THE SECURITIES OFFERED HEREBY HAVE NOT BEEN AND WILL NOT BE REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED,  AND THE RULES AND  REGULATIONS  PROMULGATED
THEREUNDER  (THE  "1933  ACT"),  AND MAY ONLY BE  OFFERED  OR SOLD  PURSUANT  TO
REGISTRATION  UNDER OR AN EXEMPTION FROM THE  REGISTRATION  REQUIREMENTS  OF THE
1933 ACT.

                   7.5% CONVERTIBLE DEBENTURE DUE JUNE 7, 1998

$1,000,000                                                          June 7, 1996

         FOR VALUE RECEIVED,  INTELECT COMMUNICATIONS SYSTEMS LIMITED, a Bermuda
company (the "Company"),  hereby promises to pay to SECREST CAPITAL  LIMITED,  a
Nevis, West Indies corporation,  or registered assigns (the "Holder") on June 7,
1998  (the  "Maturity  Date"),  the  principal  amount  of ONE  MILLION  DOLLARS
($1,000,000) and to pay interest in cash on the principal amount hereof, in such
amounts, at such times and on such terms and conditions as are specified herein.
This  Debenture  (this  "Debenture")  has been issued  pursuant to that  certain
Convertible  Securities  Agreement  executed  by the  Holder,  the  Company  and
Infinity Investors, Ltd. dated June 7, 1996 (the "Agreement").


ARTICLE 1.        INTEREST.

         The Company shall pay interest on the unpaid  principal  amount of this
Debenture at the rate of Seven and One-Half Percent (7.5%) per year,  payable in
cash, payable quarterly in arrears until the principal hereof is paid in full or
has been converted. Interest on this Debenture shall accrue from the most recent
date to which interest has been paid or, if no interest has been paid, from June
7, 1996.  Interest  shall be computed  on the basis of a 360-day  year of twelve
30-day months.

ARTICLE 2.        METHOD OF PAYMENT.

         This  Debenture  must be  surrendered  to the  Company in order for the
Holder to receive payment of the principal amount hereof.  The Company shall pay
the  principal  of and  interest on this  Debenture  in United  States  dollars.
Interest and principal  payments shall be subject to withholding  (if any) under
applicable United States Federal Internal Revenue Service Regulations.

ARTICLE 3.        CONVERSION.

         SECTION 3.1.  CONVERSION PRIVILEGE

         (a) The Holder of this Debenture  shall have the right,  exercisable at
one or more times, at its option,  to convert all or a portion of this Debenture
into common  shares,  par value $.01 per share (U.S.),  of the Company  ("Common
Shares") at the times hereafter specified.  The number of Common Shares issuable
upon the  conversion  of this  Debenture is determined by dividing the



7.5% CONVERTIBLE DEBENTURE - PAGE 1
(SECREST CAPITAL LIMITED)

principal  amount hereof to be converted by the Conversion  Price (as defined in
paragraph  (b) of this Section 3.1 below) in effect on the  conversion  date and
rounding  the result to the nearest  1/100th of a share.  Upon  conversion,  all
accrued and unpaid  interest will be paid to the Holder in cash, as specified in
Article 1 above.

         (b) Less  than all of the  principal  amount of this  Debenture  may be
converted  into  Common  Shares if the portion  converted  is $10,000 or a whole
multiple  of  $10,000  and the  provisions  of this  Article 3 that apply to the
conversion of all of the Debenture  also apply to the conversion of a portion of
it. All or any portion of the  Debenture is  convertible  at any time,  and from
time to  time as  follows:  One-third  (1/3)  of the  principal  balance  of all
Debentures  issued to Holder as  described  in Section  7.1  hereafter  shall be
convertible  beginning  sixty  (60) days  after the date of this  Debenture;  an
additional  one-third  (1/3) of the  principal  balance  of all such  Debentures
issued to the Holder  shall be  convertible  beginning 90 days after the date of
such Debentures;  and the final one-third (1/3) of the principal  balance of all
such  Debentures  issued to the Holder shall be  convertible  beginning 120 days
after the date of such  Debentures.  The conversion price shall be the lesser of
(A)  $17.50  per share of Common  Stock or (B) the  product  of (i) the  current
market  price of the Common  Stock on the  conversion  date  multiplied  by (ii)
eighty two and one-half percent (82.5%) (the "Formula Price");  provided, if the
conversion  date is a date on or before the 90th day  following the date of this
Debenture, the Conversion Price shall be the greater of the Formula Price of the
Common  Stock on the  conversion  date or $4.95 per share of Common  Stock (such
applicable price being hereafter referred to as the "Conversion Price").

         (c) In the  event  any  Debenture  remains  outstanding  on the  second
anniversary of the date hereof,  the unconverted  portion of such Debenture will
automatically  be  converted  into Common  Shares on such date in the manner set
forth in this Section 3.1;  provided (i) an Event of Default does not then exist
under this  Debenture  and (ii) a  registration  statement  as  contemplated  by
Section 4 of the  Agreement is effective  with respect to the sale by the Holder
of shares of Common Stock issuable upon conversion of this Debenture.

         (d) At any time, and from time to time, the Company, at its option (the
"Redemption Option"),  may redeem this Debenture at the Agreed Redemption Amount
(which shall mean the product of the remaining principal amount of the Debenture
multiplied by 117.5%,  plus accrued and unpaid interest thereon).  Any notice of
exercise of the Redemption Option (a "Redemption  Notice") shall be delivered in
writing to Holder and shall be  irrevocable  when  delivered.  The Company shall
not,  however,  be entitled  to issue a  Redemption  Notice with  respect to any
portion of the Debenture for which Holder has  previously  delivered a Notice of
Conversion as contemplated  by this  Debenture.  The Company shall repay in full
the Agreed  Redemption  Amount upon  exercise of the  Redemption  Option  within
thirty  (30)  days  of the  delivery  of  such  Redemption  Notice.  During  the
Redemption  Period,  the Company  shall  comply with all terms,  conditions  and
covenants of this Debenture  (including,  without  limitation  timely payment of
accrued  and unpaid  interest).  Subject to the  foregoing,  Holder's  option to
convert this  Debenture  into shares of Common Stock shall be abated  during the
Redemption Period.



