INTRODUCTION TO COMPUTER
Before the use of computer, computing began from manual practices
to mechanical form as of the 1600s. Human beings had been doing
computing in less advance methods among the early methods are the
counting with fingers, toes, pebbles and the use of Abacus.
FINGERS AND TOES
Counting or calculating was done by human parts before computer was
invented. These were used for counting and the system is still in use
by uneducated people and for teaching children.
PEPPLES
All fingers added together are ten (10). When counting is more than
ten it becomes impossible to continue the counting. For this reason,
the early man changed to the use of stones (pebble) from the use of
his flock, he would build a pile of stones as the number of animals he
has. After he has done this, he would group them for easy counting.
Guess which group number he chooses of course the number he had
been familiar with, that is, the number ten (fingers).
DEFINITION OF COMPUTER
A computer can be define as an electronic device or machine that
accept as an instruction (program) through input device, process the
data within central processing unit (CPU) or System Unit and give the
result through another output device. And the result given is called
“information”.
Input
Device
Processor
The major key points in the above definition are.
 Electronic Device
 Accept data through input device
 Process data in the CPU
Output
Device
 Give the result of processed data through output device
DATA/INFORMATION
Data is the plural of the Latin word datum, which means facts. In
business, data is all the raw fact meaningful form. It is structured
and organized state suitable for decision-making. Sounds information
assists in valid decision, which results to good performance and
eventually brings out achievement.
QUALITIES OF INFORMATION
Information must possess some qualities for it to suitable for use:
they are:
1.
Accuracy: Information must be an accurate as possible for the
purpose which it is to be used. If an institution bases a decision
on an inaccurate report, the actions which follow may lead to bad
performance and objectives.
2.
Relevance: Information must be relevant to the decision that
is to used for. Irrelevant information will only waste time of the
user and can cause confusion or loss.
3.
Timely:
Information can be relevant and accurate but not
available when best suitable for use. Late information can be
termed as history not new.
4.
Well-presented:
Information must be prepared and
presented in manner, which allows it to be understood by users.
The knowledge of user and their background should be
considered when preparing a report.
5.
Complete: Information should have enough facts for its use so
that the desired result could be achieved.
6.
Up-to-date:
Information that is not up-to-date cannot help
to produce proper decision for current period; it therefore
becomes necessary that we ensure that information being used
for a decision is current.
Data Processing:
refers to all activities that are necessary to
convert raw data into useful information or it is the systematic way
of transmitting or converting raw facts (data) into useful information,
so that it can be useful for management’s decision making. And for
data to lead into meaningful information stages must be followed in
due cost called data processing stages such as:
 Collection of data from it origins sources
 Store the data
 Sort it
 Organize/Structure it
 Input data
 Process
 Give the result.
Input Device:
is a medium through which data are supplied to
computer. It is the means through which users communicate with the
computer. Example of input units:

Punch Card

Magnetic Tape Unit

Card Reader

Optical Character Recognition (OCR)

Magnetic Ink Character Recognition (MICR)

Console Typewriter

Visual Display Unit (VDU)

