computer systems and it's major components

1. Overview of Computer
Systems
COMPUTER SYSTEMS IT1023

2. Overview of Computer Systems
 The parts of a computer system
 Evolution of computers
 Generation of computers
 Types of computers

3. The Parts of a Computer System
 A computer can be identified as a device that takes raw data (unprocessed data)
and processes it and provides useful information.
 It has the ability to store data
 The computer consists of main four components:
 Hardware
 Software
 Firmware
 users

4. Parts of the computer
 There are four main devices in a computer system
 Input devices
 Output devices
 Processor, memory and integrating devices
 Storage devices

5. Part of a computer system
 Processor, memory and integrating devices
 Central Processing Unit (CPU)
 Motherboard or main board
 Main memory
 Power supply
 VGA Card
 Sound card
 LAN card
 TV card

6. Parts of a computer system
 Input devices
 Keyboard
 Pointer devices (Mouse, track-
ball)
 Joystick and game pads
 Scanner
 Microphones, still digital
cameras and video cameras

7. Parts of a computer system
 Output devices
 Monitor and LCD panel
 Printers
 Speakers
 plotters

8. Parts of a computer system
 Storage devices
 Hard drives
 DVD and CD ROM
 Tape drives
 Flash disks and memory cards
 Floppy disks

9. The Processor
 The processor = human brain
 The main difference between the
processor from the human brain is that it
is dependent on the human and can’t
provide information by thinking on its
own.
 It cannot generate new ideas (not
creative)
 It is only a device and is conducted
through instructions given by the
humans.

10. Memory
 There are two types of memory
 Random access memory (RAM)
 Read only memory (ROM)
 RAM = store temporary data, can read and write info, data is lost when the power
is switched off on the computer (volatile memory), faster access
 ROM = read only, non volatile memory (doesn’t loose the data when the
computer is switched off), BIOS ROM, CMOS (Complementary Metal Oxide
Semiconductor)

11. Input devices
 Helps the user to command instructions to the processor
 Examples:
 keyboard
 Mouse, trackball
 Joystick
 Microphone
 Scanner
 Digital camera

12. Output devices
 Used to output information to the user.
 Example:
 speaker
 LCD Panel
 Monitor
 Projectors
Both Input and output devices – Feedback joystick, touchscreen display

13. Storage devices
 There should be a facility to store data permanently not
temporally. For that there’s special storage devices.
 Magnetic tape was the earliest forms of data storage device
but the access for data is sequential making it more
disadvantageous.
 Hard disk and floppy disk are randomly accessed storage
devices. (magnetic storage devices)
 Hard disk – not portable, fixed in a computer
 Floppy disks – portable but very limited storage capacity
 ZIP disk – can store over 100 megabytes.

14. Storage devices
 Optical storage devices – CD ROM, DVD ROM
 Easy to transport, cost effective
 CD ROM – can store around 700 megabytes
 DVD ROM – can store in excess of 4.2 gigabytes
 Blue ray – can store up to 26 gigabytes
 With the technology, flash-drive (pen drive), SD card,
compact-flash, Sony memory stick and XD picture-
card have emerged.

15. Expansion card and other components
 Motherboard – cannot function the
computer systems without a
motherboard.
 Video graphics adapter cards
 Sound card
 Ethernet card
 TV card
 Data-Fax modem card
 USB card
 FireWire card
• Hard disk and floppy drive ribbon cables CD/DVD
drive analog audio cable, video cable, printer cable,
USB cables and FireWire cables

16. Power supply unit and chassis
 Power supply unit provides power to the computer
systems to function.
 The chassis consists of the space for motherboard, power
supply, input/output connectors, expansion cards,
expansion bays, switches and wires.
 The chassis is made from steel, aluminum and or plastic.
 Chassis can be divided into tower and flatbed. It further
classified into mini tower, mid-sized tower, full-size tower
and flatbed into desktop and slim desktop.

