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COMMERCIAL NOTE: TIME OR TERM SINGLE ADVANCE/PRIME (OHIO)

<TABLE>
<CAPTION>
Amount         City, State       Date                  FOR BANK USE ONLY

<S>            <C>               <C>                   <C>
500,000.00     Dayton, Ohio      November 20, 1996     Obligor #6101893008
                                                       Tax I.D. #592209179
                                                       Obligation #
                                                       Office Corporate Banking Department
</TABLE>


FOR  VALUE  RECEIVED,   Paravant  Computer  Systems  Inc    ('Borrower'),   a(n)
Corporation  whose  mailing  address  is 780 S APOLLO  BLVD STE 1  MELBOURNE  FL
32901-1423,  hereby promises to pay to the order of NATIONAL CITY BANK OF DAYTON
('Bank'),  a national banking  association having its banking office at 6 N MAIN
ST, DAYTON, OHIO 45412-2790, at Bank's banking office (or at such other place as
Bank may from time to time  designate by written  notice) in lawful money of the
United States of America, the principal sum of
 
                    Five Hundred Thousand and 00/100 DOLLARS
 
together with interest, all as provided below
 
1. Interest. The unpaid principal balance of  this Note shall at all times  bear
interest  at a  fluctuating rate  equal to Zero  percent (0.00%)  per annum plus
Prime Rate, provided, that so  long as any principal  of or accrued interest  on
this Note is overdue, all unpaid principal of this Note and all overdue interest
on  that principal (but not interest on overdue interest) shall bear interest at
a fluctuating rate equal to two percent (2%) per annum above the rate that would
otherwise be applicable, but  in no case  less than two  percent (2%) per  annum
above  the Prime Rate; provided further, that in no event shall any principal of
or interest on this Note  bear interest at any time  after Maturity at a  lesser
rate than the rate applicable thereto immediately after Maturity.
 
2.  Repayment. Subject to section 5, the  interest on this Note shall be payable
in arrears on the 20th day of December, 1996, and on the 20th day of each  Month
thereafter,  at Maturity,  and on demand  thereafter, and the  principal of this
Note shall be payable  in one (1)  payment on March  31st, 1998. Borrower  shall
have  the  right to  prepay the  principal of  this  Note in  whole or  in part,
provided, that (a) each  such prepayment shall  be in the  principal sum of  One
Thousand dollars ($1,000.00) or any integral multiple thereof or an amount equal
to the then aggregate unpaid principal balance of this Note and (b) concurrently
with  the  prepayment  of the  entire  unpaid  principal balance  of  this Note,
Borrower shall prepay the accrued interest on the principal being prepaid.  Each
prepayment of the principal of this Note may be made without premium or penalty.
 
