KEYBANK NATIONAL ASSOCIATION
                                  MORTGAGE NOTE

BORROWER:  VICON INDUSTRIES, INC.

PRINCIPAL:     $1,200,000                          Date:  October 12, 1999


PROMISE TO PAY: The undersigned (the "Borrower"),  jointly and severally if more
than one  signer,  does hereby  promise to pay to the order of KEYBANK  NATIONAL
ASSOCIATION  (the "Bank") at its offices at 1377 Motor  Parkway,  Islandia,  New
York  11788,  or at any of its  branches,  the sum of ONE  MILLION  TWO  HUNDRED
THOUSAND ($1,200,000) DOLLARS plus interest thereon, from the date hereof in the
manner set forth below.

COMPUTATION OF INTEREST:  Interest on the outstanding  principal balance of this
Note shall be computed on the basis of "a 360-day year for the actual  number of
days elapsed"  (such  phrase,  as used  throughout  this Note shall mean that in
computing interest for the subject period, the interest rate shall be multiplied
by a fraction, the denominator of which is 360 and the numerator of which is the
actual  number of days  elapsed from the date of the first  disbursement  of the
Loan or the date of the  preceding  interest  and/or  principal due date, as the
case may be,  to the date of the  next  interest  and/or  principal  due  date).
Interest shall accrue until the date of receipt of payment.

RATE AND PAYMENT:  The unpaid principal  balance hereof shall bear interest at a
variable rate equal to, at Borrower's  option,  either (i) the 30, 60, or 90 day
LIBOR Rate (at Borrower's  option) plus One Hundred (100) Basis Points,  or (ii)
the Prime Rate minus one hundred  sixty (160) Basis Points,  payable  monthly on
the first day of the first month  following the date hereof and on the first day
of each month thereafter until this Note is paid in full. The option selected by
Borrower  shall be the  applicable  "Interest  Rate"  for such  Interest  Period
(hereinafter defined).

"LIBOR  Rate"  shall mean the rate of  interest  per annum  (rounded  upwards if
necessary  to the  nearest  1/16 of 1%) that is equal to the rate  quoted by the
Bank, or its successors or assigns, for a LIBOR Period of one (1) month, two (2)
months or three (3) months (each, a "LIBOR  Period"),  as adjusted for statutory
requirements,  two (2)  Business  Days  prior to the first  day of the  Interest
Period for which the LIBOR Rate is calculated, for the offering to leading banks
in the London interbank market of U.S. dollar deposits in immediately  available
funds,  for a period,  and in an  amount,  comparable  to such  Interest  Period
(hereinafter   defined)  and  principal  amount  of  the  Loan  which  shall  be
outstanding during such Interest Period.

"Interest  Period"  means each period  during which the Interest Rate is a LIBOR
Rate,  commencing on the date the Loan bears such LIBOR Rate based Interest Rate
and ending, as Borrower has elected,  on the 30th, 60th, or 90th day thereafter,
providing that no Interest Period shall extend beyond the Maturity Date.








"LIBOR Loan" means this Loan when the interest  rate  therefor is  determined on
the basis of a LIBOR Rate.

"Prime  Rate  shall  mean  that rate set forth in  Federal  Reserve  Publication
H15(519) under the heading "Prime  Interest  Rate". If such rate does not appear
in the Federal Reserve Publication  H15(519) the rate shall be the Prime Rate as
published in the "Money Rates" column of the Wall Street Journal. Each change in
the Interest Rate shall take effect simultaneously with the corresponding change
in the Prime Rate. The Prime Rate may not be the lowest rate of interest charged
by the Bank for commercial or other extensions of credit.

"Prime Rate Loan" means this Loan when the interest  rate therefor is determined
on the basis of the Prime Rate.

The term "Business Day" means any day other than (i) Saturday or Sunday; or (ii)
a day on which commercial banks in New York are authorized to close.

In the event  Borrower  elects a LIBOR Rate based  Interest Rate for an Interest
Period,  Borrower  shall select an Interest  Period of a duration in  accordance
with the definition of Interest Period above,  except that if an Interest Period
would end on a day which is not a Business Day,  such  Interest  Period shall be
extended to the next  Business  Day,  unless such Business Day would fall in the
next  calender  month,  in which  event such  Interest  Period  shall end on the
immediately  preceding  Business Day. Any Interest  Period which would otherwise
extend beyond the Maturity Date shall end on the Maturity Date.

