Computer

Hardware and software

COMPUTERS

1

Computers
ENIAC – 1950

2

What is a computer? A data processing device designed to: } input … } data (e.g. mp3 3ile) } software (e.g., iTunes)

} process data by

applying software } output results } store data / program /

results between uses Apple II – 1977
3

Computer hardware
Storage
Nonvolatile Non-portable (hard disk) Portable (e.g. CD) Battery Wall plug

RAM (Random Access Memory) Volatile

Power Source

Mouse Keyboard Tablet Input Microphone Devices Webcam Accelerometer

Central Central Processing Processing Units Units (cores) (cores)

Monitor Printer Output Plotter Devices Projector

Input

Processing Output
4

Components of a computer
} Hardware } CPU (Central Processor Unit):

} I/O devices (Input / Output) } Storage } Power source } Software } Operating System } Applications

Is it a computer?

Universal computation
} A processor with the right software can emulate

any other data processing device } E.g., a smartphone can be a music player,

translator, calculator, GPS navigator, still/video camera, etc.

} Most electronic devices contain

microprocessors } a modern car can have dozens of them } cheaper than developing new circuitry

} We call a device a computer if we can add

new programmed behaviour } If it has an app store, it’s a computer!

6

Units of Measure
Which is “bigger”?

7

Storage units (metrics)
} Basic unit of storage is the byte } 1 byte = 1 character

Example: “Hello World!” uses 12 bytes } Each byte has 8 bits (bit = binary digit) } A bit can be 0 or 1 } A byte has 256 unique patterns;

e.g. ‘W’ = 01010111

} Abbreviations: use ‘b’ for bit and ‘B’ for byte

8

Storage units
Metric
pre3ixes—base 10 1 kg = 1 kilogram = 103 g = 1000 grams 1 Mg = 1 megagram = 106 g = 1 tonne = 1 million grams 1 Gg = 1 gigagram = 109 g = 1 billion grams

Computer pre3ixes—base 2 1 KB = 1 kilobyte = 210 bytes

= 1024 bytes 1 MB = 1 megabyte = 220 bytes ~ 1 million bytes 1 GB = 1 gigabyte = 230 bytes ~ 1.1 billion bytes 1 TB = 1 terabyte = 240 bytes ~ 1.1 trillion bytes 1 PB = 1 petabyte = 250 bytes ~ 1.1 quadrillion bytes 9

10 3 = 1000⎫ ⎬ almost the same 10 2 = 1024 ⎭

Metric vs. base-2 units
} Base-‐2 units } describe storage capacity } because computers use binary addresses } Base-‐10 metric units } Processor clock speed is in gigahertz (GHz) } Network bandwidth is in megabits per second (Mbps) } Course rule: always use base-‐10 units } any error will be 10% or less 10

Exercise
} A computer with a 500 GB hard drive has: } operating system (36 GB) } applications (5500 MB) } 10 TV shows (~350 MB each) } 600 mp3 3iles (~5 MB each) } 20 term papers (~ 350 KB each) } 10 presentations (~ 600 KB each) } 450 digital pictures at 2 MB each } 1 high-‐def digital video (1 GB) } Approximately what percentage of the drive space is

now used?

11

Computer Hardware
Storage

12

Non-volatile storage
Non-‐volatile
storage on a personal computer: } Internal hard drive for programs and data

—could be a 3lash-‐based solid state disk (SSD) } Optical drive to load software (e.g., games) and

media (such as music, movies) } A USB (Universal Serial Bus) Hlash drive to

backup and transfer 3iles } USB-‐connected external hard drive for periodic

automatic backups

13

Storage media: hard disk
} Most common medium } A hard disk is only for

spinning platters

storage, like a Hiling cabinet; data must be in RAM when used } Magnetic coating on

disks (platters) that rotate past movable read/write heads (one per platter)

read/write heads
14

http://www.youtube.com/watch?v=9eMWG3fwiEU

Storage capacity
Hard
disk storage capacity is determined by: } Diameter } 3.5-‐inch desktop drives store up to 3 TB } 2.5-‐inch laptop drives store half as much } smaller drives are being replaced by 3lash RAM

