SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549
                               ------------------


                                 SCHEDULE 13D/A



                    Under the Securities Exchange Act of 1934

                                Amendment No. 11

                        Integrated Security Systems, Inc.
 ------------------------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
 ------------------------------------------------------------------------------
                         (Title of Class of Securities)

                                    45812J101
 ------------------------------------------------------------------------------
                                 (CUSIP Number)

                                Russell Cleveland
                         Renaissance Capital Group, Inc.
                  8080 N. Central Expressway, Suite 210, LB-59
                            Dallas, Texas 75206-1857
                                 (214) 891-8294
 ------------------------------------------------------------------------------
                 (Name, Address, and Telephone Number of Person
                Authorized to Receive Notices and Communications)

                  August 28, September 5, and September 11 2002
 ------------------------------------------------------------------------------
             (Date of Event Which Requires Filing of This Statement)

If the filing person has previously  filed a statement on Schedule 13G to report
the  acquisition  which is the subject of this  Schedule 13D, and is filing this
schedule because of Rule 13d-1(e),  13d-1(f),  or 13d-1(g),  check the following
box [ ].


                         (Continued on following pages)







CUSIP No. 45812J101                    13D
------------------------------------------------------------------------------
1.      NAME OF REPORTING PERSON                   I.R.S. IDENTIFICATION NUMBER
        Renaissance Capital Growth & Income Fund III, Inc.           75-2533518
------------------------------------------------------------------------------
2.      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
         (a)      [ ]
         (b)      [x]
------------------------------------------------------------------------------
3.      SEC USE ONLY
------------------------------------------------------------------------------
4.      SOURCE OF FUNDS
        WC
------------------------------------------------------------------------------
5.      CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEM 2(d) OR 2(e)[  ]
------------------------------------------------------------------------------
6.      CITIZENSHIP OR PLACE OF ORGANIZATION
        Texas
------------------------------------------------------------------------------
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:
------------------------------------------------------------------------------
        7.      SOLE VOTING POWER
                24,164,973
------------------------------------------------------------------------------
        8.      SHARED VOTING POWER
                None
      ------------------------------------------------------------------------
        9.      SOLE DISPOSITIVE POWER
                24,164,973
      ------------------------------------------------------------------------
       10.      SHARED DISPOSITIVE POWER
                None
------------------------------------------------------------------------------
11.     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                24,164,973
------------------------------------------------------------------------------
12.     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
        SHARES            [  ]
------------------------------------------------------------------------------
13.     PERCENT OF CLASS REPRESENTED BY AMOUNT IN  ROW (11)
                68.34%
------------------------------------------------------------------------------
14.     TYPE OF REPORTING PERSON
                IV






CUSIP No. 45812J101                       13D
------------------------------------------------------------------------------
1.      NAME OF REPORTING PERSON                   I.R.S. IDENTIFICATION NUMBER
        Renaissance US Growth Investment Trust PLC               None - Foreign
        formerly known as Renaissance US Growth and Income Trust PLC
 ------------------------------------------------------------------------------
2.      CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP
        (a)      [ ]
        (b)      [x]
------------------------------------------------------------------------------
3.      SEC USE ONLY
------------------------------------------------------------------------------
4.      SOURCE OF FUNDS
        WC
------------------------------------------------------------------------------
5.      CHECK BOX IF DISCLOSURE OF LEGAL PROCEEDINGS IS REQUIRED PURSUANT
        TO ITEM 2(d) OR 2(e)  [  ]
------------------------------------------------------------------------------
6.      CITIZENSHIP OR PLACE OF ORGANIZATION
        England
------------------------------------------------------------------------------
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:
------------------------------------------------------------------------------
        7.       SOLE VOTING POWER
                 23,328,661
        -----------------------------------------------------------------------
        8.       SHARED VOTING POWER
                 None
        -----------------------------------------------------------------------
        9.       SOLE DISPOSITIVE POWER
                 23,328,661
        -----------------------------------------------------------------------
        10.      SHARED DISPOSITIVE POWER
                 None
------------------------------------------------------------------------------
11.     AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                 23,328,661
------------------------------------------------------------------------------
12.     CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
        SHARES    [  ]
------------------------------------------------------------------------------
13.     PERCENT OF CLASS REPRESENTED BY AMOUNT IN  ROW (11)
                 67.57%
------------------------------------------------------------------------------
14.     TYPE OF REPORTING PERSON
                 IV






Item 1. Security and Issuer.

     This statement  relates to the Common Stock ("Common Shares") of Integrated
Security Systems,  Inc. (the "Company").  The principal executive offices of the
Company are located at 8200 Springwood Drive, Irving, Texas 75063.

Item 2. Identity and Background.

     (a) This  Statement is filed by  Renaissance  Capital  Growth & Income Fund
III, Inc.  ("Renaissance  III"), and Renaissance US Growth  Investment Trust PLC
(formerly  called  Renaissance  US Growth  and Income  Trust PLC)  ("Renaissance
PLC");  Renaissance  III  and  Renaissance  PLC,  collectively  (the  "Reporting
Persons").

     Certain information  concerning the directors and executive officers of the
Reporting  Persons is set forth on Attachment 1 attached hereto and incorporated
herein by reference.

