Computer port (hardware)

Examples of computer connector sockets on various laptops

Ports on the back of the Apple Mac Mini (2005)

A computer port is a

network equipment.^[1]

Electronically, the several conductors where the port and cable contacts connect, provide a method to transfer

Bent pins are easier to replace on a cable than on a connector attached to a computer, so it was common to use female connectors for the fixed side of an interface.

Computer ports in common use cover a wide variety of shapes such as round (

USB

-like outlet referred to as USB Port), into which the keyboard is connected.

Physically identical connectors may be used for widely different standards, especially on older personal computer systems, or systems not generally designed according to the current Microsoft Windows compatibility guides. For example, a 9-pin D-subminiature connector on the original

Macintosh

family computers used the mini-DIN for a serial port or for a keyboard connector with different standards than the IBM-descended systems.

Electrical signal transfer

Electronically, hardware ports can almost always be divided into two groups based on the signal transfer:

Analog ports

Digital ports:
- Parallel ports send multiple bits at the same time over several sets of wires.
- Serial ports send and receive one bit at a time via a single wire pair (Ground and +/-).

After ports are connected, they typically require handshaking, where transfer type, transfer rate, and other necessary information is shared before data is sent.

Hot-swappable ports can be connected while equipment is running. Almost all ports on personal computers are hot-swappable.

USB

ports and FireWire ports are plug-and-play.

Auto-detect or auto-detection ports are usually plug-and-play, but they offer another type of convenience. An auto-detect port may automatically determine what kind of device has been attached, but it also determines what purpose the port itself should have. For example, some

audio speakers; then a dialogue box pops up on the computer screen asking whether the speaker is left, right, front, or rear for surround sound installations. The user's response determines the purpose of the port, which is physically a 1/8" tip-ring-sleeve mini jack

. Some auto-detect ports can even switch between input and output based on context.

As of 2006, manufacturers have nearly standardized colors associated with ports on personal computers, although there are no guarantees. The following is a short list:

Orange, purple, or grey: Keyboard PS/2
Green: Mouse PS/2
Blue or magenta: Parallel printer DB-25
Amber: Serial DB-25 or DB-9
Pastel pink: Microphone 1/8" stereo (TRS) minijack
Pastel green: Speaker 1/8" stereo (TRS) minijack

FireWire

ports used with video equipment (among other devices) can be either 4-pin or 6-pin. The two extra conductors in the 6-pin connection carry electrical power. This is why a self-powered device such as a camcorder often connects with a cable that is 4-pins on the camera side and 6-pins on the computer side, the two power conductors simply being ignored. This is also why laptop computers usually have only 4-pin FireWire ports, as they cannot provide enough power to meet requirements for devices needing the power provided by 6-pin connections.

Optical (light) fiber, microwave, and other technologies (i.e., quantum) have different kinds of connections, as metal wires are not effective for signal transfers with these technologies. Optical connections are usually a polished glass or plastic interface, possibly with an oil that lessens refraction between the two interface surfaces. Microwaves are conducted through a pipe, which can be seen on a large scale by examining

microwave towers

with "funnels" on them leading to pipes.

Hardware

ISDN

B1 (64K) plus B2 (64K) equals data throughput of 128K.