Transcript History_of_Computers

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
• Not until 1820 mechanical calculator
that could + - * /
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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
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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, 5ton
• 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, rewiring - would take weeks
• Output: printed
• Speed : 357
multiplications in 1 second
John von Neuman’s EDVAC
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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 Computer
Used to Predict the 1952 US Election,
Walter Cronkite reading printer output,
tape drives in background
Companies of the Day
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IBM 701 1952
Burroughs
IBM
Sperry-Rand
Honeywell
Others ….
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 multitasking
PDP-1
• $120, 000
• OS allowed multiusers
• 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
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Radio Shack
Apple
Commodore
IBM
Atari (1980)
Applications of the Day
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Visicalc - Apple 1979
Spreadsheet
Word Processors
Video Games
Pac-Man,
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
PROCESS
INPUT
OUTPUT
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 CPU
Central Processing Unit
Central Processing
Unit CPU
INPUT
Arithmetic Logic
Unit ALU
Control Unit
Main Memory Unit
OUTPUT
Arithmetic Unit
ALU
• 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 Network
WAN
• 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
• ……