender were a
Bank hereunder.

         5.13.  NOTICE OF LITIGATION.  Promptly notify the Agent and each of the
Banks of the commencement of any litigation  against any Borrower,  Guarantor or
any of their Subsidiaries which, if adversely  determined,  would, either in any
case or in the aggregate,  result in a liability of such Borrower,  Guarantor or
any of their Subsidiaries in excess of $3,000,000 not covered by insurance.

         5.14. FURTHER ASSURANCES. Cooperate with the Banks and take such action
and execute such further instruments and documents as the Banks (or any of them)
shall  reasonably  request to carry out to their  satisfaction  the transactions
contemplated by this Agreement.

         5.15.  DOMESTIC  MATERIAL  SUBSIDIARIES AS BORROWERS.  Upon the written
request  of the  Agent or the  Majority  Banks,  cause  each  Domestic  Material
Subsidiary  of Dynatech to become a party to this  Agreement  and a Borrower for
all purposes of this Agreement,  and cause such Domestic Material  Subsidiary to
deliver to the Agent and the Banks a written  instrument  to such effect in form

<PAGE>

and substance  satisfactory to the Agent and the Majority  Banks,  together with
such  records  or  evidence  of  corporate   authorizations  and  other  related
proceedings and legal opinions, in form and substance  satisfactory to the Agent
and the  Majority  Banks,  as the Agent or the  Majority  Banks  may  reasonably
request to carry out the provisions of this Section 5.15. If a Borrower shall at
any time cease to be a Domestic Material  Subsidiary of Dynatech,  its liability
as a Borrower  under this  Agreement  shall  continue  unless the Majority Banks
otherwise agree.

         5.16. COMPLIANCE WITH LAWS, CONTRACTS,  LICENSES,  AND PERMITS.  Comply
with (a) the applicable laws and regulations wherever its business is conducted,
including all Environmental Laws, unless the failure to so comply would not have
a materially  adverse effect on the business,  assets or financial  condition of
the  Borrowers  or any of the  Subsidiaries  (b) the  provisions  of its charter
documents and by-laws,  (c) all agreements and instruments by which it or any of
its  properties  may be  bound  and  (d) all  applicable  decrees,  orders,  and
judgments. If any authorization,  consent,  approval, permit or license from any
officer,  agency or  instrumentality of any government shall become necessary or
required in order that the  Borrowers or any of their  Subsidiaries  may fulfill
any of its obligations hereunder or any of the other Loan Documents to which the
Borrowers or such Subsidiary is a party, the Borrowers will, or (as the case may
be) will cause such  Subsidiary  to,  immediately  take or cause to be taken all
reasonable  steps within the power of the Borrowers or such Subsidiary to obtain
such authorization,  consent,  approval, permit or license and furnish the Agent
and the Banks with evidence thereof.


         SECTION 6.  CERTAIN NEGATIVE COVENANTS.

         The Borrowers  and the  Guarantors  jointly and severally  covenant and
agree that,  so long as any amounts are owing with respect to this  Agreement or
any Bank has any obligation to make any Loans or the Agent has any obligation to
issue, extend or renew any Letters of Credit, each of the Borrowers will not and
will not permit any of its Subsidiaries to:

         6.1. INDEBTEDNESS.  Create, incur, assume, guarantee, agree to purchase
or  repurchase  or provide  funds in respect  of, or  otherwise  become or be or
remain liable with respect to, any  Indebtedness  of any type whatsoever owed to
any Person, except:

                  (a)      Indebtedness to the Banks under this Agreement;

                  (b)  Indebtedness  owing  by  any  Borrower  to a  Subsidiary;
         Indebtedness  owing to any  Borrower  by any of its  Subsidiaries;  and
         Indebtedness owing by any Subsidiary to any other Subsidiary so long as
         the lending  Subsidiary  (i) has not borrowed from a Borrower,  or (ii)
         has  guaranteed  the  punctual  payment  of  amounts  owing  under this
         Agreement;  provided that the aggregate amount of Indebtedness owing by
         Foreign  Material  Subsidiaries  to Dynatech  (other than  Indebtedness
         existing on the date hereof as reported on Schedule 6.1(b) hereof) plus
         the amount of equity  Investments  made as  permitted  under  ss.6.3(d)
         hereof  shall  not,  as at the end of any  fiscal  year,  exceed 20% of
         Consolidated Tangible Net Worth;

                  (c) Indebtedness and other  liabilities of Dynatech and/or any
         of its  Subsidiaries  incurred in the  ordinary  course of business not
         incurred  through  (i) the  borrowing  of money or (ii) the  leasing of
         property  except  as  permitted  by  Section  6.1(d).  No more  than an
         aggregate of  $7,000,000  in  purchase-money  indebtedness,  secured by
         liens  permitted  under Section  6.2(a),  may be outstanding at any one
         time pursuant to this Section 6.1(c);

<PAGE>

                  (d) Indebtedness of Dynatech and/or any of its Subsidiaries in
         respect of rent due under  leases of real or personal  property for use
         in the ordinary  course of business not to exceed in the  aggregate for
         any  twelve  (12)  consecutive  calendar  months  20%  of  Consolidated
         Tangible Net Worth at the beginning of such twelve months;

                  (e) Indebtedness of Dynatech and/or any of its Subsidiaries in
         respect of taxes,  assessments,  governmental  charges,  and claims for
         labor,  materials or supplies to the extent that payment  thereof shall
         not at  the  time  be  required  to be  made  in  accordance  with  the
         provisions of Section 5.7 hereof;

                  (f) Indebtedness of Dynatech and/or any of its Subsidiaries in
         respect of  judgments  or awards which have been in force for less than
         the  applicable  appeal  period  so long  as  execution  is not  levied
         thereunder,  or in respect of which  Dynatech or a Subsidiary  shall at
         the time in good  faith be  prosecuting  an appeal or  proceedings  for
         review  and in  respect  of which a stay of  execution  shall have been
         obtained  pending  such  appeal  or  review  or  which  do not,  in the
         aggregate, exceed $2,500,000 not covered by insurance;

                  (g)      Subordinated Indebtedess;

                  (h) Indebtedness of Dynatech and/or any of its Subsidiaries in
         an amount not to exceed $10,000,000 in the aggregate which Indebtedness
         is  incurred  to  purchase  real  estate  and  which  is   non-recourse
         Indebtedness secured only by such real estate; and

               (i)  Unsecured   Indebtedness  of  Dynatech  and/or  any  of  its
          Subsidiaries not otherwise specified in this ss.6.1,  provided, all of
          such  Indebtedness  shall not exceed in an aggregate  principal amount
          outstanding, $40,000,000.

     6.2. LIENS.  Create,  incur, assume or permit to exist any mortgage,  lien,
charge,  security  interest or other encumbrance on any property or asset of any
Borrower or any of its Subsidiaries, except:

                  (a)  liens  securing  the  payment  of the  purchase  price of
         personal property  purchased by any Borrower or any of its Subsidiaries
         for use in the ordinary course of business,  which liens are limited to
         the property so purchased;

                  (b) liens to secure claims for labor,  material or supplies to
         the extent that payment thereof shall not at the time be required to be
         made in accordance with Section 5.7;

                  (c) deposits or pledges made in connection  with, or to secure
         payment of, workmen's  compensation,  unemployment  insurance,  old age
         pensions  or other  social  security  or in  connection  with  contests
         thereof to the extent that  payment  thereof  shall not at that time be
         required to be made in accordance with Section 5.7;

               (d) liens for taxes or  assessments  or  governmental  charges or
          levies  if  payment  shall not at the time be  required  to be made in
          accordance with Section 5.7;

               (e) liens securing Indebtedness permitted by Section 6.1 (h);

                  (f)      those liens set forth in Schedule 3 hereto;

<PAGE>

                  (g) liens,  mortgages  or security  interests on assets of any
         entities or assets of such entities  being  acquired by any Borrower or
         any of its Subsidiaries,  which liens,  mortgages or security interests
         exist immediately prior to any such acquisition;

               (h) liens in addition to the liens  otherwise  specified  in this
          Section  6.2  securing   Indebtedness  not  to  exceed  $2,000,000  in
          aggregate amount at any one time outstanding; and

                  (i) liens,  pledges  and other  encumbrances  with  respect to
         capital  stock of Dynatech  which is held by it as treasury  stock,  is
         restored to unissued status or is eliminated from authorized shares.

         6.3.  INVESTMENTS.  Make or  permit  to exist  any  Investments  of any
Borrower and/or any of its  Subsidiaries,  directly or indirectly,  in excess of
$6,000,000 in the aggregate other than:

                  (a)  Marketable  direct  obligations  of the United  States of
         America or of the United Kingdom, France, Germany or Japan which mature
         within one year from the date of issue;

                  (b)  Certificates  of deposit  of  domestic  or foreign  banks
         having total combined  capital and surplus in excess of $100,000,000 or
         which are rated P-1 or better for  short-term  certificates  of deposit
         and A-2 or better  for  long-term  certificates  of  deposit by Moody's
         Investor Services Inc.;

                  (c) Securities  commonly known as "commercial paper" issued by
         any  domestic  corporation,  which at the time of  purchase  have  been
         rated,  and the ratings for which are not less than "Prime" if rated by
         the National Credit Office,  and not less than "A" if rated by Standard
         and Poor's;

                  (d)   Investments   in  other   Borrowers  or  Guarantors  and
         Investments  in  Foreign  Material  Subsidiaries;   provided  that  the
         aggregate amount of Investments  consisting of equity  Investments made
         after the date hereof, and debt Investments made after the date hereof,
         by Dynatech in Foreign Material  Subsidiaries  shall not, as at the end
         of any fiscal year, exceed 20% of Consolidated Tangible Net Worth;

               (e) Investments in the capital stock of Dynatech which is held by
          Dynatech as  treasury  stock,  is  restored  to unissued  status or is
          eliminated from authorized shares;

               (f)  Investments  made as permitted under Section 6.4(b) provided
          the amount of such  Investments  shall not  exceed,  in the  aggregate
          $20,000,000;

               (g) Investment  consisting of a maximum of a $4,000,000 note made
          by the  purchaser  of Micro  Processor  Systems,  Inc.  ("MPSI"),  and
          delivered  to Dynatech  pursuant to a sale by Dynatech of the stock of
          MPSI as permitted by ss.6.4(d) hereof; and

                  (h)  Investments  consisting of notes made by any purchaser of
         certain assets or stock of the Borrowers or any of their  Subsidiaries,
         and  delivered  to such seller  pursuant to a sale  permitted by ss.6.4
         hereof,  provided that the aggregate  amount of all such notes does not
         exceed $5,000,000.

