Quiz on Ch.4 is at the end of Ch.4 slides

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Chapter 5

Computing Components

Components

Circuits

Gates

Transistors

Yet another layer of

abstraction!

Chapter Goals

• Read an ad for a computer and understand the jargon

• List the components and their function in a von Neumann machine

• Describe the fetch-decode-execute cycle of the von Neumann machine

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Chapter Goals

• Describe how computer memory is organized and accessed

• Name and describe different auxiliary storage devices

• Define three alternative parallel computer configurations

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5

5.1 Individual Computer Components

Consider the following ad:

Insatavialion 640 Laptop Exceptional Performance and Portability

It’s just a made-up example!

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Computer Components

What does all this jargon mean?• Intel® Core™ 2 Duo (2.66GHz/1066Mhz

FSB/6MB cache)

• 4GB Shared Dual Channel DDR2 at 800 MHz

• 500 GB SATA Hard Drive at 5400RPM

• 15.6” High Definition (1080p) LED Backlit

LCD Display (1366 x 768)

• 8X Slot Load DL DVD+/- RW Drive

• 14.8”W X 1.2”H X10.1” D, 5.6 lbs.

Be patient!

You don't know

them now,

but you will get

used to them.

Computer Components (cont.)

• 512 MB ATI Mobility Radeon Graphics

• 85 WHr Lithium Ion Battery

• (2) USB 2.0, HDMI, 15-Pin VGA, Ethernet 10/100/1000 IEEE 1394 Firewire, Express Card, Audio line-in, line-out, mic-in

• Microsoft® Windows 7® Professional

• Microsoft® Office Home and Student 2007

• 36-Month subscription to McAfee Security Center Anti-virus

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Multipliers

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What is a hertz?

To do in notebook for next time:

• Read the entire Section 5.1 and take notes

• Answer end-of-chapter questions 1-16, 26, 27, 28

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Decimal vs. binary multipliers

1000 = 103 1,000,000 = 106 1,000,000,000 = 109

1024 = 210 1024*1024 = 220 1024*1024*1024 = 230

Rule:

For memory capacities, the multipliers are binary, for

everything else (speed, frequency, pixels, etc.) they

are decimal

k vs. K

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Decimal vs. binary multipliers

examples

What is the meaning of:

• 500 GB hard-disk

• 54 Mbps wireless Ethernet

• 3 GB of RAM

• 8 Mega-pixel camera

• 3.2 GHz CPU

5.2 Stored-Program Concept

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The von Neumann architecture is based on two fundamental ideas:

1. Instructions and data are the same, so they are stored in the same

place (memory)

2. Information processing is different from information storage, so they

are performed in different units (CPU, memory)

Memory

MemoryA collection of cells,each with a uniquephysical addressBoth addresses andcontents are in binary

Cells can be bits, nibbles, bytes, words

Memory

Addressability

Is the # of bits in each celladdressable location

What is the addressabilityof the memory pictured?

Today, most computers’ memories are byte-addressable

Arithmetic/Logic Unit = ALU

Performs:

• basic arithmetic operations such as add, subtract, increment, decrement, change sign

• logical operations such as AND, OR, XOR, NOT

Most modern ALUs have a small amount of very fast storage units called registers

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The information in them can be processed in

one CLK cycle (i.e. fast)

Input/Output Units

Input UnitA device through which data and programs fromthe outside world are entered into the computer;

Can you name three?

Output unitA device through which results stored in thecomputer memory are made available to theoutside world

Can you name two?

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Control Unit

Control unit

It is the organizing force in the computer

Implements the fetch-execute cycle

Includes two important registers:

• Instruction register (IR) →Contains the instruction that is being executed

• Program counter (PC) → Contains the address of the next instruction to be executed

ALU + Control Unit = CPU

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Flow of Information Bus = A set of wires that connect all major units in a computer

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Data flow through a von Neumann architecture

Bus width = # of bits that can be simultaneously transferred (i.e. in parallel)

Cache (go back to laptop ad)

The Fetch-Execute Cycle

Fetch the next instruction

Decode the instruction

Get data (if needed)

Execute the instruction

Why is it called a cycle?

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Remember: both

instructions and

data are stored in

the same

memory!

The Fetch-Execute Cycle

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According to the CPU’s

machine language

We have covered pp. 125-132 in the text

To do by next class in the notebook:

Read and take notes:

• John Vincent Atanasoff bio (p.126)

Answer end-of-chapter questions

1 – 16, 24 - 28

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RAM and ROMRandom Access Memory (RAM) → each location:

• can be accessed directly

• can be changed (written) in real-time

Read Only Memory (ROM) → each location:

• can be accessed directly

• cannot be changed (written) in real-time

RAM is volatile, ROM is not

EoL 22

Secondary Storage Devices

Name a few …

Why is it necessary to have secondary storage devices?

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Secondary Storage DevicesWhy is it necessary to have them?

• Saving data when computer is off

• Volume …

– “Mass storage”

• Portability …

• Reliability (backups) …

• Modularity (add as you go) …

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Magnetic Tape

The first truly mass auxiliary storage device was the magnetic tape drive

Tape drives have amajor problem; canyou describe it?