Scanner Machine

Light Pen

Joy stick

Trackballs

Touch Sensitive Display

Voice Input
Punch Cards: are the early input media.
before computers were invented
The had been in use
Card Reader: is a computer input unit for reading and transforming
data from punched cares into the computer memory.
Paper Tape Reader: an on line reader for paper tape can be
attached to a system. When punching on a tape, some length must be
left to precede the data to be transferred. This is to be used by the
main data to be read unto the reading position. Each record on a
paper tape is terminated by special code or character called “an end
of record code”, a stop code or record mark.
Magnetic Tape Unit: use of magnetic tape unit is similar to paper
tape except that instead of paper a plastic film is carefully coated
with iron oxide dispersed in a resinous base physically: marks on
magnetic tapes are not visible without a special instrument. They are
made variety of widths and lengths, the common ones half an inch by
2,400 3,600 feet.
Optical Character Recognition (OCR):
this is under the category
of Mark Sensing. It means using a light beam to scan printed
characters. This is not the same as punched holes with a light beam.
Documents are printed in a special form by printers that are fitted
with a special type face which can be recognized by a machine.
Magnetic Ink Character Recognition (MICR): is similar to OCR
except that special magnetic ink is used for printing. The reading
equipment magnetized and senses the ink, converting the magnetic
result to signal that are analyzed and stored. The coding of bank
numbers and cheque numbers printed in special ink that is magnetic in
nature.
Console Typewriter: this is similar to the manual typewriter or the
electronic typewriter that is used in office for typing document.
However, it is connected to the computer system for communicating
with the system. It is linked directly to the computer’s main memory.
It services the following purpose;
 Interrupts a program that is in progress normally done by an
operator’s enquiry:
 It can be used by the processor to demand for input or input
request from a running program.
Scanner Machine: is a device used for scanning (read and transfer)
text, pictures and documents to computer exactly the way the original
looks like.
Light Pen: is a photo sensitive detector housed in a case that can be
held by hand. It is connected to the Visual Display Unit (VDU) control
via a cable. The operator points the end of the pen at a selected area
of the screen.
Joy Stick:is a vertical printing device used in games.
It’s
performances in games are more accurate that mouse. It could come
with one or two buttons. It is not meant for business applications. It
moves the graphics cursor in the direction the device is pushed.
trackballs:
they are pointing devices that are usually
incorporated with the keyboard of laptop or portable computers.
they are built on a flat object in front of screens in some system.
Voice Input:
is a new technology where by humans can talk to the
computer. This system has some problems in efficiency compared
with other input media because people speak differently. However, I
can be used for minor operations.
Touch Sensitive Display: is another input system by which one can
enter data into the computer. Touch screen personal computer is now
available. It is operated by touching the screen. It will possibly
replace keyboard and mouse.
The Mouse:
windows applications require the use of mouse. A
mouse is a device connected to the system unit. It shows an arrow
pointer (mouse pointer) on the monitor screen for selection of
required commands from menus rather than typing by using the
keyboard. A mouse is connected to the serial or USB port of the
computer. The mouse can be moved around on a table by the help of a
ball under it.
The keyboard: the keyboard is similar to the typewriter keyboard,
only that it has more functions than the typewriter. In addition to
typing letters, it contains keys for entering command both in Ms-Dos
and Windows screen. Through the data being sent into the computer
appears on the screen immediately, but it normally posses through the
system unit. The speed at which the display is done is fast that it
does not pass through the system unit.
Type of Keyboard
1.
Standard keyboard
2.
Enhance keyboard
Difference between standard and enhance keyboard.
 Standard keyboard has total key of 99 while enhance key board
has 101, 104, 107, 108, 109, 112 etc
 Standard keyboard has functions keys ranging from F1-------F10
while enhance keyboard has functions keys ranging from F1--------F12.
Note:
The both keyboard perform the same function. Standard key
board are not longer in use except the enhance keyboard.
Types of keyboard: There are four (4) or five (5) parts of key.
They are:
 Functions keys:
They are special keys use under operating
system and application programs. They are range from F1---------F12.
 Numerical Keys:
It ranges from 0-------9 it looks similar
to that of calculator buttons use in entering numbers or
figures into the computer.
 Alphabetical keys: These are arranged A ------- Z but not
ascending or descending order. It is use to enter or create
letters in computers.
 Special keys:These are special characters on the Keyboard
such as, ESC, Tab, Shift, Cap lock, Ctrl, Alt, Space Bar, Back
Space, Delete, Home, End, Page Up, Page Down, Num Lock etc.
 Cursor key or Directional Arrow keys: These are the four
(4) directional keys representing Left, Right, Up and Down on
the keyboard.
Central Processing Unit (CPU)
From the set of computer, the main unit that performs all the
operation regardless of the task is the CPU. Within the CPU, it’s the
micro processor that execute the instructions and it the heart of the
CPU. It is fixed to the motherboard of the computer.
Micro Processor: is a small device or electronic chip located in the
system unit where data are registered before they are executed.
CPU is divided into three units, they are:
 Control unit:
This is the part of CPU that controls and
coordinates other unit. It select program instructions one at a
time from the stone, place it into instruction Register in the
control unit and the instruction is then decoded. The necessary
circuits in the in the hardware are activated so that the other
hardware devices con carry out or execute the instruction.
 Arithmetic and Logic Unit (ALU):
This unit deals with all
various forms of calculation such addition, subtraction,
multiplication, division as well as other forms of calculation such
addition, subtraction, multiplication, division as well ad other
forms of calculation. While the logical operation goes with
conditional expression which are Yes or No, True or False, If,
Otherwise etc.
 Memory Unit:
This is where all saved files are stored for
further uses. It is splited into three (3) units such as:
 Main memory:
this is where all saved files are stored
even when there is power failure for a long period they
remain intact. Any file that goes into memory unit must
have a file identity called file name for retrieving purpose.
This memory is not made to remain for life, it can get filled
up where you can not add any content at that moment
except you delete unnecessary or files that are not
important from it.
 Random Access Memory (RAM): This occupies a large part
of the memory. It is used to store application programs and
data being work upon. The content of RAM is over written
by incoming one after the previous one has been completed.
It stores temporarily, ones there is power failure the
content can be lost RAM is fixed memory care if the
motherboard has the space, and the performance of the
computer will be enhance.
 Read Only Memory (ROM): This
contains
instructions
(programs) stored by the manufacturer to control the
operations of the computer. The content of ROM is not
destroyed or modified and the selling can not be changed
because it’s a non volatile storage. The content can only be
seen read but not be overwrite on to.
Output Device
An output unit is a media through which the results of processed data
are displayed. Results are either soft or hard copy. A soft copy is
the result displayed on the screen or yet to be printed, while hard
copy is the printed output on paper.
Examples of output device:





