6. A user card transaction system, comprising:
a user card containing a microprocessor and associated memory, and a plurality of contacts for transferring data to and from said microprocessor and memory, including a first data input/output contact and a second data input/output contact;
a first peripheral device which provides at least one of the functions of user input to said microprocessor and/or presentation of data output from said microprocessor to a user, said peripheral device including a data input/output terminal that is connectable to said first input/output contact of said user card; and
a second peripheral device which provides at least one of the functions of user input to said microprocessor and/or presentation of data output from said microprocessor to a user, said peripheral device including a data input/output terminal that is connectable to said second input/output contact of said user card.
United States Patent 6,199,128 Inventors: Sarat; Jean-Marc (Belmont, CA)