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                       FIRST AMENDMENT TO LETTER AGREEMENT


         This First Amendment to the Letter Agreement dated January 14, 1999,
(the "Letter Agreement") by and among Summus, Ltd., a Delaware corporation
("Summus, Ltd."); Summus Technologies, Inc., a Delaware corporation ("Summus
Technologies"); Brad Richdale; and High Speed Net Solutions, Inc., a Florida
corporation ("High Speed"); is made and entered into as of the 16th day of
August, 1999.

1.       The Letter Agreement is hereby amended as follows:

         A.       The last two sentences of Paragraph 4 are hereby amended to
                  read in their entirety as follows:

                           Following the merger, Net Solutions shall have the
                           right to appoint two designees to serve on a seven
                           member board. If the Board is increased, Net
                           Solutions will retain the equivalent of 18% (rounded
                           up) representation on the Board.

         B.       Paragraph 5 of the Letter Agreement is hereby amended to read
                  in its entirety as follows:

                           Within one year from April 14, 1999, Net Solutions
                           agrees to deliver a $2.5 Million factorable Purchase
                           Order that is satisfactory to Summus, Ltd. for
                           products of Summus, Ltd. the specifications of which
                           will be mutually agreed upon by you and Summus, Ltd.
                           Upon your execution of this agreement, you received
                           148,182 common shares of Summus Technologies, which
                           equalled 3% of the issued and outstanding common
                           shares of Summus Technologies at that time. Upon
                           delivery of the purchase order to Summus Ltd. and its
                           acceptance, which will not be unreasonably withheld,
                           by Bjorn Jawerth, as the President of Summus, Ltd.,
                           you will receive additional common shares of Summus,
                           Ltd. up to 60,000 of the issued and outstanding
                           common shares of Summus, Ltd. as cash is received for
                           the purchase of products under this Purchase Order at
                           a rate of 10,000 shares per $416,666.66. (These
                           60,000 shares are intended to represent 6% of the
                           issued and outstanding shares of Summus, Ltd.
                           immediately following the merger of Summus, Ltd. and
                           Summus Technologies, Inc.) If the above referenced
                           shares are not issued in accordance with the terms
                           hereof, then Brad Richdale (and his designees)
                           specifically do not waive any


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                           rights they now may have with respect to their
                           existing ownership claim thereto.

2.       This Amendment shall become effective upon the consummation of the
         merger of Summus, Ltd. and Summus Technologies. If the merger is not
         consummated, then this Amendment shall be null and void and of no force
         or effect.

3.       Except as otherwise specifically modified herein the remaining terms of
         the Letter Agreement, as amended, shall remain in full force and
         effect.

         IN WITNESS WHEREOF, the parties have signed this First Amendment to the
Letter Agreement as of the date first above written.


                                  SUMMUS, LTD.


                                  By:  /s/ Bjorn Jawerth
                                     ------------------------
                                  Its:   President
                                      -----------------------

                                  SUMMUS TECHNOLOGIES, INC.


                                  By:  /s/ Bjorn Jawerth
                                     ------------------------
                                  Its:   President
                                      -----------------------



                                  HIGH SPEED NET SOLUTIONS, INC.


                                  By:
                                     ------------------------
                                  Its:
                                      -----------------------



                                  ---------------------------
                                  Brad Richdale