<PAGE>

         6.4. MERGER,  CONSOLIDATION  OR SALE OF ASSETS,  ETC. Become a party to
any merger or  consolidation or take any action looking to any Borrower's or any
Subsidiary's  dissolution  or  liquidation,  or acquire any other  business,  or
interest therein by merger or acquisition of assets, or sell, lease or otherwise
dispose of any substantial part of its assets, except that:

                  (a) a Subsidiary may be merged or consolidated with a Borrower
         if such Borrower  shall be the  continuing or surviving  corporation or
         with any one or more  other  Subsidiaries  if the  successor  formed or
         resulting from such consolidation or merger shall be a Subsidiary;

                  (b) any Borrower or any of its Subsidiaries may consolidate or
         merge  with  or  acquire   all  or  less  than  all  of  the  stock  or
         substantially  all the assets of any other corporation or other entity;
         provided  that (i) unless the  acquiring  company  demonstrates  to the
         satisfaction  of the Banks  that no  proceeds  of any Loans are used to
         fund such transaction,  such transaction must have been approved by the
         Board of Directors of such other  corporation  or the governing body of
         such other  entity,  (ii) such  Borrower  or a  Subsidiary  must be the
         survivor  in  such   transaction  and  (iii)   immediately   after  the
         effectiveness  of  any  such  transaction,  there  shall  occur  and be
         continuing no Default or Event of Default under this Agreement;

               (c) any Subsidiary may sell, lease, transfer or otherwise dispose
          of  all  or any  portion  of  its  assets  to a  Borrower  or  another
          Subsidiary, or if such Subsidiary is not a Material Subsidiary, to any
          other  Person,  and such  Subsidiary  may  thereafter  be dissolved or
          liquidated  (provided that immediately  after the effectiveness of any
          such merger, consolidation,  sale, dissolution,  liquidation, lease or
          other  disposition,  there shall have  occurred and be  continuing  no
          Default or Event of Default under this Agreement); and

                  (d) Dynatech or any Subsidiary may sell, transfer or otherwise
         dispose  of all or any  portion of the stock of a  Subsidiary,  if such
         Subsidiary is not a Material Subsidiary,  to any other Person (provided
         that   immediately   after  the   effectiveness  of  any  such  merger,
         consolidation,  sale,  dissolution,  liquidation  or other  disposition
         there  shall have  occurred  and be  continuing  no Default or Event of
         Default  under  this  Agreement)  and  if  such  Subsidiary  is  also a
         Borrower,  such  Subsidiary  shall  cease  being a  Borrower  upon  the
         effectiveness of such sale, transfer or disposition.

         6.5.  SALE  AND  LEASE-BACK.  Sell or  transfer  or  permit  any of its
Subsidiaries  to sell or transfer any of its  properties  with the  intention of
taking back a lease of any such property or substantially similar property other
than the sale and lease-back of properties having an aggregate fair market value
not in excess of  $6,000,000  occurring  after the date  hereof.  The  Borrowers
and/or  any of their  Subsidiaries  have  heretofore  entered  into the sale and
leaseback transactions set forth on Schedule 4 to this Agreement.

         6.6.  CHANGE IN TERMS AND PREPAYMENT OF SUBORDINATED INDEBTEDNESS.

                  (a)  Effect or permit any  change in or  amendment  to (i) the
         terms  by  which  any   Subordinated   Indebtedness   purports   to  be
         subordinated   to  the  payment  and   performance  of  the  Borrowers'
         obligations  under this  Agreement  or (ii) the terms  relating  to the
         repayment of any Subordinated Indebtedness; or

<PAGE>

                  (b) Directly or indirectly,  make any payment of any principal
         of  or  in  redemption,   retirement  or  repurchase  of   Subordinated
         Indebtedness  except payments  required by the  instruments  evidencing
         such Subordinated Indebtedness.

         6.7.  NATURE  OF  BUSINESS.  Substantially  change  the  nature  of its
business as presently  conducted  except with the prior  written  consent of the
Banks.

         6.8.  PENSION PLANS.  Permit any employee pension benefit plan (as that
term is defined in Section 3 of ERISA)  maintained by the Company or any Related
Entity to (i) engage in any "prohibited  transaction" as such term is defined in
Section 4975 of the Internal Revenue Code of 1986, as amended which could result
in a material liability for the Company or any Related Entity; or (ii) incur any
"accumulated  funding  deficiency",  as such term is defined  in Section  302 of
ERISA,  whether or not waived;  or (iii) fail to  contribute to or terminate any
such benefit plan in a manner which could result in the  imposition of a lien or
encumbrance  on the assets of the  Company or any  Related  Entity  pursuant  to
Sections 302(f) or 4068 of ERISA.

         SECTION 7.  EVENTS OF DEFAULT:  ACCELERATION.

         If any of the  following  events  ("Events of Default" or, if notice or
lapse of time or notice  and lapse of time is  required,  then,  prior to notice
and/or lapse of time, "Defaults") shall occur:

               (a) if any Borrower or Guarantor  shall default in any payment of
          any  principal  amount  outstanding  hereunder  or  any  Reimbursement
          Obligation  when the same  shall  become due and  payable,  whether at
          maturity  or at  any  date  fixed  for  payment  or  prepayment  or by
          declaration or otherwise; or

                  (b) if any Borrower or Guarantor  shall default in the payment
         of any interest with respect to principal  outstanding hereunder or any
         Commitment  Fee, any Letter of Credit Fee or Leverage Fee after the due
         date  thereof,  whether at maturity or at any date fixed for payment or
         prepayment or by declaration or otherwise; or

                  (c) if  written  notice  shall be  given  by the  Agent to any
         Borrower of default in the  performance of or compliance  with any term
         contained in any of Sections 5.1 through 5.4, 5.11 (and, in the case of
         a failure to comply  with  ss.5.11,  such  default  shall not have been
         cured  within 5 days after such  written  notice has been given to such
         Borrower by the Agent), 5.12 and 6.1 through 6.8 inclusive, hereof; or

                  (d)  if  any  Borrower  or  Guarantor  shall  default  in  the
         performance of or compliance  with any term contained  herein or in the
         other Loan Documents other than those referred to above in this Section
         7, and such default shall not have been  remedied  within 30 days after
         written  notice  thereof  shall have been given to such Borrower by the
         Agent; or

                  (e) if any  representation,  warranty or certification made in
         writing  by or on  behalf of any  Borrower  or  Guarantor  herein or in
         connection with any of the transactions contemplated hereby shall prove
         to have been false or incorrect in any material  respect on the date as
         of which made; or

                  (f)  if  any   Borrower,   any   Guarantor  or  any  of  their
         Subsidiaries (other than a Borrower or a Guarantor which would not be a
         Material Subsidiary of Dynatech or a Subsidiary which is not a Material
         Subsidiary  (a  "DeMinimus  Subsidiary"),  unless any  Borrower  or any

<PAGE>

         Material  Subsidiary has been  adversely  affected by the occurrence of
         such event) shall  default (as  principal or guarantor or other surety)
         in the payment of any principal or premium,  if any, or interest on any
         other  Indebtedness  in respect of  borrowed  money in an amount  which
         either individually or in the aggregate exceeds $500,000, including but
         not limited to, any other loans made by the Banks to the  Borrowers  or
         the Guarantors,  or with respect to any of the terms of any evidence of
         such  Indebtedness  or any  mortgage,  pledge,  assignment,  indenture,
         bankers  acceptance  or  other  agreement  relating  thereto,  and such
         default  shall  continue  for more than the  period  of grace,  if any,
         specified therein and if the holder of such  Indebtedness  declares all
         amounts payable with respect thereto to be due and payable by reason of
         such default; or

                  (g)  if  any   Borrower,   any   Guarantor  or  any  of  their
         Subsidiaries  makes an  assignment  for the  benefit of  creditors,  or
         petitions or applies for the appointment of a liquidator or receiver of
         such  Borrower,  Guarantor  or  any  of  their  Subsidiaries  or of any
         substantial  part of the assets of such  Borrower,  Guarantor or any of
         their  Subsidiaries  or  commences  any  proceeding  relating  to  such
         Borrower,  Guarantor or any of their Subsidiaries under any bankruptcy,
         reorganization,   arrangement,   insolvency,   readjustment   of  debt,
         dissolution or liquidation or similar law of any  jurisdiction,  now or
         hereafter in effect;  provided,  however, that this paragraph (g) shall
         not apply to the dissolution or liquidation of any Subsidiary  pursuant
         to  Section  6.4(c) hereof or to any  DeMinimus  Subsidiary  unless any
         Borrower or any  Material Subsidiary  may be adversely  affected by the
         occurrence of such event; or

                  (h) if any such petition or  application  is filed or any such
         proceeding is commenced  against any Borrower,  any Guarantor or any of
         their  Subsidiaries  (other  than a  DeMinimus  Subsidiary  unless  any
         Borrower or any Subsidiary  which is not a DeMinimus  Subsidiary may be
         adversely  affected by the occurrence of such event), and such Borrower
         or any such Material Subsidiary indicates its approval thereof, consent
         thereto or  acquiescence  therein or any such petition,  application or
         proceeding  remains  undischarged  for 45 days,  or an order is entered
         appointing  any such  liquidator  or  receiver,  or  adjudicating  such
         Borrower or any such  Material  Subsidiary  bankrupt or  insolvent,  or
         approving a petition in any such proceeding; or

