Technology & Communications

Types of computers
 The desktop (tower, monitor, keyboards,
mouse)
 The laptop (advance of portability)
 The palmtop (smallest and lightest)

Computer systems
 Process is undertaken in central processing
unit or CPU.
 Secondary storage: computer hard disk or
CD-ROM.
 Primary storage or memory

How a computer works:
First you have to tell the CPU what you want it
to do: choose the program:
Typing Keyboard CPU
Secondary
Storage
(programs and data)
signal Monitorsignal Image
on screen

Input devices
 The keyboards
 Pointing devices (mouse, touch pad,
trackball)
 Pen-based devices

Input devices
Scanners:
 Image scanners (similar to photocopiers by
taking a picture of the input document)
 Optical character recognition scanners
(capable of recognizing more fonts).
 Bar code readers

Input devices
Scanners:
 Magnetic strip readers (Automatic Teller
Machines)
 Optical Mark Recognition (shown as marks in
particular places on a document)

Input devices
 Video and audio input
 Voice recognition

The Central Processing
Unit
The CPU is the heart of the computer.
Two aspects are important:
Type of processor and speed (ability to
undertake sophisticated applications)
Main memory (RAM random access
memory, (ROM) read only memory)

Output devices
 Screens output device known as visual display
units (VDUs) with a variety of sizes such as
14”-21”

Output devices
Printers:
Serial printers: print one character at a
time.
Inkjet printers: spray painting each
character onto the paper.
Dot matrix printers: same way as a
typewriter and they are capable of
producing a number of different fonts.

Output devices
Printers:
Line printers: memorize a line at a time and
printing that line by character.
Page printers or laser printers: they produce
high quality output, also in colour and their
cost is over £500.

Output devices
 Voice output (speech is after all organized in
a particular way).
 Other types of output (microfilm, video
sound, information printed in miniature form
etc).

Storage
 Memory:
(i) random access memory
(ii) read only memory
Memory is measured in “bytes”:
1 byte is a grouping of 8bits which the
computer can operate on a single unit.

The terminology is as follows:
 1000 bytes = 1 kilobyte (or 1 kb)
 1000 kilobytes = 1 megabytes (or 1 MB)
 1000 megabytes = 1 gigabyte (or 1 Gb)
 1000 gigabytes = 1 terabyte (or 1 Tb)

DATA and FILES
The combination of data in a whole package is
package called a “file”.
The name consists in two parts: a filename and
an extension. Thus a file could be known as
“MYFILE.DOC”.

Secondary Storage
Classified in two different ways:
(i) A permanent part of the computer’s internal
structure (hard disk) or a external object.
(ii) The medium storage -tape, disks or
memory disks.

Secondary Storage
Storage devices:
(i) Magnetic tape (the oldest form of storage
device).
(ii) Data files are stored also on disks.
(iii) A computer’s hard disk is usually the main
secondary storage facility.
(iv) CD-ROM disks with capacities up to 4 Gb
(v) DVDs (digital versatile disks) which can store up
to 16G
(vi) Memory sticks: very small devices with large
memories

Software
The programs which instruct the computer to do
things.
(i) System software:
The most important part of such software is the
operating system - an integrated set of
programs which manage CPU operation,
control input, output and storage activities and
devices.(windows, ms-dos, Linux etc)

Applications - Software
Dedicated programs are those for particular business
purposes such as payroll, accounting, auditing etc.
General -purpose programs are for common information -
processing activity:
Word processing (printing, writing, editing documents, text
data)
Spreadsheets -manipulation of mathematical figures of
decision support systems

Applications - Software
Databases - allow the storage and retrieval of data and
records and their manipulation.
Graphics - cover graphic presentation of numerical data and
the creation, editing and printing of images for
presentation purposes.

TECHNOLOGY AND COMMUNICATIONS
COMPUTER COMMUNICATION
 Need to transfer data from one
computer to the other
 Need for terminals to be located far
from the main computer.

Networks –two ways of computer s which are
connected to each other and are able to
exchange data:
 In the form of wheel, (one central computer
and a number of satellite computers)

Networks –two ways of computer s which are
connected to each other and are able to
exchange data:
 In the form of a circle, (computers are
linked together and data can be easily
exchanged between all of them).

Local area Networks (LANs)
LANs link together over small distances,
usually in the same building.
 A device which provides a service to other
computers on the network is known as a
“server” (printer server).
A
B
PRINTER
DC
E

WIDE AREA NETWORKS (WANs)
A wide area network (WAN) is a
telecommunication network that covers a
broad area (i.e., any network that links
across metropolitan, regional, or national
boundaries).

INTERNET:
is a global system of interconnected
computer networks that use the standard
Internet Protocol Suite (TCP/IP) to serve
billions of users worldwide.

How does it work?
What does it do?

TELEPHONE SYSTEMS
Land line systems:

TELEPHONE SYSTEMS
Mobile phones:

TECHNOLOGY AND
COMMUNICATIONS
TELEPHONE SYSTEMS
 Pagers:
 Fax or facsimile:

Word Processing:
 Templates
 Mail merge
 Editing facilities

Word Processing:
 Formatting
Words and phrases
Paragraphs

Word Processing:
The main formatting feature
include:
 Alignment
 Indentation
 Tab stops
 Bullets
 Numbering

Working with graphics:
Drawings
Charts
Clip art
Photos

Desk top publishing
Electronic publishing

TECHNOLOGY AND
COMMUNICATIONS
Web design
E-mail

E – commerce
refers to the buying and selling of
products or services over
electronic systems such as the
Internet and other
computer networks.

Virtual interaction:
 Written discussion
 Videoconferencing

 Collaborative
working
 Telecommuting

Technology & Communications

More Related Content

What's hot (19)

Similar to Technology & Communications (20)

Technology & Communications