COMPUTER APPRECIATION
Computer
is an electronic device that can accept data as an input, process
data, store data and bring out information as an output.
WHAT IS DATA?
Data
is a piece of information which can exist in different forms e.g. a written
text on a piece of paper, bytes stored in an electronic memory and facts in a
human mind. Data is the plural form of the word datum.
Computer has three components parts
which are independent. That is, without this part combining together it is
incomplete. They are the keyboard, central processing unit also known as the
system unit and the monitor
COMPONENTS OF COMPUTER SYSTEM
1)
Keyboard
2)
System unit
3)
Mouse
1)
KEYBOARD: this is an input device use
for inputting data or information in the computer. It is very similar to the
typing keys of the typewriter. It is divided into different areas as follows:
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a)
ALPHABETICAL KEYS: it is also known as
the typewriter keys. This is the alphabetical area (A-Z) used for alphabetical
data(s).
b)
NUMERIC KEYS: it is used for inputting
numbers
c)
FUNCTIONAL KEYS: these are series of key
(F1-F12) that have their usage depending on a particular application
d)
CURSOR KEYS: these are keys that aid in movement of
the cursor, they include arrow keys (
) page up, page down, home, end, delete, insert.
e)
Modify keys: this include ctrl, alt,
shift they are also called modify keys because they depend on other keys to
carry out their functions.
f)
INDICATOR AREAS: keyboard also has a
status indicator area. This area has three light that display status ( on or
off). They are number lock, scroll lock, cap lock. This three key toggle there
in respective mode on or off when they are pressed.
g)
NUMBER LOCK: toggles the keys of the
numeric key pad between cursor movement and numeric entry.
h)
CAPS LOCK: toggles the letter keys
between lower case and upper case.
i)
Scroll lock: toggle between two ways of
using the cursor keys.
j)
LOGICAL UNITS: performs logical operations
such as or, not, and etc.
MONITOR: It can also be called the virtual display
unit or the screen. It is an output device responsible for displaying any
information after been processed.
INPUT
AND OUTPUT DEVICES
Input devices:
It accepts data from the outside and convert it to an electronic form that
computer understands.
EXAMPLES OF INPUT DEVICES
1)
Keyboard
2)
Mouse
3)
Touch screen
4)
Scanner
5)
Digital cameras and phones
Keyboard:
This
produces hard copy of information on paper, unlike the monitor which produces
the soft copy.
STORAGE DEVICES
These
are those devices used to store files in the computer system
TWO TYPES OF STORAGE DEVICES
1)
PRIMARY STORAGE DEVICES: These devices
are used during processing activities. The work saved on the primary storage
will be lost once there is power loss or failure.
2) SECONDARY
STORAGE DEVICES: This storage device saves file for permanent uses. They are
portable and can be carried about e.g. flash disk, memory card, CD, hard disk,
floppy disk and diskette etc.
TYPES OF COMPUTER
1)
DIGITAL COMPUTER: these are those
computers used for computing activities like calculations and arranging of
data.
2)
ANALOGUE COMPUTER: these are machines that are used for analogue
collections and they are based on analogue signal.
3)
HYBRID COMPUTERS: this type of computer
has the function of both the analogue and the digital computers.
CLASSES OFCOMPUTER
1) Micro
computer
2) Mini
computer
3) Main
frame computer
4) Super
computer
MICRO COMPUTER:
It is the fort generation of the pc, manufactured in 70s, they are smaller and
cheaper, they are also referred as pc (personal computer) e.g. laptop, palmtop,
hand held and pocket sized pc.
MINI COMPUTER:
It is large than the microcomputer, it was developed for the use of military
and was used before the arrival of the
micro computer. It is very expensive, most modern soldiers have mini computers
which are used to process large amount of data received from the satellite.
E.g. 1p 10000, DG900, pdpil and PDS-/E
MAIN FRAME COMPUTER:
It
process large amount of data. They are very large and have to be housed in a
room whose temperature and humidity are low. It processes large amount of data
in seconds and respond to thousand of user simultaneously.
SUPER COMPUTER:
It processes large and gigantic data in the quickest possible time and very
expensive to purchase, they are commonly used by space center worldwide.
ADVANTAGES OF COMPUTER
1)
It creates employment
2)
It saves time and has speed
3)
It makes work easier
4)
It is reliable
5)
It creates means of communication
DISADVANTAGES OF COMPUTER
1)
It enhances corruption
2)
It creates laziness
3)
It causes eye defect
4)
It is expensive to purchase and maintain
ELEMENTS OF COMPUTER
Computer
has four elements they are
1)
Hardware
2)
Software
3)
Human ware
4)
literature
a)
HARDWARE: They are those elements of computer that you
can touch feel or even carry about. The hardware is made up of the main system
and the system properties.
b)
SOFTWARE:
These are logical written instructions by the programmer for the smooth running
of the computer system. Two types of software are: system software and
application software.
SYSTEM SOFTWARE: These
are that software installed into the computer system to ensure the smooth
running of the computer. The system allows the use of application software and hardware.