                  (i) if any order is  entered in any  proceeding  by or against
         any Borrower,  any Guarantor or any of their Subsidiaries (other than a
         DeMinimus Subsidiary unless any Borrower or any Material Subsidiary may
         be adversely  affected by the  occurrence  of such event)  decreeing or
         permitting the dissolution or split-up of such Borrower, such Guarantor
         or any such Subsidiary or the winding-up of its affairs; or

                  (j) if there shall remain in force, undischarged,  unsatisfied
         and unstayed,  for more than 30 days,  whether or not consecutive,  any
         final  judgment  (which has become  non-appealable)  against any of the
         Borrowers,  the  Guarantors or any of their  Subsidiaries  which,  with
         other outstanding final judgments,  undischarged,  against any Borrower
         or  Guarantor  and  any of the  Subsidiaries  of the  Borrowers  or the
         Guarantors exceeds in the aggregate $100,000; or

                  (k) if any Domestic Material Subsidiary of Dynatech shall fail
         to become a Borrower party to this  Agreement  within 30 days after the
         Agent or the Majority Banks have requested the same in writing pursuant
         to the provisions of Section 5.15 hereof;

<PAGE>

then, and in any such event,  so long as the same may be  continuing,  the Agent
may,  and  upon  the  request  of any  combination  of  Banks  whose  Commitment
Percentages  aggregate at least 51% shall,  by written  notice to the  Borrowers
declare:  (i) the obligation of each Bank to make Advances  and/or Term Loans to
the Borrowers to be  terminated,  where upon the same shall  terminate,  and the
obligation of the Agent to issue, extend or renew any Letters of Credit shall be
relieved  and/or (ii) all  amounts to be  forthwith  due and payable  under this
Agreement,  whereupon the same shall forthwith mature and become immediately due
and payable  together  with  interest  thereon and all other  amounts then owing
under this Agreement,  without  presentment,  demand,  protest or notice, all of
which are hereby waived,  provided that upon the occurrence of any of the events
specified in subsections (g) and (h) of this Section 7, such  termination of the
obligations  to make  Advances  and/or  Term  Loans and  issue,  extend or renew
Letters of Credit and  acceleration  of the  maturity  of the Loans  shall occur
automatically and without any action by the Agent or any of the Banks.

         SECTION 8.  NOTICE AND WAIVERS OF DEFAULT.

     8.1.  NOTICE OF  DEFAULT.  If any Person  shall give any notice or take any
other action in respect of a claimed  Default  (whether or not  constituting  an
Event  of  Default)  under  this  Agreement  or  any  other  note,  evidence  of
indebtedness,  indenture  or  other  obligation  as to  which  any  Borrower  or
Guarantor is a party, or obligor,  whether as principal or surety, such Borrower
or Guarantor, as the case may be, shall forthwith give written notice thereof to
each of the Banks, describing the notice or action and the nature of the claimed
Default.

         8.2. WAIVERS OF DEFAULT.  Any Default or Event of Default may be waived
as provided in Section  11.5  hereof.  Any Default or Event of Default so waived
shall be deemed to have been cured and to be not continuing;  but no such waiver
shall  extend to or affect  any  subsequent  like  default  or impair any rights
arising therefrom.

         SECTION 9.  REMEDIES ON DEFAULT, ETC.

         9.1.  RIGHTS OF BANKS. In case any one or more of the Events of Default
specified in Section 7 shall have occurred and be continuing, and whether or not
all amounts  owing with  respect to the Loans or the  Reimbursement  Obligations
have been declared due and payable pursuant to Section 7, each Bank, if owed any
amount with respect to the Loans or the Reimbursement  Obligations,  may proceed
to protect and enforce its rights by suit in equity,  action at law and/or other
appropriate proceeding,  whether for the specific performance of any covenant or
agreement  contained  in  this  Agreement,   including  to  the  extent  legally
available, the obtaining of the ex parte appointment of a receiver, and, if such
amount shall have become due, by  declaration  or otherwise,  proceed to enforce
the payment thereof or any other legal or equitable right of the Bank.

         9.2.  SET-OFF.  Upon the occurrence  and during the  continuance of any
Event of Default,  each Bank is hereby  authorized  at any time and from time to
time,  without notice (any such notice being expressly waived hereby) and to the
fullest  extent  permitted by law and without  regard to any collateral or other
source of payment whatsoever, to set off and apply any and all deposits (general
or  specific,  time or demand,  provisional  or final,  regardless  of currency,
maturity,  or the  branch of the Bank where the  deposits  are held) at any time
held or  other  sums  credited  by or due  from  any of the  Banks to any of the
Borrowers against any and all Obligations of the Borrowers and the Guarantors to
the Banks.  Each of the Banks  agrees with the other Banks that (a) if an amount
to be set off is to be applied to Indebtedness of any Borrower or Guarantor to a
Bank,  other  than  Indebtedness  evidenced  by the  then  Outstanding  Loans or
Reimbursement Obligations held by all of the Banks, such amount shall be applied
ratably to such other  Indebtedness  and to the  Indebtedness  evidenced  by all

<PAGE>

Outstanding  Loans or Reimbursement  Obligations of such Bank, and (b) if a Bank
shall  receive  from any Borrower or  Guarantor  whether by  voluntary  payment,
exercise of the right of set-off, counterclaim, cross action, enforcement of the
claim  related to Loans by a Bank by  proceedings  against such Borrower or such
Guarantor at law or in equity or by proof thereof in bankruptcy, reorganization,
liquidation,  receivership or similar proceedings,  or otherwise, any payment so
received  shall be shared so as to give effect to the  provisions of Section 9.1
and, thereafter, in the manner contemplated by Section 2.17.

         SECTION 10.  THE AGENT.

                  (a) The Agent is  authorized  to take such action on behalf of
         each of the Banks and to exercise all such powers as are  hereunder and
         in related documents delegated to the Agent,  together with such powers
         as are  reasonably  incidental  thereto,  provided  that no  duties  or
         responsibilities  not  expressly  assumed  herein or  therein  shall be
         implied to have been assumed by the Agent.

               (b) The  relationship  between the Agent and each of the Banks is
          that of an independent contractor.  The use of the term "Agent" is for
          convenience only and is used to describe, as a form of convention, the
          independent contractual relationship between the Agent and each of the
          Banks.  Nothing  contained  in  this  Agreement  nor  the  other  Loan
          Documents  shall be  construed  to  create an  agency,  trust or other
          fiduciary relationship between the Agent and any of the Banks.

                  (c) As an  independent  contractor  empowered  by the Banks to
         exercise certain rights and perform certain duties and responsibilities
         hereunder and under the other Loan Documents, the Agent is nevertheless
         a  "representative"  of the Banks, as that term is defined in Article 1
         of the Uniform Commercial Code, for purposes of actions for the benefit
         of the Banks and the Agent with respect to all collateral  security and
         guaranties contemplated by the Loan Documents.

                  (d) The Agent may  exercise  its powers and execute its duties
         by or through employees or agents and shall be entitled to take, and to
         rely on,  advice of counsel  concerning  all matters  pertaining to its
         rights and duties under this  Agreement  and the other Loan  Documents.
         The Agent may utilize the  services of such Persons as the Agent in its
         sole  discretion may  reasonably  determine.  All  reasonable  fees and
         expenses of any auditors, financial examiners, appraisers and attorneys
         utilized by the Agent pursuant to this  paragraph  shall be paid by the
         Borrowers.

                  (e) Neither the Agent nor any of its shareholders,  directors,
         officers or  employees  nor any other  Person  assisting  them in their
         duties  nor any agent or  employee  thereof,  shall be  liable  for any
         waiver, consent or approval given or any action taken, or omitted to be
         taken,  in good faith by it or them hereunder or under any of the other
         Loan  Documents,   or  in  connection  herewith  or  therewith,  or  be
         responsible for the  consequences of any oversight or error of judgment
         whatsoever, except that the Agent or such other Person, as the case may
         be, may be liable for losses  due to its  willful  misconduct  or gross
         negligence.

<PAGE>

                  (f) The Agent shall not be  responsible  for the  execution or
         validity or enforceability  for this Agreement,  the Notes, the Letters
         of Credit, the Bankers' Acceptances, any of the other Loan Documents or
         any  instrument  at any time  constituting,  or intended to  constitute
         collateral  security  for  the  Loans  or for  the  value  of any  such
         collateral   security   or  for   the   validity,   enforceability   or
         collectibility  or any such amounts owing with respect to the Loans, or
         for any recitals or statements, warranties or representations herein or
         made in any certificate or instrument  hereafter  furnished to it by or
         on behalf of any Borrower or be bound to ascertain or inquire as to the
         performance or observance of any of the terms, conditions, covenants or
         agreements  herein or in any  instrument at any time  constituting,  or
         intended to constitute,  collateral  security for the Loans.  The Agent
         shall not be bound to ascertain whether any notice,  consent, waiver or
         request  delivered  to it by any  Borrower  or any holder of any of the
         Loans  shall  have  been  duly  authorized  or is  true,  accurate  and
         complete.   The   Agent   has  not  made  nor  does  it  now  make  any
         representations or warranties,  express or implied,  nor does it assume
         any  liability  to the Banks with respect to the credit  worthiness  or
         financial  condition  of  any  Borrower  or  Guarantor  and  each  Bank
         represents  and  warrants  to the  Agent  that  it  has  made  its  own
         independent  evaluation  of the credit  worthiness of the Borrowers and
         the  Guarantors  and has not relied  upon the Agent or any  material or
         information furnished by the Agent in making such evaluation.

                  (g) A payment by the Borrowers or the  Guarantors to the Agent
         hereunder or under any of the other Loan  Documents  for the account of
         any Bank shall  constitute  a payment to such  Bank.  The Agent  agrees
         promptly  to  distribute  to each Bank such  Bank's  pro rata  share of
         payments  received by the Agent for the account of the Banks  except as
         otherwise  expressly  provided  herein  or in  any of  the  other  Loan
         Documents. If, in the reasonable opinion of the Agent, the distribution
         of any amount  received by it in such capacity  hereunder might involve
         it in  liability,  it may refrain  from making  distribution  until its
         right to make  distribution  shall have been  adjudicated by a court of
         competent  jurisdiction.  If a court of  competent  jurisdiction  shall
         adjudge that any amount  received and distributed by the Agent is to be
         repaid,  each Person to whom any such distribution shall have been made
         shall either repay to the Agent its  proportionate  share of the amount
         so  adjudged to be repaid or shall pay over the same in such manner and
         to such Persons as shall be determined by such court.

