Exhibit 4.1

NEITHER THESE  SECURITIES  NOR THE  SECURITIES  INTO WHICH THESE  SECURITIES ARE
CONVERTIBLE HAVE BEEN REGISTERED WITH THE SECURITIES AND EXCHANGE  COMMISSION IN
RELIANCE UPON AN EXEMPTION FROM  REGISTRATION  UNDER THE SECURITIES ACT OF 1933,
AS AMENDED (THE "SECURITIES ACT"), AND, ACCORDINGLY,  MAY NOT BE OFFERED OR SOLD
EXCEPT PURSUANT TO AN EFFECTIVE  REGISTRATION STATEMENT UNDER THE SECURITIES ACT
OR PURSUANT TO AN AVAILABLE  EXEMPTION FROM, OR IN A TRANSACTION NOT SUBJECT TO,
THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT.

THIS DEBENTURE DOES NOT REQUIRE PHYSICAL SURRENDER OF THE DEBENTURE IN THE EVENT
OF A PARTIAL REDEMPTION OR CONVERSION.  AS A RESULT, FOLLOWING ANY REDEMPTION OR
CONVERSION OF ANY PORTION OF THIS DEBENTURE,  THE OUTSTANDING  PRINCIPAL  AMOUNT
REPRESENTED BY THIS DEBENTURE MAY BE LESS THAN THE PRINCIPAL  AMOUNT AND ACCRUED
INTEREST SET FORTH BELOW.


                   4% CONVERTIBLE DEBENTURE DUE JUNE 30, 2002

                                       OF

                                FONAR CORPORATION


Debenture No.:  1                          Original Principal Amount: $4,500,000
Issuance Date:  May 24, 2001               New York, New York


     THIS  DEBENTURE  ("Debenture")  is  one  of  a  duly  authorized  issue  of
debentures of FONAR CORPORATION, a corporation duly organized and existing under
the laws of the State of Delaware (the  "Company"),  designated as the Company's
4% Convertible  Debentures Due June 30, 2002  ("Maturity  Date") in an aggregate
principal amount (when taken together with the original principal amounts of all
other  Debentures) which does not exceed Four Million Five Hundred Thousand U.S.
Dollars (U.S. $4,500,000) (the "Debentures").

     FOR VALUE RECEIVED,  the Company hereby promises to pay to the order of The
Tail  Wind  Fund,  Ltd.  or its  registered  assigns  or  successors-in-interest
("Holder") the principal sum of Four Million Five Hundred Thousand Dollars (U.S.
$4,500,000),  together with all accrued but unpaid interest thereon,  if any, on
the Maturity Date, to the extent such principal amount and interest has not been
repaid or converted into the Company's Common Stock, $0.0001 par value per share
(the "Common  Stock"),  in  accordance  with the terms  hereof.  Interest on the
unpaid  principal  balance  hereof shall accrue at the rate of 4% per annum from
the date of  original  issuance  hereof  (the  "Issuance  Date")  until the same
becomes  due and  payable  on the  Maturity  Date,  or such  earlier  date  upon
acceleration  or by conversion or redemption in accordance with the terms hereof
or of the other  Agreements.  Interest  on this  Debenture  shall  accrue  daily
commencing  on the Issuance Date and shall be computed on the basis of a 360-day
year,  30-day  months and actual days elapsed and shall be payable in accordance
with Section 1 hereof. Notwithstanding anything contained herein, this Debenture
shall bear  interest on the due and unpaid  Principal  Amount from and after the
occurrence and during the continuance of an Event of Default pursuant to Section
4(a),  at the rate  (the  "Default  Rate")  equal to the  lower of  sixteen  and
one-half  percent (16.5%) per annum or the highest rate permitted by law. Unless
otherwise  agreed or required by applicable law,  payments will be applied first
to any  unpaid  collection  costs,  then to  unpaid  interest  and  fees and any
remaining amount to principal.

     All payments of principal and interest on this  Debenture  shall be made in
lawful  money of the United  States of America by wire  transfer of  immediately
available funds to such account as the Holder may from time to time designate by
written notice in accordance with the provisions of this Debenture or by Company
check. This Debenture may not be prepaid in whole or in part except as otherwise
provided herein or in the Transaction  Documents.  Whenever any amount expressed
to be due by the  terms  of  this  Debenture  is due on any day  which  is not a
Business  Day (as  defined  below),  the same  shall  instead be due on the next
succeeding day which is a Business Day.

     Capitalized  terms used  herein and not  otherwise  defined  shall have the
meanings set forth in the Purchase Agreement dated on or about the Issuance Date
pursuant  to  which  the  Debentures  were  originally   issued  (the  "Purchase
Agreement").  For purposes  hereof the  following  terms shall have the meanings
ascribed to them below:

     "Business Day" shall mean any day other than a Saturday, Sunday or a day on
which commercial banks in the City of New York are authorized or required by law
or executive order to remain closed.

     "Change in Control Transaction" will be deemed to exist if (i) there occurs
any consolidation,  merger or other business  combination of the Company with or
into any other corporation or other entity or person (whether or not the Company
is  the  surviving  corporation),  or  any  other  corporate  reorganization  or
transaction or series of related transactions in which in any of such events the
voting  stockholders of the Company prior to such event cease to own 50% or more
of the voting power, or corresponding voting equity interests,  of the surviving
corporation after such event (including  without  limitation any "going private"
transaction under Rule 13e-3 promulgated  pursuant to the Exchange Act or tender
offer by the Company under Rule 13e-4  promulgated  pursuant to the Exchange Act
for 20% or more of the Company's  Common Stock),  (ii) any person (as defined in
Section 13(d) of the Exchange Act),  together with its affiliates and associates
(as such terms are defined in Rule 405 under the Act),  beneficially  owns or is
deemed to  beneficially  own (as  described in Rule 13d-3 under the Exchange Act
without regard to the 60-day exercise  period) in excess of 50% of the Company's
voting power,  (iii) there is a replacement of more than one-half of the members
of the Company's Board of Directors  which is not approved by those  individuals
who are members of the Company's Board of Directors on the date thereof, (iv) in
one or a series of related  transactions,  there is a sale or transfer of all or
substantially  all of the assets of the Company,  determined  on a  consolidated
basis,  or (v) the execution by the Company of an agreement to which the Company
is a party or which it is bound  providing for an event set forth in (i),  (ii),
(iii) or (iv) above.

     "Conversion  Ratio" means, at any time, a fraction,  of which the numerator
is the entire  outstanding  Principal  Amount of this Debenture (or such portion
thereof that is being redeemed or repurchased),  and of which the denominator is
the  lesser of the  Conversion  Price and the  Market  Price as of the date such
ratio is being determined.