Monitors
Printers
Plotters
Computer Output Microfilm (COM)
Voice Output
Monitor: is also known as cathode Ray Tube or Visual Display Unit
(VDU. It is similar in shape and performances to a television set. A
monitor has a screen on which data and information are displayed.
A monitor could be either coloured or monochrome. A coloured
monitor can show graphics and text with several colours while
monochrome will display only one colour. Monochrome can not be used
for windows application. Common monitors now come in Video Graphic
Array (VGA) or Supper Video Graphics Array (SVGA) a VDU Card is
built in separate memory for its operations.
Screen sizes ranges from 14 to 21 inches.
Printers: are devices used to obtain results or reports of processed
data. A printer could be a parallel or serial connection (port) type.
The difference is that parallel type accepts information much faster
than a serial printer.
Types of printer
 Impact Printer: these are the old model printers they
Are capable of generating noise while printing and
They are very large in size. Examples are:
 Character Printers: These printers print a character
at a
time.

Line printers: Tese printers print a line at a Time.

LaserJet printers 4.0, 5.0: The operation of
LaserJet is similar to photo copy machine. It Incorporates the
use of laser beam, a mirror and a rotating drums to print
characters on papers. Normally the output is of high quality but
show in speed.
 Dot-Matrix Printers: it prints by creating characters in form
of tiny dots. It less expensive but show and makes much noise.
 Line printers: in organization, the outputs generated are usually
large and such require printers with high speed and be able to
use continuous papers. The first paper contains the original
printing while the others appear by the aid of the carbon papers.
 Non-impact printers: These are the commonly used printers;
they are small in size and less in noisy when printing. Examples
are:
 LaserJet printers 1110, 1200, 1320, 1010 etc. and it only
print in black and white coluor only.
 Inkjet printers: the outputs lies in quality I comparison
with LaserJet. it is also slow I speed and price is not as
high as LaserJet Printing is achieved by spraying jets that
are able to dry fast.
 DeskJet Printers: both the Inkjet and DeskJet Printers
print in coluor
The components of computer
These are the basic items that make a complete system. Having one
component means the system is not complete; therefore, it can’t
perform it task. In addition, a computer without software is like a car
without engine. The components work together to achieve it goal.
There are two (2) basic components.
1. Hardware: These are the physical part of the computer
That you can see, touch and feel. Examples are:
 Monitor
 Keyboard
 Mouse
 Mouse pad
 RAM
 CD-ROM
 C-mos battery
 Motherboard
 Hard drive
 Floppy drive
 Diskette
 Printer
 Scanner
 Speakers
 Power park
etc.
The above examples are: hard and solid parts computer that you can
always feel when touched. They cannot work or function once there is
no program to drive them.
2.
Software: these are program stores to control and support the
activities of the computer. Without the software the hardware
and other programs are not actual work or perform. These
programs are like motor engine and SIM card to the GSM phone.
Types of software:
i.
System software: these are in built programs deveveloped by
the manufacturer stored control and support the entire
activities of the computer perhaps, car without driver to control
and support it will remain immovable to remains the main
programs that give life to other component of the computer.
Examples of system software:

Operating system: These are program or set of
instruction that links application programs with other
computer resources. This serves as the third party of every`
computer, without O/S there is no way the system can
perform it function or complete immediately one obtains new
desktop computer, which signified that the hardware is
obtains or purchase. Therefore, one connected and boot it
will display message asking you to insert O/S disk. This tells
you how important are as well as other application software
can be installed.
Functions of operating system
 It controls the date flow from the input device to output
device.

It controls the booting of the computer.

It serves as intermediate between the user and
the computer.
 It makes sure the input and output devices are properly
attached to the CPU.
 It makes sure the program used is properly close before
shutting down the computer.
 It communicates with the user if there is any program that is
corrupt or system failure.

Provide user with security (pass ward) to lock
files. Etc.
Types of operating system
There are two (2) types of operating system namely:
 Single user or single tasking O/S: these are design and stored
in personal or micro computer. They are developed to serve one
person at a time:
Examples are:
Dos
Compaq Dos
Windows
Ms-Dos
Pc-dos
Macintosh
Etc
 Multi-user or multi tasking O/S: these are mostly found
within network environment where by files, folders and
hardware are shared. In this case they are developed to
serve than one person at a time.
Example are;
Novell
Pick
Xenix
Unix
Networking
Etc
Language Translation: we believe every one has dialect for
communication one cannot understand the other party language
it refers to as language barriers. Computer has it language too
for executing it instructions. It has three (3) basic languages
which are:
 Machine language: this remains the main language of
computer: It’s written in codes which are number less than
(20 but greater than -1 (1).
 Represent the binary number dec base 2, Decimal base 10,
octal dec base * and hexadecimal base 16. it can be called
computer language
 Low level language: this language was written in systoles such
as the A – Z, 0 – 9 and special characters. It can be called
Assemble language.
 High level language: this is referred to as human oriented
language. They are used by the programmer to develop or
write programs. Those who write programs are called
programmers. Examples of high level languages are:
COBOL
FORTRAN
C+
C++
DBABSE
JAVA
BASIC (VBASIC, GWBASIC, QBASIC)
Translators:
is a program when run convert the program written in
other languages into source program “Computer Language”.
Types of Translator:

Interpreters: An interpreter is a routine or a program, which
when runs, it reads a statement or the source program,
translates each high level statement to machine code and
execute that code immediately.
And these are done by
executing it line by line.

Compilers:
it uses high level language program as data, then
separate or converts it to machine language code in batch unlike
the interpreter. It requires a considerable amount of memory
for execution and are frequently written to ram on large
computers.

Assemblers:
these are commands placed in the program by
the designer, which provides information to assembler. They
are not part of the instruction set of the micro processor nor
are they transferred into an executable code. Special programs
are available for each type’s micro processor, which converts
their assembly language programs to equivalent machine code.
These programs are called assembler, and are run either on the
micro computer.
Computer virus:

We believe naturally that virus is real and life existing. We as
well believe that viruses are not friendly to our health. In
respect to computer, virus are dangerous to its hardware’s and
software’s. Viruses are in – built programs that are installed to
gradually developed and spread to affect computer activities.
Virus Transmission
Viruses are transmitted through the following ways;

Diskette Floppy Disk

Flash

Expiration of programs

Dust

Water
e.t.c.
Classes of Virus

Boot sector Virus: this mostly affects the bootable files of
the systems. Once it destroyed the files, the systems cannot
boot.

File Injection Virus: these are dangerous to the program file
such as ms word, ms excel, Corel Draw, Page maker, ms Power
Point etc.