} Data density } has increased exponentially for 25 years } 1st PC hard drive stored 10 MB on a 5.25-‐inch drive

15

Hard disk speed
} Access time: it takes 5+ milliseconds to access a

random entry on your drive } 1 million times slower than fastest RAM } almost unchanged for 20 years } depends on the rotation speed of the disk } causes noticeable delays

} Transfer rate: up to 300 MB per second } has improved in lockstep with data density } affects boot speed and program loading 16

Storage media: optical disks
Optical
disk characteristics } non-‐volatile } removable } read with tiny lasers

} also written with lasers in a computer drive

} commercial disks are stamped in a press } data stored in little pits on the surface } used for distributing software, music and movies http://commons.wikimedia.org/wiki/File:CDRomPits.jpg
17

Optical disk types
} CD (Compact Disk) } music CDs store about 70 minutes of music } CD-‐ROM (Read Only Memory): 700 MB of data } Canadian government puts levy on blank media

} DVD and Blu-‐ray } no levy on blank media

} DVD (Digital Video/Versatile Disk)

max 4.7 GB per layer per side } Blu-‐ray (www.blu-ray.com) 25 GB per layer per side 18

Storage: flash memory
USB connector Flash memory

} Flash memory is solid state—no moving parts } Advantages when compared to disks: } reliable: fewer mechanical failures } tiny: much smaller than comparable hard drive } portable: tiny drives attach to USB port } faster access: than hard drive

} Disadvantages: } more expensive per byte than hard disk 19

Flash memory packaging
} Memory Cards } For cell phones, cameras, handheld computers, etc. } Your computer may have a port to read these cards } USB Flash Drive } All-‐in-‐one package: 3lash memory + USB connector } SSD: Solid State Drive } Replaces a hard disk All images ©SanDisk Corporation http://www.sandisk.com
20
20

Computer Hardware
CPU

21

CPU (Central Processing Unit)
} “Brain of the computer” executes instructions } Internal clock sets the speed of the processor } Speeds of 2 or 3 GHz are common today } Most instructions take 1 clock cycle } 3-‐GHz CPU: up to 3 billion instructions/second } Hyper-‐Threading allows some instructions to run at

the same time, speeding up execution even more © Intel Corporation http://www.intel.com

22

CPU (2)
} Intel x86 line of CPUs—in PCs since1980 } grew vastly in size, speed, and complexity while retaining backward compatibility } advanced versions have billions of transistors

} AMD makes compatible processors } Intel’s chief competitor } Cell phones use slower, low power processors } often based on designs by ARM 23

CPU: Moore’s Law
} 1965 prediction by Gordon Moore } In today’s words:

The number of transistors on a computer or memory chip for a given cost will double every two years. } stopped doubling in 2003

Gordon E. Moore, Co-founder, Intel Corporation.

} For decades, computer speed doubled too

http://www.intel.com/technology/mooreslaw/
24

CPU: Moore’s Law

Transistor counts keep rising

Clock speed levels off Note the logarithmic vertical scale

25

CPU : Multi-core processors
} Until 2003, faster clocks sped up all software } After 2003, many cores sped up some software } Dual core processors (e.g., Intel Core i3) } Quad core processors (e.g., Intel Core i7) } 6-‐core processors (e.g., AMD Phenom II X6) } 8-‐core processors (e.g., Intel 8-‐core Xeon) } 12-‐core processors (e.g., AMD 12-‐core Opteron)

} Most desktop applications use just one core } So to compete, vendors have reduced computer

prices instead of maximizing cores 26

Computer Hardware
RAM

27

RAM (Random Access Memory)
} RAM comes in chip form } memory modules plug into motherboard } purely solid state—no mechanical parts } very fast read/write access time } volatile: needs continual power

