<PAGE>   1
                                                                    EXHIBIT 10.4


                                                            AMENDED AND RESTATED
                                                           REVOLVING CREDIT NOTE


                                                 Obligation # __________________

                                                               February 17, 1998
                                                      Philadelphia, Pennsylvania



$13,000,000



FOR VALUE RECEIVED, and intending to be legally bound hereby, the undersigned
Borrower, ECC International Corp., unconditionally promises to pay to the order
of FIRST UNION NATIONAL BANK (the "Bank"), the principal amount of all advances
that are now or may hereafter be made hereunder and that are then outstanding,
together with accrued, unpaid interest thereon and any unpaid costs and expenses
payable hereunder, on October 1, 1998.

A.       TERMS OF NOTE.

         1.       INTEREST PAYMENTS. Interest on the principal balance hereof
                  shall, except as provided in subpart A.8. below, accrue at
                  such rates and be payable in accordance with Section A.2. of
                  that certain Term Loan and Revolving Credit Agreement dated
                  September 20, 1994 between the Bank and the Borrower, as
                  amended to date, including by Amendment of even date herewith
                  (together with any exhibits thereto and amendments and
                  modifications thereto in effect from time to time, the "Loan
                  Agreement").

         2.       COMPUTATION OF INTEREST. Interest hereunder shall be computed
                  daily on the basis of a year of 360 days for the actual number
                  of days elapsed. All payments hereunder shall be made in
                  lawful currency of the United States of America and in
                  immediately available funds at the Bank's address set forth in
                  the Loan Agreement or at such other address as the Bank shall
                  notify the Borrower of in writing.

         3.       INCORPORATION BY REFERENCE. This Note is the Revolving Credit
                  Note referred to in the Loan Agreement and is subject to the
                  terms and conditions thereof, which terms and conditions are
                  incorporated herein,
<PAGE>   2
                  including, without limitation, terms pertaining to
                  definitions, representations, warranties, covenants, events of
                  default and remedies. Any capitalized term used herein without
                  definition shall have the definition contained in the Loan
                  Agreement.

         4.       BORROWING REQUESTS; CREDITING OF ACCOUNT. Any request for
                  borrowing pursuant to this Note shall be made by the Borrower
                  in writing in the form of a "Notice of Borrowing Under
                  Revolving Credit" attached hereto as Exhibit A and in
                  accordance with the terms of the Loan Agreement. Unless
                  otherwise requested by the Borrower in writing at least one
                  (1) Business Day prior to the date of a requested advance,
                  each advance hereunder shall be made by crediting the Account
                  as defined in the Loan Agreement with the amount of the
                  advance. All advances made by crediting the Account or any
                  other account of the Borrower at the Bank shall be
                  conclusively presumed to have been properly authorized by the
                  Borrower.

         5.       BANK RECORDS OF ADVANCE. The Bank may enter in its business
                  records the date and the amount of each advance, each
                  conversion from one interest rate basis to another and each
                  payment made pursuant to this Note and the Loan Agreement. The
                  Bank's records of such advance, conversion or payment shall,
                  in the absence of manifest error, be conclusively binding upon
                  the Borrower. In the event the Bank gives notice or renders a
                  statement by mailing such notice or statement to the Borrower,
                  concerning any such advance, conversion or payment, or the
                  amount of principal and interest due on this Note, the
                  Borrower agrees that, unless the Bank receives a written
                  notification of exceptions to this statement within forty-five
                  (45) calendar days after such statement or notice is mailed,
                  the statement or notice shall be an account stated, correct
                  and acceptable and binding upon the Borrower.

         6.       ADVANCE REQUESTS EXCEEDING MAXIMUM PRINCIPAL AMOUNT. The
                  Borrower shall not request the Bank to make any advances under
                  this Note or the Loan Agreement which exceeds the Maximum
                  Principal Amount set forth in Section A.2.b. of the Loan
                  Agreement. In the event that the principal balance outstanding
                  under this Note exceeds at any time the Maximum Principal
                  Amount, the Borrower shall immediately, and without demand
                  from the Bank, pay to the Bank the amount in excess thereof,
                  and the Borrower agrees that until such excess is paid to the
                  Bank, this Note shall evidence and be enforceable with respect
                  to any and all amounts outstanding hereunder including such
                  excess.

