homework_3_参考答案

Exercise 2

Question 2. Computer Purchase

Let us assume that you are purchasing a new computer for a specific usage. You need to choose a computer from various available configurations.

Listed below are four different usage cases of a computer (a-d). For each usage case, identify components of the computer configuration that are most important to consider. Explain your answers.

Components to be considered include (but are not limited to): ?Monitor size/resolution

?Graphics card/video card

?Storage devices (for example, DVD-ROM)

?Memory (RAM, cache, and hard disk)

?Disk controller interfaces (ATA, EIDE)

For example, if a computer were to be used for viewing movies, a DVD-ROM drive is needed since movies are available as CDs and now increasingly as DVDs. A l arge monitor (about 19”) that supports high resolutions and a video card will also be necessary to enjoy the movie.

a. Simultaneously running a number of programs

Large capacity memory (at least 1G ) is needed to stores data and instructions needed to execute programs when a number of programs run. In order to resolve this question, we should select the appropriate processor.T he Intel? Core? Duo processor with its two execution cores is optimized for

multi-threaded applications and multitasking. You can simultaneously run multiple demanding applications, such as 3-D games or serious scientific research programs, while downloading files or running

virus-scanning security programs in the background.

b. Running a speed-critical application

Considering system running speed: AMD processor is typically with less cost, sometimes even faster than Intel's products.

So the AMD Opteron? processor is needed. The AMD Opteron processors with Direct Connect Architecture and HyperTransport? Technology deliver leading-edge 32-bit performance today and enable you to transition to 64-bit computing at your own pace, without sacrificing your x86 technology investment.

A mother board with high speed front side bus is needed

c. Storing and retrieving huge volumes of data

A large storage hard disk is needed (at least 800G) to store huge volumes of data, at the same time, we should foresee the demand of it.

A DVD-RW is needed when you want to store your huge volumes of data in DVD-ROM.

A motherboard with EIDE interface can accommodate a total of four devices, maybe you will get up to

2 hard disk or more.

d. Purchasing a basic configuration, to be upgraded later as needed

For upgrading your system, you must set your system has ability of upgrade and extended. So one good motherboard is needed.

The Intel? Desktop Board D975XBX is designed to deliver the best experience for advance d gamers and power-users. Based on the Intel? 975X Express Chipset and Intel? Pentium? processor Extreme Edition, this board has the best performance and the ability of upgraded. The Intel? Desktop Board

D975XBX supports Intel? Viiv? technology, and comes with the software required to help meet Intel?

Viiv? technology brand verification requirements.

Question 3. Laptop Computer Selection

You are a new graduate student enrolling in a Masters in Information Technology program. The department requires you to have a computer with the following requirements:

?512 MB of RAM

?20 GB hard drive

?CD-ROM drive

?Wireless connection

?Ethernet network card

?Windows XP Professional version

Your school has wireless connection, and Ethernet jacks. However, some classes are three hours long, and your AC adapter may not be long enough to reach an outlet. You also would be carrying this computer around from class to class.

The most you can spend is US$1200.

Indicate the range of values you desire for each of the following criteria: a. Weight

b. Screen size

c. Number of USB ports

d. Number of Firewire ports

e. Need CD-RW?

f. Need DVD-ROM?

g. Need DVD-RW?

h. Manufacturer preferences?

i. Search the Internet for two suitable computers meeting the above requirements and your budget constraint. Submit screenshots of the Web pages detailing the computer configuration and price.

j. Record your search results in a MS Excel spreadsheet. Fill column A with the following category labels:

1. Manufacturer

2. Processor

3. Memory (maximum upgrade capacity)

4. Screen size

5. Weight

6. Graphics card

7. USB

8. Firewire

9. CD-ROM

10. DVD-ROM

11. Communications (e.g. wireless, Ethernet)

12. Battery life

13. Price

14. Available Rebate

Save and submit your Excel file.

k. Make your final purchase decision and justify your decision.

Unit 1 and Unit 2 Review Materials

2. Binary

a.Define bit.

b.Define byte.

c.Fill in the following chart, listing the prefixes used for

the amount of bytes shown:

d.Fill in the following chart, converting binary numbers to

decimal and decimal numbers to binary:

(Note:The numbers that appear in the table below will differ

on an exam from the numbers that appear on the exam's review sheet.)

e.Although in sales literature 1000 bytes and 1024 bytes are

both commonly referred to as a kilobyte, in computing the only correct number of bytes in a kilobyte is1024. Explain why 1024 is correct. Many quantities in binary computers are restricted to powers of 2, and 210 is 1024, which is so close to 1000 that kilo is used informally.

f.How can the difference in measuring bytes presented in part

e impact a consumer when they are purchasing a hard disk drive?

