I think all of these are 1997 or 1998, but found them while searching for something else. (you know how that happens? )

Chip and money tracking
http://www.patentstorm.us/patents/5735742.html

Chip Patent
http://www.patentstorm.us/patents/5676376.html

Antennas in gaming chips
http://www.patentstorm.us/patents/5651548.html

Gaming chip with built in timer
http://www.patentstorm.us/patents/6357746.html

Have fun!