         7.       APPLICATION OF PAYMENTS. All payments received on this Note
                  shall be applied first to the Bank's fees, costs and expenses
                  which the Borrower


                                       -2-
<PAGE>   3
                  is obligated to pay pursuant to the terms hereof and under any
                  other Loan Document, then to accrued and unpaid interest and
                  then to principal or such payments may be applied in such
                  other order as the Bank in its sole discretion shall
                  determine.

         8.       DEFAULT RATE. At the Bank's option, interest will be assessed
                  on any principal which remains unpaid at the maturity of this
                  Note, whether by acceleration or otherwise, or upon and
                  following any Event of Default, at a rate which is four
                  percent (4%) higher than the rate otherwise charged hereunder
                  (the "Default Rate") provided that at no time shall the
                  Default Rate exceed the highest rate of interest allowed by
                  law. Such Default Rate of interest shall also be charged on
                  the amounts owed by the Borrower to the Bank pursuant to any
                  judgments entered in favor of Bank in respect of this Note or
                  any other Loan Document.

         9.       PREPAYMENT. Prepayment of principal may be made subject to
                  payment of all amounts required to be paid in connection with
                  such prepayment as provided in the Loan Agreement.

B.       REMEDIES.

         1.       GENERALLY. Upon and following an Event of Default, the Bank,
                  at its option, may exercise any and all rights and remedies it
                  has under this Note, the Loan Agreement and/or the other Loan
                  Documents and under applicable law, including, without
                  limitation, the right to charge and collect interest on the
                  principal portion of the amounts outstanding hereunder at the
                  Default Rate. Upon and following an Event of Default, the Bank
                  may proceed to protect and enforce the Bank's rights under any
                  Loan Document and/or under applicable law by action at law, in
                  equity, or other appropriate proceeding, including, without
                  limitation, an action for specific performance to enforce or
                  aid in the enforcement of any provision contained herein or in
                  any other Loan Document.

         2.       REMEDIES CUMULATIVE; NO WAIVER. The remedies hereunder and
                  under the other Loan Documents are cumulative and concurrent,
                  and are not exclusive of any other remedies available to the
                  Bank. No failure or delay on the part of the Bank in the
                  exercise of any right, power, remedy or privilege shall
                  operate as a waiver thereof, nor shall any single or partial
                  exercise of any right, power, remedy or privilege preclude any
                  other or further exercise thereof, or the exercise of any
                  other right, power, remedy or privilege.



                                       -3-
<PAGE>   4
C.       MISCELLANEOUS.

         1.       GOVERNING LAW. This Note shall be construed in accordance with
                  and governed by the substantive laws of the Commonwealth of
                  Pennsylvania without reference to conflict of laws principles.

         2.       INTEGRATION. This Note and the other Loan Documents constitute
                  the sole agreement of the parties with respect to the subject
                  matter hereof and thereof and supersede all oral negotiations
                  and prior writings with respect to the subject matter hereof
                  and thereof.

         3.       AMENDMENT; WAIVER. No amendment of this Note, and no waiver of
                  any one or more of the provisions hereof shall be effective
                  unless set forth in writing and signed by the parties hereto.

         4.       SUCCESSORS AND ASSIGNS. This Note (i) shall be binding upon
                  the Borrower and the Bank and their respective successors and
                  permitted assigns, and (ii) shall inure to the benefit of the
                  Borrower and the Bank and their respective successors and
                  permitted assigns; provided, however, that the Borrower may
                  not assign its rights or obligations hereunder or any interest
                  herein without the prior written consent of the Bank, and any
                  such assignment or attempted assignment by the Borrower shall
                  be void and of no effect with respect to the Bank.

         5.       SEVERABILITY. The illegality or unenforceability of any
                  provision of this Note or any instrument or agreement required
                  hereunder shall not in any way affect or impair the legality
                  or enforceability of the remaining provisions of this Note or
                  any instrument or agreement required hereunder. In lieu of any
                  illegal or unenforceable provision in this Note, there shall
                  be added automatically as part of this Note a legal and
                  enforceable provision as similar in terms to such illegal or
                  unenforceable provision as may be possible.

         6.       INCONSISTENCIES. The Loan Documents are intended to be
                  consistent. However, in the event of any inconsistencies among
                  any of the Loan Documents, such inconsistency shall not affect
                  the validity or enforceability of each Loan Document. The
                  Borrower agrees that in the event of any inconsistency or
                  ambiguity in any of the Loan Documents, the Loan Documents
                  shall not be construed against any one party but shall be
                  interpreted consistent with the Bank's policies and
                  procedures.