A hard disk drive is typically measured traditionally, in powers of 10. Therefore

a gigabyte in a hard disk is 109, not the larger 230. Not knowing this, a

consumer might be surprised that the disk capacity was less than he thought was advertised.

3. Component Identification

Choose among the following components to label the image: Motherboard

Power supply

BIOS ROM Chip

Cooling fan

Expansion slot

RAM chip

Expansion card

Disk drives

Chipset

IDE cable

Ethernet cable

PCI bus

a)Label A is _ Power supply ____.

b)Label B is __ Cooling fan ___.

c)Label C is _ Expansion slot____.

d)Label D is _ Expansion card____.

e)Label E is _ Motherboard____.

f)Label F is __ Disk drives ___.

g)Label G is __ IDE cable ___.

Describe the functionality of each of the following

components (in 2 sentences or less):

h)Microprocessor: Processes instructions stored in main memory

i)RAM: Stores data and instructions temporarily.

j)Bus: Pathway through which data is transferred from one part of a computer to another

k)Expansion card: Enables a computer to control peripheral devices such as the monitor and the microphone

l)Disk drive: Stores data permanently (even after the computer is turned off).

m)IDE cable: Transfers data from storage devices to the motherboard

8. I/O

a.Define I/O device. An I/O device, or input/output device, provides the user

with ways of giving the processor data to process and ways of receiving

processed data

b.Consider that a computer requires I/O devices to be able to

interact with its environment. Explain why it is necessary

for computers to have these devices. The basic definition of a

computer includes input and output. These devices are necessary for the

computer to exist. Differing I/O devices allow alternate input and output, but

minimally the computer needs at least one of each

c.Give four examples of I/O devices. [Choose from] Keyboard; monitor;

tape backup drive; scanner; microphone; speakers; CD writer; …

d.For each I/O device in your answer to part c, explain the

device's function from the perspective of a user.

i.A keyboard provides data to a computer, to direct its behavior or supply

information for processing (name, address telephone number).

ii.A monitor displays to the user the status and results of work performed by the computer.

iii.A tape backup drive receives a copy of information stored on hard disk drives, and can later supply information to be stored on that hard disk drive

in case the disk drive crashes or a file is accidentally deleted.

iv.A scanner translates a picture or document to a bitmap image that can be processed by a computer, or included in other work like a web page or

Word document

v.A microphone translates speech or music into digital from that can be processed by the computer.

12. Picture Quality

a.Explain resolution, with respect to a monitor.

Number of pixels on the screen

b.List two typical monitor resolutions.

1024x768, as an example.

640x480, as an example.

c.Explain color depth, with respect to a monitor.

Maximum number of colors on the screen at one time.

d.List two typical monitor color depths.

16 bit, as an example.

24 bit, as an example.

e.Consider that the higher the resolution and the higher the

color depth, the more system resources are required to

display output on the monitor.

https://www.360docs.net/doc/2317108315.html,e the resolutions from part b and the color depths

from part d to calculate the amount of RAM required to

display the image. 1024x768x24/8=2.25MB, as an example.

ii.Explain the calculation you made in part e.i in a way

that confirms the statement made at the beginning of

part e—that "the higher the resolution and the higher

the color depth, the more system resources are required

to display output on the monitor." The calculations in part

E.i demonstrate that by increasing either the resolution or the color depth

that the amount of memory required will increase, demonstrating that

more system resources (RAM) are required.

13. Port Identification

Consider the following devices:

Mouse

Printer

Keyboard

Modem

Speaker

Digital camera

Ethernet jack

Monitor

For the following questions, indicate which device(s) should be plugged in which port(s) A-H shown in the diagram below.

f.What device(s) can be plugged into port A? Keyboard or mouse

i.What is the name of this port? PS/2 port

ii.Is this a serial port or parallel port? Serial

g.What device(s) can be plugged into port B? Digital camera, keyboard,

mouse, printer, external storage, network adapter, etc

i.What is the name of this port? USB port

ii.Is this a serial port or parallel port? Serial

h.What device(s) can be plugged into port C? Modem or mouse

i.What is the name of this port? DB-9 (serial) port

ii.Is this a serial port or parallel port? Serial

i.What device(s) can be plugged into port D? Printer

i.What is the name of this port? Parallel (printer) port

ii.Is this a serial port or parallel port? Parallel

j.What device(s) can be plugged into port E? Speaker

k.What device(s) can be plugged into port F? Monitor

l.What device(s) can be plugged into port G? Phone line

m.What device(s) can be plugged into port H? Ethernet network