Document:

EXHIBIT 10.52

                             SECURED REVOLVING NOTE

$1,500,000.00                                                       May 31, 2001

     FOR VALUE RECEIVED,  DELTA COMPUTEC INC., a corporation organized under the
laws of the State of New York (the  "Borrower"),  having its principal  place of
business at 900 Huyler Street,  Teterboro,  New Jersey 07608, hereby promises to
pay in lawful  money of the  United  States of  America,  to the order of KELTIC
FINANCIAL PARTNERS, LP ("Lender"),  having offices at 555 Theodore Fremd Avenue,
Suite C-209,  Rye, New York 10580,  or at such other place as the holder  hereof
may from time to time  designate in writing,  the  principal  sum of ONE MILLION
FIVE HUNDRED THOUSAND DOLLARS ($1,500,000.00),  or so much thereof as shall from
time to time be advanced to the Borrower pursuant to the terms and conditions of
the Loan and Security  Agreement  between the Borrower and Lender being executed
contemporaneously  herewith  (as the same may be  amended,  modified or extended
from time to time,  the "Loan  Agreement"),  together  with  interest  as herein
provided,  on  the  Termination  Date  or as  otherwise  provided  in  the  Loan
Agreement.  Each  capitalized  term used herein and not  defined  shall have the
meaning of such term set forth in the Loan Agreement.

     1. All Revolving  Loans shall be made in  accordance  with the terms of the
Loan Agreement, and the date and amount of each Revolving Loan shall be recorded
in separate ledgers maintained by Lender.  All such Revolving Loans,  whether or
not so recorded, shall be due as part of this Note.

     2. The Borrower shall pay to Lender interest upon the outstanding principal
balance  of the  Revolving  Loans  calculated  on a daily  basis,  with each day
representing  1/360th of a year. Interest shall be due and payable to Lender and
paid as provided in the Loan  Agreement on the first (1st)  Business Day of each
month.  Any failure or delay by Lender in  presenting  statements  for  interest
shall not  discharge  or relieve  the  Borrower of its  obligation  to make such
interest payments.  The interest rate that shall be used to calculate the amount
of  interest  due each  month  shall be equal at all  times to the Base  Rate in
effect  from  time to time  during  the  period  for  which  interest  is  being
calculated plus two and one-half (2.50%)  percentage  points per annum. The rate
of interest  applicable  hereto  shall  change as and when the Base Rate changes
without notice to Borrower.

     3. To the  extent  permitted  by law,  upon the  occurrence  and during the
continuance  of any Event of  Default,  the rate of interest  applicable  to the
Revolving  Loans shall,  at the option of Lender,  increase to the Default Rate.
Anything   contained   herein  or  in  the  Loan   Agreement   to  the  contrary
notwithstanding,  at no time shall the rate of interest applicable hereto exceed
the maximum  allowed by law, and any amount paid by Borrower to Lender in excess
of such maximum rate shall be deemed a payment of principal.

     4. Any  payment  received  later  than  12:00  noon  (Eastern  Time) on any
Business  Day  shall be  deemed to have  been  received  on the next  succeeding
Business Day.

<PAGE>

     5. Both interest and principal are payable to Lender in lawful money of the
United States of America, in immediately available funds.

     6. This Note is subject to and governed by the terms and  conditions of the
Loan  Agreement,  all of which terms and conditions are  incorporated  herein by
reference  with the same force and effect as though set forth  herein at length.
All sums due hereunder are secured by the Collateral.

     7.  Automatically  upon the occurrence of an Event of Default  described in
Section  10.12 of the Loan  Agreement,  and at the  option  of  Lender  upon the
occurrence  of any other Event of Default,  the aforesaid  principal  sum, or so
much  thereof as shall then  remain  unpaid,  together  with all  arrearages  of
interest  thereon,  shall,  without  notice or demand,  become  due and  payable
immediately,  anything hereinbefore  contained to the contrary  notwithstanding.
Furthermore,  Lender shall thereupon be entitled to exercise all of the remedies
of a secured  party at law or in equity,  together  with the rights and remedies
provided to it under the Loan Agreement.

     8. The Borrower  shall be liable for all costs,  charges and expenses,  and
other sums incurred or advanced by Lender  (including  reasonable legal fees and
disbursements) to preserve the Collateral,  collect on the Obligations,  protect
Lender's  interest in or realize on the  Collateral or enforce  Lender's  rights
against the Borrower or any Guarantor.

