Guide to Ports and Plugs (Keyboard and Mouse Interfaces)
There are several different types of plugs and ports that
one should be familiar with when using a computer. Here is a summary
of the all the interfaces you should need to be familiar with to connect
your keyboard or mouse.
USB Ports
USB, or Universal Serial Bus, is the most common
type of interface and has become the standard interface on all current
computers, whether they are on a PC (i.e. Windows) or Mac (OS 9, OS
X) platform. Most computers come with at least 4 USB ports built into
the computer, and many of them have additional ports on the front
of the computer (Front Side USB ports). If you run out of USB ports,
you can purchase a USB Hub which plugs into one USB port, and gives
you additional ports (i.e. like a power bar gives you multiple power
outlets from a single wall outlet).
There are two types of USB ports which look physically identical;
USB 1.1 and USB 2.0. USB 1.1 was the previous standard and is all
you need for any keyboard or mousing device. Certain high speed devices
like flash memory sticks or portable scanners will take advantage
of USB 2.0's faster speed (almost 40x as fast) or increased power
delivery capabilities. Your computer will advise you if a device would
benefit from using a USB 2.0 port if you plug it into a USB 1.1 port.
You will not harm your keyboard or mouse by plugging it into a USB
2.0 port.
Finding the USB Port on your computer is easy. It is usually
labelled with the letters USB if it is on the front of your computer
case or the words 'Univeral Serial Bus'.
If you are looking for USB ports on the back of
your computer they usually are indicated by a symbol which looks
like a cactus (shown above).
A USB plug (what is at the end of the cable which
is attached to your keyboard or mouse).
A USB port (where you insert your plug into your computer).
PS/2 Ports
PS/2 ports were the previous standard before USB for keyboards
and mice. They were no faster than Serial ports (see below) but
were primarily created to help users by assigning a different shape
to the port used for your keyboard (and mouse). This new plug was
created by IBM when they launched their PS/2 line of computers in
1987, and while their concept of proprietary hardware failed to
survive, many of their design ideas (including the color coded PS/2
ports for mice and keyboards) eventually became the industry standard.
The technical term for the PS/2 keyboard interface is a Mini-DIN
6 plug (which replaced the previous standard which was the DIN 5
plug, known as the AT connector). The Mini-DIN 6 plug for the mouse
replaced the 9 pin Serial port connector (see below).
Most computers manufactured prior to 2006 came with 2 PS/2 ports,
a purple one for the keyboard and a green one for the mouse. Computers
built more recently typically no longer have PS/2 ports on them,
although some manufacturers are still supporting this standard,
as there is no loss of performance in using a PS/2 interface for
keyboards and mice. If you need more than one PS/2 port (i.e. for
2 PS/2 keyboards), you have to purchase a PS/2 splitter or a KVM
switch.
A PS/2 plug (what is at the end of the cable which is attached
to your keyboard (purple) or mouse (green)).
A PS/2 port (where you insert in your keyboard plug (purple)
or mouse plug (green) into your computer).
Serial Ports
Serial ports come in a wide range of sizes and shapes and were
the original standard for interfacing any device with any other
device on a computer. Today, they are rarely used and when one talks
of a serial port, they usually mean the DB9 connector (shaped like
a trapesoid). Typically they are only used on computers used in
industrial environments or as a means of interfacing with an industrial
control.
A Serial plug (what is at the end of the cable which is attached
to your mouse).
A Serial port (where you insert in your mouse plug into your
computer).
We hope this guide to ports and plugs has been informative and useful.