Introduction to computer modified 2015

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Introduction TO COMPUTER
DEFINITION OF COMPUTER.
Computer is an electronic device or machine which can accept instruction and execute them at very high speed
and accuracy.
OR- Computer is an electronic device that can input data (accept data), process data (manipulate or execute),
Output data and store data either automatically or manually.
OR - A computer is a device that accepts information (in the form of digitalized data) and manipulates it for some
result based on a program or sequence of instructions on how the data is to be processed.
OR - A computer is an electronic device that manipulates information, or data. It has the ability to store,
retrieve, and process data. You probably already know that you can use a computer to type documents,
send email, play games, and browse the Web. You can also use it to edit or create spreadsheets,
presentations, and even videos.
FUNCTIONS OF COMPUTER.
Computer has four main / basic functions, namely
• Input data
• Processing data
• Output data.
• Store data
Input is the information which is entered into the computer. Processing is performing operations on or
manipulating data. Output is the result/feedback of the data processing. Storage refers to the process of retaining
the data that can used when the computer is deactivated
TYPES OF COMPUTER
A number of types have been discovered and are still being discovered. To mention a few:-
 Mainframe Computer
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 Personal Computer or Micro Computer
 Handheld Computer
 Laptop/Notebook Computers
 Tablet computers
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PARTS OF COMPUTER
Computer is divided into two main parts:
• Computer Hardware
• Computer Software
COMPUTER SOFTWARE
These are the computer instructions which tell computer what to do. Normally we don’t see these instructions but
we see their effects.
Computer Software is divided into two parts:-
• Operating System
• Application programs
OPERATING SYSTEM
These are sets of computer instructions which controls or manage other programs, It also perform basic tasks, such
as recognizing input from the keyboard, sending output to the display screen, keeping track of files on the disk, and
controlling peripheral devices such as disk drives and printers and so on.
Operating systems are designed by different manufacturers and come in versions. The most common types of
operating systems are:-
• Window operating System (window 95, window 98, Window 2000, Window New Technology (NT),
Window Millenium, Window XP, Window Vista , Window 7 and Window 8)
• Linux Operating System (Ubuntu , Fedora ,Susi , Redhat)
• UNIX Operating System.
• Macintosh Operating System ( like Lion Os etc)
• Android
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APPLICATION PROGRAMS.
These are sets of Computer instructions designed specifically to perform a certain specific tasks directly for the
user or, in some cases, for another application program.
. Among the common programs are:
• Microsoft Word – This is designed specifically for word Processing (Among its versions includes Ms
Word 2000,Ms Word 2003,Ms word 2007,Ms word 2010 and Ms word 2013)
• Microsoft Excel - This is spreadsheet program designed specifically for electronic calculations and data
analysis (Among its versions includes Ms Excel 2000, Ms Excel 2003,Ms Excel 2007,Ms Excel 2010 and
Ms Excel 2013)
• Microsoft Power Point – This is designed specifically for presentation purposes (Among its versions
includes Ms PowerPoint 2000, Ms PowerPoint 2003,Ms PowerPoint 2007,Ms PowerPoint 2010 and Ms
PowerPoint 2013)
• Tally – This is designed specifically for doing financial accounting
• SPSS – This is designed specifically for statistics. It stands for Statistical Package
For Social Scientist)
• CSPRO – This is also designed for Statistics. (It stands for Census and Survey
Professional Program)
COMPUTER HARDWARES.
These are parts of Computer which we can see and touch. They can be classified as follows:
• Input device – Devices used to input data like Keyboard, mouse, Scanner, Digital camera
• Output device – Device used to give out data like Monitor, Speakers, Printers, Projector , Modern TV
Flat screen (LED or PLASMA Technology Flat screen)
• Storage device – Device used to store data like DVD/CD,FLASH,FLOPPY,HARD DISK, MEMORY
CARDS
• Processing Device – Used to execute data like System Unit (also known as Central processing Units
abbreviated CPU)
• Communication devices - is a hardware device capable of transmitting an analog or digital signal over the
telephone, other communication wire, or wirelessly. The best example of a communication device is a
computer Modem, which is capable of sending and receiving a signal to allow computers to talk to other
computers over the telephone. Other examples of communication devices include a network interface card
(NIC),and Wi-Fi devices. Below is a picture of some of the different types of Wi-Fi devices that are all
examples of a communication device.
