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Introduction to computer
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Application of ICT in Adult Teaching and Learning
Expectations:
• Active participation in all lectures, group discussion, seminars and lab sessions
Module Code: MAU07102
Assessment• Continuous Assessment – 50%
Classroom Test- 10%
Mid Semester Test – 15%
Participation – 5%
Project/Individual assignment – 10%
Portfolio – 10%
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• End of Semester Examination – 50%
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Course Overview
• Computer Basics & Computer system– Computer Hardware– Computer Networks– System & Application Software
• Generic Software– MS Office, Spreedsheet, Databases– Managing information in Adult
Education Programmes
Course Overview ….
• Internet – Internet basics– Internet in Education– Search and browsing• ICT in Teaching and learning -ICT in Education
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What is a computer?A computer is
–an electronic device that inputs data, processes data, displays information and stores information
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Computer Systems
We usually refer to ‘a computer’. However,•A computer consists of many components, assembled to make a whole system, hence, computer system• The components helps to perform information- processing tasks
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Different Parts of Computer• Input devices (e.g keyboard, mouse etc)
• Processing devices (e.g CPU-Central Processing Unit)
• Storage devices (e.g Hard Disk, flash disk, CD, DVD etc
• Output devices (e.g Printer, Monitor or computer screen, Speaker)
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OUTPUT DEVICE e.g. Monitor
PROCESSING DEVICE e.g. CPU-Central Processing Unit
INPUT DEVICE e.g. Keyboard
INPUT DEVICE e.g. Mouse
OUTPUT DEVICE e.g. Speaker
Different Parts of Computer
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TYPES OF COMPUTERS
1. Supercomputers- most powerful and used by large organisations eg. NASA-space exploration
2. Mainframe Computers – powerful (have great processing speed and data storage) eg. Used by insurance companies
3. Minicomputers (Midrange computers)- refrigerator size e.g used by medium size companies or depts of large companies
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4. Microcomputers – least powerful, but widely used and fastest growing type
• Typesa.Desktop Pcs – small to fit on top of
or alongside the desk, too heavy to carry around
b.Notebook (Laptop) computers- portable & fit into most briefcases
c.Tablet Pcs – cf laptop, but accepts handwriting that is converted to standard text eg. MS Word
d. Handheld(Palm) Pcs–the smallest & designed to fit into one’s hand eg. PDA, mobile phones
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Representing information
• Information can be represented as analogue or digital data
• Computers use digital data
Analogue information – continuous variablee.g. Voice-continuous signals
Digital information – discrete steps
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Example – clocksAn analogue clock has hands that can be in any position around the dial
A digital clock moves from one second to the next in steps
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Computers use digits (numbers) to process data
•Characteristics (colour, sound, text) are represented by numbers.
•Numbers are easier to work with electronically
•Numbers can be stored and transmitted more accurately
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Binary System• Bi (Latin) = 2•The counting system in which all numbers consist of only two digits (0 & 1)
i.e. The binary counting system has only two values, 0 and 1, represented electronically as different voltage levels (On/Off).
Computers are digital devices working in the binary number system.
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Some examples of binary numbers
• Each digit in a binary system is called a bit (binary digit)
• A group of 8 bits is called a byte.
• A byte will represent a letter, number, or character
e.g. (A=0100 0001, 1=0011 0001, $=0010 0100)
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Forms of Data Inputs to Computers
• Data inputs can be either in digital or analogue form
• Sound• Graphics• Video• Text• NumericNote: Before any processing can take
place, the computer will convert analogue data into digital data
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Binary Coding Schemes1. ASCII(American Standard Code for
Information Interchange) is an older standard. Originally only 7 bits were used to represent each character, allowing for 128 different characters.
2. EBCDIC (Extended Binary Coded Decimal Interchange Code) cf IBM
For example:ASCII EBCDIC
1 0011 0001 1111 0001
A 0100 0001 1100 0001
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3. Unicode•The current standard used around the world with sixteen bits used for each character, giving over 64,000 different characters that can be represented.
•Hence, easy to code languages with many characters E.g. Chinese and Japanese
•The first 128 characters of the Unicode set are the same as ASCII.
