MODULE:INTRODUCTION TO COMPUTER

UNIT :ORGANIZING MICRO COMPUTER

ELEMENT: connecting peripherals to micro computer

ALPHONCE FIDELIS STEPHANO ~0716236593|BIGWA FDC 339 MOROGORO

Computer Organisation

1.It accepts data or instruction by way of input,

2. it stores data,3. it can process data as required by the user, 4. it gives results in the form of output, and5. it controls all operations inside a

computer.

Input: this is the process of entering data and programs into the computer system.

Control Unit (CU): The process of input,output,processing and storage is performed under the supervision of a unit called 'Control Unit'. It decides when to start receiving data,

when to stop it,

where to store data, etc.

It takes care of step-by-step processing of all operations in side the computer.

Memory Unit: Computer is used to store data andinstructions.Arithmetic Logic Unit (ALU): The major operations performed by the ALU are addition(+), subtraction(-),multiplication(x), division(/), logic and comparison(yes/no).Output: This is the process of producing results from the data for getting useful information.The ALU and the CU of a computer system are jointly known asthe central processing unit (CPU).

You may call CPU as the brain of any computer system.

What are the five basic operations performed by thecomputer?Define ALU, CU and CPU.Choose the correct answer.1. The task of performing arithmetic and logical operations is called

a. ALU b. editing c. storage d. Output

2. The ALU and CU jointly are known asa. RAMb. ROM c. CPU d. None of above

3. The process of producing results from the data for getting useful information is called

a. output b. input c. processingd. storage

Peripheral devices are connected to the computer externally.

These devices are used for performing some specific functions.

Peripheral devices are as follows:1. Input Devices

2. Output Devices

3. Other Peripherals

INPUT DEVICES Input devices accept data and instructions from the

user

Example1. Keyboard

2. Mouse

3. Light Pen

4. Optical/magnetic Scanner

5. Touch Screen

6. Microphone for voice as input

7. Track Ball

is the most common input device.

Several kinds of keyboards are available, but they

The keyboard in most common use is the QWERTY board.

Generally standard keyboard has 104 keys.

In these keyboards, the cursor control keys are duplicated to allow easier use of the numeric pad.

A mouse is an electro-mechanical, hand-held device .

It is used as a pointer.

It can perform functions like selecting menu commands, moving icons, resizing windows, starting programs, and choosing options.

The most common mouse uses an internal, magnetically coated ball, to detect the movement of the mouse across a flat surface,

Now a days Optical or laser mouse is used to detect the movement.

An input device that utilizes a light-sensitive detector to select objects on a display screen.

A light pen is similar to a mouse , except that with a light pen you can move the pointer and select objects on the display screen by directly pointing to the objects with the pen.

These devices are used for automatic data collection.

The devices of this category completely eliminate manual input of data.

For example, the bar-code reader is actually just a special

type of image scanner.

An image scanner translates printed images into an electronic format that can be stored in a computer’s memory, and with the right kind of software, one can alter a stored image.

Another example of scanner is optical character recognition (OCR) device, used by banks to convert the scanned image of a typed or printed page into text that can be edited on the computer.

Touch panel displays and pads are now being offered as alternatives to keyboard. Here the input can be given through the computer screen, that accepts the input through monitor; users touch electronic buttons displayed on the screen or they may use light pen.

Microphone is an input device, which takes voice as input.

The voice communication is more error-prone than information through keyboard.

There are two types of microphones available1. Desktop Microphone

2. Hand held Microphone

Hand held Microphone Desktop Microphone

Trackball, a pointing device, is a mouse nlyingon its.

To move the pointer, you rotate the ball with your thumb, your fingers, or the palm of your hand.

There are usually one to three buttons next to the ball, which you use just like mouse buttons.

Output devices return processed data that is information, back to the user.

Some of the commonly used output devices are:

1. Monitor (Visual Display Unit)

2. Printers

3. Plotter

4. Speakers

Out of all the output devices, monitor is perhaps the most important output device because people interact with this device most intensively than others.

Computer information is displayed, visually with a video adapter card and monitor. Information processed within the CPU, that needs to be visually displayed, is sent to video adapter.

The video adapter converts information from the format used, in the same manner as a television displays information sent to it by a cable service

LCD CRT

1. CRT

Cathode Ray Tube (CRT): CRT or Cathode Ray Tube Monitor is the typical monitor that you see on a desktop computer.

It looks a lot like a television screen, and works the same way.

This type uses a large vacuum tube, called cathode ray tube (CRT).

2. LCD Liquid Crystal Displays (LCD): This type of monitors are also known as

flat panel monitor. Most of these employ liquid crystal displays (LCDs) to render images. These days LCD monitor are very popular.

After a document is created on the computer, it can be sent to a printer for a hard copy (printout). Some printers offer special features such as colored and large page formats.

1.Laser printer

2. Ink jet printer

3.Dot matrix printer

4.Line printer

Speakers are another type of output device, which allow you to listen to voice like music, and conversation with people.

Software refers to a set of programs that makes the hardware perform a particular set of tasks in particular order.

Sets of instructions are called Programs.

System software's are sets of programs, responsible for running the computer, controlling various operations of computer systems and management of computer resources.eg: operating system (os).