Warm Virus: these virus affect most saved files in the
systems regardless to the program been developed.

Trojam horse Virus:
These affect and destroy the Hard
disk of the system. They are mostly unrepaireable, so they are
known as HIV/AIDS Virus
Anti Virus
These are programs developed to fight and destroy virus where ever
they are or belong.
Types of Anti Virus





Norton Anti Virus
Ma-cAfee Anti Virus
Dr. Solomon anti Virus
Avast Anti Virus
Vaccine Anti Virus
 Center Point Anti Virus
Etc.
The Classification of Computers:
There are three (3) classes of computers according to type.
1.
Digital Computers: These classes of computers processes
data in discrete numbers which 0’S and 1’s of the computer
language. They are the major computer used in the society
today. And mostly used for commercial transaction which
results are directly displayed as processed. Examples are:
Digital telephone exchange etc.
2.
Analogue Computers:
these process data continuously and
measure in quantity variation such as current, Temperature,
Speed etc. N. P. A Metre, Thermometer, Speedometre and Rain
gauge.
3.
Hybrid Computers: this combines the capabilities of the
analogue systems. In other words they are semi-digital and
semi-analogue. In most real world equipment design, it may be
necessary to apply the analogue out put of a pulse to a digital
system. This is accomplished by connecting such analogy out put
through an Analogue to-digital network. It is also a common
practice to apply the digital out put to an analog system in order
to accomplish certain goals. This too, is accomplished by
connecting the digital out put through the digital –to analog
system. Examples are; Fuel pipe, compass, system used by
methodologist etc.
1.
Classification of Computers by Size
Mainframe Computer:
these are large, general purpose
computer with extensive processing storage, and input/output
capabilities.
The more advanced computer is the supper
computer which in today’s technology, it is the apex and the
ultimate in computing power. Government and extremely large
2.
corporation including banks use this computer category to store
and manipulate data.
Mini Computer:
this is comparable smaller than mainframe
computers but still commands a horrendous computing capability
both in processing storage and input/output with the new
technology and innovations in micro chips, the clear cut between
the mainframe and mini is on the upper side. I mean where the
mini power strips and where the mainframe starts is on the
higher level.
3.
Micro Computer;
a micro computer is a computer with its
CPU and memory/storage unit put together in the same package.
Micro computers are also called personal computers but are by
for less sophisticated as their supper, mainframe and mini
computers. Hoe technology has led to a more commendable
version of micro systems, which are now classified as supper
micros with more performance and storage capabilities. The up
trend in technology borders on the up-grade of the micro
computers as well. Micro computers have become more powerful
sophisticated so, it becomes necessary to take jobs off the
bigger computers and give it to the smaller. This is known as
“down sizing”, often a time, or when the needs arises it becomes
necessary to combine supper computers with each processing a
task which it is capable, such configuration is referred to as
“right sizing”
4.
Supper Computers:
these are the most largest systems. They
are design for scientific and research purpose. It is used for
detecting a far object, military protection; it requires two (2)
engines to take care of it maintenance. It can also be called
“Monster computer” and examples are; grey and cyber computer.
Historical and Development of Computer:
With reference to my introduction, you realize that each computer
start with the following device and their inventors.
 The Abacus: the first civilization in Egypt and the river
valleys of Asia represented members by pebbles arranged in
heaps often because of human beings have ten fingers. This
systems was the fore runner of the ABACUS [Greek; Abax] a
manually operated storage device which aids the human
calculator. It consists of a row of any number of parallel
wires, rods or grooves on which slide small beads or blocks.
The groups of beads are divided into sections by means of a
bar perpendicular to the wires, rods or groove
 Napier Bones: in 1617, John Napier, the inventor of
logarithms, published a work describing methods for
