USB Connector pinout

USB A connector .

several USB plugs .

USB2.0 pinout :

1=+5V (red)
2=-Data (white)
3=+Data (green)
4=Ground (black)

mini or micro:
1=+5V (red)
2=-Data (white)
3=+Data (green)
4= n.c. (gnd in USB-on-the-go type A plug)
5=Ground (black)

USB3, A-plug .

USB type C .

USB to PS2 converter .
PS2 pins: 1=data, 2=n.c., 3=gnd, 4=+5V, 5=clock, 6=n.c.

converters from 2x PS2 (keyboard and mouse) to 1x USB .
In both converters some electronics is built-in to combine the two PS2 ports.