An operating system is a system software that provides an interface for a user to communicate with the computer, manages hardware devices (disk drives, keyboard, monitor, etc), manages

and maintains disk file systems and supports application programs.

Some popular Operating systems are UNIX, Windows and Linux

These are programs that bridge the gap between the functionality of an OS and the needs of users.

Utility programs are a broad category of software such as compress (zip)/uncompress (unzip) files software, anti virus software, split and join files software, etc.

Application software is a set of programs, which are written to perform specific tasks, for example:

1. Generalized packages

Word Processing Software(for preparing documents): Word Perfect, MS-Word, OpenOffice.org Writer

Spreadsheets (Data Analysis): Lotus Smart suites, MS-Excel, OpenOffice.org Calc, Apple Numbers

Presentations : Presentation Graphics, MS-PowerPoint, OpenOffice.org Impress

Database Management System: MS-Access, OpenOffice.org Base, MS-SQL Server, ORACLE

Graphics Tools: Paint shop pro, Adobe Photoshop

2. Customized Packages

These are the applications that are customized (or developed) to meet the specific requirements of an organization/institution.

For Example: Student information details, Payroll packages, inventory control etc.

These packages are developed using high-level computer language.

What is a Port?

A port: Is a physical docking point using which an external device can be connected to the computer.

Can also be programmatic docking point through which information flows from a program to computer or over the internet.

A port has the following characteristics:

External devices are connected to a computer using cables and ports.

Ports are slots on the motherboard into which a cable of external device is plugged in.

Examples of external devices attached via ports are mouse, keyboard, monitor, microphone, speakers etc

Serial Port Used for external modems and older computer

mouse Two versions : 9 pin, 25 pin model Data travels at 115 kilobits per second

Parallel Port Used for scanners and printers Also called printer port 25 pin model Also known as IEEE 1284-compliant Centronics

port

PS/2 Port

Used for old computer keyboard and mouse Also called mouse port Most of the old computers provide two PS/2 port, each for mouse and

keyboard Also known as IEEE 1284-compliant Centronics port

Universal Serial Bus (or USB) Port It can connect all kinds of external USB devices such as external hard

disk, printer, scanner, mouse, keyboard etc. It was introduced in 1997. Most of the computers provide two USB ports as minimum. Data travels at 12 megabits per seconds USB compliant devices can get power from a USB port

VGA Port

Connects monitor to a computer's video card.

Has 15 holes.

Similar to serial port connector but serial port connector has pins, it has holes.

Power Connector

Three-pronged plug

Connects to the computer's power cable that plugs into a power bar or wall socke

Firewire Port

Transfers large amount of data at very fast speed.

Connects camcorders and video equipments to the computer

Data travels at 400 to 800 megabits per seconds

Invented by Apple

Three variants : 4-Pin FireWire 400 connector, 6-Pin FireWire 400 connector and 9-Pin FireWire 800 connector

Modem Port

Connects a PC's modem to the telephone network

Ethernet Port

Connects to a network and high speed Internet.

Connect network cable to a computer.

This port resides on an Ethernet Card.

Data travels at 10 megabits to 1000 megabits per seconds depending upon the network bandwidth.

Game Port Connect a joystick to a PC Now replaced by USB.

Digital Video Interface, DVI port Connects Flat panel LCD monitor to the

computer's high end video graphic cards. Very popular among video card manufacturers.

Sockets Connect microphone, speakers to sound card of

the computer

I. Keyboard and mouse: Set up the keyboard right in front of where you’ll sit when you use the computer, between you and where the monitor goes. The mouse lives to the right or left of the keyboard, depending on whether you’re right- or left-handed.The PC keyboard plugs into the keyboard port on the back of the console. The mouse plugs

into the mouse port. Note that the two ports look identical but are different.

II. Monitor: Set the monitor atop your desk, generally back away from where you sit, to accommodate room for the keyboard. The monitor plugs into the VGA, or graphics adapter, jack on the back of the console. The plug goes in only one way.

III. Network: Plug the network, or Cat 5, cable into the network jack on the back of the console. This is how you connect your PC to a network, or how you connect to a broadband modem.

iv. Printer: Set up the printer where it’s within arm’s reach of the console. To get the printer and console talking to each other, you need a cable, either a USB cable or the traditional printer cable. When you’re blessed with a wireless printer, keep it close enough to the console to ensure that it’s in range of the signal.

v. USB: USB devices plug into the USB port — any USB port. The USB cable may be attached directly to the gizmo, or you may have to use (or buy) a separate USB cable.

Plug in your computer and all peripherals.Peripherals include such items as your monitor, keyboard, mouse and printer, if you have one. In order to protect your computer, you should use a surge protector.

Turn on the surge protector. Usually surge protectors feature a light that will glow when powered on.

Press the power button on your computer or CPU (Central Processing Unit). These buttons can be recognized by the power symbol, a circle with a vertical line intersecting the top of it. Your computer will boot, and you can begin using it as desired.

“using a computer should enable you to focus on what

you want to accomplish instead of how to

accomplish”

ALPHONCE ASSENGADiploma in computer science and engineering

alphoncesteven@gmail.com