                  (h) Notwithstanding anything to the contrary contained in this
         Agreement  or any of the other Loan  Documents,  any Bank that fails to
         (i) make  available  to the  Agent is pro rata  share of any Loan or to
         purchase  any  Letter  of  Credit  Participation  or  to  purchase  any
         participation as required by Section 9.1 hereto or (ii) comply with the
         provisions  of  Section  9.2 with  respect to making  dispositions  and
         arrangements  with the other  Banks,  where  such  Bank's  share of any
         payment received,  whether by setoff or otherwise,  is in excess of its
         pro rata share of such payments due and payable to all of the Banks, in
         each case as, when and to the full extent required by the provisions of
         this Agreement,  shall be deemed  delinquent (a "Delinquent  Bank") and
         shall be deemed a Delinquent  Bank until such time as such  delinquency
         is  satisfied.  A Delinquent  Bank shall be deemed to have assigned any
         and all  payments due to it from the  Borrowers,  whether on account of
         outstanding Loans, Unpaid Reimbursement Obligations,  interest, fees or
         otherwise, to the remaining nondelinquent Banks for application to, and
         reduction of, their respective pro rata shares of all outstanding Loans
         and  Unpaid  Reimbursement  Obligations.  The  Delinquent  Bank  hereby
         authorizes the Agent to distribute  such payments to the  nondelinquent
         Banks  in  proportion  to  their  respective  pro  rata  shares  of all
         outstanding  Loans and  Reimbursement  Obligations.  A Delinquent  Bank
         shall be deemed to have satisfied in full a delinquency when and if, as
         a result of  application  of the assigned  payments to all  outstanding
         Loans and Unpaid Reimbursement  Obligations of the nondelinquent Banks,
         the Banks'  respective  pro rata  shares of all  outstanding  Loans and
         Unpaid  Reimbursement  Obligations  have  returned  to those in  effect
         immediately  prior to such delinquency and without giving effect to the
         nonpayment causing such delinquency.

<PAGE>

                  (i) The  Agent may deem and treat the payee of any Note or the
         purchaser of any Letter of Credit  Participation  as the absolute owner
         or purchaser  thereof for all purposes  hereof until it shall have been
         satisfied  in  writing  with a  different  name by such  payee  or by a
         subsequent holder, assignee or transferee.

               (j) To the extent the Agent is not  otherwise  reimbursed  by the
          Borrowers  or the  Guarantors,  the  Banks  ratably  agree  hereby  to
          indemnify  and hold  harmless  the Agent from and  against any and all
          claims,  actions and suits (whether groundless or otherwise),  losses,
          damages,  costs,  expenses (including any expenses for which the Agent
          has not been reimbursed by the Borrowers or the Guarantors as required
          by this  Agreement),  and  liabilities  of every nature and  character
          arising out of or related to this Agreement,  the Notes, or any of the
          other Loan  Documents or the  transactions  contemplated  or evidenced
          hereby  or  thereby,   or  the  Agent's  actions  taken  hereunder  or
          thereunder,  except  to the  extent  that  any of the  same  shall  be
          directly caused by the Agent's willful misconduct or gross negligence.

                  (k) In its  individual  capacity,  FNBB  shall  have  the same
         obligations  and the same rights,  powers and  privileges in respect to
         its  Commitment and the Loans made by it, and as a holder of any of the
         Notes and as a purchaser of any Letter of Credit Participations,  as it
         would have were it not also the Agent.

                  (l) The Agent may resign at any time by giving sixty (60) days
         prior written notice  thereof to the Banks and the Borrowers.  Upon any
         such resignation,  the Majority Banks shall have the right to appoint a
         successor  Agent.  Unless a  Default  or Event of  Default  shall  have
         occurred and be continuing,  such  successor  Agent shall be reasonably
         acceptable to the Borrowers.  If no successor  Agent shall have been so
         appointed  by  the  Majority   Banks  and  shall  have   accepted  such
         appointment  within thirty (30) days after the retiring  Agent's giving
         of notice of resignation, then the retiring Agent may, on behalf of the
         Banks,   appoint  a  successor  Agent,   which  shall  be  a  financial
         institution  having a rating  of not less than A or its  equivalent  by
         Standard & Poor's  Corporation.  Upon the acceptance of any appointment
         as Agent  hereunder by a successor  Agent,  such successor  Agent shall
         thereupon  succeed to and become  vested with all the  rights,  powers,
         privileges  and duties of the retiring  Agent,  and the retiring  Agent
         shall be discharged  from its duties and obligations  hereunder.  After
         any retiring Agent's resignation,  the provisions of this Agreement and
         the other Loan Documents  shall continue in effect for its benefit with
         respect of any actions  taken or omitted to be taken by it while it was
         acting as Agent.

<PAGE>

         SECTION 11.  MISCELLANEOUS.

         11.1.  EXPENSES.  Whether or not the transactions  contemplated  hereby
shall be consummated, the Borrowers jointly and severally agree on demand (a) to
pay any taxes or filing fees in connection with the transactions contemplated by
this  Agreement  and save the  Agent  and each of the  Banks  harmless  from and
against any and all  liabilities  resulting from any delay in paying or omission
to pay  any  such  fee or tax;  (b) to pay the  reasonable  fees,  expenses  and
disbursements to the extent incurred by the Agent and each of the Banks to legal
counsel,  including reasonable fees and time charges of legal counsel who may be
employees of the Agent or any Bank, incurred in connection with the negotiation,
preparation  and  completion of this  Agreement and the  transactions  and other
documents  contemplated by this Agreement,  and, in the case of the Agent,  such
expenses incurred in connection with the interpretation of the rights and duties
of the Agent and the  Banks  thereunder  and the  negotiation,  preparation  and
completion  of any  subsequent  waivers,  consent or  amendments  in  connection
therewith  (provided,  that the  Borrowers  shall  not be  obligated  to pay any
expenses  of counsel  related  to  assignments  made  pursuant  to Section  11.6
hereof);  and  (c) to  pay  all  reasonable  out-of-pocket  expenses  (including
reasonable  attorney's  fees and  costs)  incurred  by the Agent and each of the
Banks in connection with the enforcement of this Agreement except as provided in
Section 5.12 herein.  The expenses of this Section 11.1 shall survive payment or
satisfaction of payment of amounts owing under this Agreement.

         11.2.  NOTICES,  ETC.  All notices,  requests and other  communications
pursuant  to  this  Agreement  shall  be in  writing  and  shall  be  mailed  by
first-class mail, postage prepaid, or sent by telegraph or telecopy confirmed by
letter, addressed as follows:

                  (a) If to  Dynatech,  at Three  New  England  Executive  Park,
         Burlington,  Massachusetts 01803, Attention: Chief Financial Officer or
         at such other  address as  Dynatech  shall last have  furnished  to the
         communicating party in writing.

                  (b) If to any other Borrower or any Guarantor, c/o Dynatech at
         the address  provided for in Section  11.2(a) above,  Attention:  Chief
         Financial  Officer  or at such other  address as such party  shall last
         have furnished to the communicating party in writing.

                  (c) If to the Agent and FNBB, at 100 Federal  Street,  Boston,
         Massachusetts 02110, Attn: Debra E. DelVecchio,  Vice President,  or at
         such  other  address  as the Agent  shall  last have  furnished  to the
         communicating party in writing.

                  (d) If to ABN AMRO,  at One Post  Office  Square,  39th Floor,
         Boston,   Massachusetts  02109,  Attn:  Lisa  Sheehan,  Assistant  Vice
         President,  or at such  other  address  as ABN  AMRO  shall  last  have
         furnished to the communicating party in writing.

                  (e) If to Mellon,  at Mellon  Bank,  N.A.,  One Boston  Place,
         Boston,  Massachusetts  02108, Attn: Robert H. Summersgill,  First Vice
         President, or at such other address as Mellon shall last have furnished
         to the communicating party in writing.

         Any  notice,  request  or  communication  so  addressed  and  mailed by
registered mail shall be deemed to have been given when mailed.

<PAGE>

     Any notice of Borrowing  under Section 2.6(b) or notices under Sections 2.8
or 2.9(a)  hereof  shall be signed on  behalf  of the  applicable  Borrower  and
Dynatech by the  President  or the chief  financial  officer  (or other  officer
designated in writing to the Banks by the President or chief financial  officer)
of such Borrower and Dynatech,  respectively, and shall not be revocable by such
Borrower  or Dynatech  and shall  obligate  such  Borrower to borrow a requested
Advance  for,  or to convert an  Advance or Term Loan to, a  currency,  Interest
Period  or  interest  rate  as may be so  specified.  Any  election  made by the
Borrowers  or any  Borrower,  as the case may be,  pursuant to  Sections  2.3 or
2.12(c)  shall be binding  upon such  Borrower  and  irrevocable.  Notice of any
prepayment having been given as required and all of the other conditions to such
prepayment having been satisfied by all applicable  Borrowers in compliance with
the  provisions of Sections 2.3 or 2.12(c),  that amount of the principal of the
Loan which shall have been  designated for  prepayment in such notice shall,  on
the date  specified in such  notice,  become  absolutely  due and payable by the
Borrowers jointly and severally.

         11.3.  RELIANCE,  ETC. All contracts,  agreements,  representations and
warranties  made herein and in certificates  delivered  pursuant hereto shall be
deemed to have been material and relied upon by the Banks,  notwithstanding  any
investigation  made by any Bank or on any Bank's  behalf and shall  survive  the
execution of this  agreement and the making of each Advance  hereunder and shall
continue in full force and effect until the obligations of the Borrowers and the
Guarantors hereunder have been paid and satisfied in full.

         11.4. CAPTIONS.   The captions in this Agreement are for convenience of
reference only and shall not define or limit the provisions hereof.

