Topic 3: System Unit

1. Topic 3: System Unit Robiatun Adawiah PCA0025 2010/2011

2. Objectives Identify types of memory inside the system unit Identify the components in the system unit Describe the types of expansion slots and expansion cards in the system unit Explain how the CPU uses the four steps of a machine cycle Explain each bus that connects devices inside the system unit Describe how a series of bits can represent data Topic 3 - System Unit

3. The System Unit • Case that contains electronic components of the computer used to process data • Sometimes called the chassis Topic 3 - System Unit

4. The System Unit • Common components inside the system unit • Motherboard • Processor • Memory • Adapter cards • Sound card • Modem card • Video card • Network card • Ports • Power supply • Hard Disk Topic 3 - System Unit

5. Motherboard/System Board • Backbone – support all the other computer component • Main circuit board of the system unit • Contains • expansion slots • processor chips • cooling fan • ports • memory slots • processor(s) Topic 3 - System Unit

6. Motherboard/System Board Topic 3 - System Unit

7. Central Processing Unit • Also known as processor/microprocessor • A small piece of semiconducting material on which integrated circuit are attached • Chips are packaged  attached to a circuit board Topic 3 - System Unit

8. Dual Core • A dual-core processor is a single silicon chip or integrated circuit that contains two separate processors Topic 3 - System Unit

9. Processor Control Unit Arithmetic Logic Unit (ALU) InstructionsDataInformation InstructionsDataInformation Central Processing Unit • Interprets and carries out basic instructions that operate a computer Control Unit Arithmetic Logic Unit (ALU) Memory InputDevices OutputDevices Data Information StorageDevices Topic 3 - System Unit

10. Control Unit Arithmetic operation Logical operation Central Processing Unit COMPONENTS IN CPU: • Control Unit (CU) • Directs and coordinates operations in computer • Each instruction - repeat 4 basic instructions  Machine cycle • Arithmetic/ Logic Unit (ALU) • Perform arithmetic operation and logical operation • Control the speed of the operation Topic 3 - System Unit

11. e-time i-time Central Processing Unit • How the CPU executes program instructions • Fetch - obtain program instruction or data item from memory • Decode - translate instruction into commands the CPU understands • Execute - carry out command • Store - write or store result in register or RAM Topic 3 - System Unit

12. Central Processing Unit • System clock • Controls timing of all computer operations • Generates regular electronic pulses, or ticks, that set operating pace of components of system unit Each tick is a clock cycle Pace of system clock is clock speed (GHz) Processor speed can also be measured in millions of instructions per second (MIPS) Topic 3 - System Unit

13. Central Processing Unit • Register • Temporary high-speed storage area that holds data and instructions Stores location from where instruction was fetched Stores instruction while it is being decoded Stores data while ALU computes it Stores results of calculation Topic 3 - System Unit

14. Central Processing Unit FETCH STORE EXECUTE DECODE Topic 3 - System Unit

15. Central Processing Unit • Ways to increase computer performances • Parallel Processing • Using multiple processors simultaneously to execute a program faster Topic 3 - System Unit

16. Central Processing Unit • Pipelining • Processor begins fetching second instruction before completing machine cycle for first instruction • Results in faster processing Topic 3 - System Unit

17. Data Representations • How do computers represent data? • Use a binary system to recognize two states (on or off) • Use number system with two unique digits: 0 and 1, called bits (short for binary digits) Topic 3 - System Unit

18. Data Representations • Byte • Eight bits grouped together as a unit • Provides enough different combinations of 0 and 1 to represent 256 individual characters • Numbers, uppercase and lowercase letters, punctuation marks & others Topic 3 - System Unit

19. ASCII Symbol EBCDIC 00110000 0 11110000 00110001 1 11110001 00110010 2 11110010 00110011 3 11110011 Data Representations • Two popular coding systems to represent data • ASCII—American Standard Code for Information Interchange • EBCDIC—Extended Binary Coded Decimal Interchange Code Topic 3 - System Unit

20. volatile memory content is lost when computer’s power is turned off nonvolatile memory content is not lost when computer’s power is turned off Memory Topic 3 - System Unit

21. Memory Module Memory Chip Memory • Random access memory (RAM) • Also called main memory or primary storage • Most RAM is volatile • Responsible : • Hold data for processing • Hold instruction to process the data • Hold data after being processed • The more RAM a computer has, the faster it responds Topic 3 - System Unit

22. seat A22 seat C22 seat B22 Memory • Storage locations and addresses • An address is a unique number that identify the location of a byte in the memory • The address numbers of the location remains the same, but the contents (instructions and data) of the locations may change Topic 3 - System Unit