7.5% CONVERTIBLE DEBENTURE - PAGE 2
(SECREST CAPITAL LIMITED)



         SECTION  3.2.  CONVERSION  PROCEDURE.  To convert this  Debenture  into
Common  Shares,  the Holder must (a) complete and sign the Notice of  Conversion
attached  hereto and (b) surrender  the Debenture to the Company.  The date upon
which the Company  receives the completed  Notice of Conversion  (by  recognized
overnight  courier,  hand-delivery,  facsimile or otherwise)  is the  conversion
date,  provided  that the Company shall not be required to deliver a certificate
for Common Shares unless and until the Company  receives the  Debenture.  Within
two (2) business  days after  receipt of the Notice of  Conversion as aforesaid,
providing  the Company has received the Debenture  from the Holder,  the Company
shall  deliver  a  certificate  with  restrictive  legend  as  specified  in the
Agreement for the number of full Common Shares  issuable upon the conversion and
a check for any  fraction of a share.  The person in whose name the  certificate
representing Common Shares is to be registered shall be treated as a shareholder
of record on and after the conversion date. Upon conversion,  unpaid interest on
the converted portion of the Debenture shall be paid in cash by the Company.  If
one person converts more than one Debenture at the same time, the number of full
shares issuable upon the conversion shall be based on the total principal amount
of Debentures  converted.  Upon surrender of a Debenture that is to be converted
in part,  the  Company  shall  issue  to the  Holder  a new  Debenture  equal in
principal  amount  to the  unconverted  portion  of the  Debenture  surrendered.
Notwithstanding  the  foregoing,  the  conversion  right of the Holder set forth
herein shall be limited,  solely to the extent required, from time to time, such
that in no  instance  shall the maximum  number of Common  Shares into which the
Holder may convert this  Debenture  exceed,  at any one time, an amount equal to
the remainder of (i) 4.99% of the then issued and  outstanding  shares of Common
Stock of the Company following such conversion,  minus (ii) the number of shares
of Common Stock of the Company then held by the Holder.

         SECTION  3.3.   FRACTIONAL  SHARES.  The  Company  shall  not  issue  a
fractional share of Common Stock upon the conversion of this Debenture. Instead,
the Company shall pay in lieu of any fractional  share the cash value thereof at
the then current  market price of the Common Shares as determined  under Section
3.7 below.

         SECTION  3.4.   TAXES  ON   CONVERSION.   The  Company  shall  pay  any
documentary,  stamp or similar  issue or transfer tax due on the issue of Common
Shares upon the conversion of this Debenture.  However, the Holder shall pay any
such tax which is due  because  such  shares are issued in a name other than its
name.

         SECTION 3.5. COMPANY TO RESERVE STOCK. The Company shall reserve out of
its  authorized  but unissued  Common  Shares enough Common Shares to permit the
conversion in full of this Debenture. All Common Shares which may be issued upon
the conversion hereof shall be fully paid and nonassessable.

         SECTION 3.6.  RESTRICTIONS  ON TRANSFER.  This Debenture and the Common
Shares issuable upon the conversion  hereof have not been  registered  under the
Securities  Act of 1933 (the "Act") and have been sold  pursuant to an exemption
under the Act. The Debenture may not be transferred or resold except pursuant to
registration under or an exemption from the Act.




7.5% CONVERTIBLE DEBENTURE - PAGE 3
(SECREST CAPITAL LIMITED)


         SECTION 3.7  CURRENT MARKET PRICE

         (a) As used herin,  the current market price per share of Common Shares
on any date is the  average of the  quoted  bid prices of the Common  Shares for
five (5)  consecutive  trading days ending on the trading day before the date in
question.

         (b) As used in this  Section  3.7, the term quoted bid price shall mean
(i) the  closing bid prices  thereof on any such  trading  date,  as reported by
Bloomberg,  L.P. or (ii) in the event the Common  Shares is not reported on such
system,  the fair market value of the Common Stock as determined by the Board of
Directors of the Company in its good faith judgment.

ARTICLE 4.        MERGERS.

         The Company  shall not  consolidate  or merge into,  or transfer all or
substantially  all of its assets to, any person,  unless such person assumes the
obligations  of the Company  under this  Debenture  and  immediately  after such
transaction  no Event of Default  exists.  Any  reference  herein to the Company
shall refer to such surviving or transferee  corporation  and the obligations of
the Company  shall  terminate  upon such  assumption.  If the Company  merges or
consolidates with another corporation or sells or transfers all or substantially
all of its assets to another  person  and the  holders of the Common  Shares are
entitled to receive  stock,  securities or property in respect of or in exchange
for Common Shares,  then as a condition of such merger,  consolidation,  sale or
transfer, either (i) the Company and any such successor, purchaser or transferee
shall amend this Debenture to provide that it may thereafter be converted on the
terms and subject to the  conditions set forth above into the kind and amount of
stock, securities or property receivable upon such merger,  consolidation,  sale
or transfer by a holder of the number of shares of Common  Stock into which this
Debenture   might  have  been   converted   immediately   before  such   merger,
consolidation,  sale or  transfer,  or (ii) if the Company is not the  surviving
entity in such merger,  consolidation,  sale or transfer, the Company shall give
the Holder at least 30 days prior written notice of the expected closing date of
such  transaction,  and if any portion of this  Debenture has not been converted
into Common Stock at the election of the Holder prior to such closing,  then the
remaining  principal  amount  of  this  Debenture  may,  at  the  option  of the
Purchaser,  be  converted  into  shares of Common  Stock at the  closing of such
transaction. The Conversion Price shall be the same as the applicable Conversion
Price defined in Section 3 above.