} 32-‐bit CPUs can address a maximum of 4 GB } We are in a transition to 64-‐bit CPUs 1 GB memory module
28

RAM: What does it do?
} RAM is like the CPU’s workbench } It contains instructions and data of active applications } Random means the CPU can access data in any

order

} Increase your RAM for better performance } Data too big for RAM is swapped out to disk } Getting it back causes noticeable delays

31

Exercise:
Write each letter from the right column beside every related term in the left column.
} } } } } } } }

Processor RAM Hard Disk Term paper DVD mp3 3ile CD-‐ROM Flash drive

______ ______ ______ ______ ______ ______ ______ ______

250 KB 500 gigabytes non-‐volatile 2 GB 4.7 GB “workbench” Core i3 1 Gig 3 GHz J. 5 Megs K. 700 MB A. B. C. D. E. F. G. H. I.
30

Computer Software

University of Manitoba 2005-Jul-11 picture from Google Earth
31

Computer software
} Software: computer programs that tell a

computer how to perform different tasks } Software categories: } Application Software programs to do speci3ic tasks, e.g. word processing, sending e-‐mail, editing photos, etc. } Operating System (OS) software to manage a computer, e.g. Windows 7 or OS X 32

Application software
} Perform speci3ic tasks with this software } write a term paper, analyze an experiment, edit photos, chat with your friends, ... } distributed often as a downloadable package

containing machine language executables that the OS installs on disk and then loads into RAM when the application starts running

36

Computer platforms
} How are application programs created? } Programmers write source code (e.g., in C++) } Software tools convert it into machine language } Each CPU type has its own machine language } Each OS has its own commands (e.g., to open a new window) } Platform = CPU + OS } e.g. Wintel = Windows OS + Intel CPU; Mactel? } Applications are platform speciHic 34

Operating systems
An
OS manages resources applications need } starts applications running } allocates resources like RAM } reclaims resources when applications quit } helps them to access devices like printers

} makes windows, icons, menus etc. work } stores/retrieves Hiles } implements network protocols } conserves energy (screensaver, hibernation) 35

Operating systems (2)
Application Software Operating System System Hardware (mouse, CPU, disk, network, …) Users near and far

A computer cannot work without an operating system 36

OS categories: Number of users
Number
of people who use the computer at a time } One user, in direct contact with the computer } iOS5 on iPhone } Mac OS X or Windows 7 on a laptop

} Many users, usually networked to the computer } web server app running on Windows Server } z/OS on an insurance company’s IBM mainframe } a Google computer centre with over 100,000 rack-‐

mounted PC servers running Linux

37

OS categories: Number of tasks
Number
of application tasks run at once } Single task on a resource-‐limited device } makes you close a document to look up an address

or check your e-‐mail } e.g., original MS-‐DOS, Wii game console

} Multitasking—can download a 3ile, or update e-‐

mail while you edit a document } Mac OS X, Windows } high end Android cell phones } UNIX, Linux

38

OS categories: User interface
Two
kinds of user interface } Command Line Interface (CLI) } user types all commands from memory } easy on computer but hard on user } e.g., Google search (what does ~planet mean?)

} Graphical User Interface (GUI) } WIMP = Window + Icon + Menu + Pointing device } easy on user but hard on computer } needs big RAM and disk space 39

Command Line Interface (CLI)

40

Categorize: users, tasks, interface?
Google Datacenter c. 2006

41

Categorize?

Sony Playstation 3 with Move Controller

48

Win 7

Microsoft Windows OS
} Over 90% market share } Single user versions in diagram } Multi-‐tasking with both a GUI and

Win 2000

Vista

Win XP

Win ME

CLI (DOS)

} Multi-‐user (server) versions … } Windows Server 2003, 2008 (not

Win 98

Win NT

shown) Win 95

} some sub-‐versions of WinNT,

Win2K

Win 3.1 43

Apple Mac OS
} 5% market share Intel 2006 - ?