3.  Definitions. As used in this Note, except where the context clearly requires
otherwise,  'Affiliate'  means,  when used with  reference  to any  Person  (the
'subject'),  a Person  that is in control  of,  under the  control  of, or under
common control with, the subject,  the term  'control'  meaning the  possession,
directly or  indirectly,  of the power to direct the management or policies of a
Person,  whether  through the ownership of voting  securities,  by contract,  or
otherwise; 'Bank Debt' means,  collectively,  all Debt to Bank, whether incurred
directly  to Bank or acquired  by it by  purchase,  pledge,  or  otherwise,  and
whether  participated  to or from Bank in whole or in part;  'Banking Day' means
any day (other  than any  Saturday,  Sunday or legal  holiday)  on which  Bank's
banking  office is open to the public for carrying on  substantially  all of its
banking functions; 'Debt' means, collectively,  all obligations of the Person or
Persons in  question,  including,  without  limitation,  every  such  obligation
whether  owing by one such Person  alone or with one or more other  Persons in a
joint,  several,  or joint and several capacity,  whether now owing or hereafter
arising,  owing  absolutely or  contingently,  whether  created by lease,  loan,
overdraft,  guaranty or payment, or other contract, or by quasi-contract,  tort,
statute,  other  operation  of law,  or  otherwise;  'Maturity'  means  the date
(whether occurring by lapse of time, acceleration,  or otherwise) upon which the
last  scheduled  principal  payment  under this Note is due;  'Note'  means this
promissory note  (including,  without  limitation,  each addendum,  allonge,  or
amendment,  if any,  hereto);  'Obligor'  means any Person  who, or any of whose
property,  shall at the time in question be  obligated  in respect of all or any
part of the Bank  Debt of  Borrower  and (in  addition  to  Borrower)  includes,
without limitation,  co-makers, indorsers, guarantors, pledgors,  hypothecators,
mortgagors, and any other Person who agrees, conditionally or otherwise, to make
any loan to,  purchase  from, or  investment  in, any other Obligor or otherwise
assure such other  Obligors'  creditors  or any of them against  loss;  'Person'
means an individual or entity of any kind,  including,  without limitation,  any
association, company, cooperative, corporation, partnership, trust, governmental
body,  or any other form or kind of entity;  'Prime Rate' means the  fluctuating
rate per annum  which is publicly  announced  from time to time by Bank as being
its so called 'prime rate' or 'base rate' thereafter in effect, with each change
in the Prime Rate  automatically,  immediately,  and without notice changing the
Prime Rate thereafter applicable hereunder, it being acknowledged that the Prime
Rate is not  necessarily the lowest rate of interest then available from Bank on
fluctuating-rate  loans;  'Proceeds'  means any  assignment  for the  benefit of
creditors,  any case in bankruptcy,  any marshalling of any Obligor's assets for
the  benefit of  creditors,  any  moratorium  on the  payment  of debts,  or any
proceeding under any law relating to conservatorship,  insolvency,  liquidation,
receivership,  trusteeship  or any similar  event,  condition,  or other  thing;
'Related Writing' means this Note and any indenture, note, guaranty, assignment,
mortgage,  security  agreement,   subordination  agreement,   notice,  financial
statement, legal opinion,  certificate, or other writing of any kind pursuant to
which all or any part of the Bank Debt of Borrower is issued, which evidences or
secures all or any part of the Bank Debt of Borrower, which governs the relative
rights and priorities of Bank and one or more other Persons to payments made by,
or the property of, any Obligor,  which is delivered to Bank pursuant to another
such  writing,  or which is  otherwise  delivered to Bank by or on behalf of any
Person (or any employee,  officer,  auditor, counsel, or agent of any Person) in
respect of or in  connection  with all or any part of the Bank Debt of Borrower;
'Reporting  Person' means each Obligor and each member of any 'Reporting  Group'
as defined in any addendum to this Note; and the foregoing  definitions shall be
applicable to the respective plurals of the foregoing defined terms.
 
4.  Events of Default.  It shall be an 'Event of Default' if (a) all or any part
of the Bank  Debt of any  Obligor  shall not be paid in full  promptly  when due
(whether by lapse of time, acceleration,  or otherwise); (b) any representation,
warranty, or other statement made by any Person (other than Bank) in any Related
Writing  shall be untrue or  incomplete  when made;  (c) any Person  (other than
Bank) shall  repudiate or shall fail or omit to perform or observe any agreement
contained in this Note or in any other Related  Writing that is on that Person's
part to be complied with; (d) any indebtedness (other than any evidenced by this
Note) of any Obligor shall not be paid when due, or there shall occur any event,
condition, or other thing which gives (or which with the lapse of any applicable
grace period,  the giving of notice,  or both would give) any creditor the right
to  accelerate  or which  automatically  accelerates  the  maturity  of any such
indebtedness;  (e) Bank  shall  not  receive  (in  addition  to any  information
described in any addendum to this Note) without  expense to Bank,  (i) forthwith
upon each request of Bank made upon Borrower  therefor,  (A) such information in
writing  regarding  each Reporting  Person's  financial  condition,  properties,
business operations, if any, and pension plans, if any, prepared, in the case of
financial   information,   in  accordance  with  generally  accepted  accounting
principles consistently applied and otherwise in form and detail satisfactory to
Bank or (B) written permission, in form and substance satisfactory to Bank, from
each  Reporting  Person to inspect (or to have  inspected by one or more Persons
selected by Bank) the  properties  and records of that  Reporting  Person and to
make  copies and  extracts  from those  records or (ii)  prompt  written  notice
whenever  Borrower (or any director,  employee,  officer,  or agent of Borrower)
knows or has  reason to know that any Event of  Default  has  occurred;  (f) any
judgment shall be entered against any Obligor in any judicial or  administrative
tribunal or before any  arbitrator  or mediator;  (g) any Obligor  shall fail or
omit to  comply  with any  applicable  law,  rule,  regulation,  or order in any
material  respect;  (h) any proceeds of the loan evidenced by this Note shall be
used for any purpose that is not in the ordinary course of Borrower's  business;
(i) any property in which any Obligor now has or  hereafter  acquires any rights
or which now or hereafter secures any Bank Debt shall be or become encumbered by
any mortgage,  security interest,  or other lien, except any mortgage,  security
interest,  or other lien consented to by Bank; (j) any Obligor shall at any time
or over any  period of time  sell,  lease,  or  otherwise  dispose of all or any
material  part  of that  Obligors'  assets,  except  for  inventory  sold in the
ordinary course of business and other assets sold, leased, or otherwise disposed
of with the consent of Bank;  (k) any  Obligor  shall cease to exist or shall be
dissolved,  become legally  incapacitated,  or die; (l) any Proceeding  shall be
commenced  with  respect to any  Obligor;  (m) there  shall occur or commence to
exist  any  event,  condition,  or other  thing  that  constitutes  an 'Event of
Default'  as defined in any  addendum  to this Note;  (n) there  shall occur any
event,  condition, or other thing that has, or, in Bank's judgment, is likely to
have, a material  adverse  effect on the  financial  condition,  properties,  or
business  operations of any Obligor or on Bank's  ability to enforce or exercise
any agreement or right arising under,  out of, or in connection with any Related
Writing;  or (o) the holder of this Note shall, in good faith,  believe that the
prospect of payment or performance  of any obligation  evidenced by this Note is
impaired.
 