EXAMPLES OF SYSTEM APPLICATION
1)
Operating system
2)
Utility system
3)
Programming language
APPLICATION
SOFTWARE: They are those software installed into the computer system by the
computer user to perform a specific task.
FORMS OF APPLICATION SOFTWARE
1)
Word processing
2)
Spread sheet
3)
Data base management system
4)
Graphic illustration
5)
Desktop publishing
6)
Graphic presentation
7)
Entertainment
HUMAN WARE: These
are trained individuals that can handle the computer system e.g.
1)
Computer programmer
2)
Computer analyst
3)
Computer engineer
4)
Computer instructors
LITERATURE: They
are those books written to teach and educate more about computer e.g. text
books, note books and handout.
HISTORY OF COMPUTER
As we all know, every good thing
underwent a gradual process.
In
the olden days, the early aids of counting were used, but because of man
numerous needs and curiosity to know more, he developed some counting machines.
Before then, the fingers and toes
were used, but they were not good enough when the numbers are larger than 20
since we humans have 10 fingers and 10 toes. Because of this, the primitive man
started to use stones.
Hence this simple way of counting
is difficult to use because stones were very awkward. The idea was colored
beads with thread in a string. This was the first counting machine which was
introduced in 1611 by a man called ABACUS; it is made of beads and thread
on a frame. It was invented to make counting easy, the beads on the first line
are called units, those in the second were counted the tens, those in the third
were counted the hundreds, and the abacus is the wood frame with strings in
which colorful beads are strings. Later a man named JOHN NAPIER came up with an instrument which they called the NAPIER BONES made of bones and strings
in the year 1617.
Then a French man called BLAISE PASCHAL invented the machine
which can do both addition and subtraction, in 1642 the machine was named PASCALINE.
It has a number of wheels which has teeth on them. The addition is done by
moving the wheels forward and subtraction is done by moving them backward.
Seeing the Pascaline was not doing
much work in terms of calculation, this French man JOSEPH JADCQUARD who was a cloth manufacturer built a machine in
1802, it help weave complicated pattern. He named this instrument the JADCQUARD SLOOM, it uses lines of holes
on a card to represent the weaving pattern, if there were ten threads, there
was space in each line for ten holes, the sloom also came with the punch cards.
These cards have holes through which rays pass through them.
As time went on an English man named SIR CHARLES BABBAGE built a machine in 1822 called DIFFERENCE MACHINE on this machine information on card are supplied
to the machine, then used wheels with teeth on them to do some mathematical
calculations.
Babbage died before he could complete the
difficult. He was the first to exploit the concepts from Jadcquard sloom in a
computing machine. Charles Babbage is known as the ala countless of love lace,
showed how the ANALYTICAL ENGINE
could be used to do some particular calculation.
Hence, he was regarded as the first
computer programmer, all the machines mentioned above are referred to as
counting machine while
ENIAC,
UNIVAC, EDVAC are the computer.
ENIAC
means electronic number intergraded and calculator
UNIVAC
means universal automatic calculator
EDVAC
means electronic discrete variable automatic computer.
CLASSIFICATION OF COMPUTER
Computer
can be classified based on the following
1)
Based on generation
2)
Based on type
3)
Based on size
CLASSIFICATION OF COMPUTER BASED ON
GENERATION
FIRST GENERATION COMPUTER: Such
as ENIAC, UNIVAC, ENVAC, etc. have all the following features.
1)
Their processing devices were vacuum
tubes
2)
They are bulky
3)
They consume much power
4)
They give out much energy
SECOND GENERATION COMPUTER:
The vacuum tube was replaced with transistors, the transistors processed data
and it also reduced the boldness of the computer system.
CHARACTERISTICS OF SECOND
GENERATION
1)
They are less expensive than the first
generation
2)
They make use of transistors as
processing devices
3)
They generate less heat
4)
They are smaller than the first
generation computer
5)
They are less expensive to maintain
6)
They are faster than the first
generation
THIRD GENERATION COMPUTER
Here the integrated circuit was used
to produce problems, it was produced by JACK
KUBY also in this generation the keyboard and the mouse were produced.
FEATURES OF THIRD GENERATION
COMPUTER
A.
They make use of integrated circuit
B.
They generate less heat than the second
generation of computer
C.
They are less expensive to maintain
D.
They are less expensive to purchase
E.
They are smaller than the first and
second generation of computer
F.
they move faster than the previous
generations
FOURTH GENERATION OF COMPUTER:
Here there was a combination of several integrated circuits. The computer used
chips where small in size could solve complicated problems. They were small enough
to sit on a small table. They were called computers and their chips were called
Micro processors metal, oxide semi –conductor ( mos) was used for internal
memory.
FIFTH GENERATION COMPUTER:
Were built with human intelligence e.g robots the race towards the end of one
millennium to the beginning of another has caused the development rate of the
computer to be very rapid new words such as “simms, “soram” were introduce to
re-christen “chips” the speed of operating could range from 233w550 MH2, the
ram from 32mb to 120mb, and the hard disk from 6\4\10 20gb as impentium 3.
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