computer fundmental

UNESCO ICTLIP Module 1. Lesson 4. 1

Midnimo Group Deeqo C/qaadir Ibraahim Ayaan C/qaadir Xasan Ikraam C/qaadir Jimcaale Faadumo Daahir

C/Raxmaan


Outlines What is computer? Hardware Software Central Processor Unit (CPU)


What Is a Computer? A computer is an electronic device, operating under

the control of instructions stored in its own memory

Page 6

Information Processing Cycle

The Components of a Computer A computer contains many electric, electronic, and

mechanical components known as hardware

Pages 6 - 8

The Components of a Computer

Page 7 Figure 1-3

Storage DevicesStorage Devices

Hard Disk Hard Disk

Flash Drive Flash Drive

CD-ROM CD-ROM

DVD-ROM DVD-ROM

http://images.google.com/imgres?imgurl=http://www.pcmech.com/wp-content/uploads/2007/08/usb_flash_drive.gif&imgrefurl=http://www.pcmech.com/article/top-uses-for-a-usb-flash-drive/&usg=__XnCeIPJOGPtJ7BNkoYlePKPnTHA=&h=300&w=300&sz=14&hl=en&start=10&sig2=1PtfgX4PnIKENKOiN7Gf1w&um=1&tbnid=fKWqxU7y_wZmlM:&tbnh=116&tbnw=116&prev=/images?q=flash+drive&hl=en&sa=N&um=1&ei=kV7aSauPOOaGmQfhg9CADw

Parts of a Computer Input DevicesParts of a Computer Input Devices

MouseMouse

KeyboardKeyboard

MicrophoneMicrophone

ScannerScanner

WebcamWebcam

Parts of a Computer Output Parts of a Computer Output DevicesDevices

Monitor

Printer

Speaker/Headphone

Advantages and Disadvantages

of Using ComputersAdvantages of

Using ComputersDisadvantages of Using Computers

Pages 9 - 10

Categories of Computers

Page 19

Personal Computers A personal computer can perform all of its input,

processing, output, and storage activities by itself Two popular architectures are the PC and the Apple

Desktop computer

Page 19 Figures 1-15 - 1-16

Mobile Computers and Mobile Devices

Pages 20 - 23


Pages 20 - 22 Figures 1-17 – 1-20

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http://www.scsite.com/dc2011cp/ch1/weblink/


Pages 22 - 23Figures 1-21 – 1-23

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Mainframes A mainframe is a

large, expensive, powerful computer that can handle hundreds or thousands of connected users simultaneously

Page 25 Figure 1-26

Super computers A supercomputer is the fastest, most powerful

computer Fastest supercomputers are capable of processing

more than one quadrillion instructions in a single second

kPage 25 Figure 1-27

Medicine. Nuclear Energy Online Banking Weather Forecasting

Computer Applications in Society

, Pages 34 - 36 Figures 1-36 – 1-39

Computer Applications in Society

Pages 36 - 38Figures 1-40 – 1-43

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Welcome to Ayaan She is Explaining Hardwar

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HARDWARE HARDWARE is the collection of

physical elements that constitute a computer system.

Basic hardware of a PC system Central Processing Unit (CPU) Memory Unit Input Devices Output Devices Secondary Storage Devices

1. Central Processing Unit

Brain of the computer. It directs and controls the entire computer

system and performs all arithmetic and logical operations.

2. Memory Unit Where the programs and data

are stored . READ ONLY MEMORY (ROM)

contains the pre-programmed computer instructions such as the Basic Input Output System (BIOS).

RANDOM ACCESS MEMORY (RAM) is used to store the programs and data that you will run. Exists only when there is power.

3. Input Devices Allows data and programs to be sent to the

CPU. Keyboard Mouse Joystick Microphone Webcam Scanner Monitor

THE KEYBOARD

The keyboard was one of the first peripherals to be used with computers, and it is still the primary input device for entering text and numbers. A standard keyboard includes about 100 keys; each key sends a different signal to the CPU.