5.  Effects of Default.  If any Event of Default (other than the commencement of
any  Proceeding  with respect to Borrower)  shall occur,  then, and in each such
case,  notwithstanding  any provision or inference to the  contrary,  Bank shall
have the right in its  discretion,  by giving  written  notice to  Borrower,  to
declare this Note to be due,  whereupon the entire unpaid  principal  balance of
this Note (if not already due) shall immediately become due and payable in full.
If  any  Proceeding   shall  be  commenced  with  respect  to  Borrower,   then,
notwithstanding  any  provision  or inference  to the  contrary,  automatically,
without presentment,  protest, or notice of dishonor, all of which are waived by
all makers and all indorsers of this Note, now or hereafter existing, the entire
unpaid  principal  balance of this Note (if not already  due) shall  immediately
become due and payable in full.





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6. Late Charges. If any principal of or interest on this Note is not paid within
ten  (10) days after its due date, then,  and in each such case, Bank shall have
the right to assess a late charge,  payable by Borrower on demand, in an  amount
equal  to the  greater of twenty  dollars ($20.00)  or five percent  (5%) of the
amount not timely paid.
 
7. No  Setoff. Borrower  hereby waives  any and  all now  existing or  hereafter
arising  rights  to recoup  or offset  any  obligation of  Borrower under  or in
connection with this Note or any Related  Writing against any claim or right  of
Borrower against Bank.
 
8.  Indemnity: Administration and Enforcement.  Borrower will reimburse Bank, on
Bank's demand from  time to  time, for  any and  all fees,  costs, and  expenses
(including,  without limitation,  the fees  and disbursements  of legal counsel)
incurred by Bank  in administering  this Note  or in  protecting, enforcing,  or
attempting  to protect  or enforce  its rights  under this  Note. If  any amount
(other than any principal of this Note and any interest and late charges)  owing
under  this Note  is not paid  when due, then,  and to each  such case, Borrower
shall pay, on Bank's demand, interest on  that amount from the due date  thereof
until  paid in full at  a fluctuating rate equal to  four percent (4%) per annum
plus the Prime Rate.
 