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Among the most common hardwares are:-
a) Monitor
b) System Unit
c) Uninterruptible Power Supply (UPS)
d) Printer
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e) Mouse
f) Keyboard
g) Scanner
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Caps lock key Space bar
Back spaceShift key
Control key
Enter key

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h) Modem
i) Speaker
j) Cables
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DETAIL DISCUSSIONS ABOUT MOST FAMOUS COMPUTER HARDWARE
A) MONITOR.
This is one of the output devices.
It is made up of the following important units:-
• Screen
o The front mirrored view of monitor
o Its size is measured in inch and it is measured diagonally (Diagonally).
o Place were results or data are displayed or viewed.
• Power Switch
o This allows electricity to be distributed to monitor when put on and vice versa.
• Light and Shape Control Buttons
o It controls lights through its Contrast and Brightness options
o Also screen can be set to assume different shape like V shape, Horizontal stretched (↔)
• Data Cable
o This cable is connected to System unit ( some calls it Central Processing unit)
o Mainly ensures transmission of data
• Power port
o This port is connected to cable which ensures supply of electricity.
o It is directly connected to CPU power supply or to uninterruptible power supply. Sometimes
indirectly connected
B) SYSTEM UNIT
This is the heart of Computer. All activities are done in here and the results are sent to appropriate devices for
display. Some people calls it Central Processing Units (CPU), this is due to the facts that it contains processors. It
is processor speed which decides this machine is Pentium I, II, III or IV. System Unit is made up of the following
important parts:-
• Motherboard
o This is the electronic circuit board. It is through this board that almost all other units are connected.
These units include Processor, Random Access Memory, and Power Supply.
• Power Supply
o This receives electricity from external source and distributes to all other peripherals as per
requirements.
• Power Switch
o This allows distribution of electricity. It is the power from the Power Supply which is allowed to be
distributed. If the switch is pressed it is set on hence distribution of electricity.
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• Drives
These are Units for storage devices. It hardly deals with the secondary Storage units. These are:-
o Floppy Disk
Is a data storage device that is made up of thin, flexible magnetic storage medium. Its 3 ½ inches
Has the storage capacity of 1.44Megabyte.
o Hard Disk Drives (Also known as Hard Drives)
Is a non volatile data storage device that store data on a magnetic surface layered on hard disk
platters.
Has the largest storage capacity and currently is some gigabytes
o USB Flash drive
is a form of non volatile memory that can be electrically erased and reprogrammed integrated with
USB interface.
It is a growing technology
It is portable and mobile technology
o CD and DVD
Stands for Compact Disks and Digital Video Disk
It’s an optical disk used to store digital data and movies respectively.
They are placed in CD Rom in order to be used
• Ports
These are the places where other hardwares are connected. Its consists of parallel, serial and USB ports
C) UNINTERRUPTABLE POWER SUPPLY (UPS)-A device that is used regulate or control the amount of
electricity that enters the computer. It is one of the most important devices. It inlet power from any available
source of electricity and outlet power to other devices as appropriately needed.
It consists of:-
• Power Switch
o Allows entrance of electricity when switched On.
• Inlet port
o Used to pass electricity into the UPS
o Allows connection cable between UPS and Source of electricity
• Outlet port
o Allows connections between UPS and other devices
o Pass appropriate amount of electricity from UPS to need device
• Battery
o This is found inside the UPS.
o Has the duty of reserving electricity which will in turn be used in time of electricity turn off or
electricity frustrations.
D) MOUSE
This is one of the inputs.
It the handheld device used to items on screen, move and resize objects. The mouse pointer assumes different
shapes depending on the locations and functions it performs.
Mouse moves on a smooth surface and this is the mouse pad. Mouse consists of:-
• BUTTONS
o They are two in number called Left and Right button respectively.
o The buttons have the following functions:-
 Left click is defined as press and release left mouse button once and quickly.