Numeric keys Function keys

Space bar Arrow keys

Shi

ft ke

yC

aps

lock

Esca

pe

Control keyENTER KEY

TAB KEY

ALT (Alternate) key

Backspace

ALPHABET KEYS

Shortcut keyStart key

Two Types of Mouse Mechanical - a type of

computer mouse that has a rubber or metal ball on its underside and it can roll in every direction.

Optical: This type uses a laser for detecting the mouse's movement.

Scanning Devices Optical scanners Card readers Bar code readers Character and mark recognition

devices

4. Output Devices Media used by the computer in

displaying its responses to our requests and instructions.

Monitor Audio Speakers Printer

Types of Monitor Cathode Ray Tube (CRT)

Liquid Crystal Display (LCD)

Printers IMPACT PRINTERS uses pressure by physically

striking the paper. Ex. Daisy wheel printers, line printers, dot matrix printers & band printers.

NON-IMPACT PRINTER does not apply pressure on the paper but instead produces character by using lasers, ink spray, photography or heat.

Dot matrix printer

Inkjet printerLaser printer

5. Secondary Storage Devices Attached to the computer system

to allow you to store programs and data permanently for the purpose of retrieving them for future use.

Floppy disk, Hard disk, CD Rom

Floppy Disk The most common secondary

storage device 3.5” disk – 1.44MB

Hard Disk Drive or Hard Disk

Made of rigid materials unlike floppy disks Holds a greater amount of data

10MB in 1980s 600MB in mid 1990s 4.3GB in 1999 180GB in 2001 400GB - 2004

Optical Discs A standard part of modern desktop

machines, especially used for multimedia purposes and preferred in loading applications.

Parts that Build Up A System Unit

Casing or cover

Power Supply Motherboard Microprocessor Memory Video Card

Sound card Floppy disk

drive Hard disk drive CD-ROM drive MODEM

Casing or cover. Protects the computer

circuits, cooling and system organization.

Power Supply Responsible for powering every device in your

computer. Parts of a Power supply:

Disk drive connectors Motherboard connector Power supply fan Power switch Input voltage selector Cover Power plugs receptacle

Motherboard The physical arrangement in a computer that

contains the computer’s basic circuitry and components.

Components are: Microprocessor (Optional) Coprocessors Memory Basic Input/Output System (BIOS) Expansion Slot Interconnecting circuitry

Expansion Slots Graphic cards Sound cards Modem cards Network interface cards/network

adapter

Welcome to Ikraam She is Explaining Softwar


SOFTWARE

Programs written in a special language with a series of instructions to a computer or its peripherals that cause the computer to solve a problem or perform a task to achieve a specific set of results.

Simply a set of instruction necessary for a computer to accomplish required tasks.


Software Software make up the set of

instructions for the computer. Without software, the computer will not be able to perform the tasks that you would like it to do.

Operating System controls all machine activities provides the user interface to the computer manages resources such as the CPU and memory DOS, Windows XP, Unix, Linux, Mac OS

Application program generic term for any other kind of software

(custom made) MS Word, MS Excel, Games,….. Library

softwares e.g, Koha, WINISIS, LIMS, LAMP….

TYPES OF SOFTWARE


Operating system An organized collection of system programs

which serve as the interface between the user or application and the computer.

It manages the hardware resources: CPU management to facilitate sharing

execution time of processes Memory management to allocate memory

resources dynamically I/O management to handle reading and

writing devices

UNESCO ICTLIP Module 1. Lesson 4.

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Disk Operating Systems (DOS)

Disk Operating System (DOS) is a generic term describing any operating system that is loaded from disk devices when the system is started or rebooted.

It is not a user friendly OS since users need to memorize commands and issue it by typing line by line. This known as command line interface. Very few end users use DOS nowadays.


Microsoft Windows A graphical user interface (GUI) originally

running on DOS (Windows 3.x) that allows multitasking or the ability to run several programs at the same time.

Windows 95 / Windows NT that no longer runs on DOS

About 75% of the world’s PCs use the Windows operating system. The present versions in use are Windows 98, Windows Me and Windows 2000.


Other operating systems

IBM OS/2 Macintosh OS SCO Unix Linux Other Proprietary OS


Applications software

A set of instructions designed to perform a specific task such as word processing, accounting, cataloguing, library management, animation, etc.