     (b) Renaissance III is a business  development  company regulated under the
Investment Company Act of 1940, as amended,  and organized under the laws of the
State of Texas,  with its  principal  business and  principal  office at 8080 N.
Central Expressway, Suite 210, LB-59, Dallas, Texas 75206-1857.

     Renaissance PLC is an investment  trust organized under the laws of England
and Wales.  Its address in the United States is c/o  Renaissance  Capital Group,
Inc., Investment Manager, 8080 N. Central Expressway,  Suite 210, LB-59, Dallas,
Texas 75206-1857.

     The  business  addresses of the  directors  and  executive  officers of the
Reporting  Persons  are  set  forth  on  Attachment  1  to  this  Statement  and
incorporated herein by reference.

     (c)  Renaissance  III and  Renaissance  PLC are engaged in the  business of
investing principally in emerging or undervalued U.S. public companies.

     (d) Neither any of the Reporting Persons nor, to the best knowledge of such
persons, any person named in Attachment 1 to this Statement,  has been convicted
in a criminal proceeding in the past five years (excluding traffic violations or
similar misdemeanors).

     (e) Neither any of the Reporting Persons nor, to the best knowledge of such
persons, any person named in Attachment 1 to this Statement, was during the last
five years a party to a civil proceeding of a judicial or administrative body of
competent  jurisdiction  as a result of which such person was or is subject to a
judgment,  decree, or final order enjoining future violations of, or prohibiting
or mandating  activities subject to, federal or state securities laws or finding
any violation with respect to such laws.

     (f) All persons named on Attachment 1 to this Statement are citizens of the
United  States  or the  United  Kingdom,  unless  otherwise  indicated  on  such
Attachment.

Item 3. Source and Amount of Funds or Other Consideration.


     The total  amount of funds  required  by  Renaissance  III to  acquire  the
securities  reported in Item 5(a) was  $4,930,769.  The source of such funds was
capital of Renaissance III.

     The total  amount of funds  required  by  Renaissance  PLC to  acquire  the
securities  reported in Item 5(a) was  $4,764,643.  The source of such funds was
capital of Renaissance PLC.



Item 4. Purpose of Transaction.

     The  Reporting  Persons each  acquired  beneficial  ownership of the Common
Stock  reported  in Item  5(a)  both in the  ordinary  course  of  business  for
investment  purposes and upon exchange of  indebtedness  in connection  with the
financial  restructuring  of the Company.  The President and CEO of  Renaissance
Capital  Group,  Inc.,  the  investment  advisor  to  Renaissance  III  and  the
investment manager of Renaissance PLC, Russell Cleveland,  has been appointed to
the board of directors of the Company.

     The Reporting  Persons may  participate in discussions  with  management or
third parties in which the Reporting  Person may suggest or take a position with
respect to potential changes in the operations, management, or capital structure
of such companies as a means of enhancing shareholder value. Such suggestions or
positions may relate to one or more of the transactions specified in clauses (a)
through (j) of Item 4 of the Schedule 13D form,  including,  without limitation,
such  matters as  disposing  of one or more  businesses,  selling  the  Company,
merging with another Company or acquiring another company or business,  changing
operating  or marketing  strategies,  changes in  management  or  marketing,  or
restructuring the Company's capitalization.

     Each Reporting Person continues to assess the Company's business, financial
condition, results of operations and prospects, general economic conditions, the
securities  markets  in  general  and  those  for the  Company's  securities  in
particular,  other developments and other investment  opportunities,  as well as
the Reporting Person's investment objectives. Depending on such assessments, one
or both of the  Reporting  Persons  may  acquire  additional  securities  or may
determine  to sell  or  otherwise  dispose  of  some  or all of its  holding  of
securities.

     Other than as described  above,  neither of the  Reporting  Persons has any
present plans or proposals  which relate to or would result in any  transaction,
change,  or event specified in clauses (a) through (j) of Item 4 of the Schedule
13D.

Item 5. Interest in Securities of the Issuer.

     (a)  Renaissance  III  beneficially  owns  24,164,973  Common  Shares,  and
Renaissance  PLC  beneficially  owns  23,328,661  Common  Shares.  The Reporting
Persons  beneficially  own 47,493,634  Common Shares.  Based upon the 11,684,763
shares of the Company's  stock  outstanding  as of April 30, 2002, as filed with
the Securities and Exchange Commission in the Company's most recent Form 10-Q SB
and using  SEC  computation  rules,  the  Common  Shares  beneficially  owned by
Renaissance III, Renaissance PLC, and together represent  approximately  68.34%,
67.57%,  and  80.26%,  respectively,  of the  outstanding  Common  Stock  of the
Company. Renaissance III and Renaissance PLC disclaim that they are members of a
group for purposes of Regulation 13D.

     The Common Shares  beneficially  owned by Renaissance  III are comprised of
393,259  shares of Common  Stock;  95,215  shares of Common  Stock  received  as
payment in kind for interest and/or dividends;  2,439,299 shares of Common Stock
issuable upon the exercise of warrants;  187,500 shares of Common Stock issuable
upon the  conversion  of 7,500  shares of Series D  Preferred  Stock;  2,714,945
shares of Common Stock  issuable  upon  conversion  of 21,720 shares of Series F
Convertible  Preferred Stock ("Series F Preferred Stock"); and 18,334,755 shares
of  Common  Stock  issuable  upon  conversion  of  146,678  shares  of  Series G
Convertible Preferred Stock ("Series G Preferred Stock"). The board of directors
of Renaissance III exercises  voting and investment  control over the securities
of the Company owned by it.