         7.       HEADINGS. The headings of sections and paragraphs have been
                  included herein for convenience only and shall not be
                  considered in interpreting this Note.


                                       -4-
<PAGE>   5
         8.       SCHEDULES. If a Schedule and/or an Exhibit is attached hereto,
                  the provisions thereof are incorporated herein.

         9.       JUDICIAL PROCEEDING; WAIVERS.

                  a.       THE BORROWER AGREES THAT ANY SUIT, ACTION OR
                           PROCEEDING, WHETHER CLAIM OR COUNTERCLAIM, BROUGHT OR
                           INSTITUTED BY THE BANK OR THE BORROWER OR ANY
                           SUCCESSOR OR ASSIGN OF THE BANK OR THE BORROWER, ON
                           OR WITH RESPECT TO THIS NOTE OR ANY OTHER LOAN
                           DOCUMENT OR THE DEALINGS OF THE PARTIES WITH RESPECT
                           HERETO, OR THERETO, SHALL BE TRIED ONLY BY A COURT
                           AND NOT BY A JURY.

                  b.       THE BANK AND THE BORROWER EACH HEREBY KNOWINGLY,
                           VOLUNTARILY AND INTENTIONALLY WAIVE ANY RIGHT TO A
                           TRIAL BY JURY IN ANY SUCH SUIT, ACTION OR PROCEEDING.
                           FURTHER, THE BORROWER WAIVES ANY RIGHT IT MAY HAVE TO
                           CLAIM OR RECOVER, IN ANY SUCH SUIT, ACTION OR
                           PROCEEDING, ANY SPECIAL, EXEMPLARY, PUNITIVE OR
                           CONSEQUENTIAL DAMAGES OR ANY DAMAGES OTHER THAN, OR
                           IN ADDITION TO, ACTUAL DAMAGES.

                  c.       THE BORROWER ACKNOWLEDGES AND AGREES THAT THIS
                           SECTION IS A SPECIFIC AND MATERIAL ASPECT OF THIS
                           NOTE AND THAT THE BANK WOULD NOT EXTEND CREDIT TO THE
                           BORROWER IF THE WAIVERS SET FORTH IN THIS SECTION
                           WERE NOT A PART OF THIS NOTE.

IN WITNESS WHEREOF, the Borrower has duly executed and delivered to the Bank
this Note as of the date first above written.


ATTEST:                                     ECC INTERNATIONAL CORP.


By:   /s/ Relland Winand                      /s/ George W. Murphy
    ------------------------------          --------------------------------
Name:  Relland Winand                       Name:  George W. Murphy
Title: Vice President, Finance              Title: President/CEO

                                            Address:  175 Strafford Avenue
                                                      Wayne, PA  19087
                                            Telecopier No. (610) 254-9268


                                      -5-
<PAGE>   6
                                    EXHIBIT A

                                      Notice of Borrowing Under Revolving Credit

DATE OF BORROWING:_______________________________
DATE OF NOTE:____________________________________
AMOUNT REQUESTED: $______________________________
INTEREST RATE BASIS:_____________________________
INTEREST PERIOD (IF APPLICABLE):_________________


         The Borrower hereby notifies the Bank that it requires a borrowing
("Borrowing") under the Term Loan and Revolving Credit Agreement, dated
September 20, 1994, as amended to date, including by Amendment of even date
herewith (together with any amendments or modifications thereto in effect from
time to time, the "Loan Agreement") established for the Borrower in the amount
set forth above. The Borrowing will be deposited in the Borrower's Account No.
__________________________. In order to induce the Bank to fund such Borrowing,
the Borrower hereby affirms the following:

         1.       The representations and warranties of the Borrower contained
                  in the Loan Agreement are correct on and as of the date of
                  this Notice of Borrowing Under Revolving Credit.

         2.       No Event of Default (as defined in the Loan Agreement) has
                  occurred and is continuing.

         3.       There has been no change in the Borrower's or any Obligor's
                  condition, financial or otherwise, since the date of the Loan
                  Agreement, which would have a Material Adverse Effect (as
                  defined In the Loan Agreement).

         4.       All of the Loan Documents (as defined in the Loan Agreement)
                  remain in full force and effect, without modification.

         5.       Use of Borrowing will be to: ________________________________.


Date:  ______________, 19__                 ECC INTERNATIONAL CORP.


