INTRODUCTION TO COMPUTER TECHNOLOGY

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2 Νοε 2013 (πριν από 4 χρόνια και 8 μέρες)

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INTRODUCTION TO
COMPUTER TECHNOLOGY

F1031
-

COMPUTER HARDWARE



COMPUTERS’ APPLICATIONS

Specifications based on the application:


Home computers


Entertainment / gaming computers


Multimedia editing computers


Application server

Computer case (chassis)

CHASSIS ABCs


The computer case or chassis is the body
of the computer.


Cases allow for manufacturers to include
all computer comments together and have
it able to be moved, if needed.


Types of cases


Mini tower


Advantages:

Excellent size which can be placed on top or below of a
computer desk.

Disadvantages:

While this case does offer upgradability, it can be filled
up much faster than the Mid
-
Sized tower.

Recommendations:

Great PC for end
-
users and small businesses.

Types of cases


Mid
-
size tower


Advantages:

Excellent case which can fit below and on top of your
computer desk.

Plenty of expandability for new devices for businesses,
end
-
users, and advanced users.

One of the most used computer cases found today.

Disadvantages:

None

Recommendations:

This case is an excellent choice for all users and
businesses.


Full size tower


Advantages:

Excellent computer for upgradability.

Excellent case for a server machine.

Disadvantages:

Cost is going to be a lot more than a standard case.

Generally a large case which cannot be placed on top or
beneath a desk.

Recommendations:

We recommend that this type of case be purchased by
advanced users or users who plan to have a stand alone
machine as a server.

Types of cases


Desktop


Advantages:

Excellent desk computer.

Great use of desk space when monitor is placed on top of
the computer.

Disadvantages:

With some types of desktop cases can be very difficult to
upgrade.

Does not really work on the floor.

Recommendations:


Excellent choice for a business and home user computer.
End users planning to upgrade or place computer on floor
we recommend going with tower computer unless the
manufacturer provides a desktop that can be converted to
tower.

Types of cases


Slimline

Desktop


Advantages:

Excellent for workstations in large companies.

Great computer for a low budget PC.

Excellent computer for locations which may not have
large area of workspace.

Disadvantages:

Generally little or no room for adding additional
peripherals.

Usually require an LPX
motherboard
.

Recommendations:

We recommend that this type of case be purchased only
for companies employees as workstations.

Types of cases


Definition:


The monitor is a hardware device which
physically connects to video card. The monitor
allows information and current status be
visually outputted similar to a TV.


Two types of monitor:


CRT


LCD/TFT

Monitor

Types of monitor


CRT


Cathode Ray Tube,


The CRT is the main component and most expensive part
within computer monitor.


Within the CRT are three electron guns, Red, Green and Blue.


Each of these guns streams a steady flow of electrons, left to
right, for each line of monitor.


As the electrons hit the phosphors on the CRT, the phosphor
will glow certain intensities.


As a new line begins, the guns will then begin at the left and
continue right; these guns will repeat this process sometimes
thousands of times until the screen has been completely drawn
line by line.


Once the phosphors on the CRT have been hit with an electron
they will only glow for a short period of time; because of this,
the CRT must be refreshed, which means the process will be
repeated as explained above.


If the video card's refresh rate is not set high enough, you may
encounter a flicker or a noticeable steady line scrolling from
the top to the bottom of the screen.

Types of monitor


CRT


MINIMUM RESOLUTION


The size is an important factor of the
computer's running resolution. When picking
the resolution, try basing it off the monitor's
size for best use.


13
-
inch = 640 x 480


15
-
inch = 800 x 600


17
-
inch = 1,024 x 768


21
-
inch = 1,280 x 1,024

Types of monitor


GHOST / BURN


If monitors, especially older CGA / EGA monitors,
are left on for long durations, the electron beams
cause the phosphors to glow.


If the electron guns continue to do this for
thousands of hours refreshing the same images,
this can cause the images to be burnt into the CRT
surface causing a ghost image to appear.


This image will become permanently displayed on
your monitor for the duration of its life.


A resolution to this problem are screen savers,
which are programs that generate a random set of
images, lines or other methods of allowing the
image to not remain static while the computer is
not being used.


Types of monitor

Advantages of CRT Monitors


Less expensive

-

Although LCD monitor prices have decreased,
comparable CRT displays still cost less.


Better color representation

-

CRT displays have historically
represented colors and different gradations of color more
accurately than LCD displays. However, LCD displays are gaining
ground in this area, especially with higher
-
end models that
include color
-
calibration technology.


More responsive

-

Historically, CRT monitors have had fewer
problems with ghosting and blurring because they redrew the
screen image faster than LCD monitors. Again, LCD
manufacturers are improving on this with displays that have
faster response times than they did in the past.


Multiple resolutions

-

If you need to change your display's
resolution for different applications, you are better off with a CRT
monitor because LCD monitors don't handle multiple resolutions
as well.


More rugged

-

Although they are bigger and heavier than LCD
displays, CRT displays are also less fragile and harder to damage.


Defintion

LCD/TFT


A TFT monitor uses
thin
-
film transistor

technology for the ultimate LCD display.
LCD
monitors
, also called flat panel displays, are
replacing the old style cathode ray tubes
(CRTs) as the displays of choice. Nearly all LCD
monitors today use TFT technology

Types of monitor


Benefits

The benefit of a TFT monitor is


a separate, tiny transistor for each
pixel

on
the display.


the amount of charge needed to control it is
also small.


very fast re
-
drawing of the display,


image is re
-
painted or refreshed several times
per second
.


Types of monitor


Resolutions


A typical 17
-
inch TFT monitor has about 1.3
million pixels and 1.3 million transistors.

Types of monitor

Advantages of LCD Monitors


Require less power

-

Power consumption varies greatly
with different technologies. CRT displays are somewhat
power
-
hungry, at about 100 watts for a typical 19
-
inch
display. The average is about 45 watts for a 19
-
inch LCD
display. LCDs also produce less heat.


Smaller and weigh less

-

An LCD monitor is significantly
thinner and lighter than a CRT monitor, typically weighing
less than half as much. In addition, you can mount an LCD
on an arm or a wall, which also takes up less desktop
space.


More adjustable

-

LCD displays are much more
adjustable than CRT displays. With LCDs, you can adjust
the tilt, height, swivel, and orientation from horizontal to
vertical mode. As noted previously, you can also mount
them on the wall or on an arm.


Less eye strain

-

Because LCD displays turn each pixel off
individually, they do not produce a flicker like CRT displays
do. In addition, LCD displays do a better job of displaying
text compared with CRT displays

Computer screen resolution


Graphics resolution is measured in pixels.


A pixel is a distinct point of light displayed on
a monitor.


The quality of a computer screen is defined
by the number of horizontal and vertical
pixels that can be displayed.


For example a widescreen monitor may be
able to display 1280 x 1024 pixels with
millions of colors.


As for image resolution in digital cameras, it
is measured by the number of mega pixels
that can captured in a photograph.