         11.5.  WAIVER,  ETC.  Except as  otherwise  expressly  set forth in any
particular  provision  of this  Agreement,  any consent or approval  required or
permitted by this Agreement to be given by the Banks may be given,  and any term
of this  Agreement,  the other Loan  Documents or any other  instrument  related
hereto or mentioned herein may be amended,  and the performance or observance by
any of the Borrowers of any term of this Agreement,  the other Loan Documents or
such other  instrument or the continuance of any Default or Event of Default may
be waived (either generally or in a particular instance and either retroactively
or prospectively)  with, but only with, the written consent of the Borrowers and
the Majority Banks, provided, however, that:

          (a)  Without  the  written  consent  of such Banks as hold 100% of the
     Total Commitment,

                           (i) no  reduction  in the  principal  amount  of,  or
                  interest  rate on,  Letter of Credit Fee, or any other  amount
                  payable in respect of, any Advance,  or any  Commitment Fee or
                  Leverage Fee shall be made;

                           (ii) no extension or  postponement of the stated time
                  of payment of the principal  amount of, or interest on, or any
                  other amount  payable in respect of, any  Advance,  Commitment
                  Fee or Leverage Fee shall be made; and

                         (iii) no increase in the amount,  or  extension  of the
                    term, of the Commitments beyond those provided for hereunder
                    shall be made.

                  (b) Without the written  consent of such Banks as hold 100% of
         the Total  Loan or after the Term Loan has been  funded,  the Term Loan
         (as reduced from time to time pursuant to the terms of this Agreement),

                         (i)  no  reduction  in  the  principal  amount  of,  or
                    interest rate on, or any other amount payable in respect of,
                    any Term Loan or Leverage Fee shall be made;

<PAGE>

                           (ii) no extension or  postponement of the stated time
                  of payment of the principal  amount of, or interest on, or any
                  other amount  payable in respect of, any Term Loan or Leverage
                  Fee shall be made

                  (c) Without the written  consent of all the Banks,  no release
         of any Guarantor shall be given,  provided,  however,  in the event the
         capital  stock of any Guarantor  shall be sold in  accordance  with the
         terms  of  this  Agreement,  or  shall  otherwise  cease  to  exist  in
         accordance with the terms of this Agreement, such Guarantor shall cease
         being a  Guarantor  as of the date such  Guarantor  is  either  sold or
         ceases to exist without any further action required by the Banks or the
         Agent

                  (d)      Without the written consent of the Agent,

                           (i)  no reduction in any of the Letter of Credit Fees
                             payable for the Agent's account shall be made; and

                           (ii)     no amendment to Section 10 shall be made.

No waiver  shall  extend to or affect any  obligation  not  expressly  waived or
impair any right consequent  thereon.  No course of dealing of delay or omission
on the  part of any Bank in  exercising  any  right  shall  operate  as a waiver
thereof or otherwise  be  prejudicial  thereto.  No notice to or demand upon any
Borrower or Guarantor  shall entitle such Borrower or such Guarantor to other or
further notice or demand in similar or other  circumstances.  No right, power or
remedy  conferred  hereby  upon any Bank or any other  holder  thereof  shall be
exclusive of any other right,  power or remedy  referred to herein or therein or
now or hereafter available at law, in equity, by statute or otherwise.

     11.6.  BENEFIT,  ASSIGNMENTS,  ETC. The rights of each of the Borrowers and
the Guarantors  under this Agreement  shall not be assignable by any Borrower or
any  Guarantor,  as the case may be,  without the prior  written  consent of the
Banks, the Agent and the other Borrowers and Guarantors. This Agreement shall be
binding upon the  successors  and assigns of any Borrower or  Guarantor,  as the
case may be, and shall inure to the benefit of and be binding upon the Agent and
each Bank and their successors and assigns.  The Banks may assign on one or more
occasions,  and to one or more  Eligible  Assignees,  all or a portion  of their
respective  interests,  rights and obligations under this Agreement  (including,
without  limitation,  all or a portion of its Commitment  hereunder and the same
portion  of the Loans at the time  owing to it and any note or notes  held by it
and its  participating  interest in the risk  relating to any Letters of Credit)
with the prior  consent of  Dynatech  (which  consent  will not be  unreasonably
withheld or delayed);  provided, however, that (i) each such assignment shall be
of a constant,  and not a varying,  percentage  of all of such Bank's rights and
obligations  under this Agreement,  (ii) the initial amount of the Commitment of
the Bank  subject  to each  such  assignment  (determined  as of the date of the
Assignment and Acceptance with respect to such assignment)  shall in no event be
less than $10,000,000 and shall be in an amount which is an integral multiple of
$500,000 and (iii) the parties to such  assignment  shall execute and deliver to
the  Agent,  for  recording  in the  Register,  an  Assignment  and  Acceptance,
substantially in the form of Exhibit C hereto (the "Assignment and Acceptance"),
together with any note or notes subject to such assignment. Upon such execution,
delivery,  acceptance and recording, from and after the effective date specified
in each Assignment and  Acceptance,  which effective date shall be at least five
Business Days after the execution thereof,  (x) the assignee thereunder shall be
a party hereto and, to the extent  provided in such  Assignment and  Acceptance,
have the rights and  obligations  of a Bank hereby,  and (y) the assigning  Bank
shall,  to the  extent  provided  in  such  assignment,  be  released  from  its
obligations under this Agreement.

         By executing and delivering an Assignment and  Acceptance,  the parties
to such assignment thereunder confirm to and agree with each other and the other
parties hereto as follows:  (i) other than the  representation and warranty that
it is the legal and beneficial owner of the interest being assigned thereby free
and clear of any adverse claim,  the assigning Bank makes no  representation  or
warranty  and  assumes  no  responsibility   with  respect  to  any  statements,
warranties or  representations  made in or in connection  with this Agreement or
the execution, legality, validity, enforceability,  genuineness,  sufficiency or
value of this  Agreement,  the other Loan  Documents or any other  instrument or
document   furnished   pursuant  hereto;   (ii)  the  assigning  Bank  makes  no
representation  or warranty  and assumes no  responsibility  with respect to the
financial  condition of Dynatech or any of its  Subsidiaries or any other Person
primarily  or  secondarily  liable in respect of any of the  obligations  of the
Borrowers to the Agent and the Banks  hereunder or the performance or observance
by  Dynatech  or any of  its  Subsidiaries  or any  other  Person  primarily  or
secondarily  liable in respect of any of the obligations of the Borrowers or the
Guarantors  to the Agent and the Banks  hereunder  or of any of its  obligations
under this Agreement or any of the other Loan Documents or any other  instrument
or document furnished pursuant hereto;  (iii) such assignee confirms that it has
received  a copy  of this  Agreement,  together  with  copies  of the  financial
statements  referred to in Section 5.11 and such other documents and information
as it has deemed  appropriate  to make its own credit  analysis  and decision to
enter  into  such   Assignment   and   Acceptance;   (iv)  such  assignee  will,
independently  and without  reliance upon the assigning  Bank,  the Agent or any
other  Bank and  based  on such  documents  and  information  as it  shall  deem
appropriate at the time,  continue to make its own credit decisions in taking or
not taking action under this Agreement; (v) such assignee confirms that it is an
Eligible Assignee;  (vi) such assignee appoints and authorizes the Agent to take
such  action as agent on its  behalf  and to  exercise  such  powers  under this
Agreement as are delegated to the Agent by the terms hereof,  together with such
powers as are reasonably incidental thereto;  (vii) such assignee agrees that it
will perform in accordance with their terms all of the obligations  which by the
terms of this  Agreement  are required to be  performed by it as a Bank;  (viii)
such assignee  represents  and warrants  that it is legally  authorized to enter
into such Assignment and Acceptance; and (ix) such assignee acknowledges that it
has made arrangements with the assigning Bank satisfactory to such assignee with
respect to its pro rata share of Letter of Credit Fees in respect of outstanding
Letters of Credit.

     The Agent shall maintain a copy of each Assignment and Acceptance delivered
to it and a register for the recordation of the names and addresses of the Banks
and the Commitment Percentage of, and principal amount of the Loans owing to and
Letter of Credit Participations  purchased by, the Banks from time to time party
to this  Agreement  (the  "Register").  The  entries  in the  Register  shall be
conclusive,  in the absence of manifest error, and the Borrowers,  the Agent and
the Banks may treat each person whose name is recorded in the Register as a Bank
hereunder for all purposes of this  Agreement.  The Register  shall be available
for  inspection  by the Borrowers or the Banks at any  reasonable  time and from
time to time upon  reasonable  prior  notice.  Upon each such  recordation,  the
assigning  Bank  agrees  to pay to the  Agent a  registration  fee in the sum of
$2,500.

         Upon its  receipt  of an  Assignment  and  Acceptance  executed  by the
parties  to such  assignment,  together  with any note or notes  subject to such
assignment,  the Agent shall (i) record the information contained therein in the
Register,  and (ii) give prompt  notice  thereof to the  Borrowers and the Banks
(other than the  assigning  Bank).  At the  request of the  assignee  Bank,  the
Borrowers, at the expense of the assignee bank, shall execute and deliver to the
Agent a new note or notes to the order of such Eligible Assignee(s) in an amount
equal to the  amount  assumed  by such  Eligible  Assignee(s)  pursuant  to such

<PAGE>

Assignment and  Acceptance  and, if the assigning Bank has retained some portion
of its obligations hereunder and holds a note evidencing such obligations, a new
note or  notes to the  order of the  assigning  Bank in an  amount  equal to the
amount  retained by it  hereunder.  Such new notes shall be dated the  effective
date of such Assignment and Acceptance and shall  otherwise be in  substantially
the form of the  assigned  notes,  if any,  and  otherwise  shall be in form and
substance satisfactory to the applicable Banks and the Borrowers,  provided that
any new notes issued to the assignor Bank shall also evidence the obligations of
the  Borrowers  to pay any accrued but unpaid  interest on the  assigned  Loans.
Within five (5) days of issuance  of any new  note(s)  pursuant to this  Section
11.6, the Borrowers, and if requested to do so by the assigning Bank or assignee
bank and at the expense of the assignee bank,  shall deliver an opinion of their
counsel, addressed to the requesting party, relating to the new note(s), in form
and substance reasonably satisfactory to the requesting party and the Borrowers.
Any note or notes  surrendered  pursuant to the  provisions of this Section 11.6
shall be cancelled and returned to the applicable Borrowers.