     Renaissance PLC is deemed the beneficial  owner of Common Shares  comprised
of 393,259  shares of Common Stock;  95,215  shares of Common Stock  received as
payment in kind for interest and/or dividends;  2,433,617 shares of Common Stock
issuable upon the exercise of warrants;  187,500 shares of Common Stock issuable
upon the  conversion  of 7,500  shares of Series D  Preferred  Stock;  2,714,945
shares of Common Stock  issuable  upon  conversion  of 21,720 shares of Series F
Preferred Stock; and 17,504,125  shares of Common Stock issuable upon conversion
of  140,033  shares of Series G  Preferred  Stock.  The  board of  directors  of
Renaissance PLC exercises  voting and investment  control over the securities of
the Company owned by it.

     (b) Number of shares as to which Renaissance III has:
         (i)    Sole power to vote or to direct the vote
                24,164,973
         (ii)   Shared power to vote or to direct the vote
                None
         (iii)  Sole power to dispose or to direct the disposition of
                24,164,973
         (iv)   Shared power to dispose or to direct the disposition of
                None

         Number of shares as to which Renaissance PLC has:
         (i)    Sole power to vote or to direct the vote
                23,328,661
         (ii)   Shared power to vote or to direct the vote
                None
         (iii)  Sole power to dispose or to direct the disposition of
                23,328,661
         (iv)   Shared power to dispose or to direct the disposition of
                None

     (c) No transaction in the Common Shares was effected by a Reporting  Person
since the last filing, except as follows: (a) the receipt on August 27, 2002, by
each  Renaissance  III and  Renaissance  PLC of 6,318  shares of common Stock as
payment in kind of  $1,698.62  in  interest  due on  promissory  notes;  (b) the
receipt on September 5, 2002, by each  Renaissance  III and  Renaissance  PLC of
Warrants  to  purchase  375,000  shares  of  common  stock of the  Company  (the
"Renaissance III Warrant") and the (Renaissance PLC Warrant") in connection with
the purchase of a $75,000 one-year,  8% promissory note. The Renaissance III and
Renaissance PLC Warrants are attached hereto as Exhibits 2 and 3,  respectively;
and  (c) the  receipt  on  September  11,  2002,  by  each  Renaissance  III and
Renaissance PLC of 6,781 shares of the Company's common stock as payment in kind
for interest of $1,630.82 due on promissory notes.

     (d) No person other than the Reporting  Persons has the right to receive or
the power to direct the receipt of dividends from, or the proceeds from the sale
of, the Common Shares beneficially owned by the Reporting Persons.

     (e) Not applicable.

Item 6. Contracts,  Arrangements,  Understandings, or Relationships With Respect
        to Securities of the Issuer.

        Not Applicable.

Item 7. Material to be Filed as Exhibits.

     Exhibit 1   Joint Filing Agreement Pursuant to Rule 13d-1(k)

                            [Signature page follows]




                                   SIGNATURES

     After reasonable inquire and to the best of their individual  knowledge and
belief,  the  signatories  below certify that the  information set forth in this
statement is true, complete, and correct as of this 11th day of September, 2002.

     The persons  whose  signatures  appear  below agree that this  statement on
Schedule 13D is filed on behalf of each of them.

                           RENAISSANCE CAPITAL GROWTH & INCOME FUND III, INC.



                           By:      /S/__________________________
                         Name:      Russell Cleveland
                        Title:      President and Chief Executive Officer


                           RENAISSANCE US GROWTH & INCOME TRUST PLC




                           By:      /S/____________________________
                         Name:      Russell Cleveland
                        Title:      Director






                                  ATTACHMENT 1

     The name, business address,  and principal  occupation of the directors and
executive officers of Renaissance III are as follows:

DIRECTORS
                                                                      Principal
Name                      Business Address                           Occupation

Edward O. Boshell, Jr.    c/o Renaissance Capital Group, Inc.        Director
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
Russell Cleveland         c/o Renaissance Capital Group, Inc.        Director
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
Peter Collins             c/o Renaissance Capital Group, Inc.        Director
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
Ernest C. Hill            c/o Renaissance Capital Group, Inc.        Director
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
OFFICERS

Russell Cleveland         c/o Renaissance Capital Group, Inc.    President and
                          8080 North Central Expressway          Chief Executive
                          Suite 210, LB-59                       Officer
                          Dallas, TX 75206-1857
John A. Schmit            c/o Renaissance Capital Group, Inc.    Vice President
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
Robert C. Pearson         c/o Renaissance Capital Group, Inc.    Vice President
                          8080 North Central Expressway
                          Suite 210, LB-59
                          Dallas, TX 75206-1857
Barbara A. Butschek       c/o Renaissance Capital Group, Inc.    Secretary and
                          8080 North Central Expressway          Treasurer
                          Suite 210, LB-59
                          Dallas, TX 75206-1857







     The name, business address, and principal occupation of the directors and
executive officers of Renaissance PLC are as follows:

DIRECTORS
                                                                      Principal
Name                            Business Address                     Occupation

