EXHIBIT 10.83(A)
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                                 PROMISSORY NOTE
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$50,000                                                            JUNE 24, 2002

For  valuable  consideration,  the receipt and  sufficiency  of which are hereby
acknowledged,  the undersigned Eric Loos, a Delaware corporation  ("Promissor"),
promises to pay to the order of Eric Loos ("Promissee"),  in lawful money of the
United States of America the principal  amount of Fifty Thousand  Dollars and No
Cents ($50,000.00 U.S.),  together with interest on the amount of such principal
outstanding from time to time at the rate of twelve (12%) per annum,  calculated
on the basis of a three  hundred  sixty  (360) day year  containing  twelve (12)
months of thirty (30) days each (the "Basic Interest Rate"), at the times and in
the manner provided herein.

1.    PAYMENT OF PRINCIPAL  AND  INTEREST.  Principal  and  interest  shall be
paid as follows:

      A. The principal, and all interest, fees, charges, and other amounts owing
hereunder  and then  unpaid  shall be due and  payable on January  24, 2003 (the
"Maturity Date").

      B.  Promissor  shall pay all amounts owing under this Note in  immediately
available funds to Promissee at Promissee's  address as set forth herein,  or at
such other place as may be specified in writing by Promissee. Each payment, when
made,  shall be credited  first to interest  then due, and then at the option of
Promissee to principal,  late charges,  and other fees and expenses  outstanding
hereunder in such order as Promissee may determine. Payments received after 1:00
p.m. on any banking day or at any time on any Saturday, Sunday, or holiday shall
be deemed received on the next banking day.

2.  COLLATERAL AS SECURITY.  This Note is secured by certain  collateral,  which
encumbers,  among  other  things,  the  interest of in certain  assets,  as more
particularly described therein (the "Collateral").  This Note and the Collateral
Pledge  Agreement of even date herewith,  between  Promissee and Pledgor(s),  of
even date herewith,  and any other documents or instruments given or to be given
to Promissee to secure the indebtedness  evidenced by this Note are collectively
referred to herein as the "Loan  Documents".  The Company under no circumstances
will cancel the stock  being held as  Collateral  unless  required to do so by a
state or federal regulatory body.

3.  INTEREST RATE UPON DEFAULT.  Should  Promissor  fail to pay any amount owing
hereunder as and when due,  whether the same is due regularly as scheduled or by
reason of  acceleration  following  default or otherwise,  then  interest  shall
accrue on the past due amount at the Basic Interest Rate. Such interest shall be
due and  payable  upon the  earlier  of demand or the first day of the  calendar
month following the month in which the same shall have accrued.

4.    DEFAULT;  REMEDIES.  Each of the following  occurrences  and  conditions
shall constitute an Event of Default:

      a.  failure  of  Promissor  to pay as and  when  due  any  money,  whether
principal,  interest, or otherwise, under this Note, or the breach or default of
any obligation to pay money under or secured by the Stock Pledge Agreement; or

      b. failure of Promissor to perform any obligation other than an obligation
to pay money, as and when  performance of such obligation is due under this Note
or Loan  Documents  which  failure  continues for fifteen (15) days after notice
thereof from Promissee to Promissor; or

      c.  failure by  Promissor  to comply  with any of the  terms,  provisions,
covenants,  conditions or restrictions now or hereafter affecting the Collateral
or any part thereof or contained in any  agreement  related or pertaining to the
Collateral,  which failure  continues for fifteen (15) days after notice thereof
from Promissee to Promissor; or


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      d.  Promissor's  making  or at any time  having  made any  representation,
warranty  or  disclosure  to  Promissee  that  is or  was  materially  false  or
misleading on the date as of which made,  whether or not that  representation or
disclosure appears in the Loan Documents; or

      e. the sale, transfer,  conveyance,  or lease of all or any portion of the
Collateral  or of  any  of  Promissor's  rights  therein,  whether  voluntarily,
involuntarily, or otherwise, or Promissor's entering into an agreement to do any
of the foregoing, in each case except as expressly permitted in the Stock Pledge
Agreement; or

At any time following the  occurrence of any Event of Default,  or following the
occurrence  of any event as a  consequence  of which the  obligations  evidenced
hereby may be accelerated, then at the election of Promissee and notwithstanding
anything to the contrary  herein or  elsewhere,  the entire  amount of principal
then  outstanding  under this Note and all interest,  fees,  charges,  and other
amounts  owing  and then  unpaid  hereunder  shall  become  immediately  due and
payable,  and  Promissee  may exercise any and all rights that it may have under
the Loan Documents,  at law, in equity, and otherwise. In the event of a default
on the Promissory  Note where (a) the stock is sold pursuant to the Stock Pledge
Agreements by MRC and Valdetaro and (b) the proceeds of these sales of stock are
is  insufficient  to cover the  principle and any interest then owed pursuant to
the Note,  Vertical  acknowledges and agrees that it will be liable for any then
outstanding amounts.

5. ATTORNEYS'  FEES.  Promissor shall pay to Promissee upon demand all costs and
expenses incurred by Promissee in connection with determination,  protection, or
enforcement of any and all of Promissee's  rights  hereunder or under any of the
Loan  Documents,  including  enforcement of any and all obligations of Promissor
hereunder and  thereunder  and  protection,  enhancement,  or maintenance of the
security  interests  securing such obligations or the priority of the same. Such
costs and expenses shall be payable  whether or not any suit is instituted,  and
the same shall include without limitation  attorneys' fees, expert witness fees,
costs of  investigation,  and all of such costs incurred in connection  with any
trial, appellate proceeding,  or any case or proceeding under Chapters 7, 11, or
13 of the Bankruptcy Code or any successor thereto.

