Transcript COMP 1017 session 1 S1 2005

COMP 1017
Digital Technologies
Session 1
What is a computer?
• In small groups
• Four attributes of a computer
– What is it?
– What does it do?
• 5 minutes
Are these computers?
•
•
•
•
•
Abacus
Stonehenge
Pocket calculator
VCR
Microphone
•
•
•
•
•
Typewriter
Bathroom scales
Car speedometer
Thermostat
A person
History of Computing (Origins)
•
•
•
•
3400 BC: counting in tens (Egypt)
2600 BC: Abacus (China)
1900-1600 BC: Stonehenge completed
260 BC: base-20 counting – including
zero (Maya – Central America)
Abacus
from http://www.tased.edu.au/schools/rokebyh/curric/infotech/stage1/assign2/pre20th.htm
Stonehenge
from http://www.astro.virginia.edu/class/courses.html
History of Computing (Europe
and Britain become important)
• 967 AD: Zero in the eastern hemisphere
(Muhammad Bin Ahmad)
• Around 1500: Design of mechanical
calculator (Leonardo da Vinci)
• 1614: Logarithms (John Napier)
• 1621: Slide rule (Edmund Gunter,
William Oughtred)
Slide rules
from http://osaki.cool.ne.jp/other/other/sliderule/sliderule.html
History of Computing
(Europeans – then Britain again)
• 1642: Adding machine (Blaise Pascal)
• 1679: Binary arithmetic (Gottfried
Leibnitz)
• 1820s and 1830s: Charles Babbage’s
Difference Engine and Analytical Engine
Babbage
from http://w1.131.telia.com/~u13101111/merschwib.html
Britain again (hooray!)
• 1843: The idea of
Computer
Programming
(Ada Lovelace
(Byron))
Image from http://www.adahome.com/Ammo/Gallery.html
More British Innovation
• 1904: Vacuum
tubes (birth of
electronics) (John
Fleming)
Image from http://www.wa3key.com/tubes.html
The Second World War
• 1936: Programmable
computer constructed
(Konrad Zuse)
• 1947: Transistors (John
Bardeen, Walter Brattain &
William Shockley)
Image from http://www.interq.or.jp/japan/se-inoue/e_transist.htm
US Corporations Take Over
• 1960: First minicomputer, the PDP-1
(Program, Data, Processor)
• 1971:Floppy disks (IBM: Alan Shugart et
al.)
• 1981: IBM PC launched
• 1989: World Wide Web founded at
CERN (Sir Tim Berners-Lee) (Brit)
Digital
(see later for more detail)
• use state to represent data
i.e. on or off
• e.g. the presence of an electric voltage
0 volts = off, 5 volts = on
• binary
Digits
from http://www.dribbleglass.com/Toes/uglytoes-2.htm
Digital multimeter
from http://www.universalradio.com/catalog/fm_txvrs/03850208.ht
ml
Analogue
• Uses physical entities to represent data
• e.g. the size of an electric voltage, the
frequency of a signal, etc.
Analogue
multimeter
from http://www.kpsec.freeuk.com/
multimtr.htm
Digital v. Analogue
• No fuzziness in digital
– exact value
• No fractions in digital
– precision of value limited to last digit
• Electronics easier with digital
Precision is important
• Computers are incredibly stupid and
gullible. (Pete Moody’s First Law of
Computing)
• A computer will do what you tell it to do,
but that may be very different from what
you had in mind. (Joseph Weizenbaum)
Information
• What is the difference between Data
and Information?
?
Measures of data
• A bit is a binary 1 or a zero
• A byte is the amount of data that stores
one character
“A” or “+” or “” or “@”
(Usually 8 bits nowadays)
• 1 kilobyte is (roughly) 1000 characters
Actually 1024 = 210 characters
Jargon
• 210 bits = 1024 bits = 1kbit
• 220 bits = 1048576 bits = 1 Mbit
• (different from normal use:
1 km = 1000 m; 1000 g = 1 kg
1 MW = 1 000 000 W)
• Also used for bytes: kbytes and Mbytes
More Measures of data
• Megabyte = one million bytes
(actually 1 048 576 = 220)
• Gigabyte = one billion bytes
(actually 1.07 x 109 = 230)
• Terabyte = one trillion bytes
(actually 1.10 x 1012 = 240)
Future Measures of Data
•
•
•
•
petabyte (250 bytes)
exabyte (260 bytes)
zettabyte (270 bytes)
yottabyte (280 bytes)
…
Hardware
• The parts of a computer that can be
picked up or touched
or thrown out of the window
Input Hardware
(see later)
• Keyboard
• Mouse
etc…
• Different designs of each
Keyboard
from http://www.iowaworkforce.org/wc/edi/edi.htm
Computer mouse
from http://company.monster.co.uk/bccuk/
Output Hardware
(see later)
• Monitor/VDU
• Printer
etc…
• Different designs of each
Computer monitor
from http://www.cheap-computers-guide.com/cheap-computer-parts.html
Computer Printer
from http://www.zylar.com/electronic-apps.html
Primary Storage
(see later)
• Electronic chips in the main computer
case
• Close to and permanently connected
(hard-wired) to the main processor
• RAM (random access memory)
• ROM (read only memory)
Computer Memory Board
from http://www.swtpc.com/mholley/Tanner64K/64K_RAM_Index.htm
Secondary storage
(see later)
• Hard disk
• Floppy disk
• CD-ROM (disc)
– Some rewritable, so not really ROMs
• Memory stick/card
• etc.