Michael B. Cannan               c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB
Russell Cleveland               c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB
Ernest J. Fenton                c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB
Lord Mark Fitzalan Howard OBE   c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB
C. A. Rundell, Jr.              c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB
William W. Vanderfelt           c/o Sinclair Henderson Limited       Director
                                23 Cathedral Yard
                                  Exeter EX11HB

OFFICERS

None








                                                                       EXHIBIT 1

                JOINT FILING AGREEMENT PURSUANT TO RULE 13d-1(k)

     The  undersigned  acknowledge  and agree that the  foregoing  statement  on
Schedule 13D is filed on behalf of each of the  undersigned and that all of each
of the  undersigned  without the  necessity  of filing  additional  joint filing
agreements.  The undersigned  acknowledge that each shall be responsible for the
timely filing of such  amendments,  and for the completeness and accuracy of the
information  concerning it contained  therein,  but shall not be responsible for
the completeness and accuracy of the information  concerning the others,  except
to the  extent  it knows or has  reason to  believe  that  such  information  is
inaccurate.  This  Joint  Filing  Agreement  may be  executed  in any  number of
counterparts  and all of such  counterparts  taken together shall constitute one
and the same instrument.

                              RENAISSANCE CAPITAL GROWTH & INCOME FUND III, INC.




                               By:     /S/___________________________
                             Name: Russell Cleveland
                            Title:     President and Chief Executive Officer


                               RENAISSANCE US GROWTH & INCOME TRUST PLC




                               By:     /S/____________________________
                             Name: Russell Cleveland
                                 Title: Director






                                                                       EXHIBIT 2


THIS WARRANT AND THE SECURITIES  ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN
REGISTERED  UNDER THE SECURITIES ACT OF 1933. THEY MAY NOT BE SOLD,  OFFERED FOR
SALE,  PLEDGED,  HYPOTHECATED,  OR OTHERWISE  TRANSFERRED  EXCEPT PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, OR AN OPINION
OF COUNSEL  SATISFACTORY TO THE COMPANY THAT  REGISTRATION IS NOT REQUIRED UNDER
SUCH ACT OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SUCH ACT.


                             STOCK PURCHASE WARRANT


     This Stock Purchase Warrant (this  "Warrant"),  dated September 5, 2002, is
issued to Frost National Bank,  Custodian,  FBO  Renaissance  Capital Growth and
Income Fund III, Inc., Trust No. W00740000,  a Texas corporation (the "Holder"),
by Integrated Security Systems, Inc., a Delaware corporation (the "Company").

     1. Purchase of Shares.  Subject to the terms and conditions hereinafter set
forth,  the Holder is entitled,  upon surrender of this Warrant at the principal
office of the Company (or at such other  place as the Company  shall  notify the
holder hereof in writing),  to purchase from the Company  375,000 fully paid and
non-assessable shares of Common stock, no par value (the "Common Stock"), of the
Company  (as  adjusted  pursuant  to  Section 7 hereof,  the  "Shares")  for the
purchase price specified in Section 2 below.

     2. Purchase  Price.  The purchase  price for the Shares is $0.20 per share.
Such price shall be subject to  adjustment  pursuant  to Section 7 hereof  (such
price,  as adjusted  from time to time,  is herein  referred to as the  "Warrant
Price").

     3. Exercise Period.  This Warrant is exercisable in whole or in part at any
time from the date hereof through September 5, 2007.

     4.  Method  of  Exercise.   While  this  Warrant  remains  outstanding  and
exercisable  in accordance  with Section 3 above,  the Holder may  exercise,  in
whole or in part, the purchase rights evidenced  hereby.  Such exercise shall be
effected by:

          (a) surrender of this  Warrant,  together with a duly executed copy of
     the form of  Exercise  Notice  attached  hereto,  to the  Secretary  of the
     Company at its  principal  officer,  and the  payment to the  Company of an
     amount equal to the aggregate purchase price for the number of Shares being
     purchased; or

          (b) if the Company's  Common Stock is publicly traded as of such date,
     the instruction to retain that number of Shares having a value equal to the


                                        1





     aggregate  exercise  price of the Shares as to which this  Warrant is being
     exercised and to issue to the Holder the remainder of such Shares  computed
     using the following formula:

                        Y(A-B)
                  X = ----------
                          A

Where:  X =  the number of shares of Common Stock to be issued to the Holder.

        Y =  the number of shares of Common Stock as to which this Warrant is
             being exercised.

        A =  the fair market value of one share of Common Stock.

        B =  the Warrant Price.

          As used herein,  the "fair market value of one share of Common  Stock"
     shall mean:

               (1) Except in the  circumstances  described  in clause (2) or (3)
          hereof,  the closing price of the Company's  Common Stock, as reported
          in the WALL STREET JOURNAL,  on the trading day  immediately  prior to
          the date of exercise;

               (2)  If  such   exercise  is  in   conjunction   with  a  merger,
          acquisition,  or other consolidation  pursuant to which the Company is
          not the  surviving  entity,  the value  received by the holders of the
          Common Stock pursuant to such transaction for each share; or

               (3) If such exercise is in  conjunction  with the initial  public
          offering of the  Company,  the price at which the Common Stock is sold
          to the public in such offering.

