Exhibit 10.12

                                   ASSIGNMENT

                  WHEREAS,  I, Robert M. Cezar,  a citizen of the United States,
having  an  address  of  1003  Acorn  Drive,  Arroyo  Grande,  California  93420
(hereinafter  referred  to as the  "ASSIGNOR"),  have  invented  certain new and
useful  improvements in the technology known as Virtual Object State Explication
(hereinafter, the "Intellectual Property"), for which an application for Letters
Patent of the United States will be filed in the name of ASSIGNEE; and

                  WHEREAS, AmeriCom USA, Inc., a corporation formed and existing
under the laws of the State of Delaware, having an office and principal place of
business at 5900 Hollis Street, R-1,  Emeryville,  California 94608 (hereinafter
referred to as the "ASSIGNEE"), is desirous of obtaining the entire right, title
and interest in, to and under the Intellectual Property and the application;

                  NOW,  THEREFORE,  in  consideration of royalty payments as set
forth in attached Schedule A, and other good and valuable  consideration paid by
ASSIGNEE  to  ASSIGNOR,   the  receipt  and   sufficiency  of  which  is  hereby
acknowledged,  ASSIGNOR has sold,  assigned,  transferred  and set over,  and by
these presents does hereby sell,  assign,  transfer and set over, unto ASSIGNEE,
its successors,  legal  representatives and assigns, the entire right, title and
interest in, to and under the Intellectual Property,  including, but not limited
to, the right to develop,  produce,  promote and  otherwise  exploit  commercial
embodiments of the  Intellectual  Property as ASSIGNEE deems  appropriate in its
business judgment, and the application and all divisions,  renewals, substitutes
and continuations  thereof, and all Letters Patent of the United States that may
be granted thereon and all reissues and extensions thereof, and all applications
for Letters  Patent and any legal  equivalent  thereof,  including  the right to
claim  priority,  that have been or may hereafter be filed for the  Intellectual
Property  in any  country or  countries  foreign to the United  States,  and all
Letters  Patent and any legal  equivalent  thereof  that may be granted  for the
Intellectual  Property in any country or countries  foreign to the United States
and all  extensions,  renewals  and  reissues  thereof,  the same to be held and
enjoyed by  ASSIGNEE  for its own use and benefit and for the use and benefit of
its successors,  assigns or other legal representatives fully and entirely as if
the same would have been held and enjoyed by ASSIGNOR if this Assignment had not
been made, to the end of the term or terms for which any Letters  Patent and any
legal equivalent thereof may be granted;

                  AND ASSIGNOR HEREBY  authorizes and requests the  Commissioner
of Patents and Trademarks of the United States,  and any Official of any country
or countries  foreign to the United  States whose duty it is to issue patents on
applications as aforesaid,  to record this Assignment,  and to issue all Letters
Patent  for  the  Intellectual  Property  to  ASSIGNEE,  its  successors,  legal
representatives and assigns, in accordance with the terms of this instrument;

                  AND ASSIGNOR HEREBY covenants that ASSIGNOR has the full right
to convey the entire interest herein assigned  without  conflict with the rights
of  others,  and that  ASSIGNOR  has not  executed,  and will not  execute,  any
agreement, assignment, sale or encumbrance in conflict herewith;

<PAGE>

                  AND ASSIGNOR HEREBY further covenants and agrees that ASSIGNOR
will communicate to ASSIGNEE, its successors, legal representatives and assigns,
any facts known to  ASSIGNOR  respecting  the  Intellectual  Property,  and will
testify in any legal proceeding, sign all lawful papers, execute all divisional,
continuing  and reissue  applications,  make all rightful oaths and generally do
everything possible to aid ASSIGNEE,  its successors,  legal representatives and
assigns,  to obtain and enforce proper patent  protection  for the  Intellectual
Property in all countries.

                  IN TESTIMONY  WHEREOF,  ASSIGNOR has caused this Assignment to
be executed effective as of the 28th day of June, 2000.

                                               ROBERT M. CEZAR


                                               /s/ Robert Cezar
                                               ------------------------------



                                      -2-

<PAGE>

                                   SCHEDULE A

                                Royalty Payments


ASSIGNEE  will pay ASSIGNOR a royalty of twenty  percent  (20%) of Net Proceeds.
"Net Sales" means the total consideration,  in any form, received by ASSIGNEE in
connection with the sale, lease or other  disposition of products  embodying the
Intellectual  Property to an independent third party, less (i) returns,  rebates
and allowances (actually paid or allowed), and (ii) freight, shipping, and sales
and other taxes.  Such royalties  shall be paid within 45 days following the end
of each fiscal quarter of ASSIGNEE.