Floppy disk
from http://www.nhsia.nhs.uk/def/pages/inform/informish7/informp6.asp
Hard disk
from http://www.partition-manager.com/
Coffee mug holder
from http://www.monitortech.com/CDDrive.html
Memory card
from
http://wwwde.kodak.com/global/en/service/digCam/dc290/ownerManual/ch18.shtml
Memory Stick
from http://www.jgas.net/promos.asp
Processing
(see later)
• Motherboard
• Microprocessing chip
• Bus (connections within the main box)
Motherboard
from http://www17.tomshardware.com/motherboard/20020514/p4x333-05.html
Software
(see later)
• The components of a computer that are
not physical
Operating Systems
• Basic general ‘housekeeping’ routines
• DOS, Windows, Mac OS, Unix, Linux,
etc.
Application software
• MS-Word
(& other word processors)
• MS-Access (see COMP1008)
(& other databases)
• MS-Excel (see BUSM1115)
(& other spreadsheets)
Applications (continued)
• MS-Powerpoint
(& other presentation packages)
• Visual Basic (see COMP 1026)
(& other programming languages)
• Other program(me)s
image processing, games,
networking software…
Communications
(see later)
• Modem
• Enables sending & receiving via a
telephone line
or a radio connection
• Connection to www
Communications
• The Digital Information Superhighway
e-mail
www (internet)
• Problems:
Accuracy of information
Junk e-mail (spam)
Referencing
The Three (+1) rules of
computing
1. Computer components get smaller.
2. Computers get more powerful.
3. Computers get less expensive.
4. Computers are always changing, so a
lecturer in Information Technology is
always out of date.
Miniaturization
from
http://www.museerimouski.qc.ca/lignesdevie/english/technologie_cap.htm
The Five Types of Computer
•
•
•
•
•
Embedded
PC
Mainframe
Super
Miniature
Embedded computers
• Hard-wired into an appliance
• Calculator, car, washing machine,
microwave…
• Single application
The car computer from a Ford Ranger
from http://electronics.howstuffworks.com/car-computer1.htm
PC
• PC: Desktop/Tower, Laptop, PDA
(Personal Digital Assistant)
• Workstation: Desktop, powerful versions
of PCs.
Used for computer-aided design,
software development, scientific
modelling, etc. (see BUSM 1115)
Workstation
from http://www.more.net/about/articles/images/images/sun-workstation.jpg
Another
workstation
(for those
really addicted
to their
computer)
from
http://www.doctorhill.com.au/
Mainframe
• Large
• Need air-conditioned room or building
• Uses: Banks, Air Traffic Control,
Scientific Research, etc.
Mainframe
from http://www.host-depot.com/coubicacion.htm
Supercomputers
• Fill a building
• Used for:
– Weather Prediction
– “Star Wars” defense systems
– Finding prime numbers
– Searching for signs of Extra Terrestrial
Intelligence (SETI)
Supercomputer
from http://www.sandia.gov/ASCI/Red/
Mobile phones
Input
Output
Sound
Radio waves
Keypad presses
Screen display,
radio waves
Radio waves
Sound, screen
display
Mobile phone mountain
from http://www.communityfonebak.com/media.html
iPods
• Stores and plays music files
– Can also store other files
• Inputs: music files, input clicks
• Outputs: screen display, sound
iPod
from http://en.wikipedia.org/wiki/IPod
Xboxes and similar
• Inputs: game files, game controller
signals
• Outputs: screen, sound, (touch?)
Xbox
from http://wirelessdigest.typepad.com/games_digest/console_hardware/
PDAs
• Functionality:
– Clock
– Diary
– Address book
– Task list
– Memo pad
– Calculator
• Can by synchronised with PC
PDAs (2)
• Other functions
– Touch-sensitive screen
– Note-taking
• Small keyboard
• or stylus input with handwriting recognition
– Web browser
– Media player
PDA
from
http://www.edmunds.com/ownership/driving/articles/104848/article.html
Speed of Computers
• Gigahertz clock speed (PCs)
• MIPS (Millions of Instructions Per
Second) (mainframes)
• TERAFLOPS (thousand billion Floating
Point Operations Per Second)
(supercomputers)
Computers don’t need
tea-breaks
From http://www.j-herb.com/TEA.HTM