Each  Bank  may sell  participations  to one or more  banks  or other  financial
institutions  in all or a portion of such Bank's  rights and  obligations  under
this Credit Agreement and the other Loan Documents;  provided that (i) each such
participation  shall be in an amount of not less than $5,000,000,  (ii) any such
sale or participation shall not affect the rights and duties of the selling Bank
hereunder to the Borrower and (iii) the only rights  granted to the  participant
pursuant to such participation arrangements with respect to waivers,  amendments
or  modifications  of the Loan Documents shall be the rights to approve waivers,
amendments or  modifications  that would reduce the principal of or the interest
rate on any Loans,  extend the term or increase the amount of the  Commitment of
such Bank as it relates to such participant, reduce the amount of any commitment
fees or Letter of Credit  Fees to which such  participant  is entitled or extend
any regularly scheduled payment date for principal or interest.

         Each of the  Borrowers  and the  Guarantors  agrees that in addition to
disclosures made in accordance with standard and customary banking practices any
Bank may disclose  information  obtained by such Bank pursuant to this Agreement
to assignees or participants and potential assignees or participants  hereunder;
provided  that  such  assignees  or  participants  or  potential   assignees  or
participants shall agree (i) to treat in confidence such information unless such
information  otherwise  becomes  public  knowledge,  (ii) not to  disclose  such
information  to a third  party,  except as required by law or legal  process and
(iii) not to make use of such information for purposes of transactions unrelated
to such contemplated assignment or participation.

     If any  assignee  Bank  is an  Affiliate  of any  of the  Borrowers  or the
Guarantors,  then any such  assignee  Bank shall have no right to vote as a Bank
hereunder  or under any of the other Loan  Documents  for  purposes  of granting
consents  or  waivers  or for  purposes  of  agreeing  to  amendments  or  other
modifications to any of the Loan Documents or for purposes of making requests to
the Agent  pursuant to Sections 7 and 9, and the  determination  of the Majority
Banks shall for all purposes of this  Agreement and the other Loan  Documents be
made without regard to such assignee Bank's interest in any of the Loans. If any
Bank  sells  a  participating  interest  in any of the  Loans  or  Reimbursement
Obligations  to a participant,  and such  participant is any of the Borrowers or
any of the  Guarantors,  or an Affiliate  of any of the  Borrowers or any of the
Guarantors,  then such  transferor  Bank shall promptly  notify the Agent of the
sale of such  participation.  A transferor Bank shall have no right to vote as a
Bank hereunder or under any of the other Loan Documents for purposes of granting
consents or waivers or for purposes of agreeing to amendments  or  modifications
to any of the Loan  Documents  or for  purposes of making  requests to the Agent
pursuant  to  Sections  7  and  9 to  the  extent  that  such  participation  is
beneficially  owned by any of the  Borrowers  or any of the  Guarantors,  or any
Affiliate  of  any  of  the  Borrowers  or  any  of  the  Guarantors,   and  the
determination of the Majority Banks shall for all purposes of this Agreement and
the  other  Loan  Documents  be made  without  regard  to the  interest  of such
transferor Bank in the Loans to the extent of such participation.

<PAGE>

Any assigning Bank shall retain its rights to be indemnified pursuant to Section
11.13 with  respect to any claims or actions  arising  prior to the date of such
assignment.  If any  assignee  Bank is not  incorporated  under  the laws of the
United States of America or any state  thereof,  it shall,  prior to the date on
which any interest or fees are payable  hereunder or under any of the other Loan
Documents for its account,  deliver to the Borrowers and the Agent certification
as to its exemption  from  deduction or withholding of any United States federal
income  taxes.   Anything  contained  in  this  Section  11.6  to  the  contrary
notwithstanding,  any Bank  may at any time  pledge  all or any  portion  of its
interest and rights under this  Agreement  (including  all or any portion of its
Notes) to any of the twelve Federal  Reserve Banks  organized  under ss.4 of the
Federal Reserve Act, 12 U.S.C. ss.341. No such pledge or the enforcement thereof
shall  release the pledgor Bank from its  obligations  hereunder or under any of
the other Loan Documents.


The Borrowers and the Guarantors  shall not assign or transfer any of its rights
or obligations under any of the Loan Documents without the prior written consent
of each of the Banks.

     11.7.  JUDGMENT EXCHANGE RATE. If, for the purpose of obtaining judgment in
any court or obtaining an order  enforcing a judgment,  it becomes  necessary to
convert any amount due under this  Agreement in dollars or an any other currency
(hereinafter  in this Section 11.7 called the "first  currency")  into any other
currency  (hereinafter in this Section 11.7 called the "second currency"),  then
the conversion shall be made at the Agent's spot rate of exchange for buying the
first  currency  with the second  currency  prevailing  at the Agent's  close of
business on the  Business  Day next  preceding  the day on which the judgment is
given or (as the case may be) the order is made.  In the event  that  there is a
difference between the rate of exchange on the basis of which the amount of such
judgment or order is determined and the rate of exchange  prevailing on the date
of  payment,  the  Borrowers  jointly  and  severally  hereby  agree to pay such
additional  amount as may be  necessary  to ensure  that the amount paid on such
date in the second currency is the amount in such second  currency  which,  when
converted  at the Agent's  spot rate of exchange  for buying the first  currency
with the second  currency  prevailing at the Agent's  opening of business on the
date of payment,  is the amount which was due under this  Agreement in the first
currency  before such  judgment  was  obtained or made.  Any amount due from the
Borrowers  to the Agent under the second  sentence of this  Section 11.7 will be
due as a separate  debt of the  Borrowers to the Agent and shall not be affected
by judgment or order being obtained for any other sum due under or in respect of
this  Agreement.  The covenant  contained in this Section 11.7 shall survive the
payment  in full of all of the other  obligations  of the  Borrowers  under this
Agreement.

         11.8.  CONSENT TO JURISDICTION.

                  (a) Each of the  Borrowers and each of the  Guarantors  hereby
irrevocably  submits to the jurisdiction of any  Massachusetts  State or Federal
court sitting in Boston over any action or proceeding arising out of or relating
to this Agreement or any note issued by any Borrower,  and each of the Borrowers
and the Guarantors hereby  irrevocably agrees that all claims in respect of such
action or proceeding may be heard and determined in such Massachusetts  State or
Federal court.  Each of the Borrowers and each of the Guarantors hereby appoints
Messrs.  Goodwin,  Procter & Hoar (the "Process  Agent"),  with an office on the

<PAGE>

date hereof at Exchange  Place,  Boston,  Massachusetts  02109 United  States of
America,  as its agent to  receive on its  behalf  and its  property  service of
copies of the summons and complaint and any other process which may be served in
any such action or  proceeding.  Such service may be made to any Borrower or any
Guarantor by mailing or  delivering  a copy of such process to such  Borrower or
such Guarantor in care of the Process Agent,  Attention:  Edward T. O'Dell, Jr.,
P.C., at the Process Agent's above address,  and such Borrower or such Guarantor
hereby  irrevocably  authorizes  and directs  the  Process  Agent to accept such
service  on its  behalf.  As an  alternative  method  of  service,  each  of the
Borrowers and each of the Guarantors also irrevocably consents to the service of
any and all process in any such  action or  proceeding  by the hand  delivery or
mailing of copies of such  process to such  Borrower  or such  Guarantor  at its
address  specified in Section 11.2.  Each of the  Borrowers  and the  Guarantors
agrees  that a  final  judgment  in any  such  action  or  proceeding  shall  be
conclusive and may be enforced in other jurisdictions by suit on the judgment or
in any other manner provided by law.

         (b)  Any  Borrower  or any  Guarantor  may  change  its  Process  Agent
hereunder by  substituting  and  appointing as its Process Agent another  Person
approved by the Banks,  such substitution and appointment to be made pursuant to
such a written  instrument  executed by such Borrower or such Guarantor and such
Person in form and substance  approved by the Banks, which approvals will not be
unreasonably withheld;  provided, however, that each Borrower and each Guarantor
shall at all times have appointed a Process Agent  hereunder or purposes of this
Section 11.8.

         (c) Nothing in this  Section 11.8 shall affect the right of any bank to
serve legal process in any other manner  permitted by law or affect the right of
any Bank to bring any action of proceeding against any Borrower or any Guarantor
or its property in the courts of any other jurisdictions.

         11.9. NO MARSHALLING. No Bank shall be required to marshall any present
or future  claims,  rights,  or  remedies  which it has or may have  against the
Borrowers or the Guarantors or any of them in respect of the obligations (or any
of them) of the Borrowers or the Guarantors or any of them under this Agreement,
or to resort to such claims, rights, or remedies in any particular order. To the
extent that it lawfully may, each Borrower and each Guarantor hereby agrees that
it will not invoke any law which might cause delay in or impede the  enforcement
of the rights of any Bank under this  Agreement,  and to the  fullest  extent it
lawfully  may, each  Borrower and each Guarantor  hereby  irrevocably waives the
benefits of all such laws.

