Computer port (hardware)

Electronically, the several conductors where the port and cable contacts connect, provide a method to transfer data signals between devices.

For example, a 9-pin D-subminiature connector on the original IBM PC could have been used for monochrome video, color analog video (in two incompatible standards), a joystick interface, or a MIDI musical instrument digital control interface.

The original IBM PC also had two identical 5 pin DIN connectors, one used for the keyboard, the second for a cassette recorder interface; the two were not interchangeable.

Plug-and-play ports are designed so that the connected devices automatically start handshaking as soon as the hot-swapping is done.

The user's response determines the purpose of the port, which is physically a 1/8" tip-ring-sleeve mini jack.

Hardware port trunking (HPT) is a technology that allows multiple hardware ports to be combined into a single group, effectively creating a single connection with a higher Bandwidth sometimes referred to as a double-barrel approach.

This technology also provides a higher degree of fault tolerance because a failure on one port may just mean a slow-down rather than a dropout.

The USB-C standard, published in 2014, supersedes previous connectors and is reversible (although not electrically), meaning it can be plugged both ways.