• Used to select icon, start and menus
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 Double click is defined as press and release left mouse button twice and quickly
• Used to open files, folders and programs
 Drag and Drop is defines as press and hold left button and moving the left mouse button
• Used to move items to distant place
 Right click is defined as press and release right button quickly
• Used to do shortcuts
• DIFFERENT TYPE OF COMPUTER MOUSE
MECHANICAL MOUSE requires a ball to move the cursor on the screen. To get more efficacies with this type
of mice, a flat surface named mouse pads is necessary.
OPTICAL MOUSE uses a laser; precisely an optical sensor to help detecting the mouse’s moving. More
expensive than the two other types, the optical mouses offer more precision and speed and even can be used on any
surface.
WIRELESS MOUSE which relies infrared, radio signals or Bluetooth to communicate with the computer. Using
no cord, the wireless mouse contains a transmitter to send information to a receiver itself connected to the
computer. The wireless mouse is usable from 2m to 10m of the computer.
To be really useful, mechanical and optical mouse has to be connected to your computer by using:-
either PS/2 port or USB port
E) SCANNER
It is a device that is used to analyse photos, printed texts/handwritten text and converts it to digital image. OR You
can define scanner as a device that is used to convert Hard copy document (paper document) to softcopy document
(digital document). It is an input device that consists of the following items:-
• Object inserting Panel
o Place where an object t(like photos) to be scanned is placed
• Data cable
o Cable that allows transmission of digital data
• Power cable
o Cable that allows passage of electricity into the scanner.
F) SPEAKER
It a device that gives out sound that is produced. It an output device which consists of:
• Power Cable
o Allows passage of electricity into the speaker
• Volume control button
o Used to minimise or maximise amount of sound from the speaker
• Quality control button
o Used to regulate quality of sound produced.
G) PRINTER
It is one of output device used to convert soft copy into hard copy. It consists of
• Power cable
o Allows passage of electricity into the printer
• Paper tray
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o Used for keeping paper used for printing
• Data cable
o Used to send data to the printer buffer and hence making it ready to be printed
• Paper Controls Buttons
o These buttons shows if the printer is ready to print, there is paper jam or paper tray is empty
H) KEYBOARD
It is one of the most important input devices designed to put text, characters and controls the operation of
Computer. Keyboard is made up of keys which are divided into three groups, namely
• Alphabets
i. These are keys from A to Z accompanied by keys like Cap Lock ( which allows capital letter
if switched On) and symbol like Full
Stop, semi colon, Question mark etc.
• Numerals
i. These are keys from 0 to 9 accompanied by keys like Num lock (which allows number to be
displayed on screen if switched ON) and mathematical symbols like Addition (+),
Subtraction (-), Multiplication (*), Division (/), equal sign (=) etc.
• Functional keys and Other Keys
i. They are keys from F1 to F2 and other keys. These keys are used lonely to perform a certain
activities or with other keys to perform a certain activities. E.g. F1 used for help or F2 used
for spelling check, Ctrl + B to Bold, Ctrl + I to do italic etc
Keyboards are of two types, which are:
i) Standard keyboard which consists of functional keys from F1 to F10
ii) Extended Keyboard which consist of functional keys from F1 to F12
Other Important keys for discussion are:-
• Enter key (Represented by symbol ┘)
i. Key used to confirm or execute command (To obey the selected operation )
ii. Used to move cursor to the next line or paragraph in some programs
iii. Used to open a new page in Ms word
iv. Used to add new rows in Ms word tables
• Delete Key (Sometimes represented by word DEL)
i. Used to erase text / characters which are in front of it.
ii. Used to erase selected texts.
iii. Remove line spacing
• Backspace Key
i. Used to erase texts which are at the left side of the cursor.
ii. Use to turn or move the text back but when the cursor is located at the beginning of the text
iii. Used to turn the text up to the font lines of the page
• Space Bar Key
i. Used to separate text or characters (Used to make a space between words)
ii. Used to move text (words) or sentences forward but when the cursor is at the beginning of
the text or sentence
• Tabs Key
i. Used to add rows to the table but when the cursor is located at the last cell of the table
ii. Move Cursor in a jumped way into fixed distance when pressed
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• Shift key-used to shift from one function (operation) of the key to the other operation of the same
key (Lower operation to Upper operation of the same key) ,some time it may be used to change
letters for small to capital and vice versa.