         11.10.  LIABILITIES  OF BORROWERS  AND  GUARANTORS  NOT  AFFECTED.  The
liability of each Borrower and each  Guarantor to the Banks under this Agreement
shall in no way be terminated, affected, diminished or impaired by reason of (a)
the assertion of, or the failure by any Bank to asset against any other Borrower
or any other  Guarantor  any of the claims,  rights or remedies  reserved to any
Bank pursuant to the terms of this Agreement or (b) any  assignment,  renewal or
extension of this Agreement in honoring a request  therefor by another  Borrower
or another Guarantor, or (c) any indulgence,  waiver, extension of time or other
action,  inaction or omission by any Bank under or in respect of this  agreement
in favor of any other  Borrower or any other  Guarantor,  or (d) any dealings or
transactions or matters occurring between any Bank and any other Borrower or any
other Guarantor or (e) any bankruptcy, insolvency, reorganization,  arrangement,
assignment for the benefit of creditors,  receivership or trusteeship  affecting
any other Borrower or Guarantor or its successors or assigns, or (f) the release
of any other Borrower or Guarantor from the  performance of observance of any of
the terms,  conditions or provisions of this  Agreement or (g) any act or matter
which  might,  but for this  provision of this  Agreement,  be deemed a legal or

<PAGE>

equitable  discharge of any other Borrower or Guarantor,  or (h) the invalidity,
irregularity  or  unenforceability  against  any  other  Borrower  or any  other
Guarantor of this Agreement or (i) any other matter, whether or not specifically
mentioned  herein,  other  than  full,  prompt  and  unconditional  payment  and
performance  when  due of  all  of the  joint  and  several  obligations  of the
Borrowers and of the  Guarantors to the Banks under this  Agreement;  whether or
not  notice  of any of the  foregoing  is given to any of the  Borrowers  or the
Guarantors.  Each Borrower and Guarantor  hereby expressly waives and surrenders
any defense to its joint and several obligations hereunder based upon any of the
foregoing acts, omissions, things, agreements or waivers.

     11.11.  GOVERNING  LAW.  This  Agreement  shall be governed by the internal
substantive  laws of the  Commonwealth  of  Massachusetts  without  reference to
conflicts of law rules and is intended to take effect as a sealed instrument.

         11.12.  COUNTERPARTS.  This  Agreement  may be  executed in one or more
counterparts each of which shall constitute an original but which taken together
shall  constitute but one  agreement.  In proving this Agreement it shall not be
necessary to produce or account for more than one such counterpart.

     11.13.  INDEMNIFICATION.  The  Borrowers  and the  Guarantors  jointly  and
severally  agree to indemnify and hold harmless the Agent and the Banks from and
against any and all claims,  actions and suits whether  groundless or otherwise,
and from and against any and all  liabilities,  losses,  damages and expenses of
every  nature and  character  arising out of this  Agreement or any of the other
Loan  Documents  or the  transactions  contemplated  hereby  including,  without
limitation,  (a) any actual or  proposed  use by the  Borrowers  or any of their
Subsidiaries  of the proceeds of any of the Loans or Letters of Credit,  (b) the
Borrowers,  the  Guarantors  or any  of  their  Subsidiaries  entering  into  or
performing this Agreement or any of the other Loan Documents or (c) with respect
to the Borrowers,  the Guarantors and their  Subsidiaries  and their  respective
properties  and assets,  the violation of any  Environmental  Law, the presence,
disposal,  escape, seepage, leakage, spillage,  discharge,  emission, release or
threatened release of any hazardous substances or any action,  suit,  proceeding
or investigation  brought or threatened with respect to any hazardous substances
(including,  but not limited to, claims with respect to wrongful death, personal
injury or damage to property), in each case including,  without limitation,  the
reasonable  fees and  disbursements  of counsel and allocated  costs of internal
counsel incurred in connection with any such investigation,  litigation or other
proceeding,  unless  such  claims,  actions or suits are the sole  result of the
gross   negligence   or   willful   misconduct   of  the  party   seeking   such
indemnification.  In litigation,  or the preparation therefor, the Banks and the
Agent  shall be entitled  to select  their own  counsel  and, in addition to the
foregoing indemnity, the Borrowers and Guarantors jointly and severally agree to
pay promptly the  reasonable  fees and expenses of such counsel.  If, and to the
extent that the obligations of the Borrowers or any of the Guarantors under this
Section 11.13 are unenforceable for any reason, the Borrowers and the Guarantors
jointly  and  severally  hereby  agree to make the maximum  contribution  to the
payment  in  satisfaction  of  such  obligations   which  is  permissible  under
applicable  law. The  covenants  contained in this Section  11.13 shall  survive
payment or  satisfaction  in full of all other  obligations of the Borrowers and
the Guarantors under this Credit Agreement.

         11.14. TRANSITIONAL  ARRANGEMENTS.  This Agreement shall on the Closing
Date supersede the Original Credit Agreement in its entirety, except as provided
in this Section 11.14.  On the Closing Date,  the rights and  obligations of the
parties  evidenced by the Original  Credit  Agreement  shall be evidenced by the
Agreement and other Loan Documents, the "Advances" and "Loans" as defined in the
Original Credit Agreement shall be "Advances" and "Loans" as defined herein, and
all outstanding  bankers  acceptances  issued by any Bank for the account of the
Borrowers  prior to the  Closing  Date  shall,  for the  purposes of this Credit
Agreement, be Bankers Acceptances.

         As soon  as  reasonably  practicable  after  its  receipt  of its  Note
hereunder on the Closing Date, the Banks will promptly  return to the Borrowers,
marked  "Substituted"  or  "Cancelled",  as the  case may be,  any  notes of the
Borrowers held by the Banks pursuant to the Original Credit Agreement.

         All interest and fees and expenses,  if any, owing or accruing under or
in respect of the Original  Credit  Agreement  through the Closing Date shall be
calculated  as of the  Closing  Date  (prorated  in the  case of any  fractional
periods),  and shall be paid in  accordance  with the method,  and on the dates,
specified in the Original Credit Agreement,  as if the Original Credit Agreement
were still in effect.  Commencing on the Closing Date, the commitment fees shall
be  payable  by the  Borrowers  to the  Agent  for the  account  of the Banks in
accordance with this Agreement.

         SECTION 12.  GUARANTY.

     12.1.  GUARANTY OF PAYMENT AND PERFORMANCE.  Each of the Guarantors  hereby
jointly  and  severally  guarantees  to the  Banks  and the  Agent  the full and
punctual payment when due (whether at stated maturity,  by required pre-payment,
by  acceleration  or  otherwise),  as  well  as the  performance,  of all of the
Obligations  including  all such which would become due but for the operation of
the automatic stay pursuant to ss.362(a) of the Federal  Bankruptcy Code and the
operation  of  ss.ss.502(b)  and 506(b) of the  Federal  Bankruptcy  Code.  This
guaranty is an absolute,  unconditional and continuing  guaranty of the full and
punctual  payment and  performance  of all of the  Obligations  and not of their
collectibility  only and is in no way conditioned  upon any requirement that the
Agent or any Bank first  attempt to collect any of the  Obligations  from any of
the Borrowers or resort to any  collateral  security or other means of obtaining
payment.  Should any of the Borrowers  default in the payment or  performance of
any of the Obligations, the obligations of each of the Guarantors hereunder with
respect to such Obligations in default shall,  upon demand by the Agent,  become
immediately  due and payable to the Agent,  for the benefit of the Banks and the
Agent, without demand or notice of any nature, all of which are expressly waived
by each of the  Guarantors.  Payments by any of the Guarantors  hereunder may be
required by the Agent on any number of occasions. All payments by the Guarantors
hereunder  shall be made to the Agent, in the manner and at the place of payment
specified in this Agreement, for the account of the Banks and the Agent.

         12.2.  GUARANTORS' AGREEMENT TO PAY ENFORCEMENT COSTS, ETC. Each of the
Guarantors further agrees, as the principal obligor and not as a guarantor only,
to pay to the Agent, on demand,  all costs and expenses  (including  court costs
and legal expenses)  incurred or expended by the Agent or any Bank in connection
with the Obligations,  this guaranty and the enforcement thereof,  together with
interest on amounts  recoverable under this Section 12.2 from the time when such
amounts become due until payment,  whether before or after judgment, at the rate
of interest for overdue  principal set forth in the Credit  Agreement,  provided
that if such  interest  exceeds the maximum  amount  permitted  to be paid under
applicable  law, then such interest  shall be reduced to such maximum  permitted
amount.

         12.3.  WAIVERS  BY  GUARANTORS;  BANK'S  FREEDOM  TO  ACT.  Each of the
Guarantors  agrees that the Obligations  will be paid and performed  strictly in
accordance with their  respective  terms,  regardless of any law,  regulation or
order now or hereafter in effect in any jurisdiction affecting any of such terms
or the  rights  of the  Agent  or any Bank  with  respect  thereto.  Each of the
Guarantors waives promptness,  diligences,  presentment, demand, protest, notice
of acceptance,  notice of any Obligations  incurred and all other notices of any
kind,  all defenses  which may be available  by virtue of any  valuation,  stay,

<PAGE>

moratorium  law or other  similar law now or hereafter  in effect,  any right to
require the  marshalling of assets of the Borrowers or any other entity or other
person  primarily or secondarily  liable with respect to any of the Obligations,
and all suretyship  defenses  generally.  Without limiting the generality of the
foregoing,  each of the  Guarantors  agrees to the  provisions of any instrument
evidencing, securing or otherwise executed in connection with any Obligation and
agrees that the obligations of such Guarantor hereunder shall not be released or
discharged, in whole or in part, or otherwise affected by (a) the failure of the
Agent or any Bank to  assert  any claim or  demand  or to  enforce  any right or
remedy  against  any of the  Borrowers  or any  other  entity  or  other  person
primarily or secondarily liable with respect to any of the Obligations;  (b) any
extensions,   compromise,   refinancing,   consolidation   or  renewals  of  any
Obligation; (c) any change in the time, place or manner of payment of any of the
Obligations or any rescissions, waivers, compromise, refinancing,  consolidation
or other  amendments or  modifications  of any of the terms or provisions of the
Credit  Agreement,  the Note,  the other Loan  Documents or any other  agreement
evidencing,  securing  or  otherwise  executed  in  connection  with  any of the
Obligations,  (d) the addition,  substitution  or release of any entity or other
person primarily or secondarily  liable for any Obligation;  (e) the adequacy of
any rights which the Agent or any Bank may have against any collateral  security
or  other  means  of  obtaining  repayment  of any of the  Obligations;  (f) the
impairment of any collateral securing any of the Obligations,  including without
limitation  the failure to perfect or preserve any rights which the Agent or any
Bank might  have in such  collateral  security  or the  substitution,  exchange,
surrender, release, loss or destruction of any such collateral security; or (gi)
any other act or  omission  which  might in any manner or to any extent vary the
risk of such  Guarantor or  otherwise  operate as a release or discharge of such
Guarantor,  all of which may be done without  notice to such  Guarantor.  To the
fullest extent permitted by law, each of the Guarantors  hereby expressly waives
any and all  rights or  defenses  arising  by reason of (i) any "one  action" or
"anti-deficiency"  law which would otherwise  prevent the Agent or any Bank from
bringing any action,  including  any claim for a deficiency,  or exercising  any
other right or remedy  (including any right of set-off),  against such Guarantor
before or after the Agent's or such Bank's  commencement  or  completion  of any
foreclosure  action,  whether  judicially,  by  exercise  of  power  of  sale or
otherwise,  or (ii) any other law which in any other way would otherwise require
any election of remedies by the Agent or any Bank.

