Transcript or 2 20 /2 10 =2 10 - Help-A-Bull

Lecture 1: What is a Modern Computer
• Computer Evolution
• Computer Components
• Computer Organization vs. Computer Architecture
Generation Zero: Mechanical
Calculating Machines (1642 - 1945)
• Calculating Clock - Wilhelm Schickard (1592 - 1635).
– First mechanical calculator, add and subtract numbers with as many as six digits.
• Pascaline - Blaise Pascal (1623 - 1662).
– Addition with carry and subtraction.
• Difference Engine - Charles Babbage (1791 - 1871), also designed but
never built the Analytical Engine.
– Based on a calculating technique called the method of difference
– The Analytical Engine included several components associated with modern
computers: an arithmetic processing unit to perform calculations, a memory,
and input and output devices.
– “the father of computing”
• Punched card tabulating machines - Herman Hollerith (1860 - 1929).
– Hollerith cards were commonly used for computer input well into the 1970s.
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The First Generation: Vacuum Tube
Computers (1945 - 1953)
– Atanasoff Berry Computer (ABC) (1937 1938) solved systems of linear
equations.
– The first completely electronic computer
– John Atanasoff and Clifford Berry of Iowa
State University.
Thermionic emission: the follow of electrons from negatively charged
cathode to the positively charged anode.
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The First Generation: Vacuum Tube
Computers (1945 - 1953)
• The ENIAC was the first all-electronic, generalpurpose digital computer.
• Electronic Numerical Integrator and Computer (ENIAC)
• John Mauchly and J. Presper Eckert
• University of Pennsylvania, 1946
• The IBM 650 first mass-produced computer. (1955)
• It was phased out in 1969.
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The Second Generation: Transistorized
Computers (1954 - 1965)
•
•
•
•
•
IBM 7094 (scientific) and 1401 (business)
Digital Equipment Corporation (DEC) PDP-1
Univac 1100
Control Data Corporation 1604.
. . . and many others.
• Transistor: the follow of electrons in the solid medium.
• The vacuum tubes are not very dependable.
• Transistors consume less power than vacuum tubes, are smaller, and
work more reliably.
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The Third Generation: Integrated Circuit
Computers (1965 - 1980)
• Multiple transistors were integrated onto one chip.
• The Third Generation: Integrated Circuit Computers
(1965 - 1980)
–
–
–
–
IBM 360
DEC PDP-8 and PDP-11
Cray-1 supercomputer
. . . and many others.
• By this time, IBM had gained overwhelming
dominance in the industry.
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The Fourth Generation: VLSI Computers
(1980 - ????)
• The Fourth Generation: VLSI Computers
(1980 - ????)
– Very large scale integrated circuits (VLSI) have
more than 10,000 components per chip.
– Enabled the creation of microprocessors.
– The first was the 4-bit Intel 4004.
– Later versions, such as the 8080, 8086, and 8088
spawned the idea of “personal computing.”
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Computer Evolution
• Electronics technology continues to evolve
– Increased capacity and performance
– Reduced cost
Year
Technology
Relative performance/cost
1951
Vacuum tube
1965
Transistor
1975
Integrated circuit (IC)
1995
Very large-scale Integrated Circuit
2,400,000
2013
Ultra large-scale Integrated Circuit
250,000,000,000
1
35
900
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Moore’s Law
• Moore’s Law (1965)
– Gordon Moore, Intel founder
– “The density of transistors in an integrated circuit will
double every year.”
• Contemporary version:
– “The density of silicon chips doubles every 18 months.”
But this “law” cannot hold forever ...
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Rock’s Law
• Rock’s Law
– Arthur Rock, Intel financier
– “The cost of capital equipment to build semiconductors
will double every four years.”
– In 1968, a new chip plant cost about $12,000.
At the time, $12,000 would buy a nice home in the suburbs.
An executive earning $12,000 per year was “making a very
comfortable living.”
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Rock’s Law
• Rock’s Law
– In 2012, a chip plants under construction cost
well over $5 billion.
$5 billion is more than the gross domestic
product of some small countries, including
Barbados, Mauritania, and Rwanda.
– For Moore’s Law to hold, Rock’s Law must fall,
or vice versa. But no one can say which will
give out first.
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Moore’s Law Exercise
It was found that the number of transistors on various chips
made by Intel could be approximated by y = 2336(1.39)x,
where x = 0 corresponds to 1971.
• What is the doubling time for the function y =
2336(1.39)x?
• Suppose a function of the form y = y0ax, where x is in
years, describes a quantity that doubles every 18
months. What is the value of a?
