A system controls access to plural devices with only four lines by grouping the devices in nodes, each node including a predetermined number of the devices and a local control circuit defining a shift register with positions respectively connected to the devices. The nodes are connected in series with...http://www.google.de/patents/US7462103?utm_source=gb-gplus-sharePatent US7462103 - Gaming system for individual control of access to many devices with few wires