6. WAIVER OF NOTICE.  Promissor and each endorser,  guarantor and surety of this
Note  hereby  waive  diligence,  demand,  presentment  for  payment,  notice  of
discharge, notice of nonpayment, protest and notice of protest, and specifically
consent to and waive notice of any renewals or extensions of this Note,  whether
made to or in favor of Promissor or any other person or persons.  Promissor  and
each endorser,  guarantor and surety of this Note further waive and renounce all
rights  to the  benefits  of all  statutes  of  limitation  and any  moratorium,
appraisement,  by any federal exception and homestead now or hereafter  provided
or state law or statute,  including but not limited to exemptions provided by or
allowed under the Bankruptcy Code, both as to each of themselves  personally and
as to all of their property,  whether real or personal,  against the enforcement
and  collection  of the  obligations  evidenced  by  this  Note  and any and all
extensions, renewals and modifications thereof.

7. NOTICES.  All notices  required  hereunder or  pertaining  hereto shall be in
writing  and shall be deemed  delivered  and  effective  upon the earlier of (i)
actual  receipt,  or (ii) the date of  delivery or refusal of the  addressee  to
accept  delivery  if such  notice is sent by express  courier  service or United
States mail, postage prepaid, certified or registered, return receipt requested,
in either case to the applicable address as follows:

To Promissee:     Eric Loos
                  40 Bridgegate Drive
                  San Rafael, CA  94903-1091


To Promissor:     Vertical Computer Systems, Inc.
                  6336 Wilshire Boulevard
                  Los Angeles, CA 90048
                  Attn: President

Notwithstanding  the  foregoing,  any  notice  under or  pertaining  to the Loan
Documents or the  obligations  secured thereby given and effective in accordance
with  applicable  law shall be effective for purposes  hereof.  Either party may
change  the  address  at which it is to  receive  notices  hereunder  to another



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business  address within the United States (but not a post office box or similar
mail  receptacle)  by giving  notice of such  change of  address  in  accordance
herewith.

9. EXERCISE OF RIGHTS. No single or partial exercise of any of Lenders rights or
powers  under this Note or any of the other Loan  Documents  shall  preclude any
other or further  exercise  thereof or the exercise of any other right or power.
Promissee  at all times  shall have the right to proceed  against any portion of
the security which secures payment of the indebtedness  evidenced hereby in such
order and manner as Promissee may elect without  waiving any rights with respect
to any other  portion of such  security.  Each and all rights  and  remedies  of
Promissee  hereunder and under the Loan Documents are cumulative and in addition
to each and all other such  rights and  remedies.  No  exercise  of any right or
remedy shall preclude exercise of any other right or remedy.

10. NO WAIVER. No failure of Promissee to insist upon strict  performance of any
obligation  of Promissor  or to exercise any right or remedy  hereunder or under
the Loan  Documents,  whether before or after any default,  shall  constitute or
give rise to a waiver thereof,  and no waiver of any default shall  constitute a
waiver of any future default or of any other  default.  No failure to accelerate
the debt evidenced  hereby by reason of default  hereunder or otherwise,  and no
acceptance  of any past due payment  hereunder or  acceptance of any amount less
than the  amount  then  due,  and no other  indulgence  that may be  granted  by
Promissee  from time to time shall (a)  preclude  the exercise of any right that
Promissee may have at law, in equity, by contract or agreement or otherwise,  or
(b) constitute or give rise to (i) a waiver of such right of acceleration or any
other  right,  or (ii) a novation  of this Note or a  reinstatement  of the debt
evidenced  hereby,  or (iii) any  waiver  of  Promissee's  rights to demand  and
receive from Promissor full and prompt payment and  performance  thereafter,  to
impose late charges retroactively,  or to declare a default.  Promissor and each
endorser,  guarantor, and surety of this Note hereby expressly waive the benefit
of any statute or rule of law or equity which would produce any result  contrary
to or otherwise in conflict with any of the foregoing.

11.  ASSIGNMENT;  SUCCESSORS  AND  ASSIGNS.  Promissee  may assign or  otherwise
transfer  all or any part of its interest  herein.  Promptly  following  written
notice  of such  assignment  or other  transfer,  duly  executed  by  Promissee,
Promissor shall render full and complete  performance  hereunder as and when due
to the  transferee so designated  by  Promissee.  Promissor  shall not assign or
transfer all or any of its interests or obligations hereunder, and any attempted
or purported  assignment or transfer by Promissor  shall be void and of no force
or effect,  except to the extent that the same may be expressly  permitted under
the Stock Pledge  Agreements.  Subject to the foregoing,  the terms of this Note
shall apply to, be binding upon,  and inure to the benefit of ail parties hereto
and their successors and assigns.

12.   MODIFICATION.  This Note shall not be modified,  amended, or terminated,
except by written  agreement duly executed and delivered by both Promissee and
Promissor.

13.  CONFLICTS.  In the event of any conflict between any provision of this Note
and  any  provision  of the  Stock  Pledge  Agreements,  which  conflict  cannot
reasonably be resolved in such a way as to give effect to all provisions  herein
and therein contained, this Note shall govern.

14. SEVERABILITY.  If any provision of this Note or any payments pursuant to the
terms hereof shall be invalid or unenforceable  to any extent,  the remainder of
this Note and any other  payments  hereunder  shall not be affected  thereby and
shall be enforceable to the greatest extent permitted by law.

15.   GOVERNING  Law.  This  Note  shall  be  governed  by  and  construed  in
accordance with the laws of the State of California.

      IN WITNESS  WHEREOF,  Promissor has executed and delivered this Note as of
the date first written above.

                                    VERTICAL COMPUTER SYSTEMS, INC.

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                                          By
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                                                Richard Wade, President



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