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Abacus
• ~3000 B.C.• Beads for counting• Merchants used for
transactions
Pascal’s Pacaline
• 1642• Numerical wheel
calculator• Used by tax collector• 8 wheels with 10 notches• Wheel moves 10x to move
next wheel 1x• Wheels represent 1s, 10s,
100s, etc • Could only add
Leibniz’s Mechanical Multiplier
• 1694• Used gears and dials• Add and multiply
QuickTimeª and aTIFF (Uncompressed) decompressor
are needed to see this picture.
• Not until 1820 - mechanical calculator that could + - * /
Jacquard’s Loom
• 1820• Used punched cards• Controlled patterns to
be woven
Babbage’s Difference Engine
• 1822• Perform differential
equations• Powered by steam• Size of a steam engine• Could store a program• Worked on it for 10
yrs
Babbage’s Analytical Engine
• 1833• 1st general purpose
COMPUTER• 50,000 components• Size of a football field
Never constructed• Worked with Countess
of Lovelace - 1st programmer
Analytical Engine cont’d
• 4 machines:– Store (memory)
– Mill (computational unit
– Input (punch card reader
– Output - punched or printed
• The store capacity was 1000 words of 50 decimal digits used to hold variables and results.
• The mill could accept operands from the store, add, subtract, multiply or divide them, and return a result to the store.
Herman Hollerith
• 1886 - 1890• US census usually
took 10 yrs• Hollerith used
punched cards to store data and compiled data mechanically
• Census took 6 weeks• Started IBM
1st Electronic Computer
• 1940• John Atanasoff & C.
Berry• Used boolean algebra
to circuitry• True/False = On/Off• Lost funding ….
Atanasoff-Berry Computer
• the size of a desk, • weighed 700 pounds, • had over 300 vacuum tubes, • contained a mile of wire.• could calculate about one operation
every 15 seconds, • today a computer can calculate 150
billion operations in 15 seconds
1st Generation - 1945 - 56
• wwII = $$$• Zuse - cpu- r airplane design• Clossus decoded German
messages• Mark I inventor … “Only six
electronic digital computers would be required to satisfy the computing needs of the entire United States" Howard Aiken, 1947.
Mark I• 55 feet long x 8 feet high, 5-
ton• 760,000 separate pieces. • gunnery and ballistic
calculations• + - * /, 23 decimal places• Input: Pre-punched paper• Output: electric typewriter• Storage: mechanical wheels• Speed: 1 multiplication -->3-
5 seconds
Eckert’s ENIAC
• 1940s• Used 18000 vacuum
tubes• 160 Kilowatts• General purpose
computer• 1000x faster than
Mark I
ENIAC• $500,000• 167 square meters, 30
tons• 357 multiplications in 1
second• Input: card reader, re-
wiring - would take weeks• Output: printed• Speed : 357
multiplications in 1 second
John von Neuman’s EDVAC
• 1945• Stored memory• Stop and resume• Central processing
unit (CPU)• Commercially
available in 1951 as UNIVAC I
• Large and expensive
1st Generation Vacuum Tubes
• Unique operating instructions
• Different machine languages
• Difficult to program• Big, expensive, and
“buggy”• Magnetic drums for
storage
2nd Generation - 1956 - 63
• Used transistors• Smaller, faster, more
reliable• Not as warm• Assembly language
used
UNIVAC
• $1,000,000• Input: magnetic tape/
card reader• Output: tape, printer,
card• Speed: multiply time
of 1,800 microseconds
Commercial successes
• Bought by business, universities, and governments
• General Electric - payroll
• Used printers, tape and disk storage, memory, Operating systems, & stored programs
1952: UNIVAC ComputerUsed to Predict the 1952 US Election,
Walter Cronkite reading printer output, tape drives in background
Companies of the Day
• Burroughs• IBM• Sperry-Rand• Honeywell• Others ….
IBM 701 1952
Programming Languages
• Langauges gave cpu flexibility
• Stored programs• High level languages -
(COBOL, FORTRAN)• New career -->
programmer, anaylst, system experts….
3rd Generation 1964 - 71
• Transistor replaced with IC - Integrated circuit
• 3 components on a silicon disc
• Smaller, faster• OS allowed multi-
tasking
PDP-1
• $120, 000• OS allowed multi-
users• Spacewrs was first
game (2 player)
• Output: Cathode-Ray Tube
4th Generation 1971 - Present
• Large scale integration (LSI) 100 of components on a chip
• VLSI - 100,000 components
• ULSI - millions of components
• Increased power, efficiency, & reliability
Intel 4004 Chip
• 1971
• Microprocessor
• All parts (Cpu, memory, input and output controls) on a chip
• Multi-purpose - cars, fridges, microwaves, tv
• Made for general consumer
Companies of the day
• Radio Shack• Apple• Commodore• IBM• Atari (1980)
Applications of the Day
• Spreadsheet• Word Processors• Video Games• Pac-Man,
Visicalc - Apple 1979
IBM’s PC
• Personal computer• Home, office, school• 2 million in 81, 65
million in 92• Desktop - -> laptop• DOS … typed line
commands
Apple’s Macintosh
• 1984• Used mouse to move
or select icons … no typing
• 512 Kb of memory
Basic Parts of a Computer
PROCESSPROCESSINPUTINPUT OUTPUTOUTPUT
Hardware
• The physical parts of a computer.
• If you can touch it is hardware
Input Devices
• To get information into the processor
• Keyboard, mouse, scanner, touch screen, switches, camera, microphone, joystick ...
Output Devices
• Converts processed information into a form that can be used by/ aids humans
• Printer, monitor, speaker, switches,
Parts of the CPUCentral Processing Unit
INPUTINPUT OUTPUTOUTPUT
Arithmetic Logic Unit ALU
Arithmetic Logic Unit ALU
Control UnitControl Unit
Main Memory UnitMain Memory Unit
Central Processing Unit CPU
Arithmetic UnitALU
• Does all of the arithmetic and logic– Arithmetic : + - x /– Logic: = <>, < , > <=,
>=
• Computers convert everything to numbers and perform these operations….
Control Unit
• Controls the parts of the computer– Tells the printer when to
print– Tells the cpu that keys
are being pressed
• The Central Nervous System of the computer
Memory
• ROM– Read Only Memory
– The initial instructions to get the computer working.
– Cannot be erased.
– Not lost when power is off.
• RAM– Random access
memory.
– Where application and data are stored while being used.
– Can be changed.
– Lost when power is off.
Software
• The information (instructions or data) that the computer processes
• Stored on hardware• Loaded into RAM
when used.• More RAM = more
applications, larger documents,
Three Classifications of Software
• Operating System: the instructions that run the computer (DOS, Windows, Mac OS, Linux, …)
• Applications… the programs that allow you to do specific activities (wp, ss, games, …)
• Data - the information that is being processed (documents, files, images …)
External Storage Devices
• Used to store data until it is needed again.
• Disks (floppy,
harddrives), CD, DVD, Tape, Flash Memory.
Local Area Networks(LAN)
• Computers and resources connected together to share resources
• CWSS’s LAN --- 200 CPUs and servers, printers, ….
Wide Area NetworkWAN
• A network of computers and resources over a larger area.
• OCDSB …. 200 sites and connection to internet
Internet
• International Network• Shared resources
world wide• Files, e-mail, web
pages …• “Information
Highway”
World Wide Web(WWW)
• Browse web pages on servers located on internet
• EXPLORER, NETSCAPE, …. And FIREFOX (new)
5th Generation
• Still to come …• AI … artificial
intelligence• Voice recognition• ……