How Computers Work

1. How Computers Work

2. You Will Learn… • That a computer requires both hardware and software to work • About the many different hardware components inside and connected to a computer • How the CPU works and how it communicates with other devices

3. Hardware Needs Softwareto Work • Hardware • Physical components of the computer (monitor, keyboard, memory chips, hard drive) • Software • Set of instructions that directs hardware to accomplish a task

4. Functions of the Microcomputer

5. Binary Number System • Technology of storing and reading only two values: on and off • Bits and bytes • Originated in the 1940s by John Atanasoff

6. Binary Number System

7. Binary Number System

8. PC Hardware Components • Input/output devices: outside computer case • Processing and storage components: inside the case • Elements required by hardware devices to operate: • Method for CPU to communicate with it • Software to instruct and control it • Electricity to power it

9. Hardware Used forInput and Output • Connects to computer case by ports • Most popular input devices: • Keyboard • Mouse • Most popular output devices: • Monitor • Printer

10. Ports

11. Input Devices

12. Output Devices

13. Hardware Inside the Case • Motherboard (contains CPU, memory, etc.) • Floppy drive, hard drive, and CD-ROM drive (permanent storage) • Power supply with cords supplying electricity to all devices inside the case continued…

14. Hardware Inside the Case • Circuit boards (used by CPU to communicate with devices inside/outside the case) • Contain microchips, which are most often manufactured using CMOS (complementary metal-oxide semiconductor) technology • Cables that connect devices to circuit boards and the motherboard • Data cables • Power cables (or power cords)

15. Peripheral Devices • Communicate with CPU but are not located directly on the motherboard • Some are linked by expansion cards in expansion slots on the motherboard

17. The Motherboard • Largest, most important circuit board in the computer • Contains the CPU, with which all devices must communicate: • Installed directly on the motherboard • Linked by a cable connected to a port on the motherboard • Indirectly linked by expansion cards • Also called the main board or system board

18. The Motherboard

19. Ports on a Motherboard

20. For processing: CPU Chip set For temporary storage: RAM Cache memory Electrical system: Power supply connections For communication with other devices: Traces Expansion slots System clock Programming and setup data: Flash ROM CMOS setup chip Major Components on All Motherboards

21. The CPU • Most important chip (the microprocessor) • Performs most of actual data processing

22. The Chip Set • Controls flow of data and instructions to and from the CPU • Provides careful timing of activities

23. The Chip Set

24. CPU and Chip Set Manufacturers • IBM-compatible PCs • Intel Corporation • AMD • VIA • SiS • Cyrix • Macintosh (Apple Computer, Inc.) • Motorola Corporation

25. Temporary (primary storage, or memory) Temporarily holds data and instructions while processing them Faster to access than permanent storage Permanent (secondary storage) Data and instructions must be copied into primary storage (RAM) for processing Storage Devices

26. Primary and Secondary Storage

27. Primary Storage Devices • Memory, or RAM, located on motherboard and other circuit boards • Volatile versus nonvolatile (or ROM) memory • Common types of boards that hold memory chips • SIMMs (single inline memory modules) • DIMMs (dual inline memory modules) • RIMMs (memory modules manufactured by Rambus, Inc.)

28. RAM Chips

29. Types of RAM Modules

30. Secondary Storage Devices • Hard disks • Floppy disks • Zip drives • CD-ROMs • DVDs

31. Hard Drive • Uses EIDE (Enhanced Integrated Drive Electronics) technology • Motherboard can accommodate up to four IDE devices on one system • IDE provides two connectors on a motherboard for two data cables

32. Motherboard with Connectors

33. A Typical System

35. Hard Drive’s Power Supply

36. Floppy Drive Cable

37. Floppy Drive Connection

38. CD-ROM Drive

39. Motherboard Components Used for Communication Among Devices • The bus • System of pathways used for communication and the protocol and methods used for transmission • Includes a data bus, address bus, and control bus

40. Bus Lines

41. Data Bus

42. System Clock • Synchronizes activity on the motherboard • Sends continuous pulses over the bus that are used by different components to control the pace of activity • Frequency of activity is measured in MHz,or 1 million cycles per second

43. System Clock

44. Bus Lines • Lines of a bus, including data, instruction, and power lines, often extend to the expansion slots • Types of expansion slots • PCI (Peripheral Component Interconnect) • For high-speed input/output devices) • AGP (Accelerated Graphics Port) • For a video card • ISA (Industry Standard Architecture) • Used by older and/or slower devices)

45. Bus Lines

46. Types of Expansion Slots

47. Interface (Expansion) Cards • Enable CPU to connect to external device or to a network

48. Interface (Expansion) Cards

50. Full View of a Video Card