1. Chapter 1 Computer Hardware1 Computer Hardware A level Computing Book (Reference) By P.M.Heathcore

2. Chapter 1 Computer Hardware2 Computer System Hardware Software

3. Chapter 1 Computer Hardware3 Differences Hardware Physical Component of a Computer We can touch these parts Allow user to enter data and information into computer and retrieve Can not perform any task without Software If problem occur in hardware then it will repaired. Software Logical Component of a Computer We can not touch These are in form of instructions that tell the computer that what to do It can not executed without hardware. If any problem in software then it will reinstall.

4. Chapter 1 Computer Hardware4 Computer Components Logical units of a computer Input unit Output unit Memory unit ( Main Memory ) Central processing unit (CPU) Secondary storage unit

5. Chapter 1 Computer Hardware5 Computer Component Input Unit CPU Unit Ram / Rom ALU & Logical Unit Control Unit Output Unit Storage Devices

6. Chapter 1 Computer Hardware6 Types of computers by Size Micro computers Mainframe Computers Super Computers Mini Computers Embedded Computers

7. Chapter 1 Computer Hardware7 Micro Computers Are the computers that you are most likely to encounter at home or in school and colleges. It consist of one or more input device,output device, memory and processor. Examples PCs Apples

8. Chapter 1 Computer Hardware8 Types of Micro Computers Desktop Computers Laptop and notebook Computers Personal Digital Assistants (PDA) Palmtop Computers

9. Chapter 1 Computer Hardware9 Mainframe computers Thousands of terminals attached to it. Larger mainframe computers carry out 250 million instructions per second. It Consist of multiple processors. Used large organizations such as banks, insurance companies, airlines and government department. Disadvantage: Due to immense power they produce large amount of heat so its require air conditioned.

10. Chapter 1 Computer Hardware10 Examples IBM43810 NEC610 DEC 10 etc

11. Chapter 1 Computer Hardware11 Supercomputers Largest category of computer, costing millions of pounds. It is complex,large storage and advanced computers. They are mostly used by scientific and industrial research departments.

12. Chapter 1 Computer Hardware12 Uses NASA Weather centre Stock Exchange Weapon design Mapping the surface of planets. Studying the neural network of brain Preparing models of chemical systems.

13. Chapter 1 Computer Hardware13 Examples CRAY-XP ETA-10 Blue sky ASCI White

14. Chapter 1 Computer Hardware14 Mini computers Have a size, power and cost somewhere between those of microcomputers and mainframes. It is much powerful then some of the mainframes still in use. It is used by business institutes and departments.

15. Chapter 1 Computer Hardware15 Examples Vax-8800 MV-1500

16. Chapter 1 Computer Hardware16 Embedded Computers or Microprocessors Is a single chip that perform the functions of a central processing unit Many microprocessors makes are Microcontrollers also called embedded. Embedded computers serve as the brain of a larger piece of machine. Their software is stored in the computer’s own. They serve as a personal computer but not have a monitor, keyboard and mouse

17. Chapter 1 Computer Hardware17 Uses Microwaves programmable ovens Blood pressure monitors Air bag sensors Washing machines Video recorders Alarms Digital cameras MP3 players Car engine Controllers

18. Chapter 1 Computer Hardware18 Processors Most computer use Ics. It hold millions of electronic components such as transistors

19. Chapter 1 Computer Hardware19 Functions It controls the transmission of data from input device to memory It processes the data held in main memory It controls the transmission of information from main memory to output device.

20. Chapter 1 Computer Hardware20 Main Memory Instructions and data are held in main memory which is divided into millions of addressable storage units called bytes. One byte can hold one character Total bytes in main memory referred to as the computer’s memory size.

21. Chapter 1 Computer Hardware21 Memory Sizes measurement I nibble = 4 bits I byte = 8 bits I kilobytes (kb) = 1024 bytes 1 Megabytes (Mb) = 1024kilobytes 1 gigabytes (Gb) = 1024Megabytes 1 terabytes (TB) = 1024Gigabytes

22. Chapter 1 Computer Hardware22 Types of Main Memory Ram (Random Access Memory) Rom (Read Only Memory)

23. Chapter 1 Computer Hardware23 RAM & ROM Ram Its temporary memory Read and Write data Data can be changed or deleted It is a Volatile memory The instructions written in Ram at the time of execution Rom Its Permanent memory It can only be read Data can not change or deleted It is non Volatile The instructions are written into Rom at manufacturing time. (BIOS)

24. Chapter 1 Computer Hardware24 Cache Memory A Cache is a small and very fast memory To speed up the transfer of data and instructions. It is located inside or close to the CPU Chip. It is faster than Ram The data and instructions that are most recently or most frequently used by CPU are stored in cache. The amount of cache memory is generally between 1kb and 512kb

25. Chapter 1 Computer Hardware25 How Cache memory Works Processor Cache Memory Main Memory Single Word of data Transferred Block of data transferred

26. Chapter 1 Computer Hardware26 CPU Memory (main store) Cache controller Cache memory Typically 4MB Typically 64 KB HitMiss

27. Chapter 1 Computer Hardware27 Disk Storage The most common form of auxiliary storage ( External or secondary or backing store) is disk Magnetic media Hard disk Tape Floppy disk Optical storage device CD DVD CD-R CD-RW CD-ROM USB Drive