17. Power supply
 Power supplied to the computer systems
 The main power is connected to the power supply through a power cable.
 The power connectors come in different shapes and sizes.
 Mini plug, Molex power connector, motherboard power connectors, 12V ATX
power connector, SATA

18. Evolution of computers and computers
today
 Chapter summary
 History of computers
 Development of computers

19. Evolution of computers and computers
today
 Key developments of computer systems
 Abacus – calculating device (3000 BC)
 Pascaline – mechanical adding machine (1642)
 Babbage – analytical engine (1830s)
 Ada – first programmer (1800s)
 Punched cards – data storage (1800s)
 Hollerith – tabulating machine (1890s)
 Mark I – general purpose computer (1944)

20. Evolution of computers and computers
today
 ENIAC - electronic computer (1946)
 UNIVAC - US Census Department (1951)
 EDVAC - Stored Program Concept (1951)
 Microprocessor chip
 Floppy disk for data storage
 Pocket Calculator
 Apple II - first personnel computer
 IBM PC
 Portable computers
 Laser Printing and Desktop Publishing
 Multimedia desktop computers
 Home video computers
 Video conferencing

21. Evolution of computers and computers
today
 Pascaline – developed by Blaise Pascal, desktop mechanical adding machine
 Analytical engine – invented by Charles Babbage (father of computer)
 Ada – world’s first computer programmer
 Punched cards – first used by Joseph Jacquard
 tabulating machine – invented by Herman Hollerith
 Mark I – invented by Dr. Howard Aiken. It’s a programmable, general purpose computer
 First electronic computer – Atanasoff-Berry Computer (ABC)

22. Evolution of computers and computers
today
 First stored-program computer concept – EDVAC by John Von Neuman
 Electronic computing machine – ENIAC – John Mauchly and J. Presper Eckert
 First real stored-program computer – EDSAC by Maurice Wilkes
 First commercial computer – UNIVAC I
 First electronic computer of IBMs – IBM 701

23. Generations of computers
 First generation (1951 – 1958)
 Used vacuum tubes for internal operations
 Used low-Level languages for programming (machine language)
 Used magnetic drums for primary memory.
 Primary memory was limited.
 Heat and maintenance problems were there.
 Used punch cards for input and outputs.
 Input and output was slow.
 e.g. UNIVAC I, EDVAC

24. Generations of computers
 Third generation (1965 – 1970)
 Used (ICs) on silicon chips for internal operations.
 Memory capacity was increased.
 Minicomputers became a common use.
 Software industry emerged.
 Reduction in size and cost of computers happened.
 Increase in speed and reliability.
 E.g. HONEY WELL-6000 SERIES

25. Generations of computers
 Fourth generation (1971 – today)
 Used Large Scale Integration (LSI) and Very Large Scale Integration (VLSI) for internal operations.
 Development of the microprocessor happened.
 Introductions of micro and super computers.
 Increase in speed, power and storage capacity.
 Parallel processing was introduced.
 Artificial intelligence and expert systems were introduced.
 Robotics was introduced.
 Increased use of Micro/Personal Computers.
 E.g. Apple II, IBM PC Micro Computers

26. Generations of computers
 Fifth generation
 A project to develop intelligent computers.
 They are computers with artificial
intelligence.
 Symbolic manipulation and symbolic
reasoning is required

27. Personal computers
 One of the most commonly used computer type
 IBM invented the first personal computer called Model 5100 in 1975

28. Modern day computers
 Classification of computers
 Supercomputers
 Mainframe computers
 Minicomputers
 Network servers
 Personal computers

29. Supercomputers
 Most powerful computers
 More sophisticated, expensive, use state-of-the-art
technology
 Designed to perform large amounts of data
 Used by researchers, universities, organizations
 Used in the simulation and modelling of complex
systems. (weather, chemical processes, US
economic predictions, motion of galaxies)
 Have thousands of microprocessors
 High processing speed

30. Mainframe computers
 Large powerful systems
 Users gain access to resources for a mainframe
computer through a terminal (dumb terminals
and intelligent terminals)
 Can handle more than 1000 users at a given time.
 E.g: flight reservation system, banking system
 Less flexible to use
 Mostly used to handle single or few tasks.
(mainly for a specific task)

31. Minicomputers
 Less powerful than mainframe computers but more powerful than personal
computers
 Small in size
 Can handle many users at a time
 Can connect to a minicomputer using a terminal or a personal computer

32. Network servers
 A network server is a computer connected to a network to share the resources
with others.
 It is much more flexible
 The uses of the network servers are:
 Using emails (email server)
 Connect to the internet (proxy server)
 To share files (printer server)
 Connect to a database (database server)

33. Personal computers and microcomputers
 Personal computers are used by a single user
 Small in size
 Used at home by individual users
 Also referred to as minicomputers
 There are some types of personal computers:
 Desktop computers
 Workstations
 Notebook computers
 Tablet PCs
 Hand-held computers
 smartphones