Lecture 1: What is a Modern Computer Computer Evolution Computer Components Computer Organization vs. Computer Architecture.

Lecture 1: What is a Modern Computer

• Computer Evolution• Computer Components• Computer Organization vs. Computer Architecture

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• 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.

Generation Zero: Mechanical Calculating Machines (1642 - 1945)

The First Generation: Vacuum Tube Computers (1945 - 1953)

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– 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 ENIAC was the first all-electronic, general-purpose 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.

The First Generation: Vacuum Tube Computers (1945 - 1953)

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• IBM 7094 (scientific) and 1401 (business)• Digital Equipment Corporation (DEC) PDP-1• Univac 1100• Control Data Corporation 1604.• . . . and many others.

The Second Generation: Transistorized Computers (1954 - 1965)

• 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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• 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.

The Third Generation: Integrated Circuit Computers (1965 - 1980)

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• 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.”

The Fourth Generation: VLSI Computers (1980 - ????)

Computer Evolution

• Electronics technology continues to evolve– Increased capacity and performance– Reduced cost

Year Technology Relative performance/cost

1951 Vacuum tube 1

1965 Transistor 35

1975 Integrated circuit (IC) 900

1995 Very large-scale Integrated Circuit 2,400,000

2013 Ultra large-scale Integrated Circuit 250,000,000,000

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• 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 ...

Moore’s Law

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• 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.”

Rock’s Law

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• Rock’s Law

– In 2012, a chip plants under construction cost well over $5 billion.

– For Moore’s Law to hold, Rock’s Law must fall, or vice versa. But no one can say which will give out first.

$5 billion is more than the gross domestic product of some small countries, including Barbados, Mauritania, and Rwanda.

Rock’s Law

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 , where is in years, describes a quantity that doubles every 18 months. What is the value of ?

• Hint: 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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• 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.

Computer Components

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Consider this advertisement:

An Example System

MHz??

MB??

PCI?? USB??

L1 Cache??

What does it all mean??

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• Typical measures of capacity: KB, MB, GB, TB• Typical measures of speed: kb/s, Mb/s, Gb/s, MHz, GHz

Measures of Capacity and Speed

Whether a metric refers to a power of 10 or a power of 2 typically depends upon what is being measured.

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

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• 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 :

is equivalent to

Measures of Processor Speed and Storage

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• Typical measures of Time: , • Typical measures of space:

Measures of Time and Space

Generally, negative powers refer to powers of 10, not powers of 2.

Prefix Symbol Power of 10 Power of 2

Milli 1 thousandth = 10-3 2-10

Micro 1 millionth = 10-6 2-20

Nano 1 billionth = 10-9 2-30

Pico 1 trillionth= 10-12 2-40

Femto 1 quadrillionth = 10-15 2-50

Atto 1 quintillionth = 10-18 2-60

Zepto 1 sexitillionth = 10-21 2-70

Yocto 1 septillionth = 10-24 2-80

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• 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.

Measures of Time and Space

Exercises

a) 1 second = milliseconds

b) 1 second = microseconds

c) 1 millisecond = nanoseconds

d) 1 microsecond = milliseconds

e) 1 nanoseconds = microseconds

f) 1 gigabyte = kilobytes

g) 1 megabyte = kilobytes

h) 1 gigabyte = megabytes

i) 20 megabytes = bytes

j) 2 gigabytes = kilobytes

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Exercises Solutiona) 1 second = 1000 milliseconds

b) 1 second = 1,000,000 microseconds

c) 1 millisecond = 1,000,000 nanoseconds

d) 1 milliseconds = 1,000 microseconds

e) 1 microseconds = 1,000 nanoseconds

f) 1 GB = 1,000,000 (or 230/210=220) KBs

g) 1 MB = 1,000 (or 220/210=210) KBs

h) 1 GB = 1,000 (or 230/220=210) MBs

i) 20 MBs = 20,000,000 or (or 20 * 220) Bytes

j) 2 GBs = 2,000,000(or 231/210=221) KBs

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