• Caps Lock-used to change form small letter to capital letters and capital to small letters.
• Arrow keys- are buttons on a computer keyboard that are programmed to move the cursor in a
specified direction (either Right, Left, Upward or Downward )
• Esc (Escape key) –used to cancel (close) the current process of running program or operation
Switching Computer On and Off in window 7
Switching On
• Start by Switching on Wall Socket
• Turn on Uninterruptible Power Supply (if available)
• Turn On System unit (CPU)
• Turn on Monitor
Switching Off
• Click start button
• Then Click Shut down
• After shutting down your CPU then
• Turn off your Monitor
• Turn off UPS( if it is connected to your PC)
• Switch off wall Socket.
CHANGING USER (window 7)
Some PCs are configured to multiple users for security. Some of the users have roles of administrator hence they
are allowed or privileged to do everything and some have the role of Guest hence they are limited to do some
works. To switch to the other user follow the following steps: -
• Click start button
• Click log off or switch user
• Select new user account ( You may be required to enter password )
CHANGING COMPUTER BACKGROUND (window 7)
This is a big picture seen at the desktop and above it laid the icons. Follow the following steps to change it:-
Lastly click Apply and
• Right Click on the Desktop of your computer
• Click personalize
• Then choose your desired background
SCREEN SAVER
• Right Click on the Desktop of your computer
• Click personalize
• Click screen saver
• Then choose your interested screen saver and setting
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CHANGING SYSTEM CLOCK
• Right click on the clock position at the Task bar
• Click adjust Date and Time
• Then set the required date, time and zone
• Click Apply
• Click Ok
MANAGING FOLD ER AND FILES.
Folder is a tool in a computer that allows people to organize their files in a way that makes sense to them OR is a
tool in a computer that is used to make good arrangement of materials or data. For example, a college student
might store all her photos in a folder named "Pictures," all her papers in a folder named "School Work," and all her
financial in formation in a folder named "Finances." All these folders might reside within a folder called "MY
DATA.
CREATING FOLDER.
Folders are the units or division made to store files or file folders. To create folder do the following:-
• Select location
• Right Click
• Select New
• From the Sub menu of New click Folder
• Write name of new folder
• Enter
RENAMING FOLDERS
This is about changing name of the folder. To Change name, follow the following steps:
• Select folder
• Right click the selected folder
• Click Rename
• Write New name
• Enter
DELETING FOLDERS
Removing folder or files and damping it at the Recycle bin. To delete folder, follow the following steps:
• Right click the folder
• Click delete
• Click Yes to agree that you want to delete folder
RESTORING FOLDER
This is returning folder or file to its original location. To restore folder or file, follow the following steps:-
• Open recycle bin
• Select the folder you want to restore
• Click file on the menu bar
• Click Restore
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Or
• Right click folder
• Click Restore
• Click yes to restore selected folders
SELECTING MULTIPLE FOLDER
Selecting more than one folder at a time. To do this, follow the following steps:-
• Select first file
• Then hold down Ctrl key without releasing
• Click other files to your satisfaction
DELETING FOLDERS OR FILES COMPLETELY
These folders if deleted then they can not be restored any more. To do this, follow the following steps:-
• Right click folder
• Click delete
• Click yes to delete selected folders
OPENING PROGRAMS
If you wish to Open any program follow the following steps:-
• Click Start button
• Go to all programs
• Click Microsoft office
• Click the program you want to Open
Or
• Double click shortcut or Icon of a program on the desktop (if available)
Any opened program will have its window opened on the desktop. The following are some few basic items of
those programs:
• Opened program will have three buttons at the title bar these are:
o Maximise & restore button – for enlargement & Shrinking window accordingly
o Minimise button – for minimising your window to appear on the status bar
o Close or Cancel button – used to close program
MANAGING DISK SIZE
Computer data are stored in variety of sizes and thus we can know the amount of data stored in any storage device.
