ADDENDUM NO. 13 REVOLVING LOAN AND SECURITY AGREEMENT CONVERTIBLE REVOLVING CREDIT PROMISSORY NOTE DATED OCTOBER 26, 1987 For consideration given and received, Robert Howard and Howtek, Inc. hereby agree to extend the repayment date in Paragraph D of...

                                 EXHIBIT 10 (d)

                                 ADDENDUM NO. 13

                      REVOLVING LOAN AND SECURITY AGREEMENT

                  CONVERTIBLE REVOLVING CREDIT PROMISSORY NOTE

                             DATED OCTOBER 26, 1987



     For consideration given and received, Xxxxxx Xxxxxx and Howtek, Inc. hereby
agree to extend  the  repayment  date in  Paragraph  D of the  above  referenced
Convertible  Revolving  Credit  Promissory  Note, as amended,  (the "Note") from
January 4, 2000 to January 4, 2001.  Also the Note  hereafter  will be a maximum
principal sum of Three Million Dollars ($3,000,000).

     Effective the 30th day of December 1999.

HOWTEK, INC.



By:  /s/  W. Xxxxx Xxxx                    /s/  Xxxxxx Xxxxxx
    -----------------------------         -------------------------------
Title:  President, CEO                    Xxxxxx Xxxxxx


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