EXHIBIT A --------- Agreement of Joint Filing ------------------------- The undersigned hereby agree that a single Schedule 13G (or any amendment thereto) relating to the Common Stock of T/R Systems, Inc. shall be filed on behalf of each of the...

                                                                   Page 15 of 17

                                   EXHIBIT A
                                   ---------

                           Agreement of Joint Filing
                           -------------------------

     The undersigned hereby agree that a single Schedule 13G (or any amendment
thereto) relating to the Common Stock of T/R Systems, Inc. shall be filed on
behalf of each of the undersigned and that this Agreement shall be filed as an
exhibit to such Schedule 13G.

Dated:  February 14, 2001


XXXXX XXXXX FUND IV L.P.      /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
By SRB ASSOCIATES IV L.P.,    Signature
Its General Partner

                              Xxxx X. Xxxxxxx
                              General Partner


SRB ASSOCIATES IV L.P.        /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                              Xxxx X. Xxxxxxx
                              General Partner


XXX X. XXXXXXX                /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                              Xxxx X. Xxxxxxx
                              Attorney-In-Fact


XXXXXXX X. XXX                /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                              Xxxx X. Xxxxxxx
                              Attorney-In-Fact


XXXX X. XXXXXXX               /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                                                                   Page 16 of 17

XXXXXXX X. XXXXXX             /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                              Xxxx X. Xxxxxxx
                              Attorney-In-Fact


XXXXXXXX XXXX XXXXXXX         /s/ Xxxx X. Xxxxxxx
                              ----------------------------------
                              Signature


                              Xxxx X. Xxxxxxx
                              Attorney-In-Fact