ICT Bachelor Degrees BACE BAECD Module Code MAU

ICT Bachelor Degrees BACE & BAECD Module Code: MAU 07102 Expectations: • Active participation lectures, group & online discussions, seminars and lab sessions 20: 26 1

Assessment • Continuous Assessment – 50% Classroom Test- 10% Mid Semester Test – 15% Participation – 5% Project/Individual assignment – 10% Portfolio – 10% • End of Semester Examination – 50% 20: 26 2

What is a computer? A computer is – an electronic device that inputs data, processes data, displays information and stores information 20: 26 3

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 20: 26 4

Computer Systems • A computer system is a set of parts, including the computer itself, that work together to perform tasks. These tasks may be relatively simple, as in a calculator, or they may be very complex, as in air traffic control systems 20: 26 5

Different Parts of Computer OUTPUT DEVICE e. g. Monitor PROCESSING DEVICE e. g. CPU-Central Processing Unit OUTPUT DEVICE e. g. Speaker INPUT DEVICE e. g. Keyboard INPUT DEVICE e. g. Mouse 20: 26 6

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How is this tied together? 20: 26 8

Discuss the function of four different parts of computer • • Input part/input devices Output part/output devices Storage part/storages devices Processing part/process devices 20: 26 9

Mention four examples of different parts of computer • • Input part/input devices Output part/output devices Storage part/storages devices Processing part/process devices 20: 26 10

Types of computer 1. Supercomputers- most powerful and used by large organisations eg. NASAspace 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 20: 26 11

4. Microcomputers – least powerful, but widely used and fastest growing type • Types a. Desktop Pcs – small to fit on top of or alongside the desk, too heavy to carry around b. Notebook (Laptop) computersportable & 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 20: 26 12 hand eg. PDA, mobile phones

Why Microcomputers are least powerful, but widely used in around the world? 20: 26 13

Information representation • Information can be represented as analogue or digital data • However, computers use digital data Analogue information – continuous variable e. g. Voicecontinuous signals 20: 26 Digital information – discrete steps 14

Example – clocks An 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 20: 26 15

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 20: 26 16

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. 20: 26 17

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) 20: 26 18

Forms of Data Inputs to Computers • Data inputs can be either in digital or analogue form • Sound • Graphics • Video • Text • Numeric Note: Before any processing can take place, the computer will convert 20: 26 19 analogue data into digital data

Characteristics of Computers Speed 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 20: 26 20

Characteristics. . • 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 20: 26 21

Characteristics. . • 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. 20: 26 22

Characteristics…. 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. 20: 26 23

Characteristics. . • 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. 20: 26 24

Characteristics. . • 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. 20: 26 25

Computer Hardware & Software • Hardware refers to the physical components of a computer system – the system unit and all its contents, the keyboard, mouse, monitor, etc. 20: 26 26

Computer Hardware & Software. . • Software refers to the information – programs and data that the computer uses • However, 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’ 20: 26 27

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. 20: 26 28

A typical PC may contain • 2. 4 GHz Pentium 4 Processor • 512 MB RAM • 80 GB Hard Disk • 52 x speed CD ROM Drive • 17” LCD Multimedia Video Display with 1280 x 1024 resolution • 56 KB Modem or Network Card 20: 26 What do all these mean? 29

The System Unit contains • • 20: 26 Motherboard Power Supply CPU RAM • • Hard disk drive Floppy Disk Drive CD-ROM Expansion cards 30

PCI expansion slots Slot for graphics card CPU socket Memory slots Gigabyte motherboard for the Intel P 4 processor 20: 26 31

Motherboard has the electrical highways (bus) printed on it has BIOS chip has CMOS chip (sometimes in with the BIOS) Controllers for memory and other hardware Socket for connecting CPU Slots for expansion cards 20: 26 32 CMOS-complementary metal oxide semiconductor BIOS-Basic input/output system

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 20: 26 bus. 33

BIOS a Read-Only Memory chip which stores the instructions the computer needs when it first starts, and instructions to communicate with hardware. Note ROM is not lost when the power is off, so this is always available to the CPU. 20: 26 34

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). 20: 26 35

CPU – Central Processing Unit • The ‘brain’ of the computer. • Performs arithmetic, logical and decision making operations 20: 26 Intel Pentium 4 CPU with cooling fan 36

Big Numbers • Kilo means a thousand 1 000 v. In binary, 210 or 1024 is pretty close to kilo • Mega means a million 1 000 v. In binary 220 or 1 048 576 is pretty close to Mega • Giga means billion 1 000 000 v 2 GHz (2 Giga. Hertz) means v 2 000 000 clock cycles every second – very fast! 20: 26 37