     "Conversion Price" shall equal 125% of the average closing bid price of the
Common  Stock as reported by the  Principal  Market  over the  twenty-five  (25)
Trading Days  immediately  preceding  the Closing Date (which  Conversion  Price
shall be subject to adjustment  as set forth herein,  and the closing bid prices
used to determine  the  Conversion  Price shall be  appropriately  and equitably
adjusted for any stock splits, stock dividends, recapitalizations and the like).

     "Convertible  Securities"  means  any  convertible  securities,   warrants,
options or other rights to subscribe for or to purchase or exchange for,  shares
of Common Stock.

     "Effective Date" means the date on which a Registration  Statement covering
all the Underlying  Shares and other  Registrable  Securities (as defined in the
Registration Rights Agreement) is declared effective by the SEC.

     "Effective  Registration"  shall have the meaning set forth in the Purchase
Agreement.

     "Exchange Act" shall mean the Securities Exchange Act of 1934, as amended.

     "Market Price" shall equal the lesser of (i) 90% of the average of the four
(4) lowest  closing bid prices of the Common Stock as reported by the  Principal
Market during the full calendar  month  immediately  preceding the date on which
such Market Price is being  determined  (such average referred to as the "Lowest
Average"), and (ii) the Lowest Average less $0.125.

     "MFN  Transaction"  shall mean a transaction in which the Company issues or
sells any  securities  in a capital  raising  transaction  or series of  related
transactions  (the  "MFN  Offering")  which  grants  to the  investor  (the "MFN
Investor") the right to receive additional  securities based upon future capital
raising  transactions  of the Company on terms more favorable than those granted
to the MFN Investor in the MFN Offering.

     "Per Share Selling  Price" shall include the amount  actually paid by third
parties for each share of Common Stock in a sale or issuance by the Company.  In
the event a fee is paid by the  Company  in  connection  with  such  transaction
directly or indirectly to such third party or its affiliates, any such fee shall
be  deducted  from  the  selling  price  pro  rata  to all  shares  sold  in the
transaction to arrive at the Per Share Selling Price. A sale of shares of Common
Stock  shall  include  the sale or  issuance  of rights,  options,  warrants  or
convertible,  exchangeable or exercisable  securities under which the Company is
or  may  become  obligated  to  issue  shares  of  Common  Stock,  and  in  such
circumstances  the Per Share Selling  Price of the Common Stock covered  thereby
shall also  include the  exercise,  exchange  or  conversion  price  thereof (in
addition to the consideration received by the Company upon such sale or issuance
less the fee amount as provided above). In case of any such security issued in a
Variable Rate  Transaction  or an MFN  Transaction,  the Per Share Selling Price
shall be deemed to be the  lowest  conversion  or  exercise  price at which such
securities  are converted or exercised or might have been converted or exercised
in the case of a Variable Rate  Transaction,  or the lowest  adjustment price in
the case of an MFN Transaction,  over the life of such securities. If shares are
issued for a consideration other than cash, the Per Share Selling Price shall be
the fair value of such  consideration as determined in good faith by independent
certified  public  accountants  mutually  acceptable  to  the  Company  and  the
Purchaser.  In the event the Company directly or indirectly  effectively reduces
the conversion,  exercise or exchange price for any Convertible Securities which
are  currently  outstanding,  then the Per Share  Selling Price shall equal such
effectively reduced conversion, exercise or exchange price.

     "Principal  Amount"  shall refer to the sum of (i) the  original  principal
amount of this Debenture,  (ii) all accrued but unpaid interest  hereunder,  and
(iii) any default payments owing under the Agreements but not previously paid or
added to the Principal Amount.

     "Principal  Market"  shall mean the NASDAQ  Small-Cap  Market or such other
principal  market or  exchange  on which the  Common  Stock is then  listed  for
trading.

     "Registration   Statement"   shall  have  the  meaning  set  forth  in  the
Registration Rights Agreement.

     "Securities Act" shall mean the Securities Act of 1933, as amended.

     "Trading  Day" shall mean a day on which there is trading on the  Principal
Market.

     "Underlying  Shares"  means  the  shares  of Common  Stock  into  which the
Debentures  are  convertible  (including  repayment in Common Stock as set forth
herein) in accordance with the terms hereof and the Purchase Agreement.

     "Variable Rate  Transaction"  shall mean a transaction in which the Company
issues or sells (a) any debt or equity  securities  that are  convertible  into,
exchangeable  or  exercisable  for, or include  the right to receive  additional
shares of Common Stock either (x) at a conversion,  exercise or exchange rate or
other  price that is based upon  and/or  varies  with the  trading  prices of or
quotations  for the Common Stock at any time after the initial  issuance of such
debt or equity securities, or (y) with a fixed conversion,  exercise or exchange
price that is  subject  to being  reset at some  future  date after the  initial
issuance of such debt or equity  security or upon the occurrence of specified or
contingent events directly or indirectly  related to the business of the Company
or the  market  for  the  Common  Stock  (but  excluding  standard  stock  split
anti-dilution  provisions),  or (b) any securities of the Company pursuant to an
"equity  line"  structure  which  provides for the sale,  from time to time,  of
securities  of the  Company  which are  registered  for resale  pursuant  to the
Securities Act.

     The following terms and conditions shall apply to this Debenture:

Section 1. Payments of Principal and Interest.

(a)  Monthly Payments. Subject to the terms of this Section 1, the Company shall
     repay ten percent (10%) of the original principal amount of this Debenture,
     together  with  interest  accrued to date on such  portion of the  original
     principal  amount  plus  any and  all  default  payments  owing  under  the
     Agreements but not previously paid  (collectively,  "Monthly  Amount"),  in
     accordance  with  subsection  1(b) below, on the first business day of each
     consecutive calendar month (each a "Repayment Date") beginning on the first
     such day which occurs following the third full calendar month following the
     Issuance Date.