ARTICLE 5.        REPORTS.

         The Company  will mail to the Holder  hereof at its address as shown on
the  Register a copy of any annual,  quarterly  or current  report that it files
with the  Securities and Exchange  Commission  promptly after the filing thereof
and a copy of any annual,  quarterly or other report or proxy  statement that it
gives to its shareholders generally at the time such report or statement is sent
to shareholders.




7.5% CONVERTIBLE DEBENTURE - PAGE 4
(SECREST CAPITAL LIMITED)


ARTICLE 6.          DEFAULTS AND REMEDIES.

         SECTION 6.1. Events of Default. An "Event of Default" occurs if (a) the
Company does not make the payment of the  principal of this  Debenture  when the
same becomes due and payable at maturity, upon redemption or otherwise,  (b) the
Company does not make a payment of interest  when such  interest  become due and
payable and such default  continues for a period of 10 days thereafter,  (c) the
Company  fails to issue Common  Shares upon  conversion,  within the time period
specified in Section 3.2, (d) the Company  fails to comply with any of its other
agreements in this Debenture and such failure continues for the period and after
the notice  specified  below,  (e) from and after October 31, 1996,  the Company
ceases to be  eligible  with  respect to the use of Form S-3 for the filing of a
resale registration  statement with the Securities and Exchange Commission,  (f)
the  Company's  Common  Shares  ceases to be quoted on any of the New York Stock
Exchange,  American Stock Exchange,  the NASDAQ-National  Market or NASDAQ-Small
Cap for a period in excess of 60 calendar  days, or (g) the Company  pursuant to
or within the  meaning  of any  Bankruptcy  Law (as  hereinafter  defined):  (i)
commences a voluntary  case;  (ii)  consents to the entry of an order for relief
against it in an  involuntary  case;  (iii)  consents  to the  appointment  of a
Custodian (as hereinafter  defined) of it or for all or substantially all of its
property;  (iv) makes a general assignment for the benefit of its creditors;  or
(v) a court of  competent  jurisdiction  enters  an order or  decree  under  any
Bankruptcy  Law that:  (A) is for relief  against the Company in an  involuntary
case; (B) appoints a Custodian of the Company or for all or substantially all of
its  property or (C) orders the  liquidation  of the  Company,  and the order or
decree remains  unstayed and in effect for 60 days. As used in this Section 6.1,
the term  "Bankruptcy  Law"  means  Title 11 of the  United  States  Code or any
similar Federal or State law for the relief of debtors or such other  applicable
laws. The term "Custodian" means any receiver, trustee, assignee,  liquidator or
similar official under any Bankruptcy Law.

         SECTION  6.2.  ACCELERATION.  If an  Event  of  Default  occurs  and is
continuing,  the  Holder  hereof by  notice  to the  Company,  may  declare  the
principal of and accrued interest on this Debenture to be due and payable.  Upon
such  declaration,  the principal  and interest  hereof shall be due and payable
immediately.

ARTICLE 7.          REGISTERED DEBENTURES.

         SECTION 7.1.  SERIES.  This  Debenture  is one of a numbered  series of
Debentures  issued to the Holder and Infinity  Investors,  Ltd.  pursuant to the
Agreement  having  an  aggregate  principal  amount  of  $5,000,000,  which  are
identical.   Such  Debentures  are  referred  to  herein   collectively  as  the
"Debentures." Holder, at its option, may exchange this Debenture for a series of
Debentures of the Company in denominations of at least $100,000.

         SECTION 7.2. RECORD OWNERSHIP. The Company shall maintain a register of
the holders of the Debentures (the "Register") showing their names and addresses
and the  serial  numbers  and  principal  amounts  of  Debentures  issues  to or
transferred  of record by them from time to time. The Register may be maintained
in electronic,  magnetic or other  computerized  form. The Company


7.5% CONVERTIBLE DEBENTURE - PAGE 5
(SECREST CAPITAL LIMITED)


may treat the person  named as the Holder of this  Debenture  in the Register as
the sole owner of this  Debenture.  The Holder of this  Debenture  is the person
exclusively entitled to receive payments of interest on this Debenture,  receive
notifications  with respect to this Debenture,  convert it into Common Stock and
otherwise exercise all of the rights and powers as the absolute owner hereof.

         SECTION 7.3. REGISTRATION OF TRANSFER.  Transfers of this Debenture may
be registered on the books of the Company  maintained for such purpose  pursuant
to Section 7.2 above (i.e.,  the Register).  Transfers  shall be registered when
this  Debenture  is  presented  to the Company  with a request to  register  the
transfer  hereof and the Debenture is duly endorsed by the  appropriate  person,
reasonable assurances are given that the endorsements are genuine and effective,
and the Company has received  evidence  satisfactory to it that such transfer is
rightful and in  compliance  with all  applicable  laws,  including tax laws and
State and Federal securities laws. When this Debenture is presented for transfer
and duly transferred hereunder, it shall be canceled and a new Debenture showing
the name of the  transferee as the record holder thereof shall be issued in lieu
hereof.  When this  Debenture  is  presented  to the Company  with a  reasonable
request to  exchange it for an equal  principal  amount of  Debentures  of other
denominations,  the  Company  shall make such  exchange  and shall  cancel  this
Debenture and issue in lieu thereof  Debentures  having a total principal amount
equal to this Debenture in the denominations requested by the Holder.