9. Waivers; Remedies; Application of Payments. Bank may from time to time in its
discretion grant  waivers and  consents in  respect of  this Note  or any  other
Related Writing or assent to amendments thereof, but no such waiver, consent, or
amendment  shall  be binding  upon Bank  unless  set forth  in a  writing (which
writing shall be  narrowly construed) signed  by Bank. No  course of dealing  in
respect  of, nor any omission or delay in  the exercise of, any right, power, or
privilege by Bank shall  operate as a  waiver thereof, nor  shall any single  or
partial  exercise thereof preclude  any further or other  exercise thereof or of
any other,  as each  such right,  power, or  privilege may  be exercised  either
independently or concurrently with others and as often and in such order as Bank
may  deem expedient. Without  limiting the generality  of the foregoing, neither
Bank's acceptance of one or more late payments or charges nor Bank's  acceptance
of  interest on overdue amounts at the respective rates applicable thereto shall
constitute a  waiver of  any right  of  Bank. Each  right, power,  or  privilege
specified or referred to in this Note is in addition to and not in limitation of
any other rights, powers, and privileges that Bank may otherwise have or acquire
by  operation of law, by other contract, or otherwise. Bank shall be entitled to
equitable remedies with respect  to each breach  or anticipatory repudiation  of
any  provision of this Note, and Borrower  hereby waives any defense which might
be asserted to bar any such equitable remedy. Bank shall have the right to apply
payments in  respect  of the  indebtedness  evidenced  by this  Note  with  such
allocation  to the respective parts thereof and the respective due dates thereof
as Bank in its sole discretion may from time to time deem advisable.
 
10. Other  Provisions. The  provisions  of this  Note  shall bind  Borrower  and
Borrower's  successors  and  assigns and  benefit  Bank and  its  successors and
assigns, including each  subsequent holder,  if any,  of this  Note. Except  for
Borrower  and Bank  and their  respective successors  and assigns,  there are no
intended beneficiaries of  this Note  or the loan  evidenced by  this Note.  The
provisions  of sections 6 through 14,  both inclusive, shall survive the payment
in full of  the principal  of and  interest on this  Note. The  captions to  the
sections  and subsections  of this  Note are  inserted for  convenience only and
shall be ignored  in interpreting the  provisions thereof. Each  reference to  a
section  includes a reference to all subsections thereof (i.e., those having the
same character or characters to the left of the decimal point) except where  the
context  clearly does not so  permit. If any provision in  this Note shall be or
become illegal or unenforceable in any case, then that provision shall be deemed
modified in that case so  as to be legal and  enforceable to the maximum  extent
permitted  by law while most  nearly preserving its original  intent, and in any
case the illegality or unenforceability  of that provision shall affect  neither
that  provision in any other  case nor any other  provision. All fees, interest,
and premiums for any given period shall accrue on the first day thereof but  not
on  the last day thereof (unless the last day is the first day) and in each case
shall be computed on the basis of a  360-day year and the actual number of  days
in  the period.  In no  event shall interest  accrue at  a higher  rate than the
maximum rate, if any, permitted by law. Bank shall have the right to furnish  to
its  Affiliates, and to such other Persons  as Bank shall deem advisable for the
conduct  of  its  business,  information  concerning  the  business,   financial
condition,  and property of Borrower,  the amount of the  Bank Debt of Borrower,
and the terms,  conditions, and  other provisions applicable  to the  respective
parts  thereof. This Note  shall be governed  by the law  (excluding conflict of
laws rules) of the jurisdiction in which Bank's banking office is located.
 
11. Integration. This  Note and, to  the extent consistent  with this Note,  the
other  Related Writings, set forth the entire  agreement of Borrower and Bank as
to the subject matter of this Note, and may not be contradicted  by  evidence of
any agreement or statement unless made in a  writing (which  writing  shall   be
narrowly construed) signed by Bank contemporaneously with or after the execution
and delivery of  this Note.  Without limiting  the generality  of the foregoing,
Borrower  hereby acknowledges  that Bank  has not based, conditioned, or offered
to base or condition the credit hereby  evidenced or any charges, fees, interest
rates,  or premiums  applicable  thereto upon Borrower's agreement to obtain any
other credit, property, or service other than any loan,  discount,  deposit,  or
trust service from Bank.
 