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Characteristics of ComputersSpeed
The computer was invented as a high speed calculator. For example if we want tomorrow’s forecast today (and not in six months time) meteorologists can use the computer to perform quickly the necessary calculations and analyses
Diligence
Being a machine, a computer does not suffer from the human traits of tiredness and lack of concentration. For example if 3 million calculations have to be performed, it will perform the 3 millionth with exactly the same accuracy and speed as the first.
Accuracy
The computer’s accuracy is consistently high. Please note here that, the errors in computing are due to human rather than to technological weaknesses of the computer itself
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Automation
A computer is much more than an adding machine, calculator or check-out till, all of which require human operators to press the necessary keys for the operations to be performed. Once a program is in the computer’s memory, the individual instructions re hen transferred, one after the other, to the control unit for execution.
Characteristics of Computers….
Versatility
Computers can perform multiple tasks of different nature at one and the same time. For example, one can write an article in MS word on computer while listening online music and at the same computer print outs of some documents simultaneously.
Storage
Computer have the ability to storing large amount of data. For example, once can stored trading materials of hundred of books on one DVD which otherwise may occupy one room for storage.
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How a Computer Functions
• Accepts Data (INPUT)
• Process Data (PROCESSING)
• Produces Output (OUTPUT)
• Stores Results (STORAGE)
Note:These are the main functions of computer as well
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How is this tied together?
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Hardware and Software• Hardware refers to the physical components of a
computer system – the system unit and all its contents, the keyboard, mouse, monitor, etc.
• Software refers to the information – programs and data that the computer uses
• Information must also be stored in some physical way. The disks, flash memory devices, tapes etc that software comes on are generally referred to as ‘media’
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PC Hardware consists of• The System Unit which is a case with a power supply
and other internal components, connections at the back and drives in the front
• Attached devices called peripherals, generally
including a monitor, keyboard and mouse, and maybe a modem, printer, scanner, etc.
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A typical PC may contain• 2.4 GHz Pentium 4
Processor• 512 MB RAM• 80 GB Hard Disk• 52x speed CD ROM Drive • 17” LCD Multimedia Video
Display with 1280 x 1024 resolution
• 56 KB Modem or Network Card
What do all these mean?
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The System Unit contains
• Motherboard
• Power Supply
• CPU
• RAM
• Hard disk drive
• Floppy Disk Drive
• CD-ROM
• Expansion cards
20:20 28Gigabyte motherboard for the Intel P4 processor
CPU socket
Memory slots
PCI expansion slots
Slot for graphics card
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Motherboard
Controllers for memory and other hardware
Socket for connecting CPU
Slots for expansion cards
has the electrical highways (bus) printed on it
has BIOS chip
has CMOS chip (sometimes in with the BIOS)
CMOS-complementary metal oxide semiconductor BIOS-Basic input/output system
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Motherboard Components
A bus •an ‘electrical highway’ consisting of many lanes.
•Data moves along these tracks between the CPU and memory, to storage devices and other hardware
More lanes means faster processing. e.g. The Pentium 4 uses a 64-bit data bus.
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BIOS a Read-Only Memory chip which stores the instructions the computer needs when it first starts, and instructions to communicate with hardware.
NoteROM is not lost when the power is off, so this is always available to the CPU.
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BIOS
•Its first job is to check the hardware.
•This is referred to as the Power-On Self-Test (POST).
•Next, the BIOS must start loading the Operating System from disk, which takes over running the computer.
•This phase is called the Initial Program Load (IPL).
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CPU – Central Processing Unit
• The ‘brain’ of the computer.
• Performs arithmetic, logical and decision making operations
Intel Pentium 4 CPU with cooling fan
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CPU Characteristics• CPUs (microprocessors) used in PCs
generally use 32 bit numbers• They run at a speed determined by the
clock. For Intel CPUs (e.g. Pentium 4) this is currently 2 – 3.6 GHz, but gets faster every year
• CPU producers: • AMD • Intel. • Motorola produces CPUs, used in Apple
and Macintosh computers
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Big Numbers
• Kilo means a thousand 1 000In binary, 210 or 1024 is pretty close to
kilo• Mega means a million 1 000 000
In binary 220 or 1 048 576 is pretty close to Mega
• Giga means billion 1 000 000 0002 GHz (2 GigaHertz) means 2 000 000 000 clock cycles every
second – very fast!