performing multiplication and division by means rods or bones.
His technique combined with the use of original data tables
marks one of the historical contributions by mechanicals
means.
 Pascal‘s Arithmetic Machines: in 1642, the Frenchman,
Blaise Pascal built a digital calculating machine to assist with
his fathers business accounts. The machine consisted of a
train number of wheals whose positions could be seen through
windows in the cover of an enclosing box. Numbers were
entered by means of dial wheels. The machine was able to
perform addition during which”carrying” occurred by means
of a gear chain, arranged so that the next left wheels 1 unit
when the dial exceeded the 9 digit.
 Babbage’s Analytical Engine:
in 1835, in England a
mathematician, Charles Babbage formulated an entirely new
device called the “an Analytic Engine” which was able to
combine to arithmetic processes with decisions based on its
own computation. Countess of lovelacs, Ada Byron analyzed
and explained the Babbage’s machine. Babbage was regarded
as the father of modern day computer because of his
invention and Byron, The first computer programmer.
Babbage’s machine had two (2) basic components:
a. A storage Unit containing fifty counter wheels that
could store 1000 numbers of fifty digits early and
b.
An arithmetic unit or “Mill” input to the machine was
by means of three types of punched cards:
i
Number cards: with the constants of a problem
ii
Directive cards: for controlling the movement of
numbers in the machine.
iii
Operational cards: for selecting the operation of
additional, subtraction, multiplication or division
required
Babbage’s machine: was known for two important innovations.
The first was the concept of conditional transfer, which enables
the machine to compare quantities and branch to another
instructions as a result of the comparison. The second future
permitted the results of a calculation to change other numbers
and instructions, making it possible for the machine to modify
its own program. The plans for the machine were complete in
every detail but were forgotten until Babbage’s writing was
rediscovered in 1937.
 Jacquards & Hollerith: a loom invented by Joseph- Marie
Jacquard in the early 1800s was the first use of a punched card in
1886,the American statistician, Herman Hollerith, working on the
1880 census, developed the idea of using holes in punched cards
to represent arithmetic. This Hollerith, inspired by Jacquard,
invented punched card, which was still one of the input media to
modern computers. In 1911, Hollerith joined with two companies to
form the computing, tabulating recording company, which later
becomes International Business Machine Corporation (IBM)
 Aiken & the Harvard Mark 1: between 1939 and 1944, Howard
Aiken of Harvard University worked with IBM engineering to
construct a fully automatic calculator. This was known as “the
Automatic sequence controlled calculator otherwise known as
Harvard Mark 1”, an electromechanical machine 15 meters long and
2.4 meters hight. The machine was sequenced by punched paper
tape and could perform five basic operations, Addition,
Subtraction Multiplication, Division and table reference numbers
were held to 23 decimal digits. Input was via punched cards and
output was either on cards or by an electronic typewriter.
 ENIAC: IN 1946, J.P. Evert and J.W Macaulay of the university
of Pennsylvania completed ENIAC (Electronic Numerical
Integrated and Calculated) the first all- purpose , all-electrical
digital computer. It was more than 1000 times faster than the
Harvard Mark 1, contained around 1000 vacuum tubes and had a
power consumption of 150KW.problems for the machine had to be
set up by hand using a cumbersome plug and-lead system, but,
despite this it was estimated that early nuclear physics
calculations carried out on the machine in two hours would have
taken 100 physicians one year to perform by hand.
 EDSAC: in 1949, a stored – program computer called Electronic
Delay Storage Automatic Computer (EDSAC) was constructed at
the University of Cambridge. It contains 3800 vacuum tubes and
used a mercury delay line store of sixteen bit words.
Generation of Computers
Computer classifications are classified as follows:
 First Generation Computers: The early computer under this
generation was developed in 1940s the built of the system
was vacuum tubes known as the miner. This perform the
following characteristics:
 Very large in size
 Slow in operation
 Not reliable