(b)  Cash or Common Stock.  Subject to the terms hereof,  the Company shall have
     the  right  to  satisfy  payment  of the  Monthly  Amount  in  full on each
     Repayment  Date either in cash or in shares of Common  Stock (but not both)
     at the  Company's  option.  The Company shall deliver to all the holders of
     Debentures a written  irrevocable  notice in the form of Exhibit B attached
     hereto  electing to pay such Monthly  Amount in full on such Repayment Date
     in  either  cash  or  Common  Stock  ("Repayment  Election  Notice").  Such
     Repayment Election Notice shall be delivered at least four (4) Trading Days
     prior to the applicable Repayment Date but no more than twenty (20) Trading
     Days  prior  to  such  Repayment  Date  (the  date  of  such  notice  being
     hereinafter  referred to as the "Notice Date"). If such Repayment  Election
     Notice is not  delivered  within  the  prescribed  period  set forth in the
     preceding  sentence,  then the  repayment  shall be made in either  cash or
     shares of Common Stock on the same terms  hereunder  at the  Holder's  sole
     option. If the Company elects or is required to repay any Monthly Amount in
     cash on a Repayment Date, then on such Repayment Date the Company shall pay
     to the Holder an amount equal to such  Monthly  Amount in  satisfaction  of
     such obligation.  If the Company elects or is required to repay any Monthly
     Amount in shares of Common  Stock,  the number of such  shares to be issued
     for such Repayment Date shall be the number  determined by dividing (x) the
     Monthly  Amount,  by (y) the Market Price as of such Repayment  Date.  Such
     shares  shall be  issued  and  delivered  within  three  (3)  Trading  Days
     following such Repayment Date and shall be duly authorized, validly issued,
     fully  paid,  non-assessable  and  free  and  clear  of  all  encumbrances,
     restrictions  and  legends.  If any Holder does not  receive the  requisite
     number of shares of Common  Stock in the form  required  above  within such
     three  Trading Day period,  the Holder  shall have the option of either (a)
     requiring  the Company to issue and deliver all or a portion of such shares
     or (b) canceling  such  election  (whether by the Company or Holder) to pay
     the Monthly Amount in Common Stock (in whole or in part), in which case the
     Company shall immediately pay in cash the full Monthly Amount due hereunder
     or such  portion as the Holder  specifies  is to be paid in cash instead of
     Common Stock.  Except as otherwise  provided in this Section 1, all holders
     of Debentures  must be treated  equally with respect to such payment of the
     Monthly Amount in shares of Common Stock.

(c)  No Effective Registration. Notwithstanding anything to the contrary herein,
     the Company  shall be  prohibited  from  exercising  its right to repay the
     Monthly  Amount in shares of Common Stock (and must deliver cash in respect
     thereof) on the  applicable  Repayment  Date if at any time from the Notice
     Date until the time at which the Holders receive such shares there fails to
     exist  Effective  Registration  (defined  below)  or an  Event  of  Default
     hereunder  exists or  occurs,  unless  otherwise  waived in  writing by the
     Holder in whole or in part at the Holder's option. "Effective Registration"
     shall mean:  (i) the Company has  complied  with its  material  obligations
     under all the  Agreements  in all  material  respects  and has not made any
     material  misrepresentations under any of the Agreements or under any other
     agreements between the Company and the Purchaser, except for those breaches
     or defaults  which are capable of being cured and have been so cured within
     a reasonable time following notice of such breach or default (not to exceed
     5 business days); (ii) the resale of all Registrable Securities (as defined
     in  the  Registration   Rights   Agreement)  is  covered  by  an  effective
     registration  statement in  accordance  with the terms of the  Registration
     Rights  Agreement  and such  registration  statement  is not subject to any
     suspension or stop orders; (iii) the resale of such Registrable  Securities
     may be effected  pursuant to a current and  deliverable  prospectus that is
     not subject to any blackout or similar circumstance;  (iv) such Registrable
     Securities  are listed,  or approved for listing  prior to issuance,  on an
     Approved  Market and are not subject to any trading  suspension  (nor shall
     trading generally have been suspended on such exchange or market),  and the
     Company  shall  not  have  been  notified  of  any  pending  or  threatened
     proceeding  or other  action to delist or suspend  the Common  Stock on the
     Approved Market on which the Common Stock is then traded or listed; (v) the
     requisite  number of shares of Common Stock shall have been duly authorized
     and reserved for issuance as required by the terms of the  Agreements;  and
     (vi) none of the  Company  or any  direct  or  indirect  subsidiary  of the
     Company  is  subject  to  any  Bankruptcy   Event.   For  purposes  hereof,
     "Bankruptcy  Event" means any of the following  events:  (a) the Company or
     any subsidiary  commences a case or other  proceeding under any bankruptcy,
     reorganization,   arrangement,  adjustment  of  debt,  relief  of  debtors,
     dissolution,  insolvency or liquidation or similar law of any  jurisdiction
     relating to the Company or any subsidiary  thereof;  (b) there is commenced
     against the Company or any subsidiary  any such case or proceeding  that is
     not  dismissed  within 60 days after  commencement;  (c) the Company or any
     subsidiary is  adjudicated  insolvent or bankrupt or any order of relief or
     other order  approving  any such case or  proceeding  is  entered;  (d) the
     Company or any subsidiary  suffers any  appointment of any custodian or the
     like for it or any substantial  part of its property that is not discharged
     or stayed within 60 days; (e) the Company or any subsidiary makes a general
     assignment for the benefit of creditors;  (f) the Company or any subsidiary
     fails to pay, or states  that it is unable to pay or is unable to pay,  its
     debts generally as they become due; (g) the Company or any subsidiary calls
     a  meeting  of its  creditors  with  a view  to  arranging  a  composition,
     adjustment  or  restructuring  of its  debts;  or (h)  the  Company  or any
     subsidiary,  by any act or failure to act, expressly  indicates its consent
     to,  approval  of or  acquiescence  in any of the  foregoing  or takes  any
     corporate  or  other  action  for  the  purpose  of  effecting  any  of the
     foregoing.

(d)  Ownership/Issuance  Limitations.  Notwithstanding  anything to the contrary
     herein,  the Company shall be prohibited from exercising its right to repay
     the  Monthly  Amount in shares of Common  Stock (and must  deliver  cash in
     respect thereof) on the applicable  Repayment Date to the extent,  and only
     to the extent,  that such  repayment in shares of Common Stock would result
     in the Holder hereof  exceeding the  limitations  contained in Section 3(i)
     below.  In such  event,  then (i) the Company on the  Repayment  Date shall
     repay such  portion of the Monthly  Amount in shares of Common Stock as may
     be effected without exceeding such limitations, (ii) the Repayment Date for
     the balance of the Monthly Amount shall be extended until such time as such
     stock payment can be made without violating Section 3(i),  provided that if
     such stock  payment  cannot be made only because it would  violate  Section
     3(i)(C)  below,  then at the Holder's  option the Company shall redeem such
     Monthly  Amount  portion of this  Debenture at a redemption  price equal to
     120% of such Monthly  Amount.  If any portion of any Monthly Amount remains
     unpaid as of the Maturity Date hereof,  such amount shall be repaid in cash
     on the Maturity Date (unless  accelerated  hereunder  pursuant to Section 4
     below).

(e)  Deemed Conversions. Any repayment of the Monthly Amount in shares of Common
     Stock  pursuant  to the  terms  hereof  shall  constitute  and be  deemed a
     conversion  of such portion of the Principal  Amount of this  Debenture for
     all purposes  under this  Debenture and the other  Agreements  (except that
     such  conversion  shall be at the  Market  Price and  except  as  otherwise
     provided herein).

Section 2. [INTENTIONALLY OMITTED]

Section 3. Conversion.