     9. The Borrower, and all other parties who at any time may be liable hereon
in any capacity, jointly and severally,  waive presentment,  demand for payment,
protest  and  notice of  protest,  and  notice of  dishonor  of this  Note,  and
authorize Lender,  without notice, to grant any extension,  postponement of time
of payment, indulgence or any substitution, exchange or release of Collateral or
any release of any party or Persons  primarily or secondarily  liable hereunder,
and to accept  partial  payments on any accounts or  instruments  and to settle,
compromise or adjust such accounts or instruments.

     10. As further  security for the performance of the obligations  hereunder,
Borrower  hereby  gives  Lender a general  lien  upon all  property  and  assets
heretofore or hereafter  delivered to Lender, and Lender shall have the right of
set-off,  in accordance  with the terms of the Loan Agreement in addition to any
other rights conferred by statute or operation of law, with respect to any funds
or tangible  assets of Borrower that may, at any time,  be in the  possession of
Lender or under Lender's custody and control.

     11.  Lender  is  hereby  authorized  to  disclose  any  financial  or other
information  about  the  Borrower  to  any  regulatory  body  or  agency  having
jurisdiction  over  the  Lender,  or  to  any  present,  future  or  prospective
participant   or  successor   in  interest  in  any  loan  or  other   financial
accommodation  made by  Lender  to  Borrower.  Lender  shall  request  that each
prospective  participant or purchaser maintain the information and documentation
submitted  to such  person or entity in  confidence  in  accordance  with  their
customary practices.

     12.  Lender  shall  not,  by any act,  be deemed to have  waived any of its
rights or  remedies  hereunder,  unless  such waiver is in writing and signed by
Lender,  and then only to the

                                       2
<PAGE>

extent  set  forth  therein.  A waiver  as to any one  event  shall in no way be
construed as  continuing  or as  preventing  the waiver or  enforcement  of such
rights or remedies available to Lender on a subsequent event.

     13. The liability of the Borrower shall be absolute and unconditional,  and
without regard to the liability of any other party.

     14. The provisions  herein contained shall bind and inure to the benefit of
the Borrower and Lender and their respective legal  representatives,  successors
and assigns (provided,  however, that Borrower shall not assign this Note or its
rights or obligations  hereunder  without first obtaining the written consent of
Lender).  Lender (and each  subsequent  assignee)  may  transfer and assign this
Note, and its rights and obligations hereunder and deliver the Collateral to the
assignee,  who shall thereupon have all of the rights of Lender; and Lender (and
each such subsequent  assignee that in turn assigns as aforesaid)  shall then be
relieved and discharged of any  responsibility or liability with respect to this
Note and said Collateral.

     15.  THE  BORROWER  HEREBY  WAIVES  ALL  RIGHTS  TO A TRIAL  BY JURY IN ALL
LITIGATION  RELATING TO THIS NOTE,  THE LOAN  AGREEMENT OR OTHER  AGREEMENTS  OR
INSTRUMENTS BETWEEN BORROWER AND LENDER.

     16. For the  purposes of this Note,  wherever  the term  "Lender"  shall be
used,  it shall refer to any  subsequent  holder,  successor or assignee  hereof
unless the context requires otherwise.

     17.  The  Borrower  agrees  that:  (i)  this  Note  shall be  construed  in
accordance  with and  governed  by the laws of the State of New  York;  (ii) any
suit,  action or  proceeding  to enforce this Note may be commenced in the State
Supreme Court in Westchester  County, New York, or any Federal District Court in
the  Southern  District of New York;  and (iii) it  generally,  irrevocably  and
unconditionally  submits to and  accepts  for  itself  (and its  successors  and
assigns) the  jurisdiction  of the aforesaid  courts for the purpose of any such
suit,  action or  proceeding  and  agrees  not to contest  the  validity  of any
judgment rendered thereby in any other jurisdiction. The Borrower further waives
and agrees not to assert,  by way of motion as a defense,  or otherwise,  in any
such suit, action or proceeding,  any claim that it is not personally subject to
the  jurisdiction  of the  aforesaid  courts or is  otherwise  immune from legal
proceedings,  or that any such  suit,  action or  proceeding  is  brought  in an
inconvenient  forum,  that the venue of any such suit,  action or  proceeding is
improper,  or that the loan documents  and/or  agreements of the Borrower or the
subject matter hereof may not be enforced by any such court.

                             SIGNATURES ON NEXT PAGE

                                       3
<PAGE>

     IN WITNESS WHEREOF,  the undersigned has caused these presents to be signed
by its proper  corporate  officers  and its proper  corporate  seal to be hereto
affixed as of the day and year first written above.

ATTEST:                                     DELTA COMPUTEC INC.

