PS/2 Keyboard Pin Out & USB Pin Out

Pin	Signal	In/Out
1	Data	Out
2	N/C
3	Ground
4	+5V
5	Clock	Out
6	N/C

About PS/2

Named in honour of IBM PS/2 these sockets today are widely used as standard interfaces for the keyboard and the mouse, but they gradually give up the place USB. For connection of the keyboard the socket of violet color is usually used.

Pin	Signal	Color	Description
1	VCC		+5V
2	D-		Data -
3	D+		Data +
4	GND		Ground

About USB

Sockets Universal Serial Bus (USB) are intended for connection to a computer of such external peripheral devices, as the mouse, the keyboard, a portable hard disk, the digital chamber, VoIP-phone (Skype) or the printer. Theoretically, it is possible to connect to one host-controller USB of about 127 devices. The maximal speed of transfer makes 12 Mbit/s for standard USB 1.1 and 480 Mbit/s for Hi-Speed USB 2.0. Sockets of standards USB 1.1 and Hi-Speed 2.0 are identical. Distinctions are covered in speed of transfer and a set of functions of host-controller USB of a computer, and USB-devices. USB provides a power supply for devices, therefore they can work from the interface without an additional power (if the USB-interface gives a necessary power, it is no more 500 mA on 5V). There are three basic types of USB connectors: USB A, USB B and mini USB.

Souce code