Upon the  expiration of an Interest  Period  bearing a LIBOR Rate based Interest
Rate,  the Loan shall be  automatically  converted to a "Prime Rate Loan" unless
Borrower  shall have  notified the Bank of its  intention to continue such LIBOR
Rate or elect a different LIBOR Rate at least two (2) Business days prior to the
end of the Interest  Period and subject to the following  conditions  and to the
terms and conditions of this Note:

               (i) the Interest Rate on the Loan may not be converted to a LIBOR
Rate less than one month before the Maturity Date;

               (ii) the Loan may be  converted  to a Prime Rate Loan only on the
last day of an Interest Period;

               (iii) if the Loan is a Prime Rate Loan, the Loan may be converted
to a LIBOR Loan only upon at least two (2)  Business  Day's prior  notice to the
Bank;

               (iv) the Loan may not be  converted  to a LIBOR  Loan  during the
occurrence and continuance of an Event of Default; and






               (v) the Interest  Period  selected shall apply to the entire Loan
balance for such Interest Period.

        In the event that the LIBOR Rate quoted by the Bank,  its  successors or
assigns, is no longer available,  the Interest Rate shall automatically  convert
to the Prime Rate minus one hundred sixty (160) Basis Points.

The LIBOR Rate may not be the lowest  rate of  interest  charged by the Bank for
commercial or other  extensions of credit.  Each change in the applicable  LIBOR
Rate shall effect a simultaneous and  corresponding  change in the interest rate
hereunder  without  notice to the  Borrower.  Interest  shall be calculated on a
three hundred sixty (360) day year and actual number of days elapsed.

Principal  repayment  shall begin on December 1, 1999 when Borrower  shall begin
making equal consecutive  monthly  installments of principal,  each in an amount
sufficient to fully amortize the  outstanding  principal  balance hereof over an
one hundred fifty-nine (159) month period, plus accrued interest at the Interest
Rate.  On February 1, 2008 (the  "Maturity  Date") (or such  earlier date in the
event Borrower defaults hereunder),  the entire unpaid principal balance of this
Note and all accrued but unpaid  interest and any other sums due hereunder shall
be due and payable.

Each installment payment shall be applied first to interest at the Interest Rate
with the  balance,  if any,  applied to  principal.  If any monthly  installment
payment is  insufficient  to pay the interest due at the Interest Rate,  KeyBank
will  notify the  Borrower  of the  amount of  additional  interest  due and the
Borrower  will remit said sum to KeyBank or KeyBank shall offset such amount (as
hereinafter provided) within five (5) business days.

PREPAYMENT: The Loan may be prepaid in whole or in part in multiples of at least
$100,000 on the first of each month  following not less than ten (10) days prior
written notice,  provided  Borrower is not then in default beyond any applicable
cure period.

Partial  prepayment shall be credited in inverse order of maturity.  Prepayments
of  borrowings  covered  by an  interest  rate  swap  agreement  or  other  rate
protection  mechanism may require termination or adjustment of the swap and will
be subject to the terms and  conditions  of the swap  agreement  with respect to
prepayment/termination.

DEFAULT  INTEREST  RATE:  After  maturity  hereof  (whether by  acceleration  or
otherwise) the principal  amount hereof and the unpaid interest and fees thereon
shall  bear  interest  at a rate per annum  equal to the  greater  of three (3%)
percent in excess of the highest applicable interest rate provided for herein or
sixteen (16%) percent per annum, but in no event shall the rate either be for or
after the occurrence of any event of default or acceleration  exceed the highest
rate of interest, if any, permitted under applicable New York or Federal Law.






RIGHT OF OFFSET: If any payment is not made when due inclusive of any applicable
grace period,  or if the entire balance becomes due and payable and is not paid,
all or part of the amount due may be offset out of any account or other property
which the  Borrower has at the Bank or any  affiliate of the Bank without  prior
notice or demand.

LATE CHARGES:  The Borrower shall pay to the Bank,  prior to maturity,  for each
payment of  principal  and  interest not paid in full within ten (10) days after
its due date, a late fee equal to the greater of five (5%) percent of the amount
of such payment or fifty ($50) dollars,  but not more than one thousand ($1,000)
dollars.