Figure 5.4 A magnetic tape

Magnetic Disks - HDD

Tracks near center are more densely packed with information

Seek time

Time it takes for read/write head to be over right track

Latency

Time it takes for sector to be in position

Access time = Seek time + latency

Transfer rate (e.g. 100 MB/s)

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Magnetic Disks - Removable

History

Floppy disks (Why "floppy"?)

Year of invention:

1969 (8-inch)1976 (5¼-inch)1982 (3½-inch)

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1.44 MB

Magnetic Disks - Removable

Zip drives

• Iomega, 1994

• 100 MB, 250 MB, 750 MB

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Optical Disks

CD (600 MB)

A compact disk that uses a laser to read information stored optically on a plastic disk; data is evenly distributed around track

CD-ROM read-only memory

CD-DA digital audio

CD-WORM or CD-R user can write once, read many times

CD-RAM or CD-RW user can both write and read many times

DVD (4.7 GB)

Digital Versatile Disk, used for storing audio and video

DL = dual layer → 8.5 GB

Blu-Ray (25 GB)30

Optical Disks

Interesting difference between [FDD + HDD] and optical disks:

– Data on optical disks is uniformly packed

– Tracks near the center have less data than tracks near the periphery

– To ensure a uniform transfer rate, the rotation speed changes as the read/write head moves in and out

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Flash memory

• Nonvolatile

• Can be erased and rewritten– But there’s a rub: Flash Endurance

• No moving parts!

Thumb drives

Solid State Drives (SSD)

Touch Screens

Touch screen

A computer monitor that can respond to the user touching the screen with a stylus or finger

There are 4 types:

– Resistive

– Capacitive

– Infrared

– Surface acoustic wave (SAW)

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Term paper

• Read and take notes in notebook: pp.137-139

• Write a 4-page term paper, that includes a description, technical and commercial data (e.g. screen size, resolution, interfaces, price) of two touch screens of different types.

• At the end of the paper, list in a reference section the websites or webpages you used.

– The references must be referenced within the text of the paper!

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Term paper

Formatting rules:

– Font: Times New Roman size 12

– Single-line (not 1.5, 2 or Multiple!)

– Paragraphs:

• No space before or after

• No hanging lines

• OK to indent the first line

– Images: allowed 2 or 3, but keep them small

– OK to leave an empty line in between Sections

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5.3 Non-von Neumann architectures

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Synchronous processingOne approach to parallelism is to have multiple processors apply the same program to multiple data sets

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Figure 5.7 Processors in a synchronous computing environment

Pipelining

Arranges processors in tandem, where each processor contributes one part to an overall computation

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Figure 5.8 Processors in a pipeline

Independent Processingwith Shared Memory

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Communicate through shared memory

Figure 5.9 Shared memory configuration of processors

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Embedded Systems

Embedded systems

Computers that are dedicated to perform

a narrow range of functions as part of a

larger system

Empty your pockets or backpacks.

How many embedded systems do you

have?

Ch. 5 - Synthesis –Data transfer rates

What is a data transfer rate?

“data rate” → units of data / units of time– bps (kbps, Mbps etc.)

– Bps (B/s, kBps, MB/s etc.)

– Blocks per second

– Characters per minute

– Pages per hour

– Frames per second (fps)

– 1x, 2x, 8x (optical disk read/write speeds)

“transfer” → The data must travel from one place to another

The data transfer rates mentioned in the text

• p.121 → “…the hard drive can transfer data at

a rate of 100MB per second”

• p.122 → “…the modem is capable of

processing 56,000 bits per second”

• p.133 → “…we talk about hard disk transfer

rates using megabytes per second and floppy

disk transfer rates using kilobytes per second”

Why aren’t the followingdata transfer rates?

• 3.2 GHz

• 400 MHz

• 7200 rpm

• 80 GB, 512 MB, 1.44 MB, 600 MB

• 0.28 mm (dot pitch)

• 1 Peta-FLOPS (FLoating-point OPerations per Second)

1015

How to convert ppm to bps

Is ppm a data transfer rate?

22 ppm = 22 x pages / min =

22 x 3297 characters / 60 s =

1208.9* characters / s =

1208.9 x 8** bits / s =

9671.2 bps ≈ 9.6 kbps

* Book Production Procedures for Today's Technology, by Fred Dahl, p.21

** Assuming that characters are represented in Extended ASCII code

Who am I?

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A law suit determined

my legacy.

What was it all about?

There’s a new book about me:

And here’s my rival from Germany: Konrad Zuse

(http://inventors.about.com/library/weekly/aa050298.htm)

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To do in notebook: read and take notes Ethical Issues

Computer Hoaxes and Scams:

What is the principal difference between a hoax and a scam?

What are the most common complaints of Internet users about computer scams and

hoaxes?

What are the most serious crimes perpetrated on the Web?

Why is it so difficult to police these schemes?

HomeworkDue Wednesday, Oct 27 :

End of chapter exercises

37, 38, 46, 47, 48, 49, 63, 64, 65, 66

Thought Questions 1, 3

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