Types of applications software

The nature of the software depends on the application General purpose office software Business management software Special discipline software Other applications


General purpose office software Word processing: Example, MS Word Spreadsheets: Example, Excel Database management systems:

Example, MS Access, Oracle Presentation/Graphics: Example,

Power Point, Corel

Welcome to Faadumo She is Explaining CPU (Centeral Processing Unit)


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Processor

What is processing ?

The processor is the brain of the PC sometimes called microprocessor or CPU (Central Processing Unit)

Converts data into in formation Control center Set of electronic circuitry that executes stored

program instruction The CPU performs the system's calculating and

processing


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Cont….. The processor and the main memory devices are

the intelligence of the computer. Housed by the system unit, the processor also known as the CPU (central processing unit) interprets and executes instructions while the main memory serves as the computer's "work space". The processing power of a computer largely depends on the speed of the processor and size of its main memory. Faster processor results to faster execution of instructions.

UNESCO ICTLIP Module 1. Lesson 3 60

Processor


Cont.

The processor is often the most expensive single component in the system.

A central processing unit (CPU) is the electronic circuitry within a computer that carries out the instructions of a computer program by performing the basic arithmetic, logical, control and input/output (I/O) operations specified by the instructions.

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Cont…..The form, design and implementation of CPUs

have changed over the course of their history, but their fundamental operation remains almost unchanged.

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cont….Principal components of a CPU include the arithmetic

logic unit (ALU) that performs arithmetic and logic operations, processor registers that supply operands to the ALU and store the results of ALU operations, and a control unit that fetches instructions from memory and "executes" them by directing the coordinated operations of the ALU, registers and other components.

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OperationThe fundamental operation of most CPUs, regardless of the physical form they take, is to execute a sequence of stored instructions that is called a program. The instructions to be executed are kept in some kind of computer memory.Nearly all CPUs follow the fetch, decode and execute steps in their operation, which are collectively known as the instruction cycle.

After the execution of an instruction, the entire process repeats with the next instruction cycle normally fetching the next-in-sequence instruction because of the incremented value in the program counter.

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Fetch The first step fetch involves retrieving

an instruction (which is represented by a number or sequence of numbers) from program memory.

The instruction's location (address) in program memory is determined by a program counter (PC), which stores a number that identifies the address of the next instruction to be fetched.

After an instruction is fetched, the PC is incremented by the length of the instruction so that it will contain the address of the next instruction in the sequence.

Decode The instruction that the CPU fetches from memory

determines what the CPU will do. In the decode step, performed by the circuitry

known as the instruction decoder, the instruction is converted into signals that control other parts of the CPU.

The way in which the instruction is interpreted is defined by the CPU's instruction set architecture (ISA).

Execute After the fetch and decode steps, the execute step

is performed. Depending on the CPU architecture, this may

consist of a single action or a sequence of actions. During each action, various parts of the CPU are

electrically connected so they can perform all or part of the desired operation and then the action is completed, typically in response to a clock pulse.

Very often the results are written to an internal CPU register for quick access by subsequent instructions.

Cont.

In other cases results may be written to slower, but less expensive and higher capacity main memory.

For example, if an addition instruction is to be executed, the arithmetic logic unit (ALU) inputs are connected to a pair of operand sources (numbers to be summed), the ALU is configured to perform an addition operation so that the sum of its operand inputs will appear at its output, and the ALU output is connected to storage (e.g., a register or memory) that will receive the sum.

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Control unit

Part of the hardware that is in-charge. Directs the computer system to execute stored

program instructions. Communicates with other parts of the hardware. The control unit of the CPU contains circuitry

that uses electrical signals to direct the entire computer system to carry out stored program instructions.


Arithmetic logic unit

Performs arithmetic operationsPerforms logical operationsThe arithmetic logic unit (ALU) is a digital circuit within the processor that performs integer arithmetic and bitwise logic operations. Depending on the instruction being executed, the operands may come from internal or external memory, or they may be constants generated by the ALU itself.


Cont….. The result consists of both a data word,

which may be stored in a register or memory, and status information that is typically stored in a special, internal CPU register reserved for this purpose.

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Arithmetic Operations


Logical Operations

Thank you for you listening

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