(a)  Conversion  Right.  Subject  to  the  terms  hereof  and  restrictions  and
     limitations  contained  herein,  the Holder  shall have the right,  at such
     Holder's  option,  at any  time  and  from  time  to time  to  convert  the
     outstanding  Principal  Amount under this  Debenture in whole or in part by
     delivering to the Company a fully executed notice of conversion in the form
     of  conversion  notice  attached  hereto  as  Exhibit  A  (the  "Conversion
     Notice"),  which may be transmitted by facsimile.  Notwithstanding anything
     to the contrary herein, this Debenture and the outstanding Principal Amount
     hereunder  shall not be  convertible  into Common  Stock to the extent that
     such conversion would result in the Holder hereof exceeding the limitations
     contained in, or otherwise violating the provisions of, Section 3(i) below.
     For clarification  purposes,  any conversions of the outstanding  Principal
     Amount under this Debenture in part pursuant to this Section 3(a) shall not
     affect the Company's  obligation to repay the Monthly Amount as provided in
     Section 1 above.

(b)  Common Stock Issuance Upon Conversion.

(i)  Conversion Date Procedures.  Upon conversion of this Debenture  pursuant to
     Section 3(a) above,  the outstanding  Principal  Amount  hereunder shall be
     converted into such number of fully paid, validly issued and non-assessable
     shares of Common Stock, free of any liens,  claims and encumbrances,  as is
     determined by dividing the outstanding  Principal Amount being converted by
     the then applicable  Conversion  Price.  The date of any Conversion  Notice
     hereunder  and any  Repayment  Date  shall be  referred  to  herein  as the
     "Conversion  Date". If a conversion under this Debenture cannot be effected
     in full for any reason, or if the Holder is converting less than all of the
     outstanding Principal Amount hereunder pursuant to a Conversion Notice, the
     Company  shall  promptly  deliver  to the  Holder  (but no later  than five
     Trading Days after the  Conversion  Date) a Debenture for such  outstanding
     Principal  Amount  as has not been  converted  if this  Debenture  has been
     surrendered to the Company for partial conversion.  The Holder shall not be
     required to  physically  surrender  this  Debenture to the Company upon any
     conversion  or payment for the  Monthly  Amount  hereunder  unless the full
     outstanding  Principal  Amount  represented  by  this  Debenture  is  being
     converted  or repaid.  The Holder and the Company  shall  maintain  records
     showing the  outstanding  Principal  Amount so converted and repaid and the
     dates of such  conversions  or  repayments  or shall use such other method,
     reasonably satisfactory to the Holder and the Company, so as not to require
     physical   surrender  of  this  Debenture  upon  each  such  conversion  or
     repayment.

(ii) Stock  Certificates  or DWAC.  The Company  will  deliver to the Holder not
     later than three (3) Trading Days after the Conversion  Date, a certificate
     or  certificates  which  shall be free of  restrictive  legends and trading
     restrictions,  representing  the  number of shares  of Common  Stock  being
     acquired  upon the  conversion  of this  Debenture.  In lieu of  delivering
     physical certificates representing the shares of Common Stock issuable upon
     conversion  of this  Debenture,  provided the Company's  transfer  agent is
     participating  in the  Depository  Trust  Company  ("DTC")  Fast  Automated
     Securities  Transfer  ("FAST")  program,  upon  request of the Holder,  the
     Company  shall use  commercially  reasonable  efforts to cause its transfer
     agent to  electronically  transmit such shares  issuable upon conversion to
     the Holder (or its designee),  by crediting the account of the Holder's (or
     such designee's) prime broker with DTC through its Deposit Withdrawal Agent
     Commission  system (provided that the same time periods herein as for stock
     certificates shall apply). If in the case of any conversion hereunder, such
     certificate  or  certificates  are not  delivered  to or as directed by the
     Holder by the third Trading Day after the Conversion Date, the Holder shall
     be entitled  by written  notice to the Company at any time on or before its
     receipt of such  certificate or  certificates  thereafter,  to rescind such
     conversion,  in which  event the  Company  shall  immediately  return  this
     Debenture  tendered for conversion.  If the Company fails to deliver to the
     Holder such certificate or certificates (or shares through DTC) pursuant to
     this Section 3(b) (free of any restrictions on transfer or legends, if such
     shares have been  registered)  in accordance  herewith,  prior to the sixth
     Trading Day after the Conversion Date, the Company shall pay to the Holder,
     in cash, an amount equal to 2% of the Principal Amount per month.

(c)  Conversion Price Adjustments.

(i)  Stock  Dividends,  Splits and  Combinations.  If the  Company or any of its
     subsidiaries,  at any time while the Debentures are  outstanding  (A) shall
     pay a stock dividend or otherwise make a distribution or  distributions  on
     any equity securities (including instruments or securities convertible into
     or exchangeable for such equity  securities) in shares of Common Stock, (B)
     subdivide  outstanding  Common Stock into a larger number of shares, or (C)
     combine outstanding Common Stock into a smaller number of shares, then each
     Affected  Conversion  Price (as defined  below)  shall be  multiplied  by a
     fraction,  the  numerator  of which shall be the number of shares of Common
     Stock  outstanding  before such event and the denominator of which shall be
     the number of shares of Common  Stock  outstanding  after such  event.  Any
     adjustment  made pursuant to this Section  3(c)(i)  shall become  effective
     immediately  after the record date for the  determination  of  stockholders
     entitled  to  receive  such  dividend  or  distribution  and  shall  become
     effective immediately after the effective date in the case of a subdivision
     or combination.

As   used herein, the Affected  Conversion Prices (each an "Affected  Conversion
     Price") shall refer to: (i) the Conversion  Price; (ii) each reported daily
     closing bid price of the Common Stock on the Principal  Market occurring on
     any Trading Day  included  in the period  used for  determining  the Market
     Price or Conversion  Price,  as the case may be, which Trading Day occurred
     before the record  date in the case of events  referred to in clause (A) of
     this subparagraph  3(c)(i) and before the effective date in the case of the
     events referred to in clauses (B) and (C) of this subparagraph 3(c)(i).

(ii) Distributions. If the Company or any of its subsidiaries, at any time while
     the Debentures are  outstanding,  shall distribute to all holders of Common
     Stock evidences of its indebtedness or assets or cash or rights or warrants
     to  subscribe  for or  purchase  any  security of the Company or any of its
     subsidiaries  (excluding those referred to in Section 3(c)(i) above),  then
     concurrently  with such  distributions  to  holders  of Common  Stock,  the
     Company shall  distribute to holders of the  Debentures  the amount of such
     indebtedness,  assets,  cash or rights or  warrants  which the  holders  of
     Debentures would have received had all their Debentures been converted into
     Common Stock at the lower of the Conversion  Price and the then  applicable
     Market Price immediately prior to the record date for such distribution.