         12.4.  UNENFORCEABILITY  OF OBLIGATIONS  AGAINST BORROWERS.  If for any
reason  any of the  Borrowers  has no  legal  existence  or is  under  no  legal
obligation to discharge  any of the  Obligations,  or if any of the  Obligations
have become irrecoverable from any of the Borrowers by reason of such Borrower's
insolvency, bankruptcy or reorganization or by other operation of law or for any
other  reason,  this  guaranty  shall  nevertheless  be  binding  on each of the
Guarantors  to the same  extent as if such  Guarantor  at all times had been the
principal obligor on all such Obligations. In the event that acceleration of the
time for  payment  of any of the  Obligations  is  stayed  upon the  insolvency,
bankruptcy or reorganization of the Borrowers, or for any other reason, all such
amounts  otherwise  subject  to  acceleration  under  the  terms  of the  Credit
Agreement, the Note, the other Loan Documents or any other agreement evidencing,
securing  or  otherwise  executed in  connection  with any  Obligation  shall be
immediately due and payable by each of the Guarantors.

         12.5.  SUBROGATION;  SUBORDINATION.  (a) Until the  final  payment  and
performance in full of all of the Obligations,  each of the Guarantors shall not
exercise and hereby waives any rights against the Borrowers  arising as a result
of payment by such Guarantor  hereunder,  by way of subrogation,  reimbursement,
restitution,  contribution  or  otherwise,  and  will  not  prove  any  claim in
competition  with the Agent or any Bank in respect of any payment  hereunder  in
any bankruptcy,  insolvency or reorganization case or proceedings of any nature;
such Guarantor will not claim any setoff, recoupment or counterclaim against the
Borrowers in respect of any liability of such  Guarantor to the  Borrowers;  and
such  Guarantor  waives  any  benefit  of and any  right to  participate  in any
collateral  security  which may be held by the  Agent or any  Bank;  and (b) the
payment of any amounts due with respect to any indebtedness of the Borrowers for
money borrowed or credit received now or hereafter owed to any of the Guarantors
is hereby  subordinated to the prior payment in full of all of the  Obligations.
Each of the Guarantor  agrees that,  after the  occurrence of any default in the
payment  or  performance  of any of the  Obligations,  such  Guarantor  will not
demand,  sue for or otherwise  attempt to collect any such  indebtedness  of the
Company to such Guarantor until all of the  Obligations  shall have been paid in
full. If, notwithstanding the foregoing sentence,  such Guarantor shall collect,
enforce  or receive  any  amounts  in  respect  of such  indebtedness  while any
Obligations are still outstanding, such amounts shall be collected, enforced and
received  by such  Guarantor  as trustee for the Banks and the Agent and be paid
over to the Agent, for the benefit of the Banks and the Agent, on account of the
Obligations  without  affecting in any manner the  liability  of such  Guarantor
under the other provisions of this guaranty. The provisions of this Section 12.5
shall be supplemental to and not in derogation of any rights and remedies of the
Banks and the Agent under any separate  subordination  agreement which the Agent
may at any time and from time to time enter into with any of the  Guarantors for
the benefit of the Banks and the Agent.

         12.6.  SECURITY;  SETOFF. Each of such Guarantors grants to each of the
Agent  and the  Banks,  as  security  for the  full  and  punctual  payment  and
performance of all of such Guarantor's  obligations hereunder, a continuing lien
on and security  interest in all securities or other property  belonging to such
Guarantor  now or  hereafter  held by the Agent or such Bank and in all deposits
(general  or  special,  time or  demand,  provisional  or final)  and other sums
credited by or due from the Agent or such Bank to such  Guarantor  or subject to
withdrawal by such Guarantor.  Upon the occurrence and during the continuance of
any Event of Default,  each Bank is hereby  authorized at any time and from time
to time,  without notice (any such notice being expressly  waived hereby) and to
the fullest  extent  permitted by law and without  regard to any  collateral  or
other  source of payment  whatsoever,  to set off and apply any and all deposits
(general  or  specific,  time or demand,  provisional  or final,  regardless  of
currency,  maturity,  or the branch of the Bank where the  deposits are held) at
any time held or other sums  credited  by or due from any of the Banks to any of
the  Guarantors  against  any  and  all  Obligations  of the  Borrowers  and the
Guarantors to the Banks.  Each of the Banks agrees with the other Banks that (a)
if an amount to be set off is to be applied to  Indebtedness  of any Borrower or
Guarantor to a Bank, other than  Indebtedness  evidenced by the then Outstanding
Loans or Reimbursement  Obligations held by all of the Banks,  such amount shall
be applied ratably to such other Indebtedness and to the Indebtedness  evidenced
by all Outstanding Loans or Reimbursement Obligations of such Bank, and (b) if a
Bank shall receive from any Borrower or Guarantor whether by voluntary  payment,
exercise of the right of set-off, counterclaim, cross action, enforcement of the
claim  related to Loans by a Bank by  proceedings  against such Borrower or such
Guarantor at law or in equity or by proof thereof in bankruptcy, reorganization,
liquidation,  receivership or similar proceedings,  or otherwise, any payment so
received  shall be shared so as to give effect to the  provisions of Section 9.1
and, thereafter, in the manner contemplated by Section 2.17.

         12.7 FURTHER  ASSURANCES.  Each of such Guarantors  agrees that it will
from time to time,  at the request of the Agent,  do all such things and execute
all such documents as the Agent may consider necessary or desirable to give full
effect to this guaranty and to perfect and preserve the rights and powers of the
Banks and the Agent hereunder.  Each of the Guarantors acknowledges and confirms
that such Guarantor  itself has  established its own adequate means of obtaining
from the  Borrowers  on a  continuing  basis  all  information  desired  by such
Guarantor  concerning  the  financial  condition of the  Borrowers and that such
Guarantor  will look to the  Borrowers and not to the Agent or any Bank in order
for such  Guarantor  to keep  adequately  informed of changes in the  Borrowers'
financial condition.

<PAGE>

         12.8  TERMINATION;  REINSTATEMENT.  This guaranty  shall remain in full
force and  effect  until the Agent is given  written  notice of the  Guarantors'
intention to discontinue  this Guaranty,  notwithstanding  any  intermediate  or
temporary payment or settlement of the whole or any part of the Obligations.  No
such notice shall be effective unless received and acknowledged by an officer of
the Agent at the  address of the Agent for notices set forth in Section 8 of the
Credit  Agreement.  No such notice  shall  affect any rights of the Agent or any
Bank hereunder, including without limitation the rights set forth in ss.ss.4 and
6, with respect to any  Obligations  incurred or accrued prior to the receipt of
such notice or any Obligations  incurred or accrued  pursuant to any contract or
commitment in existence  prior to such receipt.  This Guaranty shall continue to
be effective or be reinstated,  notwithstanding  any such notice, if at any time
any payment made or value  received with respect to any  Obligation is rescinded
or must  otherwise  be  returned  by the Agent or any Bank upon the  insolvency,
bankruptcy or reorganization of the Borrowers, or otherwise,  all as though such
payment had not been made or value received.

<PAGE>

         IN WITNESS WHEREOF, this Agreement has been executed by or on behalf of
the parties hereto on the day first above written.

Borrowers:                              DYNATECH CORPORATION
                                        DYNATECH USA, INC.
                                        DYNATECH VIDEO GROUP, INC.
                                        INDUSTRIAL COMPUTER SOURCE
                                        TELECOMMUNICATIONS
                                           TECHNIQUES CORP.



                                        By:____________________________________
                                        Title:


Guarantors:                             ASINC, INCORPORATED
                                        COMCOTEC, INC.
                                        COMPUTERIZED MEDICAL
                                           SYSTEMS, INC.
                                        DATAVIEWS CORPORATION
                                        DaVINCI SYSTEMS, INC.
                                        DIGITAL TECHNOLOGY, INC.
                                        DYNATECH COMMUNICATIONS, INC.
                                        DYNATECH LABORATORIES, INC.
                                        DYNATECH LEASING CORPORATION
                                        DYNATECH NEVADA, INC.
                                        DYNATECH NEWSTAR, INC.
                                        DYNATECH PRECISION SAMPLING
                                           CORPORATION
                                        DYNATECH TACTICAL
                                           COMMUNICATIONS, INC.
                                        PARALLAX GRAPHICS, INC.
                                        TRONTECH, INC.
                                        UNEX CORPORATION



                                        By:_________________________________
                                        Title:


                                         THE FIRST NATIONAL BANK OF
                                           BOSTON, individually and as Agent


                                         By:_________________________________
                                         Title:




<PAGE>




                                         ABN AMRO BANK N.V., BOSTON
                                            BRANCH


                                         By:_________________________________
                                         Title:

                                         By:_________________________________
                                         Title:



                                         MELLON BANK, N.A.



                                         By:_________________________________
                                         Title:



<PAGE>

                                      -1-
                                                                      EXHIBIT A


                           DESIGNATED FUNDING SOURCES

The First National Bank of Boston:

100 Federal Street
Boston, Massachusetts  02110


ABN AMRO Bank N.V. Boston Branch:

One Post Office Square
Boston, Massachusetts  02109


Mellon Bank, N.A.

One Boston Place
Boston, Massachusetts  02108