} popularized GUI in early 1980s—

no CLI } changed CPUs twice } became OS X around 2000 } pronounced “OS ten” } major rewrite } now a UNIX variant } UNIX gave it a CLI

44

PowerPC 1994 2006

Motorola 1984-1994

UNIX / Linux
} UNIXTM is a multi-‐user OS from the 1970s } designed for many users with terminals } 3irst had a CLI } X-‐windows GUI added in the 1980s } licensed by IBM, HP, … à many versions } used for high-‐end workstations and servers

} Linux looks and works like UNIX } it is open-‐source software (led by Linus Torvalds) } adopted by major companies, like IBM 45

Open-Source Software
} FOSS = Free and Open-‐Source Software } means you can see and change the source code } free to pass on to others on the same terms } any fee is to cover distribution or support } almost any kind of software available

} E.g., to run a Web site, use LAMP } OS: Linux } Webserver: Apache (over 50% of the market) } Database: MySQL } Scripting language: PHP or Perl or Python 46

Credits
} Slide 2: ENIAC in Philadelphia, Pennsylvania, circa 1947-‐55. U.S. Army photo commons.wikimedia.org/wiki/File:Eniac.jpg

} Slide 3: Apple II computer vernier.com/caliper/fall06/images/apple_ii_large.jpg

} Slides 5, 6: Smartphone by Cynthia Tesla srtcynthia.deviantart.com/#/d2vz9uo

} Slides 7, 12: Flash drive image © Terry Andres 2010 } Slides 7, 12, 17, 18: CD image © Terry Andres 2010 } Slides 12, 14-‐16: Image of hard drive open wdc.com/en/products/Products.asp?DriveID=810

} Slides 12, 20: Image of SanDisk 128 GB SSD ajappeandsons.com/filer/C25_3G_SSD_128GB_front-‐168271.jpg

} Slide 19: Flash RAM and USB connector © Terry Andres 2010 } Slide 20: 64 GB Ultra SDXC card sandisk.com/media/480688/Main.jpg
58

Credits (2)
} Slide 20: Ultra Backup Flash Drive sandisk.com/media/6958/ultrabkpflashdrive.jpg

} Slide 20: Ultra MemoryStick Pro sandisk.com/media/358530/pro-‐hg_duo32_productimage.jpg

} Slides 21-‐23: Three views of Intel Core i7 software.intel.com/file/20376 } Slide 24: Gordon E. Moore, Co-‐founder, Intel Corporation developer.intel.com/pressroom/kits/events/moores_law_40th/index.htm or tinyurl.com/3xb96ev

} Slide 25: Moore’s Law chart

www.gotw.ca/publications/concurrency-‐ddj.htm

} Slides 27-‐29: Memory module image © Terry Andres 2010 } Slide 31: Image of University of Manitoba from Google Earth © DigitalGlobe } Slide 33: Numerous icons taken as screen captures from the respective

applications

59

Credits (3)
} Slide 40: Screen capture of command prompt window in Windows XP } Slide 41: Image of Google Datacenter flickr.com/photos/65116125@N00/132421088/ kotaku.com/5490887/first-‐look-‐at-‐playstation-‐move-‐with-‐ professional-‐models-‐and-‐photoshop/gallery/gallery/1

} Slide 42: People using Sony Move Controller tinyurl.com/29g9qby or

} Slide 45: Linux logo www.linux.org/info/logos.html } Slide 47: Word document icon from Jojo Mendoza’s package called Soft

Scraps at deleket.deviantart.com/gallery/#/d2hkouy
} Slide 49: Multilevel list screen shot from Word 2010 } Slide 50: Right side of “Up arrow icon button” is a resizable image from

Microsoft online clipart; the left side has been converted to a 12x24 png 3ile } Slide 52: Screen capture of Picture Tools tab from Word 2010 on Windows 7 } Slide 57: Posner, Richard A. 2007. The Little Book of Plagiarism. Random

House of Canada Limited, Toronto. 60

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