By: /s/ Mary Metrick                        By: /s/ John DeVito
   ---------------------------------           ---------------------------------
   Name: Mary Metrick                          Name: John DeVito
   Title: Assistant Secretary                  Title: President

                                       4EXHIBIT 4.1

                               AMENDMENT NO. 10 TO
                                     TEKELEC
                             1994 STOCK OPTION PLAN

Section 3 of the Tekelec 1994 Stock Option Plan is hereby amended to read in its
entirety as follows:

          "3. Shares Reserved.

               The maximum  aggregate  number of Shares  reserved  for  issuance
          pursuant  to the Plan  shall be  24,700,000  Shares  or the  number of
          shares of stock to which such Shares  shall be adjusted as provided in
          Section 10 of the Plan.  Such number of Shares may be set aside out of
          authorized but unissued Shares not reserved for any other purpose,  or
          out of issued  Shares  acquired  for and held in the  treasury  of the
          Company from time to time.

               Shares  subject  to,  but not sold or issued  under,  any  Option
          terminating, expiring or canceled for any reason prior to its exercise
          in full, shall again become available for Options  thereafter  granted
          under the Plan,  and the same shall not be deemed an  increase  in the
          number of Shares reserved for issuance under the Plan."

Section 7.e. of the Tekelec 1994 Stock Option Plan is hereby  amended to read in
its entirety as follows:

          "7.e. Termination of Eligibility.

          If an  Optionee  ceases to serve as an Employee  for any reason  other
          than death or permanent  and total  disability  (within the meaning of
          Section  22(e)(3)  of the  Code)  and  thereby  terminates  his or her
          Continuous  Status as an Employee he or she may, but only within three
          (3) months  following the date he or she ceases his or her  Continuous
          Status as an  Employee  (subject  to any  earlier  termination  of the
          Option as provided by its  terms),  exercise  his or her Option to the
          extent that he or she was  entitled to exercise it at the date of such
          termination. To the extent that he or she was not entitled to exercise
          the Option at the date of such  termination,  or if he or she does not
          exercise such Option (which he or she was entitled to exercise) within
          the time specified herein, the Option shall terminate.

               Notwithstanding  anything to the contrary  herein,  the Committee
          may at any time and from time to time  prior to the  termination  of a
          Non-Statutory Stock Option,  with the consent of the Optionee,  extend
          the period of time during  which the  Optionee may exercise his or her
          Non-Statutory  Stock Option following the date he or she ceases his or
          her  Continuous  Status as an Employee;  provided,  however,  that the
          maximum period of time during which a Non-Statutory Stock Option shall
          be exercisable  following the date on which an Optionee terminates his
          or her Continuous  Status as an Employee shall not exceed an aggregate
          of six (6)

<PAGE>

          months,  that the  Non-Statutory  Stock  Option  shall not be, or as a
          result of such extension  become,  exercisable after the expiration of
          the term of such  Option as set  forth in the  Option  Agreement  and,
          notwithstanding  any extension of time during which the  Non-Statutory
          Stock  Option may be  exercised,  that such Option,  unless  otherwise
          amended by the Committee,  shall only be exercisable to the extent the
          Optionee  was entitled to exercise it on the date he or she ceased his
          or her Continuous Status as an Employee.

               Notwithstanding  anything to the contrary  herein,  the Committee
          may at the time of  granting  an Option  and at any time  prior to the
          termination  of such  Option,  with the  consent of the  Optionee  and
          subject  to  such  terms  and  conditions  as  the  Committee  in  its
          discretion  deems advisable or appropriate,  extend the period of time
          during which the Optionee may exercise his or her Option following the
          date he or she ceases his or her Continuous  Status as an Employee due
          to retirement after having reached the age of 55 and having engaged in
          Continuous Employment for at least five years prior to such retirement
          (hereafter  referred  to  as  a  "Qualifying  Retirement");  provided,
          however,  that (i) the maximum period of time during which such Option
          shall be exercisable  following such Qualifying  Retirement  shall not
          extend  beyond  the term of such  Option  as set  forth in the  Option
          Agreement; and (ii) notwithstanding any extension of time during which
          such Option may be exercised following a Qualifying  Retirement,  such
          Option,  unless otherwise  granted or amended by the Committee,  shall
          only be exercisable  following Qualifying Retirement to the extent the
          Optionee  was  entitled to exercise  such option on the date he or she
          ceased his or her Continuous Status as an Employee."

Dated:  May 18, 2001

Source: [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00028-of-00352.parquet"}, [{"source": "alea-institute/alea-institute/kl3m-data-edgar-agreements/train-00028-of-00352.parquet"}]]