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                                                                EXHIBIT (a)(4)

                           Offer to Purchase for Cash

                     All Outstanding Shares of Common Stock

                                       of

                         CSI Computer Specialists, Inc.

                                       at

                               $1.00 Net Per Share

                                       by

                            Interactive Systems, Inc.

- --------------------------------------------------------------------------------
THE OFFER AND  WITHDRAWAL  RIGHTS WILL  EXPIRE AT 5:00 P.M.,  EASTERN  TIME,  ON
TUESDAY, MAY 23, 2000, UNLESS THE OFFER IS EXTENDED.

- --------------------------------------------------------------------------------

To Brokers, Dealers, Commercial Banks, Trust Companies and Other Nominees:

     We are asking  you to  contact  your  clients  for whom you hold  shares of
Common Stock, par value $0.001 per share (the "Common Shares"),  of CSI Computer
Specialists, Inc., a Delaware corporation (the "Company"). Please bring to their
attention as promptly as possible the offer being made by  Interactive  Systems,
Inc. (the  "Purchaser")  to purchase all of the  outstanding  Common Shares at a
purchase  price of $1.00 per Common  Share,  net to the seller in cash (less any
required  withholding  taxes),  without  interest  thereon,  upon the  terms and
subject to the  conditions  set forth in the Offer to Purchase,  dated April 26,
2000 (the "Offer to Purchase")  and in the related  letter of  transmittal  (the
"Letter of Transmittal," which,  together with the Offer to Purchase, as amended
or supplemented from time to time, collectively constitute the "Offer") enclosed
herewith.

     Please  furnish  copies of the enclosed  materials to those of your clients
for whose accounts you hold Common Shares registered in your name or in the name
of your nominee.

     The Board of Directors  of the Company has  determined  that,  based on the
Company's current financial condition, its inability to obtain financing for its
operations,  recent bid prices for the Common  Shares on the OTC Bulletin  Board
and the Company's  current book value, the Offer is in the best interests of the
Company  and its  stockholders,  and  has  voted  to  recommend  to the  Company
stockholders  acceptance  of the Offer.  The Board of  Directors  of the Company
recommends that the Company's  stockholders  tender their Common Shares pursuant
to the Offer.

     Enclosed  herewith for your  information and forwarding to your clients are
copies of the following documents:

1.       The Offer to Purchase, dated April 26, 2000.

2.       The Letter of Transmittal  for your use to tender Common Shares and for
         the  information  of your  clients.  Facsimile  copies of the Letter of
         Transmittal may be used to tender Common Shares.

3.       A printed  form of letter  which may be sent to your  clients for whose
         accounts you hold Common Shares  registered in your name or in the name
         of your  nominee,  with space  provided  for  obtaining  such  clients'
         instructions with regard to the Offer.

4.       The Notice of  Guaranteed  Delivery for Shares to be used to accept the
         Offer if certificates for Common Shares ("Share  Certificates") and all
         other  required  documents are not  immediately  available or cannot be
         delivered  to   Continental   Stock   Transfer  &  Trust  Company  (the
         "Depositary")  by the  Expiration  Date  (as  defined  in the  Offer to
         Purchase)  or if  the  procedure  for  book-entry  transfer  cannot  be
         completed by the Expiration Date.

5.       A letter to  stockholders  from  William F.  Pershin,  President of the
         Company,  accompanied  by  the  Company's   Solicitation/Recommendation
         Statement on Schedule 14D-9.

6.       Guidelines  of  the  Internal  Revenue  Service  for  Certification  of
         Taxpayer Identification Number on Substitute Form W-9.

     Your prompt  action is  requested.  We urge you to contact  your clients as
promptly  as  possible.  Please note that the Offer and  withdrawal  rights will
expire at 5:00 P.M., Eastern Time, on Tuesday, May 23, 2000, unless the Offer is
extended.

     In order to accept the Offer, a duly executed and properly completed Letter
of Transmittal and any required signature guarantees,  or an Agent's Message (as
defined in the Offer to Purchase) in  connection  with a book-entry  delivery of
Common Shares, and any other required documents should be sent to the Depositary
and either Share Certificates  representing the tendered Common Shares should be
delivered to the  Depositary,  or Common Shares should be tendered by book-entry
transfer into the  Depositary's  account  maintained at the Book Entry  Transfer
Facility (as  described in the Offer to Purchase),  all in  accordance  with the
instructions set forth in the Offer.

     If holders of Common  Shares wish to tender,  but it is  impracticable  for
them to forward their Share Certificates or other required documents on or prior
to the Expiration Date or to comply with the book-entry transfer procedures on a
timely  basis,  a tender may be effected by following  the  guaranteed  delivery
procedures  specified  in Section 3,  "Procedures  for  Accepting  the Offer and
Tendering Shares," of the Offer to Purchase.

     The Purchaser will not pay any commissions or fees to any broker, dealer or
other  person  (other  than  the  Depositary  and  the  Information  Agent)  for
soliciting  tenders of Common Shares pursuant to the Offer.  The Purchaser will,
however, upon request, reimburse you for customary clerical and mailing expenses
incurred by you in forwarding any of the enclosed materials to your clients. The
Purchaser  will pay or cause to be paid any stock  transfer taxes payable on the
transfer of Common Shares to it, except as otherwise  provided in  Instruction 6
of the Letter of Transmittal.

     Any  inquiries  you may have with  respect to the Offer should be addressed
to, and  additional  copies of the enclosed  material may be obtained  from, the
Information  Agent at its  address  and  telephone  number set forth on the back
cover of the Offer to Purchase.

                                Very truly yours,

                            Interactive Systems, Inc.

     Nothing contained herein or in the enclosed  documents shall constitute you
or any other person the agent of the Purchaser,  the Company,  the Depositary or
the Information  Agent, or any affiliate of any of them, or authorize you or any
other person to make any  statement or use any document on behalf of any of them
in  connection  with  the  Offer  other  than  the  enclosed  documents  and the
statements contained therein.