     5.  Certificates  for  Shares.  Upon the  exercise of the  purchase  rights
evidenced by this Warrant,  one or more certificates for the number of Shares so
purchased  shall be issued as soon as practicable  thereafter,  and in any event
within thirty (30) days of the delivery of the subscription notice.

     6. Reservation of Shares.  The Company  covenants that it will at all times
keep available such number of authorized  shares of its Common Stock,  free from
all preemptive  rights with respect thereto,  which will be sufficient to permit
the exercise of this Warrant for the full number of Shares specified herein. The
Company further covenants that such Shares, when issued pursuant to the exercise
of this Warrant,  will be duly and validly issued, fully paid and non-assessable
and free from all taxes, liens and charges with respect to the issuance thereof.


                                        2





     7. Adjustment of Warrant Price and Number of Shares. The number and kind of
securities purchasable upon exercise of this Warrant and the Warrant Price shall
be subject to adjustment from time to time as follows:

          (a) Stock Dividends,  Subdivisions,  Combinations and Other Issuances.
     If the Company  shall at any time prior to the  expiration  of this Warrant
     subdivide its Common Stock, by stock split or otherwise, combine its Common
     Stock or issue  additional  shares of its Common  Stock as a dividend  with
     respect to any shares of its Common Stock, the number of Shares issuable on
     the exercise of this Warrant shall forthwith be  proportionately  increased
     in  the  case  of a  subdivision  or  stock  dividend  and  proportionately
     decreased in the case of a combination.  Appropriate adjustments shall also
     be made to the purchase price payable per share, but the aggregate purchase
     price payable for the total number of Shares purchasable under this Warrant
     (as adjusted) shall remain the same. Any adjustment under this Section 7(a)
     shall become effective at the close of business on the date the subdivision
     or combination becomes effective or as of the record date of such dividend,
     or, in the  event  that no record  date is fixed,  upon the  making of such
     dividend.

          (b) Reclassification, Reorganization, Merger, Sal or Consolidation. In
     the event of any reclassification,  capital  reorganization or other change
     in  the  Common  Stock  of  the  Company  (other  than  as  a  result  of a
     subdivision,  combination  or stock  dividend  provided  for in Section (a)
     above) or in the event of a consolidation  or merger of the Company with or
     into, or the sale of all or substantially  all of the properties and assets
     of the Company, to any person, and the connection  therewith  consideration
     is  payable  to  holders  of  Common  Stock  in cash,  securities  or other
     property,  then as a condition of such reclassification,  reorganization or
     change, consolidation,  merger or sale, lawful provision shall be made, and
     duly  executed  documents  evidencing  the same shall be  delivered  to the
     Holder,  so that the  Holder  shall have the right at any time prior to the
     expiration  of this  Warrant to  purchase,  at a total  price equal to that
     payable upon the exercise of this Warrant  immediately prior to such event,
     the kind and amount of cash,  securities  or other  property  receivable in
     connection   with  such   reclassification,   reorganization   or   change,
     consolidation,  merger or sale, by a holder of the same number of shares of
     Common Stock as were  exercisable by the Holder  immediately  prior to such
     reclassification,  reorganization or change, consolidation, merger or sale.
     In any such case,  appropriate provisions shall be made with respect to the
     rights and  interest  of the  Holder so that the  provisions  hereof  shall
     thereafter be applicable  with respect to any cash,  securities or property
     deliverable upon exercise hereof. Notwithstanding the foregoing, (i) if the
     Company merges or consolidates  with, or sells all or substantially  all of
     its property and assets to, any other person,  and consideration is payable
     to holders of Common Stock in exchange for their Common Stock in connection
     with such merger,  consolidation  or sale which consists solely of cash, or
     (ii) in the event of the  dissolution,  liquidation  or  winding  up of the
     Company,  then the Holder shall be entitled to receive distributions on the
     date of such  event on an equal  basis with  holders of Common  Stock as if
     this Warrant had been exercised  immediately  prior to such event, less the
     Warrant  Price.  Upon  receipt of such  payment,  if any, the rights of the
     Holder shall terminate and cease, and this Warrant shall expire. In case of

                                        3





     any  such  merger,  consolidation  or  sale of  assets,  the  surviving  or
     acquiring  person  and,  in the event of any  dissolution,  liquidation  or
     winding up of the Company,  the Company  shall  promptly,  after receipt of
     this surrendered Warrant, make payment by delivering a check in such amount
     as is appropriate (or, in the case of  consideration  other than case, such
     other consideration as is appropriate) to such person as it may be directed
     in writing by the Holder surrendering this Warrant.

          (c) Certain Distributions. In case the Company shall fix a record date
     for the  making  of a  dividend  or  distribution  of cash,  securities  or
     property  to all  holders  of Common  Stock  (excluding  any  dividends  or
     distributions  referred  to in Sections  7(a) or 7(b) above,  the number of
     Shares  purchasable upon an exercise of this Warrant after such record date
     shall be adjusted to equal the product  obtained by multiplying  the number
     of Shares purchasable upon an exercise of this Warrant immediately prior to
     such record date by a fraction, the numerator of which shall be the Warrant
     Price immediately prior to such distribution,  and the denominator of which
     shall be the Warrant Price immediately prior to such distribution, less the
     fair market  value per Share,  as  determined  by the Holder,  of the cash,
     securities  or  property  so  distributed.  Such  adjustment  shall be made
     successively  whenever  any  such  distribution  is made and  shall  become
     effective on the effective date of distribution.

