Exhibit 10.93(d)


                                October 17, 2002


Robert Farias
Paradigm Sales, Inc.
3436 Verdugo Road, Suite 250
Glendale, CA 91208


         Re:  PUT AND CALL AGREEMENT

Dear Robert,

Reference  is  hereby  made to that  certain  Asset  Purchase  Agreement,  dated
November 14, 2001, by and between Vertical Computer Systems,  Inc.  ("Vertical")
and Paradigm Sales,  Inc.  ("Paradigm")  and a certain letter  agreement,  dated
October 17, 2002, by and between Vertical and Mountain Reservoir Corporation, on
the one hand, and Robert Farias on the other.

1.   Vertical has issued to Paradigm and Paradigm has accepted  50,000 shares of
Vertical  Class C  Preferred  Stock.  Each share of Class C  Preferred  stock is
convertible  into 400 Shares of Vertical  Common Stock.  Paradigm shall have the
right to sell to  Vertical  and  Vertical  agrees to  redeem  the  common  stock
represented  by 12,500 shares of  Vertical's  Class C Preferred  Stock,  held by
Paradigm,  pursuant to that certain Asset Purchase Agreement, dated November 14,
2001 by and between Vertical and Paradigm  ("Paradigm's  Preferred Stock"), at a
price of $0.04 per share ("Put").  Such Put shall be exercisable,  upon ten (10)
days prior written notice delivered  personally to Vertical,  on March 17, 2003,
Vertical  shall have the option of paying the put price within ten (10) business
days or issuing an additional 2500 shares of its Class C Preferred Stock,  which
shall have the same conversion rights.

2.   Vertical shall have the option of redeeming,  at anytime prior to March 17,
2003,  Paradigm's  holdings of Vertical Common Stock represented by the Vertical
Preferred  Stock at a price of $0.06  per  share  ("Call").  Paradigm  expressly
acknowledges  that  its  rights  as  set  forth  in  paragraph  1 are  expressly
conditioned upon this paragraph 2.

3.   Paradigm  may assign  this  agreement  to third  party,  provided  that the
aggregate  number of shares of stock is no more the 12,500 of Vertical's Class C
Preferred  Stock and Paradigm  provides  notice to Vertical of such  assignment.
Such notice shall also include any legal  documents or  instruments by which the
applicable shares of Vertical's Class C Preferred Stock were transferred as well
as any other documentation reasonably requested by Vertical.

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This agreement  will be governed by California  and subject to the  jurisdiction
and venue of the state and federal courts of Los Angeles, California.


                                    Yours truly,


                                    VERTICAL COMPUTER SYSTEMS, INC.


                                    By:
                                         ---------------------------------------
                                         Richard Wade, President

ACCEPTED AND AGREED:


BY:
   ------------------------------------
   Robert Farias, on behalf of Paradigm

Dated:
       --------------------

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