Limited memory unit
Generate a lot of heat
Process date in mini second
Characteristics of Second Generation Computers:

Comparably small compares to the first generation computers.

Its reliable with large storage unit

Generate less heat

Process data in micro second

Less expensive etc.
Third Generation of Computers: this exist in middle 1960s, discrete
electronic component were replaced by integrated circuit later known
as microchips or microprocessor.
The third generation computers are microcomputers.
Characteristics of the third generation computers
 Small in size less expensive
 Large storage capacity
 Use of other peripherals device
 Use of high level language e.g. COBOL
 Process data in Nine-Second etc
Fourth Generation of Computers: this was developed in 1970s the
integrated circuit of the third generation was replaced with very
large-scale integrated circuit the computers of this generation are
very high in speed operation, small in size and less expensive. However
the architecture of the third generation was maintain but had been
improved on. Examples are:
Laptop computers
Notebook computers
Pam Top computers
Internet
Network etc.
Fifth Generation Computers: these are sensitive and powerful. These
computers can communicate with humans mimic human intelligence
manual skills, making crucial decision without human intervention. E.g.
Robot, Voice recognition e.t.c.
COMPUTER CONFIGURATION
This is the installation of all computer peripherals devices. The
assembling of all the hardware of the computer e.g. CPU, Monitor,
Keyboard Mouse e.t.c.
COMPUTER PERFORMANCE: this determines the capacity of the
processor. Microprocessor is a small device fixed in CPU if the
executor of all data and process every instruction in … seconds. The
higher the capacity of the processor the faster it process or execute
its instruction verse versa. The processor determine through:
a. Number of Transistors: transistors chips that make up the
processor. The higher the number of transistors in the
computer the faster the processor works and lower it is, the
slower it works.
b. clock
speed: this determine and measure the capacity of
microprocessor in hertz (Hz) which refer to number of
instructions a processor can execute less than seconds. This can
be measure as followings:
Kilo Hertz (KHz) means thousands of instruction a computer
can execute less than seconds.
Mega Hertz (MHz) means million of instruction computer can
execute in less than second
Giga Hertz (GHz): this means Billion of instruction computer
can execute in less than second.
Note: in determining the best computer, microprocessor is one of the
major parts to considered of the capacity is very high to improve the
speed processing of the system. At list for personal Desktop
computer, the processor should be from MHz and above. While for
Business purpose the processor speed should be GHz.
DATA STORAGE:
this determine the availability of space in
computer Hart Disk like out houses you find out that the space
provide for parlor is quite large than that of kitchen or bathroom is
quit large than therefore hart disk require enough space in order to
store more programs. If you must have a limited space and you insist
you must install all software you should realize that it will work slowly
because is like enforcing a twelve year old boy to push five bags of
cement you don’t expect him to move faster.
Data storage can be view in two ways:
Bit: this represents the smallest and of a byte and in every byte
there are eight bits.
Byte: in computer it means space where character is stored as a
Data it can also represent figure, character and special
character
Example 1: Normally in English language if you have this word
“SCHOOL” it represents “SIX” (6) character while in computer term
It represents “SIX” (6) bytes. In knowing the total bits in school it
…………………… apply this step
If a byte is equal to eight (8) bits then
8 X 6=48 bits
Example 2: if bits are calculated to be 112, what is the number of
byte involved?
Therefore
112/ 8 =14, which is equal to “Douglas Sunday”
Example 3 if a hard disk has total space of 19,531,041,321, availed
7.631, 201, 301, used spaced calculate the free space available?
Therefore
19,531,041, 321
(7,631,201,301
in rounding to digits
11, 899,840,020 free space
In measuring the hard k understand the following
Kilobyte this indicate thousands of space (KB)
Mega byte: this indicate million of space (MB)
Giga byte: this means bill ns of space (GB)
The faster the faster the processor work and lower it is the slower it
work
Trigs byte this means trillions of space (TB)
Explaining the following
i. p4
ii.
iii.
iv.
80GB HDD
1.2 GB RAM
2.0 GHz
The computer with above capacity is a Pentium 4 model computer
Having 80 Giga byte (Billions space ) hard disk 1.2 Giga byte Random
Access memory (PAM) and 2.0 Giga hertz processors speed and this
represent two billion instruction the processor can execute less than
second
Understand the acronym meaning of the following:
Ms – Dos: Microsoft Disk Operating System
Pc – Dos: personal computer Disk Operating System
ALU:
Arithmetic and logic unit
IBM
International Business Machine
UPS:
uninterrupted power supply
GIGO:
Garbage in – Garbage Out
RAM:
Random Access memory
ROM:
Read Only memory
DBM:
Data Base management
DBMS:
Data Base management System
COBOL: commons Business Orientated Language