     8. Pre-Exercise Rights. Prior to exercise of this Warrant, the Holder shall
not be  entitled  to any rights of a  shareholder  with  respect to the  Shares,
including without limitation,  the right to vote such Shares, receive preemptive
rights or be  notified  of  shareholder  meetings,  and the Holder  shall not be
entitled to any notice or other communication concerning the business or affairs
of the Company.

     9. Restricted Securities.  The Holder understands that this Warrant and the
Shares  purchasable  hereunder  constitute  "restricted  securities"  under  the
federal  securities  laws inasmuch as they are being,  or will be, acquired from
the Company in transactions  not involving a public offering and accordingly may
not,  under  such laws and  applicable  regulations,  be  resold or  transferred
without  registration  under  the  Securities  Act of 1933,  as  amended,  or an
applicable  exemption  from  registration.   In  this  connection,   the  Holder
acknowledges that Rule 144 of the Securities and Exchange Commission is not now,
and may not in the  future be,  available  for  resales of the Shares  purchased
hereunder.  The  Holder  further  acknowledges  that the  Shares  and any  other
securities   issued  upon   exercise  of  this  Warrant   shall  bear  a  legend
substantially in the form of the legend appearing on the face hereof.

     10.  Certification  of Investment  Purpose.  Unless a current  registration
statement under the Securities Act of 1933, as amended,  shall be in effect with
respect to the securities to be issued upon exercise of this Warrant, the Holder
hereof,  by accepting  this  Warrant,  covenants and agrees that, at the time of
exercise hereof, the Holder will deliver to the Company a written  certification
that the securiti4es acquired by the Holder are acquired for investment purposes
only and that such  securities  are not acquired  with a view to, or for sale in
connection with, any distribution thereof.


                                        4





     11.  Registration  Rights.  This Warrant and the Shares shall be subject to
the  registration  rights set forth in the  Registration  Rights Agreement dated
September  27,  2001,  by and among the Holder and the  Company,  and the Holder
shall be entitled to all rights and benefits thereof.

     12. Successors and Assigns.  The terms and provisions of this Warrant shall
inure to the  benefit  of, and be binding  upon,  the Company and the Holder and
their respective successors and assigns.

     13.  Governing Law. This Warrant shall be governed by the laws of the State
of Texas, excluding the conflicts of laws provisions thereof.

                                     INTEGRATED SECURITY SYSTEMS, INC.



                             By:      ___________________________________
                                      C. A. Rundell, Jr.
                                      Chairman and Chief Executive Officer




                                        5




                                 EXERCISE NOTICE


                                                   Dated ______________, _______

     The undersigned  hereby  irrevocably  elects to exercise the Stock Purchase
Warrant,  dated September 5, 2002, issued by Itegrated Security Systems, Inc., a
Delaware  corporation  (the  "Company")  to the  undersigned  to the  extent  of
purchasing  _______________  shares of Common Stock and hereby makes  payment of
$____________ in payment of the aggregate Warrant Price of such Shares.

                                        RENAISSANCE CAPITAL GROWTH AND
                                        INCOME FUND III, INC.



                               By:      ___________________________________






                                                                       EXHIBIT 3


THIS WARRANT AND THE SECURITIES  ISSUABLE UPON THE EXERCISE HEREOF HAVE NOT BEEN
REGISTERED  UNDER THE SECURITIES ACT OF 1933. THEY MAY NOT BE SOLD,  OFFERED FOR
SALE,  PLEDGED,  HYPOTHECATED,  OR OTHERWISE  TRANSFERRED  EXCEPT PURSUANT TO AN
EFFECTIVE REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933, OR AN OPINION
OF COUNSEL  SATISFACTORY TO THE COMPANY THAT  REGISTRATION IS NOT REQUIRED UNDER
SUCH ACT OR UNLESS SOLD PURSUANT TO RULE 144 UNDER SUCH ACT.


                             STOCK PURCHASE WARRANT


     This Stock Purchase Warrant (this  "Warrant"),  dated September 5, 2002, is
issued to Frost National Bank,  Custodian,  FBO Renaissance US Growth Investment
Trust PLC, Trust No. W00740100,  a public limited company  registered in England
and Wales (the  "Holder"),  by  Integrated  Security  Systems,  Inc., a Delaware
corporation (the "Company").

     1. Purchase of Shares.  Subject to the terms and conditions hereinafter set
forth,  the Holder is entitled,  upon surrender of this Warrant at the principal
office of the Company (or at such other  place as the Company  shall  notify the
holder hereof in writing),  to purchase from the Company  375,000 fully paid and
non-assessable shares of Common stock, no par value (the "Common Stock"), of the
Company  (as  adjusted  pursuant  to  Section 7 hereof,  the  "Shares")  for the
purchase price specified in Section 2 below.

     2. Purchase  Price.  The purchase  price for the Shares is $0.20 per share.
Such price shall be subject to  adjustment  pursuant  to Section 7 hereof  (such
price,  as adjusted  from time to time,  is herein  referred to as the  "Warrant
Price").