         SECTION 7.4. WORN AND LOST DEBENTURES.  If this Debenture becomes worn,
defaced or mutilated but is still  substantially  intact and  recognizable,  the
Company  or its  agent  may  issue a new  Debenture  in  lieu  hereof  upon  its
surrender. Where the Holder of this Debenture claims that the Debenture has been
lost,  destroyed or wrongfully taken, the company shall issue a new Debenture in
place of the original  Debenture if the Holder so requests by written  notice to
the Company  actually  received by the  Company  before it is notified  that the
Debenture  has  been  acquired  by a bona  fide  purchaser  and the  Holder  has
delivered  to the  Company an  indemnity  bond in such amount and issued by such
surety as the Company  deems  satisfactory  together  with an  affidavit  of the
Holder  setting forth the facts  concerning  such loss,  destruction or wrongful
taking and such other  information in such form with such proof or  verification
as the Company may request.

ARTICLE 8.        NOTICES.

         Any notice  which is  required  or  convenient  under the terms of this
Debentures  shall be duly given if it is in writing and delivered in person,  by
telecopy, by recognized overnight courier or mailed by first class mail, postage
prepaid and directed to the Holder of the Debenture at its address as it appears
on the Register or if to the Company to its  principal  executive  offices.  The
time when such notice is sent shall be the time of the giving of the notice.



7.5% CONVERTIBLE DEBENTURE - PAGE 6
(SECREST CAPITAL LIMITED)




         All notices to Holders are to be mailed to:

         27 Wellington Road
         Cork, Ireland
         Attn:  James G. O'Brien
         Telephone: 353 21 501 109
         Fax: 353 21 501 255

         All notices to the Company are to be mailed to:

         Intelect Communications Systems Limited
         Reid House 31 Church Street
         Hamilton, Bermuda
         Attn:  Chief Executive Officer
         Telephone:  441/295-8639
         Fax:  441/292-5560


ARTICLE 9.        TIMES.

         Where this Debenture authorizes or requires the payment of money or the
performance  of a condition  or  obligation  on a Saturday or Sunday or a public
holiday,  or authorizes or requires the payment of money or the performance of a
condition or obligation within, before or after a period of time computed from a
certain date, and such period of time ends on a Saturday or a Sunday or a public
holiday,  such payment may be made or condition or  obligation  performed on the
next  succeeding  business day, and if the period ends at a specified hour, such
payment may be made or condition  performed,  at or before the same hour of such
next  succeeding  business  day,  with the same  force and  effect as if made or
performed in accordance with the terms of this Debenture. Where time is extended
by virtue of the  provisions  of this Article 9, such extended time shall not be
included in the computation of interest.

ARTICLE 10.       RULES OF CONSTRUCTION.

         In this Debenture,  unless the context otherwise requires, words in the
singular number include the plural, and in the plural include the singular,  and
words of the masculine gender include the feminine and the neuter,  and when the
sense so  indicates,  words of the neuter  gender may refer to any  gender.  The
numbers and titles of sections  contained  in this  Debenture  are  inserted for
convenience  of reference  only,  and they neither form a part of this Debenture
nor are they to be used in the construction or interpretation hereof.  Wherever,
in this Debenture,  a determination of the Company is required or allowed,  such
determination  shall be made by a  majority  of the  Board of  Directors  of the
Company and if it is made in good faith, it shall be conclusive and binding upon
the Company and the Holder of this Debenture.



7.5% CONVERTIBLE DEBENTURE - PAGE 7
(SECREST CAPITAL LIMITED)



ARTICLE 11.       GOVERNING LAW.

         The validity,  terms,  performance  and  enforcement  of this Debenture
shall be governed and construed by the provisions  hereof and in accordance with
the laws of Bermuda.


         IN WITNESS WHEREOF,  the Company has duly executed this Debenture as of
the date first written above.

                                       INTELECT COMMUNICATIONS SYSTEMS LIMITED


                                        By: /s/ Peter G. Leighton
                                            ---------------------
                                        Name Peter G. Leighton
                                        Title President

[Corporate Seal]


7.5% CONVERTIBLE DEBENTURE - PAGE 8
(SECREST CAPITAL LIMITED)





                                    EXHIBIT A

                                FORM OF DEBENTURE


                     (The attached form applies to Secrest)





                              NOTICE OF CONVERSION

         [To be completed and signed only upon conversion of Debenture]

         The  undersigned,  the  Holder of this  Debenture,  hereby  irrevocably
elects to exercise the right to convert it into common shares, par value $10 per
share, of Intelect Communications Systems Limited as follows:

[Complete if less than all of                       Dollars ($       )*
principal amount is to be          ---------------------------------------------
converted]                          ($10,000 or integral  multiples of $10,000)


[Signature must be guaranteed      ---------------------------------------------
if registered  holder of stock     (Name of Holder of shares if different than
differs from registered Holder     registered Holder of  Debenture]
of Debenture)
                                   ---------------------------------------------
                                   (Address of Holder if different than address
                                   of registered Holder of Debenture)

                                   ---------------------------------------------
                                   (Social Security or EIN of Holder of shares
                                   if different than Holder of Debenture)

         *If the principal  amount of the Debenture to be converted is less than
         the entire principal amount thereof, a new Debenture for the balance of
         the principal  amount shall be returned to the Holder of the Debenture.
         All notices to be transmitted by hand delivery,  facsimile or overnight
         courier.


Date:_______       Sign:________________________________________________________
                         (Signature  must  conform  in all  respects  to name of
                         Holder shown on face of this Debenture)



NOTICE OF CONVERSION









                               ASSIGNMENT OF NOTE



         The undersigned hereby sell(s) and assign(s) and transfer(s) unto

________________________________________________________________________________
                   (name, address and SSN or EIN of assignee)

                                                        Dollars ($             )
________________________________________________________________________________
(principal amount of Debenture, $10,000 or integral multiples of $10,000)

of principal amount of this Debenture together with all accrued interest hereon.


