Widely used in the analog audio/video world as well as for electrical connections (see NuBus and VMEbus), DIN connectors were the plugs and sockets for mice and keyboards on earlier PCs. The first PC keyboards used a 5-pin DIN "AT" connector. The 5-pin was superseded by a smaller 6-pin Mini-DIN, which also replaced the serial port for the mouse. Eventually, all DIN-based mice and keyboards were replaced by USB. See DIN, DIN radio and PC keyboard.