The most common way of implementing 8 and 16 bit multitaps is to multiplex the signals from each attached controller in some way. Some systems have unused lines available on the controller port, designed for future expansion, which can be used. Another popular technique is to serialise the data from each controller. Since the NES and Super NES both use a serial bus for standard controllers, creating a multitap is simply a case of increasing the amount of serial data available to the console. In that way, an almost unlimited number of extra controllers can be connected.