     3. Exercise Period.  This Warrant is exercisable in whole or in part at any
time from the date hereof through September 5, 2007.

     4.  Method  of  Exercise.   While  this  Warrant  remains  outstanding  and
exercisable  in accordance  with Section 3 above,  the Holder may  exercise,  in
whole or in part, the purchase rights evidenced  hereby.  Such exercise shall be
effected by:

          (a) surrender of this  Warrant,  together with a duly executed copy of
     the form of  Exercise  Notice  attached  hereto,  to the  Secretary  of the
     Company at its  principal  officer,  and the  payment to the  Company of an
     amount equal to the aggregate purchase price for the number of Shares being
     purchased; or

          (b) if the Company's  Common Stock is publicly traded as of such date,
     the instruction to retain that number of Shares having a value equal to the


                                        1





     aggregate  exercise  price of the Shares as to which this  Warrant is being
     exercised and to issue to the Holder the remainder of such Shares  computed
     using the following formula:

                        Y(A-B)
                  X = ----------
                          A

Where:  X = the number of shares of Common Stock to be issued to the Holder.

        Y = the number of shares of Common Stock as to which this Warrant is
            being exercised.

        A = the fair market value of one share of Common Stock.

        B = the Warrant Price.

          As used herein,  the "fair market value of one share of Common  Stock"
     shall mean:

               (1) Except in the  circumstances  described  in clause (2) or (3)
          hereof,  the closing price of the Company's  Common Stock, as reported
          in the WALL STREET JOURNAL,  on the trading day  immediately  prior to
          the date of exercise;

               (2)  If  such   exercise  is  in   conjunction   with  a  merger,
          acquisition,  or other consolidation  pursuant to which the Company is
          not the  surviving  entity,  the value  received by the holders of the
          Common Stock pursuant to such transaction for each share; or

               (3) If such exercise is in  conjunction  with the initial  public
          offering of the  Company,  the price at which the Common Stock is sold
          to the public in such offering.

     5.  Certificates  for  Shares.  Upon the  exercise of the  purchase  rights
evidenced by this Warrant,  one or more certificates for the number of Shares so
purchased  shall be issued as soon as practicable  thereafter,  and in any event
within thirty (30) days of the delivery of the subscription notice.

     6. Reservation of Shares.  The Company  covenants that it will at all times
keep available such number of authorized  shares of its Common Stock,  free from
all preemptive  rights with respect thereto,  which will be sufficient to permit
the exercise of this Warrant for the full number of Shares specified herein. The
Company further covenants that such Shares, when issued pursuant to the exercise
of this Warrant,  will be duly and validly issued, fully paid and non-assessable
and free from all taxes, liens and charges with respect to the issuance thereof.


                                        2





     7. Adjustment of Warrant Price and Number of Shares. The number and kind of
securities purchasable upon exercise of this Warrant and the Warrant Price shall
be subject to adjustment from time to time as follows:

          (a) Stock Dividends,  Subdivisions,  Combinations and Other Issuances.
     If the Company  shall at any time prior to the  expiration  of this Warrant
     subdivide its Common Stock, by stock split or otherwise, combine its Common
     Stock or issue  additional  shares of its Common  Stock as a dividend  with
     respect to any shares of its Common Stock, the number of Shares issuable on
     the exercise of this Warrant shall forthwith be  proportionately  increased
     in  the  case  of a  subdivision  or  stock  dividend  and  proportionately
     decreased in the case of a combination.  Appropriate adjustments shall also
     be made to the purchase price payable per share, but the aggregate purchase
     price payable for the total number of Shares purchasable under this Warrant
     (as adjusted) shall remain the same. Any adjustment under this Section 7(a)
     shall become effective at the close of business on the date the subdivision
     or combination becomes effective or as of the record date of such dividend,
     or, in the  event  that no record  date is fixed,  upon the  making of such
     dividend.

          (b) Reclassification, Reorganization, Merger, Sal or Consolidation. In
     the event of any reclassification,  capital  reorganization or other change
     in  the  Common  Stock  of  the  Company  (other  than  as  a  result  of a
     subdivision,  combination  or stock  dividend  provided  for in Section (a)
     above) or in the event of a consolidation  or merger of the Company with or
     into, or the sale of all or substantially  all of the properties and assets
     of the Company, to any person, and the connection  therewith  consideration
     is  payable  to  holders  of  Common  Stock  in cash,  securities  or other
     property,  then as a condition of such reclassification,  reorganization or
     change, consolidation,  merger or sale, lawful provision shall be made, and
     duly  executed  documents  evidencing  the same shall be  delivered  to the
     Holder,  so that the  Holder  shall have the right at any time prior to the
     expiration  of this  Warrant to  purchase,  at a total  price equal to that
     payable upon the exercise of this Warrant  immediately prior to such event,
     the kind and amount of cash,  securities  or other  property  receivable in
     connection   with  such   reclassification,   reorganization   or   change,
     consolidation,  merger or sale, by a holder of the same number of shares of
     Common Stock as were  exercisable by the Holder  immediately  prior to such
     reclassification,  reorganization or change, consolidation, merger or sale.
     In any such case,  appropriate provisions shall be made with respect to the
     rights and  interest  of the  Holder so that the  provisions  hereof  shall
     thereafter be applicable  with respect to any cash,  securities or property
     deliverable upon exercise hereof. Notwithstanding the foregoing, (i) if the
     Company merges or consolidates  with, or sells all or substantially  all of
     its property and assets to, any other person,  and consideration is payable
     to holders of Common Stock in exchange for their Common Stock in connection
     with such merger,  consolidation  or sale which consists solely of cash, or
     (ii) in the event of the  dissolution,  liquidation  or  winding  up of the
     Company,  then the Holder shall be entitled to receive distributions on the
     date of such  event on an equal  basis with  holders of Common  Stock as if
     this Warrant had been exercised  immediately  prior to such event, less the
     Warrant  Price.  Upon  receipt of such  payment,  if any, the rights of the
     Holder shall terminate and cease, and this Warrant shall expire. In case of

