1. Chapter 3 Hardware and Software

2. Purpose To be an intelligent consumer of hardware products To ask intelligent question –What is it? –How can I use it? –Is it the best choice?

3. Agenda Computer Hardware Computer Data and Instruction CPU (Central Processing Unit) and Memory Computer Performance Software Computer Virus Discussion and Case Study

4. Computer Components: hardware and software Hardware: electronic components and related gadgetry that input, process, output, and store data according to software Software: instructions encoded in computer programs Types: general purpose (desk top) and special purpose (cell phone)

5. Hardware - I Input – keyboard, mouse, document scanner, bar-code scanner, microphone, etc. Processing –Central processing unit (CPU) –CPU selects instructions, processes them, performs arithmetic and logical comparisons, and stores results of operations in memory –CPU is vary in speed, function, and cost –Special function cards to augment basic capabilities (video display card)

6. Hardware - II Output –video displays, printers, audio speakers, overhead projectors, etc. Storage –Save data and program –Magnetic disk, optical disk (CD, DVD), magnetic tape Communication –Wire, bus, etc.

7. Figure 3-9 Magnetic Disk Components

8. Magnetic Disk Long-term and nonvolatile data storage Performance depends on type and size Recording data on magnetic disk in concentric circles Read/write head Data transfer speed –Rotational delay –Seek time –Width and speed of the channel

9. Optical Disk Type –CD (compact disk) –DVD (digital versatile disk) –The differences are their capacity and speed Burning a pit into the photosensitive material using a low-power laser to represent data –The presence of a pit causes light to reflect and signifies a one –The absence of reflection signifies a zero Usage –Playing music and video –Nonvolatile

10. Video Display Type –CRT (cathode ray tubes) –LCD (liquid crystal display) Illuminating small spots on the screen called pixels to display image CRT monitor –The dot pitch: the distance between pixels on the screen –The smaller the dot pitch, the sharper and brighter the screen image LCD monitor –The pixel pitch: the distance between pixels on the screen –The smaller the pixel pitch, the sharper and brighter the image will be Optimal resolution –The size of the screen, the dot or pixel pitch, etc.

11. Input, Process, Output, and Storage Hardware

12. Computer Data and Instruction - I Binary digits (bits) –Zero or one –Closed or open of a switch –Orientation of a magnetic field –Light reflection of a optical media –Represent data and instruction Byte: 8-bit –Numbers, characters, currency amounts, photos, recordings, or whatever

13. Bits Are Easy to Represent Physically

14. Important Storage-Capacity Terminology

15. Computer Data and Instruction - II Instruction set: a collection of instructions for directing computer process –Microsoft Windows: Intel instruction set by Intel Corporation –Macintosh computers: PowerPC instruction set using Powerful PC processor –Macintosh computers: either Intel or PowerPC processor starting 2006

16. CPU and Memory - I Motherboard: a circuit board mounted and/or connected with processing components Main memory –RAM (random access memory) –Volatile –A set of cells holding bytes of data or instruction –Each cell has a address for identification –Speed and amount –House OS, application programs, and data

17. CPU and Memory - II Cache memory –Very fast and expensive memory to improve overall throughput of the CPU –Stores frequently used data, intermediate results, and the most frequently used computer instructions CPU reads instructions and data from main memory and writes data to main memory via a data channel (bus) CPU speed –Cycles per second, or hertz (3.0 gigahertz or 3.0 GHz or 3 billion cycles per second) Data transfer speed –The speed of main memory –The speed and width of the data bus –The wider the bus (by no. of bits), the more data transferring

18. Computer Performance Memory swapping –A request to the operating system to store data in RAM and there is not enough free memory to store the requested data –The operating system has to remove something to make space –Slow down the performance Adding more main memory to substantially improve the computer performance

19. Software Operating system (OS) Application software

20. Operating System Types –Windows for business users –Mac OS for arts community –Unix for scientific and engineering community –Linux developed by open-source community for web servers Own versus License issue

21. Application Software In terms of source –Off-the-shelf –Custom software in house or consultant Difficulty and risky In terms of capability –Horizontal-market application software for all organization and industry –Vertical-market application software for specific industry Firmware –Software installed into the device –Print server, communication devices, etc.

22. Computer Virus A computer program that replicates itself, consumes the computer’s resources, take unwanted and harmful actions Payload: the program code causing unwanted activity Type –Trojan horse –Macro virus –Worm Prevention –Download –Email –File extension –Antivirus –OS patch

23. Discussion Security (53a-b) –How to enforce employees to follow the antivirus policy and procedure in any organization? –State your opinions related to the statement “the viruses are developed by the antivirus software vendor.” Opposing forces (57a-b) –State your opinions related to the statement “the new computer products are the conspiracy between hardware and software vendors to ripe off consumers.” Ethics (61a-b) –State your opinions about the major impacts in terms of social, entertainment, government, and business operations by implementing the TCG/NGSCB (Trusted Computing Group/Next Generation Secure Computing Base)

24. Case Study Case 3-1 not 6 and 9 (69-70) Case 3-2 only 1 and 2 (70-71)

25. Points to Remember Computer Hardware Computer Data and Instruction CPU (Central Processing Unit) and Memory Computer Performance Software Computer Virus Discussion and Case Study