Date:_________               Sign:______________________________________________
                                 (Signature must conform in all respects to name
                                 of Holder shown on face of Debenture)




ASSIGNMENT OF NOTE











THE SECURITIES OFFERED HEREBY HAVE NOT BEEN AND WILL NOT BE REGISTERED UNDER THE
SECURITIES ACT OF 1933, AS AMENDED,  AND THE RULES AND  REGULATIONS  PROMULGATED
THEREUNDER  (THE  "1933  ACT"),  AND MAY ONLY BE  OFFERED  OR SOLD  PURSUANT  TO
REGISTRATION  UNDER OR AN EXEMPTION FROM THE  REGISTRATION  REQUIREMENTS  OF THE
1933 ACT.

                   7.5% CONVERTIBLE DEBENTURE DUE JUNE 7, 1998

$4,000,000                                                          June 7, 1996

         FOR VALUE RECEIVED,  INTELECT COMMUNICATIONS SYSTEMS LIMITED, a Bermuda
company (the "Company"),  hereby promises to pay to INFINITY INVESTORS,  LTD., a
Nevis, West Indies corporation,  or registered assigns (the "Holder") on June 7,
1998  (the  "Maturity  Date"),  the  principal  amount of FOUR  MILLION  DOLLARS
($4,000,000) and to pay interest in cash on the principal amount hereof, in such
amounts, at such times and on such terms and conditions as are specified herein.
This  Debenture  (this  "Debenture")  has been issued  pursuant to that  certain
Convertible Securities Agreement executed by the Holder, the Company and Secrest
Capital Limited dated June 7, 1996 (the "Agreement").

ARTICLE 1.        INTEREST.

         The Company shall pay interest on the unpaid  principal  amount of this
Debenture at the rate of Seven and One-Half Percent (7.5%) per year,  payable in
cash, payable quarterly in arrears until the principal hereof is paid in full or
has been converted. Interest on this Debenture shall accrue from the most recent
date to which interest has been paid or, if no interest has been paid, from June
7, 1996.  Interest  shall be computed  on the basis of a 360-day  year of twelve
30-day months.

ARTICLE 2.        METHOD OF PAYMENT.

         This  Debenture  must be  surrendered  to the  Company in order for the
Holder to receive payment of the principal amount hereof.  The Company shall pay
the  principal  of and  interest on this  Debenture  in United  States  dollars.
Interest and principal  payments shall be subject to withholding  (if any) under
applicable United States Federal Internal Revenue Service Regulations.

ARTICLE 3.        CONVERSION.

         SECTION 3.1.  CONVERSION PRIVILEGE

         (a) The Holder of this Debenture  shall have the right,  exercisable at
one or more times, at its option,  to convert all or a portion of this Debenture
into common  shares,  par value $.01 per share (U.S.),  of the Company  ("Common
Shares") at the times hereafter specified.  The number of Common Shares issuable
upon the  conversion  of this  Debenture is determined by dividing the



NOTICE OF CONVERSION



principal  amount hereof to be converted by the Conversion  Price (as defined in
paragraph  (b) of this Section 3.1 below) in effect on the  conversion  date and
rounding  the result to the nearest  1/100th of a share.  Upon  conversion,  all
accrued and unpaid  interest will be paid to the Holder in cash, as specified in
Article 1 above.

         (b) Less  than all of the  principal  amount of this  Debenture  may be
converted  into  Common  Shares if the portion  converted  is $10,000 or a whole
multiple  of  $10,000  and the  provisions  of this  Article 3 that apply to the
conversion of all of the Debenture  also apply to the conversion of a portion of
it. All or any portion of the  Debenture is  convertible  at any time,  and from
time to  time as  follows:  One-third  (1/3)  of the  principal  balance  of all
Debentures  issued to Holder as  described  in Section  7.1  hereafter  shall be
convertible  beginning  sixty  (60) days  after the date of this  Debenture;  an
additional  one-third  (1/3) of the  principal  balance  of all such  Debentures
issued to the Holder  shall be  convertible  beginning 90 days after the date of
such Debentures;  and the final one-third (1/3) of the principal  balance of all
such  Debentures  issued to the Holder shall be  convertible  beginning 120 days
after the date of such  Debentures.  The conversion price shall be the lesser of
(A)  $17.50  per share of Common  Stock or (B) the  product  of (i) the  current
market  price of the Common  Stock on the  conversion  date  multiplied  by (ii)
eighty two and one-half percent (82.5%) (the "Formula Price");  provided, if the
conversion  date is a date on or before the 90th day  following the date of this
Debenture, the Conversion Price shall be the greater of the Formula Price of the
Common  Stock on the  conversion  date or $4.95 per share of Common  Stock (such
applicable price being hereafter referred to as the "Conversion Price").

         (c) In the  event  any  Debenture  remains  outstanding  on the  second
anniversary of the date hereof,  the unconverted  portion of such Debenture will
automatically  be  converted  into Common  Shares on such date in the manner set
forth in this Section 3.1;  provided (i) an Event of Default does not then exist
under this  Debenture  and (ii) a  registration  statement  as  contemplated  by
Section 4 of the  Agreement is effective  with respect to the sale by the Holder
of shares of Common Stock issuable upon conversion of this Debenture.

