Exhibit 10.31

                        AMENDMENT TO EMPLOYMENT AGREEMENT

This amendment  ("Amendment") to the Employment Agreement ("Agreement") executed
between Exigent  International,  Inc. and William K. Presley dated June 11, 1997
is entered  into as of October  27, 1998  between  Exigent  International,  Inc.
("Exigent"),  a corporation  duly  authorized and existing under the laws of the
State of  Delaware  with a  principal  place of  business  at 1225  Evans  Road,
Melbourne,  Florida  32904 and William K. Presley  ("Employee"),  an  individual
domiciled at 220 Columbia Dr., Apt. 19, Cape Canaveral, FL 32920.

NOW, THEREFORE,  for one dollar and other good and valuable  consideration,  the
receipt and  sufficiency of which is hereby mutually  acknowledged,  Exigent and
Employee hereby agree as follows:

1.       Executive  Incentive  Program for FY98(b).  Exigent and Employee  agree
         that the  Executive  Incentive  Plan  Summary for fiscal  year  1998(b)
         (i.e.,  February 1, 1998 through  December 31, 1998) attached hereto as
         Attachment "1" of this Amendment shall form an integral part of Exhibit
         "B" to the Agreement and shall contain the parameters for any incentive
         compensation to be awarded to Employee in the fiscal year of 1998(b).

2.        Corporate  Goals.  Exigent  and  Employee  agree  that  the  incentive
          compensation   tied  to  the  financial   performance  of  Exigent  as
          identified  in Attachment  "1" hereto is subject to the  attainment of
          Employee's  corporate  goals  described in  Attachment  "2",  attached
          hereto and  incorporated  herein by this reference.  One hundred (100)
          percent of the  incentive  compensation  set forth in  Attachment  "1"
          shall be earned if and only if one  hundred  percent of the  corporate
          goals  set  forth  in  Attachment  "2"  are  fulfilled.   An  internal
          compensation  committee shall be established by the CEO for Exigent to
          determine  whether the  corporate  goals have been  fulfilled.  In the
          event less than one hundred (100)  percent of the corporate  goals are
          fulfilled,  the  compensation  committee may make a pro-rata  award of
          incentive  compensation.   All  determinations  by  said  compensation
          committee shall be final and binding.

3.       Ratification  and  Approval.  In all other  respects  the  Agreement is
         hereby  ratified by Exigent and  Employee and remains in full force and
         effect, as previously  amended.  The FY1998(b)  executive  compensation
         program  supersedes any and all prior  compensation plans in effect for
         FY1998(b).

IN WITNESS  WHEREOF,  this  Amendment  has been duly executed as of the date set
forth above and is retroactively effective from February 1, 1998.

For Exigent:                                           For Employee:
Exigent International, Inc.                            William K. Presley


By: /s/ B.R. Smedley                                 By:  /s/ William K. Presley
    -----------------------                               ----------------------
     B.R. "Bernie" Smedley,
     Chief Executive Officer


<PAGE>


                                                                    Attachment 1

                     Annual Executive Incentive Plan Summary
                             Chief Technical Officer

I.       Executive Target Incentive Payments
         Target  incentive  payments are based on market  competitive  incentive
         levels. The target incentive payment for this position is:

|X|      CTO:  30% of base salary

II.      Incentive  Plan  Financial  Goals and Plan  Effectivity  Corporate  and
         Business Unit financial goals for 1998(b) are as follows:

                                         Corporate
                              Revenue                 Earnings
                            $36 Million             $2.0 Million

         The Annual  Incentive  Plan will be  implemented  only if the following
earning goal is met for 1998(b) |X| 80% of 1998(b) corporate  earnings target is
met, i.e., $1.6 Million

III.      Executive  Incentive  Plan  Performance  Measures  and Weights |X| The
          following table summarizes the performance  measures applicable to the
          plan participant:


<TABLE>
<CAPTION>
   Employee       Title       Corporate Financial Goals Percentage       Business Unit Financial Goals      Individual
                                                                                   Percentage                 Goals
                                                                                                            Percentage
                            Revenue     Earnings      Share       EPS      Revenue    Operating Profit
                                                      Price                              (after tax)

<S>                <C>        <C>          <C>         <C>        <C>        <C>            <C>                <C>            <C>
Bill Presley       CTO        20%          60%         N/A        N/A        N/A            N/A                20%
</TABLE>


IV.      Payout Calculation
         The following matrix will be used to establish the payout a participant
         will receive for Corporate,  Business  Unit, or individual  performance
         for each goal:

  Level of Corporate, Business Unit, 
      or Individual Performance                             Incentive Payout
---------------------------------------------     ----------------------------
Less than 80% of target performance              0% of target incentive
80% of target performance                        20% of target incentive
80% - 100% of target  performance                20% - 100% of target incentive
                                                  (straight line interpolation)
100% of target  performance                      100% of target incentive
100% - 125% of target performance                100% - 125% of target incentive
                                                   (straight line interpolation)
125% of target performance                       200% of target incentive

<PAGE>

VI.  Payout Method

|X|  Bonuses will be paid in a  combination  of 50% cash,  and 50% stock grants.
     Participants  may elect for all or part of the cash  portion of their bonus
     paid in stock  instead  of cash.  The number of shares  will be  calculated
     based on the closing stock price on the last day of the fiscal year

|X|  For example, if a $10,000 incentive payment was earned, and the stock price
     is $5.00, the participant  would receive $5,000 cash (less withholding tax)
     and would be granted 1,000 shares of stock.


<PAGE>

                                                                    Attachment 2

                                 Corporate Goals
                          FY'98(b) Bonus Award Program
                                  Bill Presley


    FY98(b) Goals               CTO        Achieved          Comments

CORPORATE MEASURES
o Meet Corporate financial                           Bonus amount determined
  objectives (based on 11 month                      Company performance to the
  fiscal year)                                       1998(b) Executive Incentive
  - Revenue 36M (20%)           20                   Program Payout Matrix
  - Earnings 2M (60%)           60

CORPORATE TOTAL                 80%


                                Individual Goals
                          FY'98(b) Bonus Award Program
                                  Bill Presley

FY98(b) Individual Goals         CTO       Achieved        Comments

NEW BUSINESS DEVELOPMENT
o Secure Teledesic/Celestri      10                  Points will be prorated for
  and INX Business                                   the percent of achieved
                                                     goal

o  Support Other Initiatives,    5                   Points will be prorated for
   i.e., Hughes, Loral, Harris,                      the percent of achieved
   NRL, Government, etc.                             goal

o  Introduce new products for    5                   Points will be prorated for
   development of X-Labs         5                   the percent of achieved
                                                     goal

NEW BUSINESS DEV. TOTAL         20%

GRAND TOTAL                    100%