Definition - Shape & Size- Symbol - "Gender" - Serial & Parallel

- Advantages & Disadvantages - Common Peripherals - Practice

 

Definition:

A computer port is an external connection device used to connect different peripherals to a computer *. Concretely it is a socket (and the corresponding plug) that enables an external device (peripheral) to be attached to a computer (usually to a motherboard or adapter card).

In daily terms a port is a door that a computer use to communicate (input and output) with the rest of the world, what includes other computers, the Internet, a printer, a keyboard, mouse, digital camera, external modem, etc. etc.

All external computer ports have the following general characteristics that are useful to identify and discriminate and to make proper decisions related to ports when the time comes.

(* Note: In this Website we are excluding other two meanings that are common when talking about computers: port as a hardware internal connection and also port as a computer communications logical address.)

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Shape & Size:

This are very obvious but important characteristics of all ports. Since they are a pieces of hardware, an object, they have specific shapes that are the first and best way of recognizing them. Some are round (PS2), some are trapezoid (LPT, COM, SCSI) and some are rectangular (USB and FireWire). They also have a determined size that is rather small, running for example from the size of a penny (for the round ports) to the size of an electric plug (for a trapezoid shaped one like COM ports).

Here you have and idea of actual sizes and shapes of the ports you will be learning

 

Remember, to survive in the jungle of ports, when trying to identify one always look for shape and size!

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Symbol

Some computer ports have a special well known symbol that identifies it, like USB. COM, FireWire or SCSI, and for other computer ports often computer manufacturers provide a symbol that is similar and also identifies the port, like having a symbol of a printer to identify a LPT port, or a keyboard or mouse for a PS2 port. However there is not a unique icon for these other ports.

Normally the symbol is present right next to the place where the port is located, usually in the back of the computer. You can also find the symbols in manuals or in peripherals boxes when you buy them.

On the specific section for each port you will learn more about the symbols but here you have some examples of how they will look like:

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Also some ports are color coded. Even though it is not totally standardized, and may be slightly different on each computer, it is helpful because the color on the port matches the color of the provided plug.

For example normally green for mouse, purple for keyboard:

Mouse
Keyboard

 

Symbols are like a map in the middle of the jungle and they will always be useful to know where a computer port is located or when you will need them. Watch for them in the back of your computer and on product boxes!

 

"Gender"

Even though it may sound funny computer ports (and their matching plugs) have "gender". They are either male or female. The male ones (only few) have pins and the female ones have holes where those pins fit.

This may seem like a detail but it may be helpful to identify computer ports and also it is something good to know so you don't try to match a male plug with a male socket. That may damage your port.

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Male		Notice the pins!
Female		Watch for the holes!

Serial & Parallel

Probably you have often herd the terms serial and parallel when talking about computers and of course about ports. Well, it can be a little confusing because they are a characteristic of every port (they are either one or the other) but at the same time there are two ports that are commonly know by these names (LPT = parallel, COM = serial).

Actually serial and parallel refers to the way the port communicates the data that it's being transferred (Remember that ports are communication devices!).

In technical language serial ports are defined as a communication interface in which data is transferred one bit at a time, with no synchronization. That is to say serial ports communicates the information (input or output) one series a t a time.

Parallel ports, technically defined as a communication interface in which multiple bits of information are transferred on multiple parallel wires, are the ones that have the capacity of send or receive more than one group of data at the same time.

Actually among the ports that we are going or be studying the only parallel ones are the LPT or printer port and SCSI or scuzzy ports. All the other ports are serial ones.

Advantages & Disadvantages:

Different ports have different pros and cons. Some are faster (to communicate) some are cheaper (the port itself and peripherals, cables, adapters, etc.). Some are more versatile some are very specific.

 

Common Peripherals:

Every port can work with specific peripherals, some of them can work with almost any one, and some work only with one or two. However there are some ports that are often associated with a specific peripheral, like it happen for example with LPT and printers, even though they can work with other types. This happen because they are widely use with a specific kind equipment that become the "common peripheral" for that port.

It is also important to notice that this is a dynamic condition. For example when COM ports just started they where the common peripherals for the mouse, later when PS2 came mouses moved to this port, and now there are also available mouses that use USB ports.

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To survive out there in the port's jungle it's helpful to know what are the most common peripherals that are used with each port. It will save you time and trouble!

 

Practice:

1.	These are a list of major things to look for when trying to identify a computer port. Choose the one that doesn't belong.
	Symbol	Shape and Size	Plastic Quality	Color	Gender
2.	Size and shape are important because:
	A. The quality of the port depends on both.
	B. They help you to easily identify a port.
	C. Different size and shape means different peripherals that can be plugged.
3.	Computer ports are:
	A. Virtual windows for computer outputs
	B. A type of software
	C. Where you connect equipment to a computer
	D. Adapters used to connect two computers