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Introduction to Information Technology ch 01_b


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B.S Ist semester

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Introduction to Information Technology ch 01_b

  1. 1. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education McGraw-Hill Technology Education Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved. Edited by:Edited by: Rahman Ali, Lecturer inRahman Ali, Lecturer in Computer Science, QACC,Computer Science, QACC, University of PeshawarUniversity of Peshawar
  2. 2. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education Chapter 1B Looking Inside the Computer System
  3. 3. 1B-3 Parts of the Computer System • Computer systems have four parts – Hardware – Software – Data – User
  4. 4. 1B-4 Parts of the Computer System • Hardware – Mechanical devices in the computer – Anything that can be touched • Software – Tell the computer what to do – Also called a program – Thousands of programs exist
  5. 5. 1B-5 Parts of the Computer System • Data – Pieces of information – Computer organize and present data • Users – People operating the computer – Most important part – Tell the computer what to do
  6. 6. 1B-6 Information Processing Cycle • All the steps that are followed to process data into information is called IPC. – Input – Processing – Output – Storage
  7. 7. Information Processing Cycle 1B-7
  8. 8. 1B-8 Essential Computer Hardware • Computers use the same basic hardware • Hardware categorized into four types: – Input – Memory devices – Processor – Output – Storage
  9. 9. Essential Computer Hardware 1B-9
  10. 10. 1B-10 Input devices • Input devices – Allows the user to interact with the computer – Input devices accept data • Keyboard, mouse
  11. 11. 1B-11 Memory devices • Memory devices – Computer Memory are internal storage areas in the computer used to either temporarily or permanently store data or instructions to be processed
  12. 12. Memory devices • Types of memory – Primary memory is also called • main memory or internal memory or volatile memory) 1B-12
  13. 13. Memory devices … • Primary memory – RAM – ROM – CPU registers – Cache memory 1B-13
  14. 14. Memory devices … • Random Access Memory (RAM) – RAM is a type of memory device within the computer system which is responsible for storing data on temporary basis – The data from the RAM is washed out when it is switched off – The data from the RAM is accessed by the processor for processing 1B-14
  15. 15. Memory devices • RAM types – Static RAM (SRAM): • Not refreshed, more power consumption, faster than DRAM – Dynamic RAM (DRAM): • Refreshed regularly, consume less power, slower than SRAM • Examples are: – SDRAM, DDR and Rambus DRAM • Size of RAM – 2GB, 4GB, 8GB, 16GB and 24GB (installed on Core i7) 1B-15
  16. 16. Memory devices … • Read Only Memory (ROM) – This type of memory is active, regardless of whether the system is turned on or is switched off. – It is a kind of permanent non-volatile storage memory. – As the name 'read only' suggests, the contents in it cannot be changed or modified. – It is an integrated circuit which is pre-programmed with important data that should necessarily be present for the computer to carry out its normal functionalities. 1B-16
  17. 17. Memory devices … 1B-17 • ROM chips – It usually contains a small startup program (BIOS) that is used to bootstrap the computer
  18. 18. Memory devices … • Read Only Memory (ROM) Types – ROM – • Read Only Memory – PROM – • Programmable Read Only Memory : Programmed once – EPROM – • Erasable Programmable Read Only Memory: Programed many times – EEPROM – • Electrically Erasable Programmable Read Only Memory – Flash EEPROM memory 1B-18
  19. 19. Memory devices … • CPU register – Processor registers are located inside the processor. – Each register typically holds a word of data (often 32 or 64 bits). – Registers are the fastest of all forms of computer data storage. 1B-19
  20. 20. Memory devices … • Cache memory – Processor cache is an intermediate stage between ultra-fast registers and much slower main memory – It is used to reduce the speed mismatch between fastest speed registers and slow speed RAM – It's introduced solely to increase performance of the computer. – Cache is divided into multiple level • Level 1 (L1) cache or primary cache – being smallest, fastest and located inside the processor • Level 2 (L2) and Level 3 (L3) cache or secondary cache – larger and slower than level 1 and located outside the CPU on motherboard 1B-20
  21. 21. Memory devices … 1B-21
  22. 22. 1B-22 Processing devices (CPU) • Processing devices – Brains of the computer – Carries out instructions from the program – Manipulate the data – Most computers have several processors – Central Processing Unit (CPU) – Secondary processors – Processors made of silicon and copper
  23. 23. Processor 1B-23
  24. 24. Processor … 1B-24
  25. 25. Processor … 1B-25
  26. 26. Processor… • Components of processor – CU (Control Unit): • The control unit control all the activities of the processor • It communicates with both the arithmetic/logic unit and memory (registers) – ALU (Arithmetic Logic Unit): • Perform arithmetic and logical operations • Arithmetic operation: X=a+b • Logical operation: – X>Y or – percentage>=70 && percentage<80 then grade=A – Registers: • A processor register is a small amount of storage available as a part of a CPU • 64 bits registers and 128 bits registers are used in latest CPU’s 1B-26
  27. 27. Output devices • Output devices deliver data – Monitor, printer, speaker 1B-27
  28. 28. Input/output devices • Some devices are input and output both – Touch screens 1B-28
  29. 29. 1B-29 Storage devices … • Secondary storage (also known as external memory or auxiliary storage), is a permanent storage that stores a large volume of data • It differs from primary storage in that it is not directly accessible by the CPU and is also a permanent storage • Types of secondary storage – Magnetic storage – Optical storage
  30. 30. Storage devices … • Magnetic storage – Floppy and hard drive – Uses a magnet to access data 1B-30
  31. 31. Storage devices … • Optical storage – CD and DVD drives – Uses a laser to access data 1B-31
  32. 32. Storage devices … • Other secondary storage devices – Flash Memory: This is another non-volatile (permanent) kind of memory which is intended to contribute to portable storage and a convenient transfer of data from one computer to another • Memory cards and • USB flash drives are some modes of this type of memory storage. 1B-32
  33. 33. 1B-33 Software Runs The Machine • Softwares are the computers programs that tell the computer to perform a specific task • Two types – System software – Application software
  34. 34. 1B-34 Software Runs The Machine • System software – These are the most important softwares that control the computer hardwares and make them ready for users operations
  35. 35. System softwares • Types of system softwares – Operating system • Is the most important system software that that controls the computer hardwares and run other application softwares. • Examples: Windows XP, Vista, Windows 7 – Network operating system (OS) • Allows computers to communicate and share data across a network • Examples: Windows Server 2003 – Utility • These are computer programs that are used to perform highly specialized tasks • Examples: Symantec AntiVirus, disk management, calculator etc.1B-35
  36. 36. 1B-36 Application software • Application software – Accomplishes a specific task – Most common type of application softwares • Word processing – MS Word • Graphics • Spreadsheet – MS Excel • Database management – MS Access • Multimedia • Web designing
  37. 37. 1B-37 Computer data • Fact with no meaning on its own • Stored using the binary number system • Data can be organized into files • Always be in raw form • Cannot be used for decision making purpose • Always used as input to the computers
  38. 38. 1B-38 Computer users • Role depends on ability – Setup the system – Install software – Mange files – Maintain the system • “Userless” computers – Run with no user input – Automated systems – Controlled by the installed operating system – Examples: washer and dryers machines, automatic cars etc.
  39. 39. Copyright © 2006 by The McGraw-Hill Companies, Inc. All rights reserved.McGraw-Hill Technology Education Chapter 1B End of Chapter