(iii)Common  Stock  Issuances.  In the  event  that  the  Company  or any of its
     subsidiaries  (A) issues or sells any Common Stock or securities  which are
     convertible  into or  exercisable or  exchangeable  for Common Stock (other
     than issuances of Debentures, Warrants and of Underlying Shares pursuant to
     Debentures or Warrants  issued under the Purchase  Agreement and other than
     issuances  described in and  permitted  under  Section  7.2(b)(iii)  of the
     Purchase  Agreement  and other than  issuances  of Common  Stock  under the
     Company's  duly  adopted  stock  option and bonus plans for  employees  and
     directors), or any warrants or other rights to subscribe for or to purchase
     or any options  for the  purchase  of its Common  Stock or (B)  directly or
     indirectly  effectively reduces the conversion,  exercise or exchange price
     for any Convertible  Securities which are currently outstanding (other than
     pursuant to terms  existing on the date hereof),  at or to an effective Per
     Share Selling Price which is less than:

(A)  the  closing  sale  price per share of the  Common  Stock on the  Principal
     Market on the Trading Day next preceding such issue or sale or, in the case
     of  issuances  to  holders  of its  Common  Stock,  the date  fixed for the
     determination of stockholders entitled to receive such warrants, rights, or
     options  ("Fair  Market  Price"),  then in each  such  case,  the  Affected
     Conversion  Price in  effect  immediately  prior  to such  issue or sale or
     record  date,  as  applicable,  shall be  automatically  reduced  effective
     concurrently with such issue or sale to an amount determined by multiplying
     the  Affected  Conversion  Price  then in  effect  by a  fraction,  (x) the
     numerator  of which  shall be the sum of (1) the number of shares of Common
     Stock  outstanding  immediately  prior to such issue or sale,  plus (2) the
     number of shares of Common Stock which the aggregate consideration received
     by the  Company  for such  additional  shares  would  purchase at such Fair
     Market  Price,  and (y) the  denominator  of which  shall be the  number of
     shares of Common Stock of the Company  outstanding  immediately  after such
     issue or sale; or

(B)  the  Conversion  Price,  then in each such case,  the  Conversion  Price in
     effect  immediately  prior  to  such  issue  or  sale or  record  date,  as
     applicable, shall be automatically reduced effective concurrently with such
     issue or sale to an amount equal to such Per Share Selling Price.

     The foregoing  provision of this subsection shall not apply to issuances or
sales  pursuant to the  Company's  duly adopted  employee or director  bona fide
options plans and/or compensation arrangements.

     For the purposes of the foregoing adjustments,  in the case of the issuance
of any  Convertible  Securities,  the maximum  number of shares of Common  Stock
issuable upon exercise,  exchange or conversion of such  Convertible  Securities
shall be deemed to be outstanding,  provided that no further adjustment shall be
made upon the  actual  issuance  of Common  Stock  upon  exercise,  exchange  or
conversion of such Convertible Securities.

     For purposes of this Section  3(c)(iii),  if an event occurs that  triggers
more than one of the above adjustment provisions, then only one adjustment shall
be made and the calculation method which yields the greatest downward adjustment
in the Affected Conversion Price shall be used.

(iv) Rounding of Adjustments. All calculations under this Section 3 or Section 1
     shall be made to the nearest cent or the nearest 1/100th of a share, as the
     case may be.

(v)  Notice of Adjustments.  Whenever any Affected  Conversion Price is adjusted
     pursuant  to  Section  3(c)(i),  (ii) or (iii)  above,  the  Company  shall
     promptly  deliver to each holder of the Debentures,  a notice setting forth
     the Affected  Conversion  Price after such  adjustment  and setting forth a
     brief statement of the facts requiring such  adjustment,  provided that any
     failure to so provide such notice shall not affect the automatic adjustment
     hereunder.

(vi) Change  in  Control  Transactions.   In  case  of  any  Change  in  Control
     Transaction,  the Holder shall have the right thereafter to, at its option,
     (A)  convert  this  Debenture,  in whole or in  part,  at the  lower of the
     Conversion  Price and the then  applicable  Market Price into the shares of
     stock and other securities,  cash and/or property receivable upon or deemed
     to be held by  holders of Common  Stock  following  such  Change in Control
     Transaction,  and the Holder  shall be entitled  upon such event to receive
     such  amount of  securities,  cash or  property as the shares of the Common
     Stock of the Company into which this  Debenture  could have been  converted
     immediately  prior to such  Change in Control  Transaction  would have been
     entitled  if such  conversion  were  permitted,  subject  to  such  further
     applicable  adjustments  set  forth in this  Section 3 or (B)  require  the
     Company or its successor to redeem this Debenture,  in whole or in part, at
     a redemption  price equal to the greater of (i) the  outstanding  Principal
     Amount  being  redeemed and (ii) the product of (x) the average of the Fair
     Market  Price  for the five (5)  Trading  Days  immediately  preceding  the
     Holder's  election to have its  Debentures  redeemed and (y) the Conversion
     Ratio.  The terms of any such Change in Control  Transaction  shall include
     such terms so as to  continue  to give to the  Holders the right to receive
     the amount of  securities,  cash and/or  property  upon any  conversion  or
     redemption  following such Change in Control  Transaction to which a holder
     of the number of shares of Common Stock  deliverable  upon such  conversion
     would  have been  entitled  in such  Change  in  Control  Transaction,  and
     interest payable  hereunder shall be in cash or such new securities  and/or
     property,  at the Holder's option.  This provision shall similarly apply to
     successive reclassifications,  consolidations, mergers, sales, transfers or
     share exchanges.

(vii) Notice of Certain Events. If:

     A.   the Company  shall declare a dividend (or any other  distribution)  on
          its Common Stock; or

     B.   the Company shall declare a special nonrecurring cash dividend on or a
          redemption of its Common Stock; or

     C.   the Company shall  authorize the granting to all holders of the Common
          Stock  rights or warrants to  subscribe  for or purchase any shares of
          capital stock of any class or of any rights; or

     D.   the approval of any  stockholders  of the Company shall be required in
          connection  with  any  reclassification  of the  Common  Stock  of the
          Company,  any consolidation or merger to which the Company is a party,
          any sale or transfer of all or substantially  all of the assets of the
          Company,  of any compulsory share of exchange whereby the Common Stock
          is converted into other securities, cash or property; or

     E.   the Company shall authorize the voluntary or involuntary  dissolution,
          liquidation or winding up of the affairs of the Company;

     then  the  Company  shall  cause  to be  filed  at each  office  or  agency
     maintained for the purpose of conversion of this Debenture, and shall cause
     to be mailed to the Holder at its last  address as it shall appear upon the
     books of the  Company,  on or prior to the  date  notice  to the  Company's
     stockholders  generally is given,  a notice stating (x) the date on which a
     record  is to be taken  for the  purpose  of such  dividend,  distribution,
     redemption, rights or warrants, or if a record is not to be taken, the date
     as of which the  holders of Common  Stock of record to be  entitled to such
     dividend,   distributions,   redemption,  rights  or  warrants  are  to  be
     determined or (y) the date on which such  reclassification,  consolidation,
     merger, sale, transfer or share exchange is expected to become effective or
     close, and the date as of which it is expected that holders of Common Stock
     of record  shall be entitled to exchange  their  shares of Common Stock for
     securities,  cash or other property deliverable upon such reclassification,
     consolidation, merger, sale, transfer or share exchange.