                                        3





     any  such  merger,  consolidation  or  sale of  assets,  the  surviving  or
     acquiring  person  and,  in the event of any  dissolution,  liquidation  or
     winding up of the Company,  the Company  shall  promptly,  after receipt of
     this surrendered Warrant, make payment by delivering a check in such amount
     as is appropriate (or, in the case of  consideration  other than case, such
     other consideration as is appropriate) to such person as it may be directed
     in writing by the Holder surrendering this Warrant.

          (c) Certain Distributions. In case the Company shall fix a record date
     for the  making  of a  dividend  or  distribution  of cash,  securities  or
     property  to all  holders  of Common  Stock  (excluding  any  dividends  or
     distributions  referred  to in Sections  7(a) or 7(b) above,  the number of
     Shares  purchasable upon an exercise of this Warrant after such record date
     shall be adjusted to equal the product  obtained by multiplying  the number
     of Shares purchasable upon an exercise of this Warrant immediately prior to
     such record date by a fraction, the numerator of which shall be the Warrant
     Price immediately prior to such distribution,  and the denominator of which
     shall be the Warrant Price immediately prior to such distribution, less the
     fair market  value per Share,  as  determined  by the Holder,  of the cash,
     securities  or  property  so  distributed.  Such  adjustment  shall be made
     successively  whenever  any  such  distribution  is made and  shall  become
     effective on the effective date of distribution.

     8. Pre-Exercise Rights. Prior to exercise of this Warrant, the Holder shall
not be  entitled  to any rights of a  shareholder  with  respect to the  Shares,
including without limitation,  the right to vote such Shares, receive preemptive
rights or be  notified  of  shareholder  meetings,  and the Holder  shall not be
entitled to any notice or other communication concerning the business or affairs
of the Company.

     9. Restricted Securities.  The Holder understands that this Warrant and the
Shares  purchasable  hereunder  constitute  "restricted  securities"  under  the
federal  securities  laws inasmuch as they are being,  or will be, acquired from
the Company in transactions  not involving a public offering and accordingly may
not,  under  such laws and  applicable  regulations,  be  resold or  transferred
without  registration  under  the  Securities  Act of 1933,  as  amended,  or an
applicable  exemption  from  registration.   In  this  connection,   the  Holder
acknowledges that Rule 144 of the Securities and Exchange Commission is not now,
and may not in the  future be,  available  for  resales of the Shares  purchased
hereunder.  The  Holder  further  acknowledges  that the  Shares  and any  other
securities   issued  upon   exercise  of  this  Warrant   shall  bear  a  legend
substantially in the form of the legend appearing on the face hereof.

     10.  Certification  of Investment  Purpose.  Unless a current  registration
statement under the Securities Act of 1933, as amended,  shall be in effect with
respect to the securities to be issued upon exercise of this Warrant, the Holder
hereof,  by accepting  this  Warrant,  covenants and agrees that, at the time of
exercise hereof, the Holder will deliver to the Company a written  certification
that the securiti4es acquired by the Holder are acquired for investment purposes
only and that such  securities  are not acquired  with a view to, or for sale in
connection with, any distribution thereof.


                                        4





     11.  Registration  Rights.  This Warrant and the Shares shall be subject to
the  registration  rights set forth in the  Registration  Rights Agreement dated
September  27,  2001,  by and among the Holder and the  Company,  and the Holder
shall be entitled to all rights and benefits thereof.

     12. Successors and Assigns.  The terms and provisions of this Warrant shall
inure to the  benefit  of, and be binding  upon,  the Company and the Holder and
their respective successors and assigns.

     13.  Governing Law. This Warrant shall be governed by the laws of the State
of Texas, excluding the conflicts of laws provisions thereof.

                                            INTEGRATED SECURITY SYSTEMS, INC.



                                   By:      ___________________________________
                                            C. A. Rundell, Jr.
                                            Chairman and Chief Executive Officer




                                        5




                                 EXERCISE NOTICE


                                                   Dated ______________, _______

     The undersigned  hereby  irrevocably  elects to exercise the Stock Purchase
Warrant, dated September 5, 2002, issued by Integrated Security Systems, Inc., a
Delaware  corporation  (the  "Company")  to the  undersigned  to the  extent  of
purchasing  _______________  shares of Common Stock and hereby makes  payment of
$____________ in payment of the aggregate Warrant Price of such Shares.

                                             RENAISSANCE US GROWTH INVESTMENT
                                             TRUST PLC



                                    By:      ___________________________________