Overview of Computer Systems

computer systems and it's major components

1. Overview of Computer Systems Computer Systems IT1023

2. Overview of Computer S ystems 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 c ard, 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 F ourth 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 F ifth 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 o thers. 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