(d)  Reservation and Issuance of Underlying  Securities.  The Company  covenants
     that it will at all times reserve and keep  available out of its authorized
     and  unissued  Common  Stock  solely  for  the  purpose  of  issuance  upon
     conversion of this  Debenture  (including  repayments in stock),  free from
     preemptive rights or any other actual contingent purchase rights of persons
     other than the  holders  of the  Debentures,  not less than such  number of
     shares of Common Stock as shall (subject to any additional  requirements of
     the  Company as to  reservation  of such  shares set forth in the  Purchase
     Agreement)  be issuable  (taking  into account the  adjustments  under this
     Section 3 but without regard to any ownership limitations contained herein)
     upon the conversion of this Debenture  hereunder in Common Stock (including
     repayments in stock). The Company covenants that all shares of Common Stock
     that shall be so issuable shall,  upon issue, be duly  authorized,  validly
     issued, fully paid, nonassessable and freely tradeable.

(e)  No Fractions. Upon a conversion hereunder the Company shall not be required
     to issue  stock  certificates  representing  fractions  of shares of Common
     Stock,  but may if otherwise  permitted,  make a cash payment in respect of
     any final  fraction  of a share  based on the  closing  price of a share of
     Common Stock at such time. If the Company elects not, or is unable, to make
     such a cash  payment,  the Holder shall be entitled to receive,  in lieu of
     the final fraction of a share, one whole share of Common Stock.

(f)  Charges, Taxes and Expenses.  Issuance of certificates for shares of Common
     Stock upon the conversion of this Debenture  (including repayment in stock)
     shall be made without charge to the holder hereof for any issue or transfer
     tax or  other  incidental  expense  in  respect  of the  issuance  of  such
     certificate,  all of which taxes and expenses shall be paid by the Company,
     and such certificates  shall be issued in the name of the Holder or in such
     name or names as may be directed by the Holder; provided,  however, that in
     the event  certificates  for  shares of Common  Stock are to be issued in a
     name other than the name of the Holder, this Debenture when surrendered for
     conversion  shall  be  accompanied  by an  assignment  form;  and  provided
     further,  that the  Company  shall not be  required to pay any tax or taxes
     which may be payable in respect of any such transfer.

(g)  Cancellation.  After all of the  Principal  Amount  (including  accrued but
     unpaid  interest and default  payments at any time owed on this  Debenture)
     have been paid in full or converted into Common Stock, this Debenture shall
     automatically  be deemed  canceled and the Holder shall promptly  surrender
     the Debenture to the Company at the Company's principal executive offices.

(h)  Notices  Procedures.  Any  and  all  notices  or  other  communications  or
     deliveries  to be  provided  by the Holder  hereunder,  including,  without
     limitation,  any  Conversion  Notice,  shall be in  writing  and  delivered
     personally, by confirmed facsimile, or by a nationally recognized overnight
     courier service to the Company at the facsimile telephone number or address
     of the  principal  place of  business  of the  Company  as set forth in the
     Purchase  Agreement.  Any  and  all  notices  or  other  communications  or
     deliveries to be provided by the Company  hereunder shall be in writing and
     delivered personally, by facsimile, or by a nationally recognized overnight
     courier service  addressed to the Holder at the facsimile  telephone number
     or address of the Holder  appearing on the books of the  Company,  or if no
     such facsimile  telephone number or address appears, at the principal place
     of business of the Holder. Any notice or other  communication or deliveries
     hereunder  shall be  deemed  delivered  (i) upon  receipt,  when  delivered
     personally,  (ii) when sent by  facsimile,  upon  receipt if  received on a
     Business Day prior to 5:00 p.m.  (Eastern  Time),  or on the first Business
     Day  following  such  receipt if received on a Business Day after 5:00 p.m.
     (Eastern  Time) or (iii) upon  receipt,  when  deposited  with a nationally
     recognized overnight courier service.

(i)  Conversion Limitations.

(A)  9.9% Limitation. Notwithstanding anything to the contrary contained herein,
     the  number of shares of Common  Stock that may be  acquired  by the Holder
     upon  conversion  pursuant  to the terms  hereof  shall not exceed a number
     that,  when  added to the total  number of  shares of Common  Stock  deemed
     beneficially owned by such Holder (other than by virtue of the ownership of
     securities or rights to acquire securities  (including the Debentures) that
     have  limitations  on the Holder's  right to convert,  exercise or purchase
     similar to the limitation  set forth  herein),  together with all shares of
     Common Stock deemed  beneficially  owned at such time (other than by virtue
     of the ownership of securities  or rights to acquire  securities  that have
     limitations  on the right to convert,  exercise or purchase  similar to the
     limitation set forth herein) by the holder's  "affiliates" at such time (as
     defined  in Rule  144 of the Act)  ("Aggregation  Parties")  that  would be
     aggregated for purposes of determining  whether a group under Section 13(d)
     of the  Securities  Exchange Act of 1934 as amended,  exists,  would exceed
     9.9% of the total  issued and  outstanding  shares of the Common Stock (the
     "Restricted Ownership Percentage"). Each holder shall have the right (w) at
     any  time  and  from  time to  time  to  reduce  its  Restricted  Ownership
     Percentage  immediately  upon  notice to the  Company  and (x)  (subject to
     waiver)  at any time and from  time to time,  to  increase  its  Restricted
     Ownership  Percentage  immediately  in the  event  of the  announcement  as
     pending or planned, of a Change in Control Transaction.

(B)  Limitation  Covenants.  The Holder covenants at all times on each day (each
     such day being  referred  to as a "Covenant  Day") as  follows:  During the
     balance of such Covenant Day and the  succeeding  sixty-one  (61) days (the
     balance of such Covenant Day and the  succeeding 61 days being  referred to
     as the  "Covenant  Period")  such Holder will not acquire  shares of Common
     Stock pursuant to any right (including  conversion of Debentures)  existing
     at the  commencement  of the  Covenant  Period to the  extent the number of
     shares so acquired by such Holder and its Aggregation Parties (ignoring all
     dispositions) would exceed:

(x)  the Restricted Ownership Percentage of the total number of shares of Common
     Stock outstanding at the commencement of the Covenant Period, minus

(y)  the number of shares of Common Stock  actually owned by such Holder and its
     Aggregation Parties at the commencement of the Covenant Period.

     A new and independent  covenant will be deemed to be given by the Holder as
of each moment of each  Covenant Day. No covenant  will  terminate,  diminish or
modify any other covenant.  The Holder agrees to comply with each such covenant.
This  Section  3(i)(B)  controls  in the case of any  conflict  with  any  other
provision of the Purchase  Agreement or any agreement entered into in connection
therewith.