23. Memory • Read-only memory (ROM) • Memory chips that store permanent data and instructions • Data can only be read; cannot be modified in ROM • Nonvolatile memory, content is not lost when computer’s power is turned off • BIOS (basic input/output system) • Stored on ROM • Sequence of instructions that computer follows to load operating system and other files when you turn on the computer Topic 3 - System Unit

24. Used in some RAM chips, flash memory chips, and other types of memory chips Uses battery power to retain information when other power is turned off Stores date, time, and computer’s startup information Memory • CMOS (Complementary metal-oxide semiconductor) Topic 3 - System Unit

25. Memory • Cache • Helps speed computer processes by storing frequently used instructions and data • Also called memory cache Topic 3 - System Unit

26. Memory • Flash memory • Nonvolatile memory that can be used with PDAs, smart phones, printers, digital cameras, automotive devices, audio players, digital voice recorders, and pagers • Plug and play device Topic 3 - System Unit

27. Bus Lines • A set of parallel electrical paths that allows devices inside computer to communicate with each other • Bus width determines number of bits transmitted at one time • Two kinds of buses: • System bus connects processor and RAM • Expansion bus (data bus or I/O bus) Topic 3 - System Unit

28. Bus Lines • Expansion Bus • An opening, or socket, where circuit board is inserted onto motherboard • Allows processor to communicate with peripherals • Expansion card is inserted in expansion slot expansion card expansion slot Topic 3 - System Unit

29. Bus Lines • Types of expansion bus • ISA bus (Industry Standard Architecture) /AT bus • Old low speed 16 bit bus • Used to connect devices such as mouse, modem and sound cards Topic 3 - System Unit

30. Bus Lines • PCI bus (Peripheral Component Interconnect) • 32 bit bus • Used to connect to higher speed devices such as network cards and sound cards Topic 3 - System Unit

31. Bus Lines • AGP bus (Accelerated Graphic Port) • Used for the graphics card • Designed to improve the of video and 3-D graphics transmission Topic 3 - System Unit

32. Bus Lines • PCMCIA bus (Personal Computer Memory Card International Association) • Better known as PC cards • Normally used in laptops • Used to connect PC cards such as modem or network card Topic 3 - System Unit

33. Bus Lines Topic 3 - System Unit

34. Ports and Connectors • Ports • Connects external devices to system unit Topic 3 - System Unit

35. Ports and Connectors • Connectors • Physical device used to plug to the system unit • Used to join a cable to an external peripheral • Available in genders: male and female Topic 3 - System Unit

36. serial transmission of data Byte representation for number 5 (00110101) Byte representation for number 5 (00110101) Byte representation for number 5 (00110101) DB-9 femaleconnector DB-9 male connector Ports and Connectors • Serial port • Transmits one bit of data at a time • Used to connect slow-speed devices, such as mouse, keyboard, modem Topic 3 - System Unit

37. byte representation for number 1 byte representation for number 3 byte representation fornumber 5 DB-25 male connector DB-25 female connector Ports and Connectors • Parallel port • Connects devices that can transfer more than one bit at a time, such as a printer, scanner Topic 3 - System Unit

38. It has “hot swap” features – you don’t have to reboot the system USB is plug and play -attaching devices without having to reconfigure or load device drivers Ports and Connectors • USB (universal serial bus) port Scanners, printers, mouse, digital camera, keyboards can be connected to USB port Topic 3 - System Unit

39. Ports and Connectors • FireWire ports • High-speed serial bus created by Apple • Previously known as IEEE 1394 port • Commonly used to connect digital video devices - digital cameras, DVD drives, digital video cameras & etc • Support Plug and Play Topic 3 - System Unit

40. Ports and Connectors • Ethernet ports • Also known as RJ-45 jack • To connect computer to a LAN Topic 3 - System Unit

41. Ports and Connectors • IrDA ports • Developed by Infrared Data Association - transmitting data • Allows you to transmit data using infrared light waves • Requires line of sight transmission Topic 3 - System Unit

42. Ports and Connectors • Bluetooth ports • Uses radio waves to transmit data wirelessly over short distance • Doesn’t require line of sight transmission Topic 3 - System Unit

43. Ports and Connectors • MIDI (Musical Instrument Digital Interface) ports • Allows you to connect electrical musical instruments to the computer Topic 3 - System Unit

44. Ports and Connectors • SCSI (Small Computer Systems Interface) ports • It is a high-speed parallel port attached to SCSI devices - hard drives, tape drives or disk drives Topic 3 - System Unit

45. Ports and Connectors New ports are replacing traditional port Topic 3 - System Unit

46. That's all for topic 3.... thank you Topic 3 - System Unit