INTRODUCTION
The
present day computer is a result of so many outdated technologies initiated by
inventors, scientists and engineers.
The idea of computing was first initiated by a French
boy by name Bless Pascal; he invented a device named The Pascalina which he
used to help his father in doing basic calculations since his father was a tax
collector. Later another device was invented known as the Differential Engine use
to solve differential equations and so on. All these inventions let to the
development of the various generation of computer.
COMPUTER SYSTEM
Definition of a computer:
A
computer is an electronic device capable of receiving data in the form of
input, stores this data, process these data and sending out the result
(information) in the form of output.
A
computer system refers to the entire computer and all the devices and component
related to the computer (environment).
A computer system is practically divided into three
parts;
SOFTWARE
These are the components related to
the computer environment which can neither been seen nor touch. It generally
refers to programs installed on the computer that tells the computer how to interact
with the users.
Examples of software includes those that can carry
out text product, video editing, graphics design or web browsing.
Computer software is further divided into 3 divisions
i)
System
software.
System software refers to the governor
program of the computer. They are divided into operating system and compiler.
They coordinate and controls hardware and operations in the computer and it
devices.
Example of system software includes; MS DOS, WINDOWS
(e.g. XP, VISTA, SEVEN, 98, ETC), LINUX, UNIX, Mac O.S, Device drivers, Programming
languages, utility programs etc.
Operating system: They are defined
as system software capable of controlling and managing soft and hardware
operations including memory and disk storage.
The most common operating systems are; Windows (the
most popular world known), Mac O.S, Apple Mac OS X. they operate on GUI (some
time called gooey). The advantage of GUI is that it provides the ability to
carry out multitasking (i.e., working on many windows at once). It also
provides the ability to use graphical icons and text to execute task or to run
programs rather than typing instructions as in the MS DOS (the first operating
system).
Without the operating system, the computer is
useless. Some measure functions of the operating system comprise;
-
Running
applications: Calling package such as Microsoft Word so that the user can
interact with them directly.
-
Running
programming languages: This is a situation where the user can create a new
program using a program editor.
-
File
Management: Creating, moving, copying, pasting, deleting, merging files on
disk or other storage.
-
Device
management: This is when the operating system instructs the computer on the
use of different peripheral devices such as, printer, display, keyboard, etc.
We have two types of operating system i.e. the server
operating system use for a computer instructing or sharing data with other
computers on the network and the client operating system that can only
accommodate a single user at a time hence designed for personal use.
Utility programs: These are programs
that perform task involving computer disk management system and use of hard
ware resources disk drives and printers. Their function covers disk formatting
(dividing the disk into sectors so as to use it to store information) and disk
decrementing (rearranging files on a disk in an orderly manner). They include;
-
Memory management software for handling
locations in the RAM where programs put their current data.
-
Disk checker to scan the content of a hard disk
to identify portions or files that are corrupt or not correctly saved and
delete them.
-
Backup program to copy all information stored on
a disk and restore them in case of disk failure or accidental deletion.
-
Data compression program to reduce a data so
that it requires less storage space.
-
Disk defragmenter to identify files whose
content are broken across several locations and bring them to one so as to
increase efficiencies.
Device drivers: A device driver is software
that allows the computer controls a peripheral device. It is this driver the translate
responses from the computer to the device and from the device back to the computer.
Computer programming languages: They
are sometime called compilers use by programmers to write programs by
translating the instructions into electrical signals.
Compilers are programmes installed on a computer to
convert data from a high level language to a language that is understandable by
the computer.
Compilers are usually use for programming. Examples includes; JAVA, C++, C, PASCAL,
COBOL, Visual Basic, etc.
ii)
Application
software
These are programs or software installed on a
computer to carry out particular functions. These programs can be installed on
a computer only after the operating system has been installed. Example of
application software includes;
Word processing software,
Spreadsheet software,
Data Base management software,
Presentation software,
Computer Aided Design
Desktop publishing software,
Accounting software,
Paint and image editing software,
Video and audio editing software,
Multimedia authoring software,
Web page authoring software.
Application
software is made up of Productivity software and Connectivity software.
Productivity software: it is
designed to be use by business or organization, it help users to work more
effectively. E.g. spreadsheet, word processing etc.
Connectivity software: Connect a
computer to a local area network or the internet and provides tools that you
can use to take advantage of the information and communication they offer.
An
antivirus is use to protect a computer system from virus attack.
A virus is programmes designed by software engineers
and publish to the internet. These programmes are downloaded automatically by
computer while browsing the internet. These programmes when present in a
computer, cause the computer to function negatively (malfunction).
The effect is usually slowness of the computer,
freezing of the computer or malfunctioning of other programmes which includes
unnecessary lost of data or information.
This refers to the computer components which can be
seen and touch. They are made up of electrical circuit and mechanical parts. Hardware
devices can function as input, processing and output devices. Hardware
components provide the working space for software’s.
Storage devices are also examples of hardware
components. Example of hardware components include; mouse, keyboard, printer,
hard disk drive, etc.
PEOPLE WARE
This refers to the persons working on the computer.
This idea of people ware has been introduced here because the computer hardware
and software components can not work on their own, a human being is needed to
instruct the computer on what to do at a particular time.
ABBREVIATIONS
LCD : Liquid Crystal Display
USB :Universal Serial Bus
MAN :Metropolitant
Area Network
LAN : Local Area Network
WAN : Wide Area Network
RAM : Random
Access Memory
ROM : Read Only Memory
HDD Hard Disk Drive
DVD :
Digital Versatile Disc
CD : Compact Disc
VCD : Video Compact Disc
SDRAM Synchronous Dynamic Random Access Memory
IP : Internet Protocol
VGA : Video Graphics Accelerator
RW : Rewritable
MSDOS : Microsoft Disk Operating System
ALU : Arithemetic Logical Unit
CPU : Central Processing Unit
SU : System Unit
CRT : Cathode
Ray Tube
ISP :
Internet Service Provider
GUI : Graphical
User Interface
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