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


                                  SCHEDULE 13D



                    Under the Securities Exchange Act of 1934

                                 Amendment No. 3

                        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)

                               September 27, 2001
 ------------------------------------------------------------------------------
             (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
                  22,594,758
------------------------------------------------------------------------------
         8.       SHARED VOTING POWER
                  None
         ---------------------------------------------------------------------
         9.       SOLE DISPOSITIVE POWER
                  22,594,758
         ---------------------------------------------------------------------
         10.      SHARED DISPOSITIVE POWER
                  None
------------------------------------------------------------------------------
11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  22,594,758
------------------------------------------------------------------------------
12.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
         SHARES            [  ]
------------------------------------------------------------------------------
13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN  ROW (11)
                  68.61%
------------------------------------------------------------------------------
14.      TYPE OF REPORTING PERSON
                  IV






CUSIP No. 45812J101                                     13D
------------------------------------------------------------------------------
1        NAME OF REPORTING PERSON                 I.R.S. IDENTIFICATION NUMBER
         Renaissance US Growth & Income Trust PLC               None - Foreign
------------------------------------------------------------------------------
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
                  21,758,446
         ---------------------------------------------------------------------
         8.       SHARED VOTING POWER
                  None
         ---------------------------------------------------------------------
         9.       SOLE DISPOSITIVE POWER
                  21,758,446
         ---------------------------------------------------------------------
         10.      SHARED DISPOSITIVE POWER
                  None
------------------------------------------------------------------------------
11.      AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON
                  21,758,446
------------------------------------------------------------------------------
12.      CHECK BOX IF THE AGGREGATE AMOUNT IN ROW (11) EXCLUDES CERTAIN
         SHARES            [  ]
------------------------------------------------------------------------------
13.      PERCENT OF CLASS REPRESENTED BY AMOUNT IN  ROW (11)
                  67.79%
------------------------------------------------------------------------------
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 & 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, except as 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  $4,654,589.  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  $4,488,463.  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 22,594,758  Common Shares,  and
Renaissance  PLC  beneficially  owns  21,758,446  Common  Shares.  The Reporting
Persons  beneficially own 44,353,204 Common Shares. Based upon information filed
with the Securities and Exchange Commission and using SEC computation rules, the
Common  Shares  beneficially  owned by  Renaissance  III,  Renaissance  PLC, and
together represent  approximately 68.61%, 67.79%, and 81.68%,  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;  964,299 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 393,258  shares of Common  Stock;  958,617  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)  Holders of Series D Preferred  Stock are  entitled to one vote for
each share of Common  Stock into  which such share of Series D  Preferred  Stock
could  then be  converted.  Presently,  the  holder  of each  share of  Series D
Preferred stock is entitled to 25 votes. Holders of Series F Preferred Stock are
entitled to vote with the holders of Common Stock, the Series D Preferred Stock,
the  Series E  Preferred  Stock , and the Series G  Preferred  Stock as a single
class on all matters on which  stockholders are entitled to vote,  including the
election of directors,  except as otherwise required by law. Holders of Series F
Preferred  Stock  are also  entitled  to vote  with any  other  class of  equity
securities which may vote with the holders of the Common Stock as a single class
with respect to any matter.  Holders of Series F Preferred Stock are entitled to
a number of votes per share of Series F  Preferred  Stock equal to the number of
shares of Common  Stock into which the  shares of Series F  Preferred  Stock are
convertible on the record date of the determination of stockholders  entitled to
receive  notice of and to vote on such  matter.  In  addition,  the  consent  of
holders of 80% of the Series F Preferred Stock and the Series G Preferred Stock,
voting together as a single class, will be required to (a) authorize, create, or
increase the  authorized  amount of any class of senior  stock or parity  stock,
other than Preferred Stock of the same class or securities to evidence bank debt
or asset  securitization  or (b) authorize a merger,  consolidation,  or sale of
assets, other than in the ordinary course of business, of the Company, including
the capital stock of the Company's  subsidiaries.  The consent of holders of 80%
of the Series F Preferred Stock,  voting as a single class,  will be required to
approve any action to amend the Company's certificate of incorporation or bylaws
that would  materially and adversely affect the rights of the Series F Preferred
Stock.