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Moore’s Law – Exercise Solution
It was found that the number of transistors on various chips
made by Intel could be approximated by y = 2336(1.39)x,
where x = 0 corresponds to 1971.
• What is the doubling time for the function y =
2336(1.39)x?
– Hint: (1.39)x =2 => x≈ 2.1 years
• Suppose a function of the form 𝑦 = 𝑦0𝑎𝑥, where 𝑥 is in
years, describes a quantity that doubles every 18
months. What is the value of 𝑎?
.
• Hint: 𝑎1 5 = 2 => a ≈ 1.59
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What is a Modern Computer
• A modern computer is an electronic, digital,
general purpose computing machine that
automatically follows a step-by-step list of
instructions to solve a problem.
• This step-by-step list of instructions that a
computer follows is also called an algorithm or a
computer program.
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Computer Components
• At the most basic level, a computer is a device
consisting of three pieces:
– A processor to interpret and execute programs
– A memory to store both data and programs
– A mechanism for transferring data to and from the
outside world.
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An Example System
Consider this advertisement:
What does it all mean??
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Measures of Capacity and Speed
• Typical measures of capacity: KB, MB, GB, TB
• Typical measures of speed: kb/s, Mb/s, Gb/s, MHz, GHz
Prefix
Symbol
Power of 10
Power of 2
Kilo
K
1 thousand = 103
210=1024
Mega
M
1 million = 106
220
Giga
G
1 billion = 109
230
Tera
T
1 trillion= 1012
240
Peta
P
1 quadrillion = 1015
250
Exa
E
1 quintillion = 1018
260
Zetta
Z
1 sexitillion = 1021
270
Yotta
Y
1 septillion = 1024
280
Whether a metric refers to a power of 10 or a power of 2 typically
depends upon what is being measured.
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Measures of Processor Speed and Storage
• Byte = a unit of storage
–
–
–
–
1KB = 210 = 1024 Bytes
1MB = 220 = 1,048,576 Bytes
Main memory (RAM) is measured in MB
Disk storage is measured in GB for small systems, TB for large
systems.
• Hertz = clock cycles/second (frequency)
– 1MHz = 1,000,000Hz
– Processor speeds are measured in MHz or GHz.
– Clock frequency is the reciprocal of cycle time.
• A bus operating at 133MHz has a cycle time of 7.52 𝑛𝑠:
133 × 106 cycles/second is equivalent to
1
133×106 cycles/second
= 7.52 𝑛𝑠/cycle
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Measures of Time and Space
• Typical measures of Time: 𝑚𝑠, 𝜇𝑠
• Typical measures of space: 𝑚𝑚, 𝜇𝑚, 𝑛𝑚
Prefix
Symbol
Power of 10
Power of 2
Milli
𝑚
1 thousandth = 10-3
2-10
Micro
𝜇
1 millionth = 10-6
2-20
Nano
𝑛
1 billionth = 10-9
2-30
Pico
𝑝
1 trillionth= 10-12
2-40
Femto
𝑓
1 quadrillionth = 10-15
2-50
Atto
𝑎
1 quintillionth = 10-18
2-60
Zepto
𝑧
1 sexitillionth = 10-21
2-70
Yocto
𝑦
1 septillionth = 10-24
2-80
Generally, negative powers refer to powers of 10, not powers of 2.
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Measures of Time and Space
• Millisecond = 1 thousandth of a second
– Hard disk drive access times are often 10 to 20
milliseconds.
• Nanosecond = 1 billionth of a second
– Main memory access times are often 50 to 70
nanoseconds.
• Micron (micrometer) = 1 millionth of a meter
– Circuits on computer chips are measured in microns.
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Exercises
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
1 second =
1 second =
1 millisecond =
1 microsecond =
1 nanoseconds =
1 gigabyte =
1 megabyte =
1 gigabyte =
20 megabytes =
2 gigabytes =
milliseconds
microseconds
nanoseconds
milliseconds
microseconds
kilobytes
kilobytes
megabytes
bytes
kilobytes
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Exercises Solution
a)
b)
c)
d)
e)
f)
g)
h)
i)
j)
1 second =
1000
milliseconds
1 second = 1,000,000
microseconds
1 millisecond =
1,000,000
nanoseconds
1 milliseconds = 1,000
microseconds
1 microseconds = 1,000
nanoseconds
1 GB = 1,000,000 (or 230/210=220)
KBs
1 MB = 1,000 (or 220/210=210)
KBs
1 GB = 1,000 (or 230/220=210)
MBs
20 MBs = 20,000,000 or (or 20 * 220)
Bytes
2 GBs = 2,000,000(or 231/210=221)
KBs
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