PCs and Others

typoweheeElectronics - Devices

Nov 8, 2013 (4 years and 6 months ago)

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1


PCs and Others

Category

Pros (advantages)

Cons (disadvantages)

DESKTOP

Extended memory

Permanent location

LAPTOP or NOTEBOOK

Portability, hardcover
-
book size,
lightness

Bat
t
ery
-
operated system,
less
extended
memory

WEARABLE PC

Computer and user are me
ld
together

Specific
-
purpose machine

PALMTOP or

HANDLED COMPUTERS

No external device,
paperback
-
book size

Interaction via electronic pen, by
onscreen keyboard, by speech

Flash memory

THIN CLIENT

Less expensive than a PC

Connection to a central server (o
n
which it depends totally
), small
processor, less RAM, no permanent
installed disk

WORKSTATION

Speed, very powerful processor,
additional memory, enhanced
capabilities
to

perform

special tasks

Specific
-
purpose machine


1.

What is a docking station or port
replicator?

It is an easy way to connect peripheral devices to a notebook; it is designed to transform a
notebook into a desktop computer.

2.

How does it work?

You connect your peripherals to the port replicator rather than to the ports on your notebook,
then

connect your notebook to the port replicator. Instead of disconnecting multiple devices
from your notebook you’re unplugging only one.

3.

What is the origin of the name “mainframe computer”?

Mainframe computer is a term originated from the early mainframes w
hich were housed in
enormous room
-
sized boxes or FRAMES
.

4.

What is a CLIENT?

It
is a kind of
computer
. It is
connected to a server from which it obtains information.

5.

What is a SERVER?

It is a large central computer.

6.

Why can’t
you move your
desktop PCs

?

Beca
use they depend on a POWER SOURCE

Focus on ... POWER


{

plugs: male electrical connectors that fit into female electrical sockets

POWER



s
ockets
: power outlet or power point (= device to which a item of electrical
equipment can be connected to provid
e it with electricity)



2



The Functions of a Computer System

Each computer system has four fundamental functions:

1.

INPUT: it is the raw data entered via
input peripheral devices

2.

STORAGE:
the way that information is kept on a computer

2.1

RAM
: temporary storag
e (=main store or primary memory)

2.2

DISK
: permanent storage (=mass or backing storage)

3.

PROCESSING: the way of performing operations on data; the Control Unit takes data from the
RAM and directs all the operation
s; the Arithmetic Logic Unit performs all the o
perations;
CU+ALU= CPU (=Central Processing Unit =processor =nucleus of any computer system)

4.

OUTPUT:
the information produced by a computer; they can be:

4.1

printed
→ HARD COPY

4.2

displayed on a screen or sent to audio speakers → SOFT COPY


a)

What makes our output available?

The results of our processed data are available

thanks to
output peripheral devices
.

b)

What
is an output device?

We define output machine, a
ny machine c
apable of representing information from a
computer
. This
includes
, for instance,

display screens
,
printers

and

plotters.

c)

What is a plotter?

A
device

that draws pictures on paper based on
commands

from a
computer
. Plotters differ from
printers

in that they draw lines using a pen. As a result, they can produce continuous lines, whereas
printers

can only simulate lines by printing a closely spaced series of
dots
. Multicolor plotters use
different
-
col
ored pens to draw different colors. In general, plotters are considerably more expensive
than
printers are
. They are used in engineering
applications

where precision is mandatory.










plotter

3


The Operating Environment

1.

What is the operating environment?

In computing, an
operating environment

is the environment
, the place

in which users run programs
.

An operating environment does not mean that the system is a full operating system.









2.

What is the operating system?

The
operating system is the
most important
program

that
runs

on a
computer
.

Every general
-
purpose computer must have
an
operating system

to run other programs
. Operating
systems perform basic tasks, such as recognizing
inpu
t

from the
keyboard
, sending
output

to the
display s
creen
, keeping track of
files

and
directories

on the
disk
, and controlling
peripheral devices

such as
disk drives

and
printers
.





























3.

Ho
w
do users and
information system interact?

What allows people to interact with electronic devices such as computers, hand
-
held devices (MP3
Players, Portable Media Players, Gaming devices) and household appliances and office equipment is
the
user interface
.

input

out
pu
t

4


4.

What is an interface?

A boundary across w
hich two indepe
ndent systems meet and

communicate with each other.

In computer technology, there are several types of interfaces.

-

user interface

-

the keyboard, mouse, menus of a
computer

system
. The user interface allows
the user to communicate with the

operating system
.

-

software interface

-

the languages and codes that the applications use to communicate with
ea
ch other and with the hardware (
system software
and
application software
)

-

hardware interface

-

the wires, plugs and sockets that hardware device
s use to communicate
with each other.

5.

How
can you classify user interfaces?

User
interfaces can be classified as:

a)

Command
-
driven
:
r
efers to programs and operating systems that accept commands in the form
of
special words or letters
. In contrast, programs t
hat allow you to
choose

from a list of
options

in
a
menu

are said to be
menu driven
. Command
-
driven
interface

is often more flexible than menu
-
driven software, but it is more difficult to learn.

b)

Menu
-
driven
:
r
efers to programs whose user interface employs

menus. The antithesis of a
menu
-
driven program is a
command
-
driven

program.

c)

Graphical
or
GUI
(graphical user interface)
: refers to a program interface
that takes advantage of
the computer's graphics capabilities to make the program
easier to use
. Well
-
des
igned graphical
user interfaces can free the user from learning complex command languages.

Graphical user interfaces, such as Microsoft Windows and the one used by the Apple Macintosh,
include

the following basic components:



pointer

:

a

symbol that appe
ars on the
display screen

and that you move to
select

objects

and
commands
.

Usually, the pointer appears as a small
angled arrow
.


Text

-
processing
applications
, however, use an
I
-
beam
pointer

that is shaped like
a capital
I

(=blinking cursor).




pointing

device

:

a

device, such as a mouse or trackball, that enables you to select objects on
the display screen.



icons

:

s
mall pictures that represent commands, files, or windows. By moving the pointer to
the icon and pressing a mouse button, you can execute a
command or convert the icon into a
window. You can also move the icons around the display screen as if they were real objects
on your desk.




desktop

:

t
he area on the display screen where icons are grouped is often referred to as the
desktop because the i
cons are intended to represent real objects on a real desktop
.




windows:

y
ou can divide the screen into different areas. In each window, you can run a
different program or display a different file. You can move windows around the display
screen, and change

their shape and size at will
.



menus

:

m
ost graphical user interfaces let you execute commands by selecting a choice from
a menu.