         Holders of Series G  Preferred  Stock will be entitled to vote with the
holders of Common Stock,  the Series D Preferred  Stock,  the Series E Preferred
Stock,  and the Series F  Preferred  Stock as a single  class on all  matters on
which  stockholders  are entitled to vote,  including the election of directors,
except as  otherwise  required by law.  holders of Series G Preferred  Stock are
also entitled to vote with any other class of equity  securities  which may vote
with the  holders of the  Common  Stock as a single  class  with  respect to any
matter.  Holders of Series G Preferred  Stock are  entitled to a number of votes
per share of Series G Preferred Stock equal to the number of shares of Common






Stock into which the Shares of Series G Preferred  Stock are  convertible on the
record date of the  determination of stockholders  entitled to receive notice of
and to vote on such matter.  In  addition,  the consent of holders of 80% of the
Series G Preferred Stock and the Series F Preferred Stock,  voting together as a
single  class,  will be required  (a) to  authorize,  create,  or  increase  the
authorized  amount of any class of senior  stock or  parity  stock,  other  than
Preferred  Stock of the same  class  or  securities  to  evidence  bank  debt or
securitization  or (b)  authorize  a merger,  consolidation,  or sale of assets,
other than in the ordinary  course of business,  of the Company,  including  the
capital  stock of the Company's  subsidiaries.  The consent of holders of 80% of
the Series G  Preferred  Stock,  voting as a single  class,  will be required to
approve any action to amend the Company's certificate of incorporation or bylaws
that would  materially and adversely affect the rights of the Series G Preferred
Stock.

         In addition to their right to vote with the holders of the Common Stock
on the  election of  directors,  the  Reporting  Persons,  as the holders of the
Series G Preferred Stock and the holders of the Series F Preferred Stock, voting
together as a single class,  are entitled to elect two  additional  directors to
the Company's board of directors.

         Each of the Reporting Persons has or will have upon the exercise of the
warrants  issued to it by the  Company the sole power to vote and dispose of all
of the Common Shares that it beneficially  owns.  None of the Reporting  Persons
shares  voting or  disposition  power with any person with respect to the Common
Shares.

         (c) No  transaction  in the Common  Shares was  effected by a Reporting
Person during the past 60 days, except as follows:  (1) the issuance on July 27,
2001,  of 3,000 shares of Series G Preferred  Stock for $75,000 and the issuance
of 1,000 shares of Series F Preferred  Stock for $25,000 to Renaissance  III and
the  issuance of 3,000  shares of Series G  Preferred  Stock for $75,000 and the
issuance of 1,000 shares of Series F Preferred  Stock for $25,000 to Renaissance
PLC; and (2) the purchase on September 27, 2001,  of a $75,000  non-convertible,
8%, 120 day promissory  note and five- year warrants to purchase  150,000 shares
of  Common  Stock at  $0.20 a share by  Renaissance  III and the  purchase  of a
$75,000  non-convertible,  8%, 120 day promissory note and five-year warrants to
purchase 150,000 shares of Common Stock at $0.20 a share by Renaissance PLC.

         (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)

                  Exhibit 2    Stock Purchase Warrant for Renaissance III

                  Exhibit 3    Stock Purchase Warrant for Renaissance PLC


                                                    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 10th day of October, 2001.

         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:      ______________________________
                             Name: Russell Cleveland
                                   Title:  President and Chief Executive Officer


                           RENAISSANCE US GROWTH & INCOME TRUST PLC




                           By:      _______________________________
                             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 27, 2001, is
issued to Frost  National  Bank,  Custodian,  FBO  Renaissance  Capital Growth &
Income  Fund III,  Inc.,  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  150,000 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 27, 2006.

     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  offices,  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
     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.

     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, Sale 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 7(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 in 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
     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 cash, 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 securities acquired by the Holder are acquired for investments purposes
only and that such  securities  are not acquired  with a view to, or for sale in
connection with, any distribution thereof.

     11.  Registration  Rights.  This Warrant and the Shares shall be subject to
the registration  rights set forth in the Registration  Rights Agreement of even
date  herewith 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:
                                         /S/----------------------------------
                                         C. A. Rundell, Jr.
                                         Chairman and Chief Executive Officer







                                 EXERCISE NOTICE


                              Dated _________, ____


         The  undersigned  hereby  irrevocably  elects  to  exercise  the  Stock
Purchase  Warrant,  dated  September  27, 2001,  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 CAPITAL GROWTH &
                                        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 27, 2001, is
issued to Frost National  Bank,  Custodian,  FBO  Renaissance US Growth & Income
Trust  PLC,  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  150,000 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 27, 2006.

     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  offices,  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
     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.

     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, Sale 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 7(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 in 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
     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 cash, 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 securities acquired by the Holder are acquired for investments purposes
only and that such  securities  are not acquired  with a view to, or for sale in
connection with, any distribution thereof.

     11.  Registration  Rights.  This Warrant and the Shares shall be subject to
the registration  rights set forth in the Registration  Rights Agreement of even
date  herewith 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:
                                   /S/--------------------------------------
                                   C. A. Rundell, Jr.
                                   Chairman and Chief Executive Officer







                                 EXERCISE NOTICE


                              Dated _________, ____


         The  undersigned  hereby  irrevocably  elects  to  exercise  the  Stock
Purchase  Warrant,  dated  September  27, 2001,  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 & INCOME
                                   TRUST PLC


                             By:
                                   ----------------------------------------