         (d) At any time, and from time to time, the Company, at its option (the
"Redemption Option"),  may redeem this Debenture at the Agreed Redemption Amount
(which shall mean the product of the remaining principal amount of the Debenture
multiplied by 117.5%,  plus accrued and unpaid interest thereon).  Any notice of
exercise of the Redemption Option (a "Redemption  Notice") shall be delivered in
writing to Holder and shall be  irrevocable  when  delivered.  The Company shall
not,  however,  be entitled  to issue a  Redemption  Notice with  respect to any
portion of the Debenture for which Holder has  previously  delivered a Notice of
Conversion as contemplated  by this  Debenture.  The Company shall repay in full
the Agreed  Redemption  Amount upon  exercise of the  Redemption  Option  within
thirty  (30)  days  of the  delivery  of  such  Redemption  Notice.  During  the
Redemption  Period,  the Company  shall  comply with all terms,  conditions  and
covenants of this Debenture  (including,  without  limitation  timely payment of
accrued  and unpaid  interest).  Subject to the  foregoing,  Holder's  option to
convert this  Debenture  into shares of Common Stock shall be abated  during the
Redemption Period.



NOTICE OF CONVERSION


         SECTION  3.2.  CONVERSION  PROCEDURE.  To convert this  Debenture  into
Common  Shares,  the Holder must (a) complete and sign the Notice of  Conversion
attached  hereto and (b) surrender  the Debenture to the Company.  The date upon
which the Company  receives the completed  Notice of Conversion  (by  recognized
overnight  courier,  hand-delivery,  facsimile or otherwise)  is the  conversion
date,  provided  that the Company shall not be required to deliver a certificate
for Common Shares unless and until the Company  receives the  Debenture.  Within
two (2) business  days after  receipt of the Notice of  Conversion as aforesaid,
providing  the Company has received the Debenture  from the Holder,  the Company
shall  deliver  a  certificate  with  restrictive  legend  as  specified  in the
Agreement for the number of full Common Shares  issuable upon the conversion and
a check for any  fraction of a share.  The person in whose name the  certificate
representing Common Shares is to be registered shall be treated as a shareholder
of record on and after the conversion date. Upon conversion,  unpaid interest on
the converted portion of the Debenture shall be paid in cash by the Company.  If
one person converts more than one Debenture at the same time, the number of full
shares issuable upon the conversion shall be based on the total principal amount
of Debentures  converted.  Upon surrender of a Debenture that is to be converted
in part,  the  Company  shall  issue  to the  Holder  a new  Debenture  equal in
principal  amount  to the  unconverted  portion  of the  Debenture  surrendered.
Notwithstanding  the  foregoing,  the  conversion  right of the Holder set forth
herein shall be limited,  solely to the extent required, from time to time, such
that in no  instance  shall the maximum  number of Common  Shares into which the
Holder may convert this  Debenture  exceed,  at any one time, an amount equal to
the remainder of (i) 4.99% of the then issued and  outstanding  shares of Common
Stock of the Company following such conversion,  minus (ii) the number of shares
of Common Stock of the Company then held by the Holder.

         SECTION  3.3.   FRACTIONAL  SHARES.  The  Company  shall  not  issue  a
fractional share of Common Stock upon the conversion of this Debenture. Instead,
the Company shall pay in lieu of any fractional  share the cash value thereof at
the then current  market price of the Common Shares as determined  under Section
3.7 below.

         SECTION  3.4.   TAXES  ON   CONVERSION.   The  Company  shall  pay  any
documentary,  stamp or similar  issue or transfer tax due on the issue of Common
Shares upon the conversion of this Debenture.  However, the Holder shall pay any
such tax which is due  because  such  shares are issued in a name other than its
name.

         SECTION 3.5. COMPANY TO RESERVE STOCK. The Company shall reserve out of
its  authorized  but unissued  Common  Shares enough Common Shares to permit the
conversion in full of this Debenture. All Common Shares which may be issued upon
the conversion hereof shall be fully paid and nonassessable.

         SECTION 3.6.  RESTRICTIONS  ON TRANSFER.  This Debenture and the Common
Shares issuable upon the conversion  hereof have not been  registered  under the
Securities  Act of 1933 (the "Act") and have been sold  pursuant to an exemption
under the Act. The Debenture may not be transferred or resold except pursuant to
registration under or an exemption from the Act.



NOTICE OF CONVERSION




         SECTION 3.7.  CURRENT MARKET PRICE.

         (a) As used herein, the current market price per share of Common Shares
on any date is the  average of the  quoted  bid prices of the Common  Shares for
five (5)  consecutive  trading days ending on the trading day before the date in
question.

         (b) As used in this  Section  3.7, the term quoted bid price shall mean
(i) the  closing bid prices  thereof on any such  trading  date,  as reported by
Bloomberg,  L.P. or (ii) in the event the Common  Shares is not reported on such
system,  the fair market value of the Common Stock as determined by the Board of
Directors of the Company in its good faith judgment.

ARTICLE 4.        MERGERS.

         The Company  shall not  consolidate  or merge into,  or transfer all or
substantially  all of its assets to, any person,  unless such person assumes the
obligations  of the Company  under this  Debenture  and  immediately  after such
transaction  no Event of Default  exists.  Any  reference  herein to the Company
shall refer to such surviving or transferee  corporation  and the obligations of
the Company  shall  terminate  upon such  assumption.  If the Company  merges or
consolidates with another corporation or sells or transfers all or substantially
all of its assets to another  person  and the  holders of the Common  Shares are
entitled to receive  stock,  securities or property in respect of or in exchange
for Common Shares,  then as a condition of such merger,  consolidation,  sale or
transfer, either (i) the Company and any such successor, purchaser or transferee
shall amend this Debenture to provide that it may thereafter be converted on the
terms and subject to the  conditions set forth above into the kind and amount of
stock, securities or property receivable upon such merger,  consolidation,  sale
or transfer by a holder of the number of shares of Common  Stock into which this
Debenture   might  have  been   converted   immediately   before  such   merger,
consolidation,  sale or  transfer,  or (ii) if the Company is not the  surviving
entity in such merger,  consolidation,  sale or transfer, the Company shall give
the Holder at least 30 days prior written notice of the expected closing date of
such  transaction,  and if any portion of this  Debenture has not been converted
into Common Stock at the election of the Holder prior to such closing,  then the
remaining  principal  amount  of  this  Debenture  may,  at  the  option  of the
Purchaser,  be  converted  into  shares of Common  Stock at the  closing of such
transaction. The Conversion Price shall be the same as the applicable Conversion
Price defined in Section 3 above.

