Chapter 3 Hardware and Software

• 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 computers 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