                                            By:____________________________
                                            Name:
                                            Title:



                                       -6-
<PAGE>   7
                                                            AMENDED AND RESTATED
                                                           REVOLVING CREDIT NOTE


                                                  Obligation # _________________

                                                               February 17, 1998
                                                      Philadelphia, Pennsylvania


$5,500,000


FOR VALUE RECEIVED, and intending to be legally bound hereby, the undersigned
Borrower, ECC SIMULATION LIMITED, unconditionally promises to pay to the order
of FIRST UNION NATIONAL BANK, (the "Bank"), the principal amount of all advances
that are now or may hereafter be made hereunder and that are then outstanding,
together with accrued, unpaid interest thereon and any unpaid costs and expenses
payable hereunder, on October 1, 1998.

A.       Terms of Note.

         1.       INTEREST PAYMENTS. Interest on the principal balance hereof
                  shall, except as provided in subpart A.8. below, accrue at
                  such rates and be payable in accordance with Section A.1. of
                  that certain Revolving Credit Agreement dated September 20,
                  1994 between the Bank and the Borrower, as amended to date,
                  including by Amendment of even date herewith (together with
                  any exhibits thereto and amendments and modifications thereto
                  in effect from time to time, the "Loan Agreement").

         2.       COMPUTATION OF INTEREST. Interest hereunder shall be computed
                  daily in accordance with the Loan Agreement. All payments
                  hereunder shall be made in lawful currency of the United
                  States of America or in pounds sterling, as set forth in the
                  Loan Agreement, and in immediately available funds at the
                  Bank's address set forth in the Loan Agreement or at such
                  other address as the Bank shall notify the Borrower of in
                  writing.

         3.       INCORPORATION BY REFERENCE. This Note is the Revolving Credit
                  Note referred to in the Loan Agreement and is subject to the
                  terms and conditions thereof, which terms and conditions are
                  incorporated herein, including, without limitation, terms
                  pertaining to definitions, representations, warranties,
                  covenants, events of default and remedies.


                                       -7-
<PAGE>   8
                  Any capitalized term used herein without definition shall have
                  the definition contained in the Loan Agreement

         4.       BORROWING REQUESTS; CREDITING OF ACCOUNT. Any request for
                  borrowing pursuant to this Note shall be made by the Borrower
                  in writing in the form of a "Notice of Borrowing Under
                  Revolving Credit" attached hereto as Exhibit A and in
                  accordance with the terms of the Loan Agreement. Unless
                  otherwise requested by the Borrower in writing at least five
                  (5) Business Days prior to the date of a requested advance,
                  each advance hereunder shall be made by crediting the Account
                  as defined in the Loan Agreement with the amount of the
                  advance. All advances made by crediting the Account or any
                  other account of the Borrower at the Bank shall be
                  conclusively presumed to have been properly authorized by the
                  Borrower.

         5.       BANK RECORDS OF ADVANCE. The Bank may enter in its business
                  records the date and the amount of each advance, each
                  conversion from one interest rate basis to another and each
                  payment made pursuant to this Note and the Loan Agreement. The
                  Bank's records of such advance, conversion or payment shall,
                  in the absence of manifest error, be conclusively binding upon
                  the Borrower. In the event the Bank gives notice or renders a
                  statement by mailing such notice or statement to the Borrower,
                  concerning any such advance, conversion or payment, or the
                  amount of principal and interest due on this Note, the
                  Borrower agrees that, unless the Bank receives a written
                  notification of exceptions to this statement within forty-five
                  (45) calendar days after such statement or notice is mailed,
                  the statement or notice shall be an account stated, correct
                  and acceptable and binding upon the Borrower.

         6.       ADVANCE REQUESTS EXCEEDING MAXIMUM PRINCIPAL AMOUNT. The
                  Borrower shall not request the Bank to make any advances under
                  this Note or the Loan Agreement which exceeds the Maximum
                  Principal Amount set forth in Section A.1.b. of the Loan
                  Agreement. In the event that the principal balance outstanding
                  under this Note exceeds at any time the Maximum Principal
                  Amount, the Borrower shall immediately, and without demand
                  from the Bank, pay to the Bank the amount in excess thereof,
                  and the Borrower agrees that until such excess is paid to the
                  Bank, this Note shall evidence and be enforceable with respect
                  to any and all amounts outstanding hereunder including such
                  excess.

