Transcript Generation_1-3

Computing in the Modern
World
Mr. Van Nus
Colquitt County High School
The History of Computers
Generations 1, 2, & 3
Mr. Van Nus
Colquitt County High School
Generation 1 (1945-1954)
• Electro. Relays required open/closing
of switches…so…computing speed
was limited by the inertia of moving
parts
• Often jammed
– “a bug”
• 1940’s Electo. Relays were replaced
with “Vacuum tubes”.
– Small glass tube with all gases removed
allowing electrons to move with minimal
interference
Timeline
• Although vacuum tubes had been
invented in 1906, they were not cost
effective until the 1940’s
• Without moving parts the Vacuum
tubes could perform 1000 times faster
Timeline
• Computing during World War II
• 1943
– British govt. built the first electronic
computer to decode NAZI messages
• It was called COLOSSUS
– Contained 230 vacuum tubes
– Remained classified for 30 yrs
• No one knew about it
Timeline
• Roughly the same time John Mauchly
and J. Presper Eckert were building
ENIAC, an electric computer
– Designed to compute ballistic tables for
the U.S. Army
– 18000 vacuum tubes and 1500 relays
– Weighed 30 tons
– Required 140 kilowatts of power
– Less memory and 500 times faster than
Mark I
– It was also programmable, reconfigured
Timeline
• John von Neumann
– Recognized that programming with
switches and cables was tedious and
error prone
– Created a computer architecture where
programs along with data could be
stored in memory.
– Also created the binary (base2) memory
– First used in vacuum tube computers such
as the EDVAC, and IAS
Timeline
• Because of the “stored program”
architecture, computer programming
became more important than
computer design
– First language used was “machine
language”
• 0’s and 1’s correspond to instructions
– Faster than rewiring, but still slow and tedious
– 1950’s programmers began to use
“assembly languages”
• Used mnemonic names for binary #
Timeline
• 1950 – Commercial computer industry
began
• Echert, Mauchly left Univ. of Penn. to
form own company
– 1951 – began selling UNIVAC I
– First purchased by the US Census Bureau
– CBS used it to predict the Presidential Elec.
Generation 2…Timeline
• The weaknesses of Vacuum tubes became
known:
– Relatively large
– Produces large amounts of heat
• Required lots of space for cooling
– Burnt out frequently
• Replacement of vacuum tubes with
transistors began
– A piece of silicon whose conductivity can be
turned on and off with electric current
– Smaller, cheaper, more reliable, and more
efficient
• = smaller, faster machines that were cheaper
Timeline
• Transistors led to many small, affordable
electronic devices, including: radios,
televisions, phones, computers, etc…
• The scientific community recognized the
potential impact immediately awarding
Bardeen, Brattain, and Shockley the 1956
Nobel Prize in physics
• First transistorized computers were SperryRand’s, “LARC” and IBM’s, “STRETCH”
• 1960 – transistor-based comp. marketed
to private business
Timeline
• High-level Programming languages
– With more affordable computers being
produced, a larger emphasis began to be
placed on programming
– Why?...if non “geniuses” or common
people were going to have computers,
they would have to be more simple
– 1957, John Backus produced FORTRAN
• FORmula TRANslator
• a very high level programming language
– Followed by: LISP
59), and
(John McCarthy, 59),
COBOL (Grace Murray-Hopper, 60)
BASIC (John Kemey,
Generation 3…Timeline
• Integrated Circuits (1963-1973)
– Before I.C. chips, transistors would be produced
individually and connected via wire
• Tedious, often included 100’s & 1000’s of transistors
• This also limited the size of transistors
– To small and could not be connected by hand
– 1958 – Jack Kilby (Texas Instruments) began
developing techniques to mass produce much
smaller, already-connected transistors on a
silicon disk
• Silicon disc not electrically conductive
• Metal wires connecting transistors were conductive
Timeline
• This allowed transistor’s to be created
much smaller and placed much closer
together
– Hundreds could be placed on a disc
– Packaged in metal or plastic and
connected by external pins
• This capability allowed computers to
once again be produced quicker,
cheaper, and perform faster
• Jack Kilby was awarded the Nobel
Prize in physics in 2000
Timeline
• Large Scale Integration
• As manufacturing improved the # of
transistors that could be mounted
increased.
• 1965, Gordon Moore noticed that
about every 12-18 months the # of
transistors that could be fit on 1 chip
doubled
– This became known as “Moore’s Law”
Timeline
• 1970’s – Large Scale Integration (LSI),
where thousands of transistors could
be loaded on a single chips became
possible
• 1971 – Intel combined all the control
circuitry for a calculator on 1 chip
– Called a “microprocessor”
– It was called the Intel 4004
– It contained 2300+ transistors
• 1974 – Intel released 8080
– 6000+ transistors
Timeline
• The 8080 and it’s successors (8086,
8088) served as the Central Processing
Units (CPU’s) for many personal
computers in the 70’s
• Tex. Instru., National Semiconductors,
Fairchild Semiconductors, and
Motorola began producing
microprocessors at this time also
Timeline
• Computing for Business
– Again this led to development of smaller,
faster, and cheaper computers
– Which allowed business other than the
very large corporations to purchase and
integrate them into daily business
• What comes next?
– Education
• For non-technical users
– Simplification
• Operating sys, master control programs, peripheral
(keyboards, mice, monitors) device managers, etc…
Timeline
• New programming languages were
developed to meet the needs of the
computers new, broader base of users
– 1971, Niklaus Wirth developed “Pascal”
• Simple language for teaching programming
skills
– 1972, Dennis Ritchie developed “C”
• Used in the development of “UNIX” and other
operating systems of the 70’s and 80’s
Electro-magnetic Relay Tube
When an electrical
current is applied to the
wire at the bottom, the
metal coil to the left
generates a magnetic
field. The magnetic
attraction pulls the
armature on the right,
closing the switch and
allowing electricity to
flow through the relay.
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Vacuum Tube
Vacuum tube - A
filament inside the
tube controls the flow
of electricity –when a
current is applied to
the filament, electrons
are released to bridge
the vacuum and allow
electrical current to
flow through the tube.
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The COLOSSUS
The COLOSSUS at
Bletchley Park,
England. The messages
to be decoded were
fed into the machine
on paper tape, as
shown on the right. The
panels show some of
the more than 2,300
vacuum tubes that
comprised the logic for
breaking German
codes.
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ENIAC
ENIAC, with some
of its 18,000
vacuum tubes
visible (U.S.
Army photo).
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IAS computer
John von Neumann
with the IAS
computer
(Princeton
University).
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Transistors
Many experts
consider transistors
to be the most
important
technological
development of
the 20th century.
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Electronic Circuitry
• Microscopic
photograph of
electronic circuitry.
Transistors (seen as
small rectangles) and
connecting wires (seen
as lines) are
constructed out of
layers of metal on a
silicon chip.
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Integrated Circuits
Early integrated
circuits,
packaged in
plastic with
metal pins as
connectors.
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Intel 4004
Microscopic image of
the Intel 4044
microprocessor, with
the connections
between transistors
dyed to appear
white. The blue
rectangles around the
outside represent the
pins, which
connected the
circuitry of the chip to
the other computer
components.
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