Quiz on Ch.4 is at the end
of Ch.4 slides
1
Chapter 5
Computing Components
Yet another
layer of
abstraction!
Components
Circuits
Gates
Transistors
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
3
Chapter Goals
• Describe how computer memory is organized
and accessed
• Name and describe different auxiliary storage
devices
• Define three alternative parallel computer
configurations
4
5.1 Individual Computer
Components
Consider the following ad:
Insatavialion 640 Laptop
Exceptional Performance and Portability
5
It’s just a madeup example!
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
Be patient!
You don't know
• 14.8”W X 1.2”H X10.1” D, 5.6 lbs.
them now,
but you will get
used to them.
6
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
7
Multipliers
What is a hertz?
8
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
9
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
10
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
11
5.2 Stored-Program Concept
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)
12
Memory
Cells can be bits, nibbles, bytes, words
Memory
A collection of cells,
each with a unique
physical address
Both addresses and
contents are in
binary
Memory
Addressability
Is the # of bits in each cell
addressable location
What is the addressability
of 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
The information in them can be processed in
one CLK cycle (i.e. fast)
15
Input/Output Units
Input Unit
A device through which data and programs from
the outside world are entered into the computer;
Can you name three?
Output unit
A device through which results stored in the
computer memory are made available to the
outside world
Can you name two?
16
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
17
Flow of Information
Bus = A set of wires that connect all major units
in a computer
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)
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The Fetch-Execute Cycle
Fetch the next instruction
Decode the instruction
Get data (if needed)
Execute the instruction
Remember: both
instructions and
data are stored in
the same
memory!
Why is it called a cycle?
19
The Fetch-Execute Cycle
According to the CPU’s
machine language
20
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
21
RAM and ROM
Random 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?
23
Secondary Storage Devices
Why is it necessary to have them?
• Saving data when computer is off
• Volume …
– “Mass storage”
• Portability …
• Reliability (backups) …
• Modularity (add as you go) …
24
Magnetic Tape
The first truly mass
auxiliary storage device
was the magnetic tape
drive
Tape drives have a
major problem; can
you 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)
27
Magnetic Disks - Removable
History
Floppy disks (Why "floppy"?)
Year of invention:
1969 (8-inch)
1976 (5¼-inch)
1982 (3½-inch)
1.44 MB
28
Magnetic Disks - Removable
Zip drives
• Iomega, 1994
• 100 MB, 250 MB, 750 MB
29
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
31
Flash memory
• Nonvolatile
• Can be erased and rewritten
– But there’s a rub: Flash Endurance
• No moving parts!
Thumb drives
Solid State Drives (SSD)
32
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
35
5.3 Non-von Neumann
architectures
36
Synchronous processing
One approach to parallelism is to have multiple processors apply
the same program to multiple data sets
Figure 5.7 Processors in a synchronous computing environment
37
Pipelining
Arranges processors in tandem, where each
processor contributes one part to an overall
computation
Figure 5.8 Processors in a pipeline
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Independent Processing
with Shared Memory
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?
40
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 following
data 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?
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)
48
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?
49
Homework
Due 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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