         7.       APPLICATION OF PAYMENTS. All payments received on this Note
                  shall be applied first to the Bank's fees, costs and expenses
                  which the Borrower is obligated to pay pursuant to the terms
                  hereof and under any other Loan Document, then to accrued and
                  unpaid interest and then to


                                       -8-
<PAGE>   9
                  principal or such payments may be applied in such other order
                  as the Bank in its sole discretion shall determine.

         8.       DEFAULT RATE. At the Bank's option, interest will be assessed
                  on any principal which remains unpaid at the maturity of this
                  Note, whether by acceleration or otherwise, or upon and
                  following any Event of Default, at a rate which is four
                  percent (4%) higher than the rate otherwise charged hereunder
                  (the "Default Rate") provided that at no time shall the
                  Default Rate exceed the highest rate of interest allowed by
                  law. Such Default Rate of interest shall also be charged on
                  the amounts owed by the Borrower to the Bank pursuant to any
                  judgments entered in favor of Bank in respect of this Note or
                  any other Loan Document

         9.       PREPAYMENT. Prepayment of principal may be made subject to
                  payment of all amounts required to be paid in connection with
                  such prepayment as provided in the Loan Agreement.

B.       REMEDIES.

         1.       GENERALLY. Upon and following an Event of Default, the Bank,
                  at its option, may exercise any and all rights and remedies it
                  has under this Note, the Loan Agreement and/or the other Loan
                  Documents and under applicable law, including, without
                  limitation, the right to charge and collect interest on the
                  principal portion of the amounts outstanding hereunder at the
                  Default Rate. Upon and following an Event of Default, the Bank
                  may proceed to protect and enforce the Bank's rights under any
                  Loan Document and/or under applicable law by action at law, in
                  equity, or other appropriate proceeding, including, without
                  limitation, an action for specific performance to enforce or
                  aid in the enforcement of any provision contained herein or in
                  any other Loan Document.

         2.       REMEDIES CUMULATIVE; NO WAIVER. The remedies hereunder and
                  under the other Loan Documents are cumulative and concurrent,
                  and are not exclusive of any other remedies available to the
                  Bank. No failure or delay on the part of the Bank in the
                  exercise of any right, power, remedy or privilege shall
                  operate as a waiver thereof, nor shall any single or partial
                  exercise of any right, power, remedy or privilege preclude any
                  other or further exercise thereof, or the exercise of any
                  other right, power, remedy or privilege.



                                       -9-
<PAGE>   10
C.       MISCELLANEOUS.

         1.       GOVERNING LAW. This Note shah be construed in accordance with
                  and governed by the substantive laws of the Commonwealth of
                  Pennsylvania without reference to conflict of laws principles.

         2.       INTEGRATION. This Note and the other Loan Documents constitute
                  the sole agreement of the parties with respect to the subject
                  matter hereof and thereof and supersede all oral negotiations
                  and prior writings with respect to the subject matter hereof
                  and thereof.

         3.       AMENDMENT; WAIVER. No amendment of this Note, and no waiver of
                  any one or more of the provisions hereof shall be effective
                  unless set forth in writing and signed by the parties hereto.

         4.       SUCCESSORS AND ASSIGNS. This Note (i) shall be binding upon
                  the Borrower and the Bank and their respective successors and
                  permitted assigns, and (ii) shall inure to the benefit of the
                  Borrower and the Bank and their respective successors and
                  permitted assigns; provided, however, that the Borrower may
                  not assign its rights or obligations hereunder or any interest
                  herein without the prior written consent of the Bank, and any
                  such assignment or attempted assignment by the Borrower shall
                  be void and of no effect with respect to the Bank.

         5.       SEVERABILITY. The illegality or unenforceability of any
                  provision of this Note or any instrument or agreement required
                  hereunder shall not in any way affect or impair the legality
                  or enforceability of the remaining provisions of this Note or
                  any instrument or agreement required hereunder. In lieu of any
                  illegal or unenforceable provision in this Note, there shall
                  be added automatically as part of this Note a legal and
                  enforceable provision as similar in terms to such illegal or
                  unenforceable provision as may be possible.

         6.       INCONSISTENCIES. The Loan Documents are intended to be
                  consistent. However, in the event of any inconsistencies among
                  any of the Loan Documents, such inconsistency shall not affect
                  the validity or enforceability of each Loan Document. The
                  Borrower agrees that in the event of any inconsistency or
                  ambiguity in any of the Loan Documents, the Loan Documents
                  shall not be construed against any one party but shall be
                  interpreted consistent with the Bank's policies and
                  procedures.