     The Company's obligation to issue shares of Common Stock which would exceed
such limits  referred to in this  Section  3(i) shall be suspended to the extent
necessary  until such time,  if any, as shares of Common  Stock may be issued in
compliance with such restrictions.

(C)  Overall Limit on Common Stock Issuable.  Notwithstanding anything contained
     herein to the  contrary,  the number of shares of Common Stock  issuable by
     the  Company and  acquirable  by the Holders of  Debentures,  together  the
     number of shares issued under the  Warrants,  shall not exceed 19.9% of the
     number of shares of Common Stock  outstanding on the Closing Date,  subject
     to  appropriate  adjustment  for stock splits,  stock  dividends,  or other
     similar  recapitalizations  affecting the Common Stock (the "Maximum Common
     Stock Issuance"),  unless the issuance of shares hereunder in excess of the
     Maximum  Common  Stock  Issuance  shall first be approved by the  Company's
     shareholders in accordance with applicable law and the By-laws and Articles
     of Incorporation  of the Company.  If at any point in time and from time to
     time (each a "Trigger Date") the number of Common Shares issued pursuant to
     conversion of the  Debentures  and exercise of the Warrants,  together with
     the number of Common  Shares  that would then be issuable by the Company in
     the event of  conversion  of all the  Debentures  and  exercise  of all the
     Warrants then  outstanding,  would exceed the Maximum Common Stock Issuance
     but for this Section  3(i)(C),  then the Company  shall,  at the  Company's
     election,  either  (A)  promptly  call a  shareholders  meeting  to  obtain
     shareholder  approval for the issuance of Common Shares hereunder in excess
     of the Maximum Common Stock Issuance, which such shareholder approval shall
     be obtained  within 60 days of the Trigger  Date,  or (B) purchase from the
     holders of  Debentures  and  Warrants  on a pro rata  basis such  Principal
     Amount of  Debentures  and number of Warrants  which cannot be converted or
     exercised   due  to  such   Maximum   Common  Stock   Issuance   limitation
     ("Shortfall")  at a  redemption  price equal to the  "Mandatory  Repurchase
     Price"  (as  defined  in the  Registration  Rights  Agreement),  which such
     redemption  price  shall be paid  within  three (3)  Trading  Days  after a
     Trigger  Date if this  clause (B) is elected.  The Company  shall make such
     election  with two (2) days  following  the Trigger Date by giving  written
     notice to all holders of Debentures  and Warrants.  If the Company fails to
     timely make such  election,  or elects  clause (A) but then fails to obtain
     such  shareholder  approval within 60 days following the Trigger Date, then
     the Company shall purchase the Shortfall at the Mandatory  Repurchase Price
     within three (3) Trading Days following any such failure.

Section 4. Defaults and Remedies.

(a)  Events of Default.  An "Event of  Default"  is: (i) a default in payment of
     the Principal  Amount or accrued but unpaid interest  thereon of any of the
     Debentures  on or after the date such  payment is due (to the  extent  such
     principal  and/or  amount  has not  been  converted  into  Common  Stock in
     accordance with the terms hereof),  which default  continues for 5 business
     days after  written  notice of such  non-payment  has been  received by the
     Company;  (ii) a default in the timely  issuance of Underlying  Shares upon
     and in  accordance  with terms  hereof,  which  default  continues for five
     business days after the Company has received  written notice  informing the
     Company  that it has failed to issue shares or deliver  stock  certificates
     within the fifth day following the  Conversion  Date;  (iii) failure by the
     Company for thirty (30) days after written  notice has been received by the
     Company to comply with any material provision of any of the Debentures, the
     Purchase  Agreement,  the  Registration  Rights  Agreement  or the Warrants
     (including  without limitation the failure to issue the requisite number of
     shares of Common  Stock upon  conversion  hereof and the  failure to redeem
     Debentures  upon  the  Holder's  request  following  a  Change  in  Control
     Transaction  pursuant to Section  3(c)(vi),  (iv) a material  breach by the
     Company of its  representations  or warranties  in the Purchase  Agreement,
     Registration  Rights Agreement or Warrants;  (v) any default after any cure
     period under, or acceleration prior to maturity of, any mortgage, indenture
     or  instrument  under  which  there may be issued or by which  there may be
     secured or evidenced any indebtedness for money borrowed by the Company for
     in excess of $1 million or for money  borrowed  the  repayment  of which is
     guaranteed  by the  Company  for in  excess  of $1  million,  whether  such
     indebtedness or guarantee now exists or shall be created hereafter; or (vi)
     if the Company is subject to any Bankruptcy Event.

(b)  Remedies.  If an Event of Default occurs and is continuing  with respect to
     any of the Debentures,  the Holder may declare all of the then  outstanding
     Principal  Amount of this  Debenture and all other  Debentures  held by the
     Holder,  including  any  interest  due  thereon,  to  be  due  and  payable
     immediately,  except that in the case of an Event of Default  arising  from
     events  described in clauses (v) and (vi) of Section 4(a),  this  Debenture
     shall become due and payable without further action or notice. In the event
     of such  acceleration,  the amount due and owing to the Holder shall be the
     greater of (1) 125% of the outstanding  Principal  Amount of the Debentures
     held by the Holder (plus all accrued and unpaid  interest,  if any) and (2)
     the product of (A) the highest  closing price for the five (5) Trading days
     immediately  preceding  the Holder's  acceleration  and (B) the  Conversion
     Ratio. In either case the Company shall pay interest on such amount in cash
     at the Default  Rate to the Holder if such amount is not paid within 7 days
     of Holder's request. The remedies under this Debenture shall be cumulative.

Section 5. General.

(a)  Payment of Expenses.  The Company agrees to pay all reasonable  charges and
     expenses,  including attorneys' fees and expenses, which may be incurred by
     the Holder in successfully  enforcing this Debenture and/or  collecting any
     amount due under this Debenture.

(b)  Savings Clause.  In case any provision of this Debenture is held by a court
     of competent  jurisdiction to be excessive in scope or otherwise invalid or
     unenforceable,  such  provision  shall be adjusted  rather than voided,  if
     possible, so that it is enforceable to the maximum extent possible, and the
     validity and  enforceability of the remaining  provisions of this Debenture
     will not in any way be affected or impaired thereby.  In no event shall the
     amount of interest  paid  hereunder  exceed the maximum rate of interest on
     the unpaid principal balance hereof allowable by applicable law. If any sum
     is collected in excess of the applicable maximum rate, the excess collected
     shall be applied to reduce the  principal  debt.  If the interest  actually
     collected  hereunder is still in excess of the applicable maximum rate, the
     interest  rate shall be reduced so as not to exceed the  maximum  allowable
     under law. (c) Amendment. Neither this Debenture nor any term hereof may be
     amended,  waived,   discharged  or  terminated  other  than  by  a  written
     instrument signed by the Company and Holders of 75% of the Principal Amount
     of all Debentures.

