THE NEPTUNE GROUP, INC.
                                1266 MAIN STREET
                               STAMFORD, CT 06902
                       (203) 356-9282 Fax: (203) 348-0506



                                                                  July 10, 1997


Mr. David Horowitz, Chairman
Intelligent Decision Systems, Inc.
88 Danbury Road
Wilton, CT 06897

Dear David:

         Reference  is made to the  Agreement  of  Sale dated June 27, 1996 (the
"Sale Agreement") between  Intelligent  Decision  Systems,  Inc.  ("IDSI"),  The
Neptune   Group,   Inc.   ("Neptune"),   Stephen  M.  Chaleff  and  Fred  Wiener
(collectively the "Stockholders").  As a result of various discussions regarding
IDSI's  failure  to pay  certain  amounts  due and  owing  pursuant  to the Sale
Agreement and certain disputes which have arisen over certain other sums claimed
by Neptune to be due and owing, we have agreed,  in settlement  thereof,  to the
following:

         1. Discharge of Outstanding  Obligations.  For and in  consideration of
the execution,  delivery and performance by IDSI of this Agreement,  Neptune and
the Stockholders  hereby release and forever  discharge IDSI from any obligation
or liability with respect to the outstanding  amounts  (approximately  $140,000)
heretofore  claimed by  Neptune  to be due and owing to  Neptune  under the Sale
Agreement.  All other obligations,  liabilities and representations set forth in
the Sale Agreement shall remain in full force and effect.  In  consideration  of
the  foregoing,  IDSI hereby  releases,  forever  discharges  and agrees to hold
Neptune and its  Stockholders  harmless from any obligation or liability to make
any payments or assume any liability  under or in  connection  with that certain
dispute  involving DVI Financial  Services,  Inc. as lender and American  Mobile
Imaging as lessee,  including any  obligations or liabilities to IDSI (including
with  respect  to the  escrow of  warrant  shares)  under  that  certain  letter
agreement dated June 27, 1996 between IDSI and Neptune regarding said dispute.

         2. Warrant Amendment.  The Warrant to purchase 300,000 shares of Common
Stock  of IDSI  issued  on or  about  December  27,  1995  by IDSI to  Neptune's
wholly-owned  subsidiary (then known as Neptune  Technology Leasing Corp.) shall
be amended to reduce the exercise price thereunder from $2.50 to $1.00 per share
pursuant to an  Amendment  in the form of Exhibit A hereto which shall be issued
by IDSI simultaneously  herewith. As so modified, said Warrant shall continue in
full force and effect.


                                       -1-

<PAGE>



         3. Continuance of Sale Agreement.  Except as herein modified, the  Sale
Agreement shall remain in full force and effect in accordance with its terms.

         4. Miscellaneous.

          (a) Any notice,  request,  instruction  or other  document to be given
hereunder  shall be in writing,  and except as  otherwise  provided  for herein,
shall be delivered  personally,  or sent by registered or certified  mail to the
parties at their  respective  addresses set forth on the first page hereof or to
such other address as either of the parties hereto may hereinafter  designate in
writing to the other party hereto.

: (b) After the date  hereof,  each of the  parties  hereto,  at the  reasonable
request of the other, will take such action and execute and deliver such further
documents and  instruments  as may be necessary to assure  complete and full and
effective consummation of the transactions contemplated hereunder.

         (c) This Agreement shall be binding upon and shall inure to the benefit
of the parties hereto and their respective successors and assigns. Except as set
forth  above,  nothing in this  Agreement  expressed  or implied is  intended to
confer  upon any  persons,  other than the parties  hereto and their  respective
successors and assigns, any rights or remedies under or by reason thereof.

         (d)  This  Agreement  cannot  be  modified,   changed,   discharged  or
terminated except by an instrument in writing,  signed by the party against whom
the enforcement of any waiver, change,  discharge or termination is sought. This
Agreement contains the entire understanding  between the parties with respect to
the transactions covered hereby.

         (e) In the  event  that any one or more  provisions  of this  Agreement
shall  be  deemed  to  be  illegal  or   unenforceable,   such   illegality   or
unenforceability  shall  not  affect  the  validity  and  enforceability  of the
remaining legal and enforceable  provisions hereof,  which shall be construed as
if such illegal or unenforceable provision or provisions had not been inserted.

         (f) This  Agreement  will be construed and governed in accordance  with
the laws of the State of  Connecticut,  without giving effect to the conflict of
laws provisions thereof.

         (g) This Agreement may be executed in any number of counterparts,  each
of which  shall be deemed to be an  original,  but all of which  together  shall
constitute one and the same instrument.

         (h) Each of the  parties  hereto  represents  and  warrants  that  this
Agreement has been duly  authorized by all requisite  corporate and other action
including,  in the case of IDSI, approval of the Board of Directors of IDSI with
authorization for David Horowitz to execute this Agreement on its behalf.

                                       -2-

<PAGE>






         Please  acknowledge and confirm your agreement with, and acceptance of,
this  Agreement  by executing  same below  whereupon it shall become the binding
agreement of the parties hereto.


                                            Very truly yours,

                                            THE NEPTUNE GROUP, INC.


                                            By  /s/  Stephen M. Chaleff
                                               ---------------------------

                                            Title  President
                                                  ------------------------


                                            THE STOCKHOLDERS:

                                             /s/ Stephen M. Chaleff
                                            --------------------------
                                            Stephen M. Chaleff

                                             /s/  Fred Wiener
                                            --------------------------
                                            Fred Wiener


ACCEPTED AND AGREED TO:

INTELLIGENT DECISION SYSTEMS, INC.


By   /s/  David Horowitz
  ------------------------------------
Title     Chairman
      --------------------------------
Date      7/11/97
     ---------------------------------

                                       -3-

<PAGE>




                                    Exhibit A

                           AMENDMENT TO WARRANT NO. 3





Reference is made to that certain Warrant No. 003 to purchase 300,000 shares of
common stock of Intelligent Decision Systems, Inc.  (formerly  Digital Sciences,
Inc.)  issued to NTLC Asset Corp. (formerly Neptune Technology Leasing Corp.) on
December 27, 1995.

Intelligent  Decision  Systems,  Inc.,  hereby amends the  foregoing  Warrant as
follows:  The purchase  price in said Warrant is hereby  changed from "$2.50 per
share" to "$1.00 per share". All other terms and conditions remain in full force
and effect.

The  undersigned  represents  and warrants that this Warrant  Amendment has been
duly authorized by all requisite  corporate and other action including  approval
of the Board of  Directors  of  Intelligent  Decision  Systems,  Inc.  for David
Horowitz to execute this revision on its behalf.


                                             Intelligent Decision Systems, Inc.


Attest:
                                             By_____________________________
_________________________                      David Horowitz, Chairman

                                             Date___________________________