         7.       HEADINGS. The headings of sections and paragraphs have been
                  included herein for convenience only and shall not be
                  considered in interpreting this Note.



                                      -10-
<PAGE>   11
         8.       SCHEDULES. If a Schedule and/or an Exhibit is attached hereto,
                  the provisions thereof are incorporated herein.

         9.       JUDICIAL PROCEEDING; WAIVERS.

                  a.       THE BORROWER AGREES THAT ANY SUIT, ACTION OR
                           PROCEEDING, WHETHER CLAIM OR COUNTERCLAIM, BROUGHT OR
                           INSTITUTED BY THE BANK OR THE BORROWER OR ANY
                           SUCCESSOR OR ASSIGN OF THE BANK OR THE BORROWER, ON
                           OR WITH RESPECT TO THIS NOTE OR ANY OTHER LOAN
                           DOCUMENT OR THE DEALINGS OF THE PARTIES WITH RESPECT
                           HERETO, OR THERETO, SHALL BE TRIED ONLY BY A COURT
                           AND NOT BY A JURY.

                  b.       THE BANK AND THE BORROWER EACH HEREBY KNOWINGLY,
                           VOLUNTARILY AND INTENTIONALLY WAIVE ANY RIGHT TO A
                           TRIAL BY JURY IN ANY SUCH SUIT, ACTION OR PROCEEDING.
                           FURTHER, THE BORROWER WAIVES ANY RIGHT IT MAY HAVE TO
                           CLAIM OR RECOVER, IN ANY SUCH SUIT, ACTION OR
                           PROCEEDING, ANY SPECIAL, EXEMPLARY, PUNITIVE OR
                           CONSEQUENTIAL DAMAGES OR ANY DAMAGES OTHER THAN, OR
                           IN ADDITION TO, ACTUAL DAMAGES.

                  c.       THE BORROWER ACKNOWLEDGES AND AGREES THAT THIS
                           SECTION IS A SPECIFIC AND MATERIAL ASPECT OF THIS
                           NOTE AND THAT THE BANK WOULD NOT EXTEND CREDIT TO THE
                           BORROWER IF THE WAIVERS SET FORTH IN THIS SECTION
                           WERE NOT A PART OF THIS NOTE.

IN WITNESS WHEREOF, the Borrower has duly executed and delivered to the Bank
this Note as of the date first above written.


ATTEST:                                     ECC SIMULATION LIMITED


  /s/ Relland Winand                        By:  /s/ George W. Murphy
------------------------------                  ------------------------------
Name:  Relland Winand                             Name:  George W. Murphy
Title: Secretary                                  Title: President

                                            Address:   175 Strafford Avenue
                                                       Wayne, PA  19087
                                            Telecopier No.:  (215) 254-9268


                                      -11-
<PAGE>   12
                                    EXHIBIT A

                                                       NOTICE OF BORROWING UNDER
                                                                REVOLVING CREDIT


DATE OF BORROWING:_______________________________
DATE OF NOTE:____________________________________
AMOUNT REQUESTED: $______________________________
INTEREST RATE BASIS:_____________________________
INTEREST PERIOD (IF APPLICABLE):_________________


The Borrower hereby notifies the Bank that it requires a borrowing ("Borrowing")
under the Revolving Credit Agreement dated September 20, 1994 (together with any
amendments or modifications thereto in effect from time to time, the "Loan
Agreement") established for the Borrower in the amount set forth above. The
Borrowing will be deposited in the Borrower's Account No. _____________________.
In order to induce the Bank to fund such Borrowing, the Borrower hereby affirms
the following:

         1.       The representations and warranties of the Borrower contained
                  in the Loan Agreement are correct on and as of the date of
                  this Notice of Borrowing Under Revolving Credit.

         2.       No Event of Default (as defined in the Loan Agreement) has
                  occurred and is continuing.

         3.       There has been no change in the Borrower's or any Obligor's
                  condition, financial or otherwise, since the date of the Loan
                  Agreement, which would have a Material Adverse Effect (as
                  defined in the Loan Agreement).

         4.       All of the Loan Documents (as defined in the Loan Agreement)
                  remain in full force and effect, without modification.

         5.       Use of Borrowing will be: ____________________________________
                  _____________________________________________________________.


Date:  ______________, 19__

                                            ECC SIMULATION LIMITED

                                            By:____________________________
                                            Name:
                                            Title:



                                      -12-