12 Computer Service and Repair
to issue commands through the use of special
purpose keys, such as the function keys and key
combinations. The mouse is used to interact with
coordinates on the display. When an area on the
display is selected followed by a left mouse click,
a command is entered. A touch screen monitor
is both an input and output device. The screen
is used to display data as output and to input
commands by touching the screen. These devices
are covered later in the textbook.
Case Style
There are many different case styles that are
used to contain and protect the electronic parts of
a computer. Some of the most common case styles
are referred to as desktop, tower, mini tower,
Oleksiy Mark/Shutterstock.com
Figure 1-13. Front view of a typical PC. micro tower, laptop, and notebook. Case selection
is usually based on individual taste.
Exterior Connections
The outside of the computer allows access to
the electronic parts inside. Data can be entered
into the computer system through the hard drive,
optical (CD/DVD) drive, keyboard, mouse, or one
of the ports in the back. See Figure 1-14.
The exterior connections to a computer
are well worth a closer look. The connectors
discussed in this section are some of the more
common connectors you will find on a PC. More
information is given on these connectors in the
sections detailing the components with which
they work.
Be sure you can identify PC exterior ports
and connections.
A+ Note
Mini-DIN
The mini-DIN connection is used for the
mouse and keyboard, Figure 1-15. Be aware that
this connection type may not be interchangeable
on some computers as it is for the connection
Line in
PS/2 mouse
(green)
PS/2 keyboard
(purple)
Center
speaker
Side
speaker
Rear
speaker
Coaxial
audio out
ToskLink
audio out
IEEE
1394
USB
port
Parallel
port
RJ-45
port LAN-1
RJ-45
port LAN-2
Line out
Mic
Goodheart-Willcox Publisher
Figure 1-14.
Ports accessible at
the back of a typical
computer.