12.  Notices  and   Other  Communications.   Each  notice,   demand,  or   other
communication,  whether or not received,  shall be deemed to  have been given to
Borrower whenever Bank shall have mailed  a writing to that effect by  certified
or  registered mail to Borrower's mailing address (or any other address of which
Borrower shall have given Bank notice  after the execution and delivery of  this
Note);  however, no other method  of giving actual notice  to Borrower is hereby
precluded. Borrower hereby  irrevocably accepts Borrower's  appointment as  each
Obligor's  agent  for the  purpose  of receiving  any  notice, demand,  or other
communication to be given by Bank to  each such Obligor pursuant to any  Related
Writing.  Bank shall be entitled  to assume that any  knowledge possessed by any
Obligor other than Borrower is possessed  by Borrower. Each communication to  be
given  to  Bank shall  be in  writing  unless this  Note expressly  permits that
communication to  be made  orally, and  in any  case shall  be given  to  Bank's
Corporate  Banking Department at Bank's banking  office (or any other address of
which Bank shall have given notice to Borrower after the execution and  delivery
this  Note). Borrower hereby  assumes all risk  arising out of  or in connection
with each oral communication given by  Borrower and each communication given  or
attempted  by Borrower in contravention of  this section. Bank shall be entitled
to rely on each communication believed in good faith by Bank to be genuine.
 
13. Warrant of Attorney. Borrower hereby  authorizes any attorney at law at  any
time  or times to appear in  any state or federal court  of record in the United
States of America after  all or any  part of the  obligations evidenced by  this
Note  shall  have  become  due,  whether  by  lapse  of  time,  acceleration, or
otherwise, and in each  case to waive  the issuance and  service of process,  to
present  to the court  this Note and  any other writing  (if any) evidencing the
obligation or obligations  in question, to  admit the due  date thereof and  the
nonpayment  thereof when due,  to confess judgment against  Borrower in favor of
Bank for the full amount then appearing due, together with interest and costs of
suit, and thereupon to release all errors and waive all rights of appeal and any
stay of execution. The foregoing warrant of attorney shall survive any judgment,
it being understood that should any judgment against borrower be vacated for any
reason, Bank  may nevertheless  utilize  the foregoing  warrant of  attorney  in
thereafter obtaining one or more additional judgments against Borrower.
 
                                       2






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14.   Jurisdiction  and  Venue;  Waiver  of   Jury  Trial.  Any  action,  claim,
counterclaim, crossclaim,  proceeding, or  suit, whether  at law  or in  equity,
whether sounding in tort, contract, or otherwise at any time arising under or in
connection  with this  Note or  any other  Related Writing,  the administration,
enforcement, or negotiation of  this Note or any  other Related Writing, or  the
performance  of any  obligation in  respect of  this Note  or any  other Related
Writing (each such action, claim, counterclaim, crossclaim, proceeding, or suit,
an ''Action'') may be brought in any federal or state court located in the  city
in which Bank's banking office  is  located.  Borrower  hereby   unconditionally
submits  to  the jurisdiction   of  any  such court  with respect  to each  such
Action and hereby waives any objection Borrower may now   or  hereafter  have to
the venue  of any  such  Action brought in any such  court. Borrower HEREBY, AND
EACH  HOLDER  OF  THIS   Note,   BY TAKING  POSSESSION  THEREOF,  KNOWINGLY  AND
VOLUNTARILY WAIVES  JURY TRIAL IN RESPECT OF ANY Action.
 

                                  Borrower: Paravant Computer Systems Inc

                                  ----------------------------------------------

                                  By:     RICHARD P. McNEIGHT
                                      ------------------------------------------
               
                                  Printed Name: Richard P. McNeight
                                                -------------------

                                  Title: President
                                         ---------

(complete only if required)       And By:     KEVIN J. BARTCZAK
                                          ----------------------

                                  Printed Name: Kevin J. Bartczak
                                                -----------------

                                  Title: Chief Financial Officer
                                         -----------------------
 
WARNING  -- BY  SIGNING THIS PAPER  YOU GIVE UP  YOUR RIGHT TO  NOTICE AND COURT
TRIAL. IF YOU  DO NOT  PAY ON TIME  A COURT  JUDGMENT MAY BE  TAKEN AGAINST  YOU
WITHOUT  YOUR PRIOR KNOWLEDGE AND  THE POWERS OF A COURT  CAN BE USED TO COLLECT
FROM YOU REGARDLESS OF ANY CLAIMS YOU MAY HAVE AGAINST THE CREDITOR WHETHER  FOR
RETURNED  GOODS, FAULTY GOODS, FAILURE ON HIS PART TO COMPLY WITH THE AGREEMENT,
OR ANY OTHER CAUSE.
 
                                       3



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