The smallest unit in computer system is bit (in binary language).Bits refers to zeros and ones (0, 1). Other units are
byte, kilobyte, megabyte, Gigabyte and Terabyte. Byte is referred as one character that is to say whenever key is
touched on the keyboard you refer to 1 byte.
The relationship between units is as follows:-
(0, 1) refers as bits
8 bits =1 byte
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1024 byte=1KB (kilobyte)
1024 KB =1MB (Megabyte)
1024 MB =1GB (Gigabyte)
1024 GB =1 TB (Terabyte)
CHECKING SIZES OF DISKS, FILES AND FOLDERS
To check sizes of your disk, file or folders follow the following steps:-
• Select your Disk, folder(s),file (s)
• Right click your disk, file or folder
• From the popup menu
• Click properties
• Then read the size shown
Illustratively.
COMPUTER PORTS
1. Ethernet/NIC
Ethernet port- A socket on a computer or network device for plugging in an Ethernet cable
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2. Parallel
Parallel port- Uses a 25-pin connector and is used to connect printers, computers and other devices.
3. PS/2
PS/2 connector- A type of port developed by IBM for connecting a mouse or keyboard to a PC
4. Serial
Serial port- The serial port is a type of connection on PCs that is used for peripherals such as gaming
controllers, modems, and older printers. It is sometimes called a COM port
5. USB
USB- A USB socket on a computer or peripheral device into which a USB cable is plugged
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6. VGA- The socket on the back of a PC that is used to connect a monitor
7. AUDIO PORTS
Practically every board today has on-board sound. However you can use an expansion
slot to have your own card added. There are also external sound cards that connect
through a USB port. Some people like buying their own card because many of them have
more features than what's on a motherboard. But whichever you choose, there are three
common ports: Line-In, Line-Out, and Mic.
• Line-In: This port is where sound from an external source enters the card, such as
recording from a tape recorder. On many sound cards this port is light blue.
• Line-Out (Speaker Out or Front): Where sound is output; usually to headphones or
stereo speakers. On many cards this port is lime green.
• Mic: Microphone port; usually pink.
QUESTIONS FOR DISCUSSIONS (INTRODUCTION TO COMPUTER)
1. What do you understand by the term Computer
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Line
In
Line
Out
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2. Mention and explain the Main/basic functions of Computer
3. Briefly discuss Computer types
4. Mention two main parts of computer
5. Mention two parts of Computer software
6. Give the difference between Operating system and Applications programs
7. Give the difference between system software and Applications software
8. What is the difference between computer hardware and computer software
9. What is the difference between Printer and Scanner
10. What is the different between Softcopy and hardcopy
11. What are the most common types of Operating system
12. Mention all versions of window Operating system
13. Mention all versions of Microsoft office programs
14. Mention all versions of Ms word application programs
15. Mention at least 5 examples of applications programs
16. Computer hardware can be categorized into Input devices, Output devices, Storage devices, processing
devices. Briefly explain and give examples in each category
17. List about ten (10) most famous computer hardware
18. Briefly explain the functions of the following keys is computer keyboard (i) Shift key (ii) Backspace key
(iii) Enter key (iv) Space bar (v) Caps lock Key (vi) Escape key (vii) Tab key (viii) Delete key (ix) Control
key (x) print screen key.
19. What are the procedures of switching off your computer that contain Window 7 operating system?
20. What do folders mean in computer point of view?
21. Suppose you need to change the name of the folder, what are the procedures?
22. Convert 12,288 MB into GB
23. Convert 32 MB into Kilo bytes
24. Suppose you have a flash disk of 2 GB that contain 1500 MB of data , calculate the empty space
25. Briefly discus the following computer ports (i) Ethernet/NIC (ii) Parallel port (iii) Serial port
(iv) PS/2 (v) USB (viii) VGA (ix) Line Inn (x) Line out (xii) Mic
26. What are the uses of the following button (i) Maximize button (ii) Minimize button (iii) Close button
27. What is the use of UPS (Uninterruptable Power Supply)
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Introduction to computer modified 2015

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Introduction to computer modified 2015