ARTICLE 5.        REPORTS.

         The Company  will mail to the Holder  hereof at its address as shown on
the  Register a copy of any annual,  quarterly  or current  report that it files
with the  Securities and Exchange  Commission  promptly after the filing thereof
and a copy of any annual,  quarterly or other report or proxy  statement that it
gives to its shareholders generally at the time such report or statement is sent
to shareholders.



NOTICE OF CONVERSION


ARTICLE 6.        DEFAULTS AND REMEDIES.

         SECTION 6.1. Events of Default. An "Event of Default" occurs if (a) the
Company does not make the payment of the  principal of this  Debenture  when the
same becomes due and payable at maturity, upon redemption or otherwise,  (b) the
Company does not make a payment of interest when such  interest  becomes due and
payable and such default  continues for a period of 10 days thereafter,  (c) the
Company  fails to issue Common  Shares upon  conversion,  within the time period
specified in Section 3.2, (d) the Company  fails to comply with any of its other
agreements in this Debenture and such failure continues for the period and after
the notice  specified  below,  (e) from and after October 31, 1996,  the Company
ceases to be  eligible  with  respect to the use of Form S-3 for the filing of a
resale registration  statement with the Securities and Exchange Commission,  (f)
the  Company's  Common  Shares  ceases to be quoted on any of the New York Stock
Exchange,  American Stock Exchange,  the NASDAQ-National  Market or NASDAQ-Small
Cap for a period in excess of 60 calendar  days, or (g) the Company  pursuant to
or within the  meaning  of any  Bankruptcy  Law (as  hereinafter  defined):  (i)
commences a voluntary  case;  (ii)  consents to the entry of an order for relief
against it in an  involuntary  case;  (iii)  consents  to the  appointment  of a
Custodian (as hereinafter  defined) of it or for all or substantially all of its
property;  (iv) makes a general assignment for the benefit of its creditors;  or
(v) a court of  competent  jurisdiction  enters  an order or  decree  under  any
Bankruptcy  Law that:  (A) is for relief  against the Company in an  involuntary
case; (B) appoints a Custodian of the Company or for all or substantially all of
its  property or (C) orders the  liquidation  of the  Company,  and the order or
decree remains  unstayed and in effect for 60 days. As used in this Section 6.1,
the term  "Bankruptcy  Law"  means  Title 11 of the  United  States  Code or any
similar Federal or State law for the relief of debtors or such other  applicable
laws. The term "Custodian" means any receiver, trustee, assignee,  liquidator or
similar official under any Bankruptcy Law.

         SECTION  6.2.  ACCELERATION.  If an  Event  of  Default  occurs  and is
continuing,  the  Holder  hereof by  notice  to the  Company,  may  declare  the
principal of and accrued interest on this Debenture to be due and payable.  Upon
such  declaration,  the principal  and interest  hereof shall be due and payable
immediately.

ARTICLE 7.        REGISTERED DEBENTURES.

         SECTION 7.1.  SERIES.  This  Debenture  is one of a numbered  series of
Debentures  issued to the Holder and  Secrest  Capital  Limited  pursuant to the
Agreement  having  an  aggregate  principal  amount  of  $5,000,000,  which  are
identical.   Such  Debentures  are  referred  to  herein   collectively  as  the
"Debentures." Holder, at its option, may exchange this Debenture for a series of
Debentures of the Company in denominations of at least $100,000.

         SECTION 7.2. RECORD OWNERSHIP. The Company shall maintain a register of
the holders of the Debentures (the "Register") showing their names and addresses
and the  serial  numbers  and  principal  amounts  of  Debentures  issues  to or
transferred  of record by them from time to time. The Register may be maintained
in electronic,  magnetic or other  computerized  form. The Company



NOTICE OF CONVERSION


may treat the person  named as the Holder of this  Debenture  in the Register as
the sole owner of this  Debenture.  The Holder of this  Debenture  is the person
exclusively entitled to receive payments of interest on this Debenture,  receive
notifications  with respect to this Debenture,  convert it into Common Stock and
otherwise exercise all of the rights and powers as the absolute owner hereof.

         SECTION 7.3. REGISTRATION OF TRANSFER.  Transfers of this Debenture may
be registered on the books of the Company  maintained for such purpose  pursuant
to Section 7.2 above (i.e.,  the Register).  Transfers  shall be registered when
this  Debenture  is  presented  to the Company  with a request to  register  the
transfer  hereof and the Debenture is duly endorsed by the  appropriate  person,
reasonable assurances are given that the endorsements are genuine and effective,
and the Company has received  evidence  satisfactory to it that such transfer is
rightful and in  compliance  with all  applicable  laws,  including tax laws and
State and Federal securities laws. When this Debenture is presented for transfer
and duly transferred hereunder, it shall be canceled and a new Debenture showing
the name of the  transferee as the record holder thereof shall be issued in lieu
hereof.  When this  Debenture  is  presented  to the Company  with a  reasonable
request to  exchange it for an equal  principal  amount of  Debentures  of other
denominations,  the  Company  shall make such  exchange  and shall  cancel  this
Debenture and issue in lieu thereof  Debentures  having a total principal amount
equal to this Debenture in the denominations requested by the Holder.