SECURITY:  This Note is secured by:

        (1) a security  interest  in and  assignment  and pledge of all  monies,
deposits,  or  other  sums now or  hereafter  held by the  Bank on  deposit,  in
safekeeping,  transit or otherwise,  at any time credited by or due from Bank to
the Borrower, or in which the Borrower shall have an interest; and

        (2) a third mortgage on property  located at 89 Arkay Drive,  Hauppauge,
New York 11788 and known on the Suffolk  County Tax Map as District 0800 Section
181.00 Block 03.00 Lot 002.013 (the "Mortgage"); and

        (3) an  Assignment of All Leases and Rents from the premises that is the
subject of the Mortgage.

DEFAULT:  The Bank may declare the entire  unpaid  balance of this Note due and
payable on the happening of any of the following events ("Events of Default"):

               (a) Failure to pay any amount  required by this Note when due and
Borrower  fails to cure  such  default  within  five (5)  business  days or,  if
applicable, failure to have sufficient funds in its account for loan payments to
be debited on the due date and Borrower  fails to cure such default  within five
(5) business days;

               (b) Failure to perform or keep or abide by any term,  covenant or
condition  contained  in this  Note,  the  Mortgage,  or any other  document  or
instrument  given to the Bank in connection  with this loan  (collectively,  the
"Loan Documents") within any applicable cure period;

               (c) The filing of a  bankruptcy  proceeding,  assignment  for the
benefit of creditors,  issuance of any execution,  garnishment, or levy against,
or the commencement of any proceeding for relief from indebtedness by or against
the Borrower;

               (d) The  happening  of any event  which,  in the  judgment of the
Bank,  materially adversely affects the Borrower's ability to repay or the value
of any collateral;






               (e) If any material written  representation  or statement made to
the Bank by the Borrower is untrue;

               (f) If any material written representation,  covenant or warranty
made to the Bank by the Borrower is breached;

               (g) The occurrence of a default under the Mortgage,  or any other
document  or  instrument  given to the Bank in  connection  with  this  loan and
Borrower fails to cure such default within any applicable cure period;

               (h) Failure to provide any  reasonable  financial  information on
request upon  reasonable  notice or permit an  examination  of books and records
upon reasonable notice.

        Notwithstanding  the  foregoing,  the balance of this Note shall  become
immediately  due and payable upon the  occurrence of any of the events set forth
in (c) above.

ATTORNEYS  FEES:  In  the  event  the  Bank  retains  counsel  with  respect  to
enforcement of this Note or any other  document or instrument  given to the Bank
by  reason  of  Borrower's  default,  the  Borrower  agrees  to pay  the  Bank's
reasonable  attorneys fees (whether or not an action is commenced and whether or
not in the court of original jurisdiction, appellate court, bankruptcy court, or
otherwise).

SUBSEQUENT  AGREEMENTS:  The Borrower shall be bound by any agreement  extending
the  time or  modifying  the  above  terms of  payment  made by the Bank and any
owner(s) of the  property  covered by the mortgage  referred to herein,  without
notice to the Borrower,  and the Borrower shall continue to be liable to pay all
amounts due hereunder,  but at an interest rate not exceeding the rate set forth
herein,   according  to  the  terms  of  any  such  agreement  of  extension  or
modification.

MISCELLANEOUS:  Delay or failure of the Bank to exercise any of its rights under
this Note shall not be deemed a waiver  thereof.  No waiver of any  condition or
requirement  shall operate as a waiver of any other or  subsequent  condition or
requirement.  The Bank or any other holder of this Note does not have to present
it before  requiring  payment.  The Borrower waives trial by jury,  offset,  and
counterclaim with respect to any action arising out of or relating to this Note.
This Note may not be modified or terminated orally.  This Note shall be governed
by the laws of the State of New York  without  regard to its  conflicts  of laws
rules.  The Borrower  irrevocably  consents to the jurisdiction and venue of the
New York State Supreme Court, Suffolk County in any action concerning this Note.
This Note is binding upon the Borrower, its heirs, successors and assigns.






               IN WITNESS  WHEREOF,  the Borrower has signed this Note as of the
12th day of October, 1999.

                                        VICON INDUSTRIES, INC.

                                        By:___________________________
                                           John Badke, Vice President-Finance

STATE OF NEW YORK     )
                      )  SS.:
COUNTY OF SUFFOLK     )

          On  the  12th  day of  October,  1999,  before  me,  the  undersigned,
personally  appeared JOHN BADKE,  personally  known to me or proved to me on the
basis of satisfactory  evidence to be the individual whose name is subscribed to
the within  instrument and  acknowledged  to me that he executed the same in his
capacity,  and that by his signature on the instrument,  the individual,  or the
person on behalf of which the individual acted, executed the instrument.


                                                              NOTARY