(d)  Assignment,  Etc. The Holder may assign or transfer  this  Debenture to any
     transferee  only with the prior written  consent of the Company,  which may
     not be unreasonably  withheld or delayed,  provided that (i) the Holder may
     assign  or  transfer  this  Debenture  to any of such  Holder's  affiliates
     without the consent of the Company and (ii) upon any Event of Default,  the
     Holder may assign or  transfer  this  Debenture  without the consent of the
     Company.  The Holder  shall  notify the Company of any such  assignment  or
     transfer promptly. This Debenture shall be binding upon the Company and its
     successors  and shall inure to the benefit of the Holder and its successors
     and permitted assigns.

(e)  No Waiver.  No failure on the part of the Holder to exercise,  and no delay
     in  exercising  any right,  remedy or power  hereunder  shall  operate as a
     waiver thereof,  nor shall any single or partial  exercise by the Holder of
     any right,  remedy or power hereunder preclude any other or future exercise
     of any other right,  remedy or power. Each and every right, remedy or power
     hereby granted to the Holder or allowed it by law or other  agreement shall
     be cumulative  and not exclusive of any other,  and may be exercised by the
     Holder from time to time.

(f)  Governing Law; Jurisdiction.

(i)  Governing  Law.  THIS  DEBENTURE  WILL  BE  GOVERNED  BY AND  CONSTRUED  IN
     ACCORDANCE  WITH THE LAWS OF THE  STATE OF NEW YORK  WITHOUT  REGARD TO ANY
     CONFLICTS  OF LAWS  PROVISIONS  THEREOF  THAT WOULD  OTHERWISE  REQUIRE THE
     APPLICATION OF THE LAW OF ANY OTHER JURISDICTION.

(ii) Jurisdiction. The Company irrevocably submits to the exclusive jurisdiction
     of any State or Federal Court  sitting in the State of New York,  County of
     New York, or San Jose,  California,  over any suit,  action,  or proceeding
     arising  out of or  relating to this  Debenture.  The  Company  irrevocably
     waives,  to the fullest extent permitted by law, any objection which it may
     now or hereafter have to the laying of the venue of any such suit,  action,
     or proceeding  brought in such a court and any claim that suit,  action, or
     proceeding has been brought in an inconvenient forum.

     The Company  agrees that the service of process upon it mailed by certified
     or registered mail (and service so made shall be deemed complete three days
     after the same has been posted as aforesaid)  or by personal  service shall
     be deemed in every respect effective service of process upon it in any such
     suit or  proceeding.  Nothing  herein shall affect  Holder's right to serve
     process in any other manner  permitted  by law.  The Company  agrees that a
     final  non-appealable  judgement  in any such suit or  proceeding  shall be
     conclusive  and may be  enforced  in  other  jurisdictions  by suit on such
     judgment or in any other lawful manner.

(iii)No Jury Trial. The COMPANY hereto knowingly and voluntarily  waives any and
     all rights it may have to a trial by jury with  respect  to any  litigation
     based on, or arising out of, under, or in connection with, this Debenture.

(g)  Replacement  Debentures.  This  Debenture may be exchanged by Holder at any
     time and from time to time for a Debenture  or  Debentures  with  different
     denominations representing an equal aggregate outstanding Principal Amount,
     as reasonably  requested by Holder,  upon surrendering the same. No service
     charge will be made for such  registration  or exchange.  In the event that
     Holder  notifies the Company that this  Debenture has been lost,  stolen or
     destroyed,  a  replacement  Debenture  identical  in  all  respects  to the
     original Debenture (except for registration number and Principal Amount, if
     different  than that shown on the original  Debenture),  shall be issued to
     the Holder,  provided that the Holder  executes and delivers to the Company
     an  agreement  reasonably  satisfactory  to the  Company to  indemnify  the
     Company from any loss incurred by it in connection with the Debenture.

                            [Signature Page Follows]



     IN WITNESS  WHEREOF,  the  Company  has caused  this  Debenture  to be duly
executed on the day and in the year first above written.


                                             FONAR CORPORATION

                                    By:    /s/
                                           ---------------------------
                                    Name:
                                           ---------------------------
                                    Title:
                                           ---------------------------

Attest: /s/

Sign:
        Print Name:
                    ---------------------------



                                    EXHIBIT A

                            FORM OF CONVERSION NOTICE

(To be executed by the Holder
in order to convert a Debenture)

Re:  Debenture (this  "Debenture")  issued by FONAR  CORPORTION to THE TAIL WIND
     FUND,  LTD. on or about May 24, 2001 in the  original  principal  amount of
     $4,500,000.

     The  undersigned  hereby  elects  to  convert  the  aggregate   outstanding
     Principal  Amount (as  defined in the  Debenture)  indicated  below of this
     Debenture  into  shares of Common  Stock,  $0.0001 par value per share (the
     "Common Stock"),  of FONAR  CORPORATION.  (the "Company")  according to the
     conditions hereof, as of the date written below. If shares are to be issued
     in the name of a person other than  undersigned,  the undersigned  will pay
     all transfer taxes payable with respect thereto and is delivering  herewith
     such  certificates  and opinions as reasonably  requested by the Company in
     accordance  therewith.  No fee  will  be  charged  to the  holder  for  any
     conversion,  except  for  such  transfer  taxes,  if any.  The  undersigned
     represents  as of  the  date  hereof  that,  after  giving  effect  to  the
     conversion  of this  Debenture  pursuant  to this  Conversion  Notice,  the
     undersigned will not exceed the "Restricted Ownership Percentage" contained
     in Section  3(i)(A) of this  Debenture and will remain in  compliance  with
     Section 3(i)(B) of this Debenture.

Conversion information:
                       Date to Effect Conversion

                       Aggregate Principal Amount of Debenture Being Converted

                       Number of Shares of Common Stock to be Issued

                       Applicable Conversion Price

                                       Signature

                                       Name

                                       Address



                                    EXHIBIT B

                        FORM OF REPAYMENT ELECTION NOTICE

To:      [Holder at Holder's Address]

     Pursuant to Section 1(b) of Debenture  No. of FONAR  CORPORATION  issued to
you (or your  assignor or  predecessor-in-interest)  on May --, 2001,  we hereby
notify you that we are  irrevocably  electing to repay the  outstanding  Monthly
Amount (as defined in the  Debenture)  due on the Repayment  Date (as defined in
the Debenture) which occurs on ---------, 200- (check one):

     In full in cash on such Repayment Date.

     In full in shares of the  Company's  Common  Stock within three (3) Trading
Days following such Repayment Date.

                                           FONAR CORPORATION

                                        By:
                                           ---------------------
                                      Name:
                                           ---------------------
                                     Title:
                                           ---------------------