         SECTION 7.4. WORN AND LOST DEBENTURES.  If this Debenture becomes worn,
defaced or mutilated but is still  substantially  intact and  recognizable,  the
Company  or its  agent  may  issue a new  Debenture  in  lieu  hereof  upon  its
surrender. Where the Holder of this Debenture claims that the Debenture has been
lost,  destroyed or wrongfully taken, the company shall issue a new Debenture in
place of the original  Debenture if the Holder so requests by written  notice to
the Company  actually  received by the  Company  before it is notified  that the
Debenture  has  been  acquired  by a bona  fide  purchaser  and the  Holder  has
delivered  to the  Company an  indemnity  bond in such amount and issued by such
surety as the Company  deems  satisfactory  together  with an  affidavit  of the
Holder  setting forth the facts  concerning  such loss,  destruction or wrongful
taking and such other  information in such form with such proof or  verification
as the Company may request.

ARTICLE 8.        NOTICES.

         Any notice  which is  required  or  convenient  under the terms of this
Debentures  shall be duly given if it is in writing and delivered in person,  by
telecopy, by recognized overnight courier or mailed by first class mail, postage
prepaid and directed to the Holder of the Debenture at its address as it appears
on the Register or if to the Company to its  principal  executive  offices.  The
time when such notice is sent shall be the time of the giving of the notice.




NOTICE OF CONVERSION


         All notices to Holders are to be mailed to:

         27 Wellington Road
         Cork, Ireland
         Attn:  James G. O'Brien
         Telephone: 353 21 501 109
         Fax: 353 21 501 255

         All notices to the Company are to be mailed to:

         Intelect Communications Systems Limited
         Reid House 31 Church Street
         Hamilton, Bermuda
         Attn:  Chief Executive Officer
         Telephone:  441/295-8639
         Fax:  441/292-5560


ARTICLE 9.        TIMES.

         Where this Debenture authorizes or requires the payment of money or the
performance  of a condition  or  obligation  on a Saturday or Sunday or a public
holiday,  or authorizes or requires the payment of money or the performance of a
condition or obligation within, before or after a period of time computed from a
certain date, and such period of time ends on a Saturday or a Sunday or a public
holiday,  such payment may be made or condition or  obligation  performed on the
next  succeeding  business day, and if the period ends at a specified hour, such
payment may be made or condition  performed,  at or before the same hour of such
next  succeeding  business  day,  with the same  force and  effect as if made or
performed in accordance with the terms of this Debenture. Where time is extended
by virtue of the  provisions  of this Article 9, such extended time shall not be
included in the computation of interest.

ARTICLE 10.       RULES OF CONSTRUCTION.

         In this Debenture,  unless the context otherwise requires, words in the
singular number include the plural, and in the plural include the singular,  and
words of the masculine gender include the feminine and the neuter,  and when the
sense so  indicates,  words of the neuter  gender may refer to any  gender.  The
numbers and titles of sections  contained  in this  Debenture  are  inserted for
convenience  of reference  only,  and they neither form a part of this Debenture
nor are they to be used in the construction or interpretation hereof.  Wherever,
in this Debenture,  a determination of the Company is required or allowed,  such
determination  shall be made by a  majority  of the  Board of  Directors  of the
Company and if it is made in good faith, it shall be conclusive and binding upon
the Company and the Holder of this Debenture.


NOTICE OF CONVERSION



ARTICLE 11.       GOVERNING LAW.

         The validity,  terms,  performance  and  enforcement  of this Debenture
shall be governed and construed by the provisions  hereof and in accordance with
the laws of Bermuda.


         IN WITNESS WHEREOF,  the Company has duly executed this Debenture as of
the date first written above.

                                         INTELECT COMMUNICATIONS SYSTEMS LIMITED


                                          By: /s/ Peter G. Leighton
                                             ------------------------------
                                          Name Peter G. Leighton
                                          Title President

[Corporate Seal]





NOTICE OF CONVERSION


                              NOTICE OF CONVERSION

         [To be completed and signed only upon conversion of Debenture]

         The  undersigned,  the  Holder of this  Debenture,  hereby  irrevocably
elects to exercise the right to convert it into common shares, par value $10 per
share, of Intelect Communications Systems Limited as follows:

[Complete if less than all of                     Dollars ($       )*
 principal  amount is to be        ---------------------------------------------
 converted]                         ($10,000 or integral  multiples of $10,000)

[Signature must be guaranteed      ---------------------------------------------
if registered holder of stock       (Name of Holder of shares if different than
differs from registered Holder      registered Holder of Debenture)
of Debenture] 

                                   ---------------------------------------------
                                    (Address of Holder if different than address
                                    of registered Holder of Debenture)

                                   ---------------------------------------------
                                    (Social Security or EIN of Holder of shares
                                    if different than Holder of Debenture)

         *If the principal  amount of the Debenture to be converted is less than
         the entire principal amount thereof, a new Debenture for the balance of
         the principal  amount shall be returned to the Holder of the Debenture.
         All notices to be transmitted by hand delivery,  facsimile or overnight
         courier.


Date:_________           Sign:__________________________________________________
                              (Signature must conform in all respects to name of
                              Holder shown on face of this Debenture)






NOTICE OF CONVERSION



                               ASSIGNMENT OF NOTE



        The undersigned hereby sell(s) and assign(s) and transfer(s) unto

- --------------------------------------------------------------------------------
                   (name, address and SSN or EIN of assignee)

                                                        Dollars ($             )
- --------------------------------------------------------------------------------
   (principal amount of Debenture, $10,000 or integral multiples of $10,000)

of principal amount of this Debenture together with all accrued interest hereon.


Date:________                 Sign:_____________________________________________
                              (Signature must conform in all respects to name of
                              Holder  shown on face of Debenture)